1 Glossary

2 Introduction

2.1 Purpose

The purpose of this project is to rework the SNOMED CT cataract sub-hierarchy, defined as 193570009|Cataract (disorder)| and its descendants, to accomplish the following:

• Make the Cataract sub-hierarchy consistent with typical SNOMED CT modeling patterns for diseases.
• Make the sub-hierarchy consistent with common clinical practice and classifications of cataracts.
• Recommend clear and consistent guidance for the management of requests for new content related to cataract disorders.

2.2 Audience and stakeholder domain 

The audience for this document includes all standards terminology leaders, implementers and users of SNOMED CT.

A further significant audience is the community of SNOMED CT terminologists that may be requested to implement the recommended specification.

Specifically, the audience will include anyone interested in authoring or using SNOMED CT in the domain of cataract disorders, including the community of clinical ophthalmologists and their support staffs (as potential users).

.2.2.1 Input from stakeholders

In addition to conforming to the desired SNOMED CT modeling patterns, the revised cataract hierarchy should be consistent with current ophthalmological practice and be suitable for use in an international standard. Clinical input was sought from Dr. Stevie Tan, an ophthalmologist who is active in the SNOMED CT community and graciously agreed to help with this project. Dr. Tan subsequently consulted Dr. Nic Reus, who kindly provided a reference to a clinically useful cataract classification scheme, based on an electronic version of the cataract chapter from an ophthalmology textbook.

2.2.2 Degree of consensus on the statement of problem

There appears to be a reasonable degree of consensus about the problem, since it is clearly described in JIRA item IHTSDO-791 (artf222563) and there is no evidence to suggest that the problem as stated there is controversial.

3 Statement of the problem or need

3.1 Summary of problem or need, as reported

As reported, the primary problems with the cataract sub-hierarchy are missing attributes that could make primitive concepts defined, inconsistent modeling of finding sites, inconsistent modeling of associated morphologies, inconsistent pre-coordination, and concepts that are currently modeled as primitive even though the concept definitions appear to be sufficient for making them fully defined.

3.2 Summary of requested solution

The requested solution is to review the concepts in the cataract disorder sub-hierarchy to correct the deficiencies reported above.

3.3 Statement of problem as understood

The cataract disorder sub-hierarchy requires revision to make it more consistent and possibly to improve its hierarchical structure. Areas needing review include:

• Designation of concepts as primitive or defined
• Values of the FINDING SITE attribute
• Values of the ASSOCIATED MORPHOLOGY attribute
• Representation of laterality
• Conformance to a consistent modeling pattern
• Conformance to current editorial policies regarding FSNs and synonyms.

IHTSDO-791 was created in 2011, and it appears that many of the requested revisions have been made in subsequent International Releases.

3.4 Detailed analysis of reported problem, including background

The January 2016 International Release of SNOMED CT was originally used for this detailed analysis. In addition to the IHTSDO SNOMED CT browser (http://browser.ihtsdotools.org), Apelon DTS was used for selected counts and queries. This is an open source tool available from http://www.apelondts.org.

The analysis has been revisited using the January 2017 International Release, and modifications to this Inception/Elaboration document have been made where significant difference between the two releases were observed.  As noted above, IHTSDO-791 tracker item is accompanied by a detailed “Cataract Report” and many of the proposed changes have made since the original tracker item was created more than five years ago. This revised Inception/Elaboration document has consequently been modified to make it easier to identify “at a glance” the cases where no further content changes are deemed necessary. These cases are shown in a blue, italic font so that a reviewer can more easily focus on proposed changes that still deserve consideration.

3.4.1 Primitive Concepts Missing Attributes that Could Make Them Defined

Multiple concepts in the cataract sub-hierarchy appear to be missing attributes that could be added to make these concepts fully defined. In this regard, the following specific issues were identified in the IHTSDO-791 tracker item:

3.4.1.1 Inconsistent Use of the OCCURRENCE Attribute for Cataract Concepts Related to Periods of Life

• 193571008|Infantile, juvenile and presenile cataracts (disorder)| has OCCURRENCE attributes with values of 255398004|Childhood (qualifier value)| and 3658006|Infancy (qualifier value)|.
• Recommended action as of the January 2017 release: This concept should be considered for retirement because it currently has two OCCURRENCE attributes, one with a value 3658006 |Infancy (qualifier value)| and the other with a value of 255398004 |Childhood (qualifier value)|. The children of 282032007 |Periods of life (qualifier value)| are intended to be mutually exclusive siblings. Thus, it is not possible for a concept to be both a disorder of childhood and and a disorder of infancy. There should only be one OCCURRENCE attribute in any single concept.

• 79410001|Congenital cataract (disorder)| has an OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|, and this attribute is inherited by its descendants.
• Recommended action as of the January 2017 release: None.

• 39450006|Age-related cataract (disorder)| does not have an OCCURRENCE attribute. This issue is the subject of IHTSDO-811, which has been closed because it is being incorporated into this project, as described in Section 3.5. The meaning of the phrase "age-related" is unclear, because it presumably refers to old age but could arguably refer to any age (such as infancy, for example). Note that “Senile cataract” is an associated description and IHTSDO-791 appears to say this was previously the FSN for 39450006.
• Recommended action as of the January 2017 release: Change the FSN to represent the semantics explicitly. Either "Old-age related cataract" or "Senile cataract" is a better FSN than "Age-related cataract." Also add an OCCURRENCE attribute with a value of 271872005|Old age (qualifier value)| to the stated definition.

3.4.1.2 Toxic Cataract

• IHTSDO-791 states that 38583007|Toxic cataract (disorder)| currently has no relationship to 441952005|Poisoning (disorder)|. Note that SCTID 441952005 now has a fully specified name of “Poisoning caused by chemical substance (disorder)” and this concept is now a direct children of 75478009|Poisoning (disorder)|.
• Recommended action as of the January 2017 release: Add a CAUSATIVE AGENT attribute with a value of 35331000 |Toxic substance (substance)| instead of a DUE TO attribute with a value of 441952005 | Poisoning caused by chemical substance (disorder)| because this will represent the semantics more directly.

3.4.1.3 Concussion Cataract

• IHTSDO-791 states that 231967008|Concussion cataract (disorder)| has no relationship to “Concussion (110030002).” Searching for the latter SCTID in the January 2016 International Release yields 110030002|Concussion injury of brain (disorder)|, indicating that the FSN has been changed since IHTSDO-791 was created. However, it appears that the suggested relationship between these two concepts is not correct, because concussion cataract is a type of traumatic cataract in which there is an injury to the lens itself and is not secondary to a concussion injury of the brain.
  
•  Recommended action as of the January 2017 release: None.

3.4.2 Imprecise Finding Site

• IHTSDO-791 states that 53889007|Nuclear cataract (disorder)| should have a FINDING SITE of 56707006|Structure of nucleus of lens (body structure)| in order to be consistent with the finding sites of its subconcepts. In January 2016 International Release, there is a FINDING SITE attribute with a value of 56707006|Structure of nucleus of lens (body structure)| in the definition of 53889007|Nuclear cataract (disorder)|.

• Recommended action as of the January 2017 release: None.

3.4.3 Cataract as a Morphologic Abnormality

• Currently, 128306009|Cataract (morphologic abnormality)| is a direct child of 128305008|Abnormally opaque structure (morphologic abnormality)|. IHTSDO-791 raises a question about whether “cataract should be a morphology.” As explained in Section 3.5, this question is closely related to IHTSDO-424, which proposes that 128305008|Abnormally opaque structure (morphologic abnormality)| replace 128306009|Cataract (morphologic abnormality)| as the value of the PROCEDURE MORPHOLOGY attribute for cataract procedures.
• Recommended action as of the January 2017 release: The 128306009|Cataract (morphologic abnormality)| concept is problematic because it arguably conflates a structure and a finding site. All cases where there is an ASSOCIATED MORPHOLOGY attribute with a value of 128306009|Cataract (morphologic abnormality)| should be identified and the value of the attribute should be changed to its immediate parent 128305008|Abnormally opaque structure (morphologic abnormality)|. These ASSOCIATED MORPHOLOGY attributes will typically be found in a role group containing a FINDING SITE attribute with a value of 78076003 |Structure of lens of eye (body structure)| or one of its subtypes. The 128306009|Cataract (morphologic abnormality)| concept can be retired once all of the concepts that use it as an attribute value have been remodeled.
• Note: This replacement action can presumably be accomplished by a batch process (such as a global search and replace operation). Accordingly, it is not explicitly stated in this document as a recommended action for each cataract concept. When the recommended action for an individual concept is shown as “None,” that does not include the batch replacement of 128306009|Cataract (morphologic abnormality)| with 128305008|Abnormally opaque structure (morphologic abnormality)|. When other changes are required, however, the change from 128306009|Cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)| will often be included in the description of the recommendation.

• 3.4.4 Pre-coordination of Laterality

• IHTSDO-791 suggests that 95722004|Bilateral cataracts (disorder)| be retired because it represents bilaterality by using pre-coordinated lateralized anatomy concepts, whereas post-coordination by users should be the preferred approach to representing laterality. However, considerable analysis of laterality issues has occurred since IHTSDO-791 was created. Post-coordination by users would require support for nesting so that the LATERALITY attribute can be applied to a body structure concept. A decision on laterality was reached in October 2015, and pre-coordinated body structure concepts will be added as needed. For bilateral concepts, two relationship groups are used, as is the case for 95722004|Bilateral cataracts (disorder)|.
• Recommended action as of the January 2017 release: None.

3.4.5 Concepts That Appear to be Defined but are Classified as Primitive

• IHTSDO-791 suggest that all the concepts listed in Table 1 be made fully defined after additional attributes are added as specified by the Cataract Pattern Report, as detailed in Section 3.4.6. Eight of the 21 concepts in Table 1 are already fully defined in the January 2016 International Release. Thus, the suggestions only apply to the 13 concepts that are still primitive.

Table 1: Concepts listed in IHTSDO-791 as potentially being fully defined instead of primitive

• Recommended action as of the January 2017 release: Since all of the primitive concepts in Table 1 remain primitive in the January 2017 release, see Section 6.1.1.4 for a recommended approach to defining these concepts.

3.4.6 Details of the Cataract Pattern Report

The Cataract Pattern Report associated with IHTSDO-791 is an attempt to enforce consistent modeling patterns for concepts in the cataract disorders sub-hierarchy. It is linked to this document as Appendix A. Each concept mentioned in the Cataract Pattern Report is represented in the following sections. For each concept, the recommendations in the Cataract Pattern Report were originally compared with the state of the concept in the January 2016 International Release. A subsequent comparison was made with the state of the concept in the January 2017 release.

3.4.6.1 Postoperative cataract syndrome

• The Cataract Pattern Report suggests modifying the definition of 70388009|Postoperative cataract syndrome (disorder)| by adding an AFTER attribute with a value of 387713003|Surgical procedure (procedure)|. The report also questions whether this change would allow this concept to become fully defined. This change has already been made in the January 2016 International Release, but the concept is still primitive.

• This concept arguably requires further editorial review because it refers to a complex disease following cataract surgery, as opposed to a cataract that develops following eye surgery. Known as Pseudophakic Cystoid Macular Edema or Irvine Glass Syndrome, a more detailed description of this disorder is available at http://eyewiki.aao.org/Pseudophakic_Cystoid_Macular_Edema_(Irvine-Gass_Syndrome): where the following explanation appears:

“The major etiology appears to be inflammatory mediators that are upregulated in the aqueous and vitreous humors after surgical manipulation. Inflammation breaks down the blood-aqueous and blood-retinal-barriers, which leads to increased vascular permeability. Eosinophilictransudate accumulates in the outer plexiform and inner nuclear layers of the retina to create cystic spaces that coalesce to form larger pockets of fluid. In chronic CME, lamellar macular holes and subretinal fluid may also form.”

Although the value of the AFTER attribute should presumably be changed to 110473004|Cataract surgery (procedure)|, there is a question about whether other aspects of the current definition are correct. It could be argued that the syndrome is not a kind of cataract at all. While 363342003|Visual system complication of procedure (disorder) and 385486001|Postoperative complication (disorder)| certainly appear to be appropriate defining superconcepts, an IS-A relationship to 193570009|Cataract (disorder)| may not be strictly correct. Moreover, perhaps the ASSOCIATED MORPHOLOGY should be 23583003| Inflammation (morphologic abnormality)| and the FINDING SITE should be something fairly general like 302151004|Eyeball segment structure (body structure)|, since there is involvement of the aqueous and vitreous humors as well as the retina

• Recommended action as of the January 2017 release: Make the value of the AFTER attribute more specific by changing it from  387713003|Surgical procedure (procedure)| to 110473004|Cataract surgery (procedure)|.

3.4.6.2 Combined nonsenile cataract vs. Infantile, juvenile and presenile cataracts

• The Cataract Pattern Report points out that 193579005|Combined nonsenile cataract (disorder)| has the same attributes as 193571008|Infantile, juvenile and presenile cataracts (disorder)|.
• As noted in Section 3.4.1.1, 193571008|Infantile, juvenile and presenile cataracts (disorder)| should be considered for retirement. 193579005|Combined nonsenile cataract (disorder)| is most likely a residual concept from the ICD-9-CM integration. It is not clinically useful as a grouper concept and should be retired as well.
• Recommended action as of the January 2017 release: Retire 193579005|Combined nonsenile cataract (disorder)|.

3.4.6.3 Adherent cataract

• The Cataract Pattern Report suggests that the definition of 111000003|Adherent cataract (disorder)| be modified by adding an ASSOCIATED MORPHOLOGY attribute with a value of 42685002|Adhesion (morphologic abnormality)| and it questions whether adding this attribute could make the concept fully defined. In the January 2016 International Release, 111000003|Adherent cataract (disorder)| does have an ASSOCIATED MORPHOLOGY attribute with a value of 42685002|Adhesion (morphologic abnormality)|, but the concept is still primitive.

• Recommended action as of the January 2017 release: None.

3.4.6.4 Diabetic cataract

• The Cataract Pattern Report suggests that the definition of 43959009|Diabetic cataract (disorder)| be modified by adding an ASSOCIATED WITH attribute having a value of 73211009|Diabetes mellitus (disorder)|, and it also raises the question of whether adding this attribute could make the concept fully defined. In the January 2016 International Release, 43959009|Diabetic cataract (disorder)|has a more specific DUE TO attribute (which is a child of the ASSOCIATED WITH attribute) with a value of 73211009|Diabetes mellitus (disorder)|and the concept is now fully defined.
• Recommended action as of the January 2017 release: Change the FSN to “Cataract co-occurrent with and due to diabetes”. In accordance with recommendations from the Event-Condition-Episode Group, the more specific DUE TO attribute is strongly preferred over ASSOCIATED WITH, which has essentially been deprecated for use in stated definitions.

3.4.6.5 Drug-induced cataract

• The Cataract Pattern Report suggests that the definition of 193609000|Drug-induced cataract (disorder)| be modified by the addition of a CAUSATIVE AGENT attribute with a value of 410942007|Drug or medicament (substance)|. This attribute has been added in the January 2016 International Release, and the concept is now fully defined.

• Recommended action as of the January 2017 release: None.

3.4.6.6 Cataract associated with radiation

• The Cataract Pattern Report suggests that the definition of 416071001|Cataract associated with infrared radiation (disorder)| be modified by adding a CAUSATIVE AGENT attribute with a value of 17871006|Infrared radiation (physical force)|, and it raises the question of whether adding this attribute could make the concept fully defined. In the January 2016 International Release, a CAUSATIVE AGENT attribute with a value of 17871006|Infrared radiation (physical force)| has been added to the definition and the concept is now fully defined.

• Recommended action as of the January 2017 release: None.

3.4.6.7 Cataract associated with infrared radiation

• The Cataract Pattern Report suggests that the definition of 416071001|Cataract associated with infrared radiation (disorder)| be modified by adding a CAUSATIVE AGENT attribute with a value of 17871006|Infrared radiation (physical force)|, and it raises the question of whether adding this attribute could make the concept fully defined. In the January 2016 International Release, a CAUSATIVE AGENT attribute with a value of 17871006|Infrared radiation (physical force)| has been added to the definition and the concept is now fully defined.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.8 Cataract in inflammatory disorder

• The Cataract Pattern Report suggests that the definition of 23273003|Cataract in inflammatory disorder (disorder)| be modified by adding an ASSOCIATED WITH attribute with a value of 128139000|Inflammatory disorder (disorder)|, and it raises the question of whether adding this attribute could make the concept fully defined. In the January 2017 International Release, the suggested attribute is present and the concept is now fully defined.

• Recommended action as of the January 2017 release: Change the ASSOCIATED WITH attribute to the more specific DUE TO.

 3.4.6.9 Vossius' ring

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 77155007|Structure of lens capsule (body structure)| to the definition of 72180004|Vossius' ring (disorder)|. This attribute has been added in the January 2016 International Release, and the concept remains primitive.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.10 Capsular cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 77155007|Structure of lens capsule (body structure)| to the definition of 204125003|Capsular cataract (disorder)|. This attribute has been added in the January 2016 International Release, and the concept remains primitive.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.11 Diabetic cataract associated with type II diabetes mellitus

• The Cataract Pattern Report suggests that the definition of 420756003|Diabetic cataract associated with type II diabetes mellitus (disorder)| be modified by adding an ASSOCIATED WITH attribute having a value of 44054006|Diabetes mellitus type 2 (disorder)|. In the January 2016 International Release, 43959009|Diabetic cataract (disorder)| has a more specific DUE TO attribute (which is a child of the ASSOCIATED WITH attribute) with a value of 44054006|Diabetes mellitus type 2 (disorder)| and the concept remains fully defined.
• Recommended action as of the January 2017 release: Change the FSN to “Cataract co-occurent with and due to type II diabetes mellitus. In accordance with recommendations from the Event-Condition-Episode Group, the more specific DUE TO attribute is strongly preferred over ASSOCIATED WITH, which has essentially been deprecated for use in stated definitions.

3.4.6.12 Diabetic cataract associated with type I diabetes mellitus

• The Cataract Pattern Report suggests that the definition of 421920002|Diabetic cataract associated with type I diabetes mellitus (disorder)| be modified by adding an ASSOCIATED WITH attribute having a value of 46635009|Diabetes mellitus type 1 (disorder)|. In the January 2016 International Release, 43959009|Diabetic cataract (disorder)| has a more specific DUE TO attribute (which is a child of the ASSOCIATED WITH attribute) with a value of 46635009|Diabetes mellitus type 1 (disorder)| and the concept remains fully defined.
• Recommended action as of the January 2017 release: Change the FSN to the “Cataract co-occurrent with and due to type 1 diabetes mellitus.” In accordance with recommendations from the Event-Condition-Episode Group, the more specific DUE TO attribute is strongly preferred over ASSOCIATED WITH, which has essentially been deprecated for use in stated definitions.

3.4.6.13 Cataract with neovascularization

• The Cataract Pattern Report suggests that the definition of 76309006|Cataract with neovascularization (disorder)| be modified by adding an ASSOCIATED MORPHOLOGY attribute having a value of 13018008|Neovascularization (morphologic abnormality)|, and the report also raises the question of whether adding this attribute could make the concept fully defined. This attribute has been added in the January 2016 International Release, but the concept remains primitive.
• Recommended action as of the January 2017 release: Make the concept fully defined by using two role groups.One should have an ASSOCIATED MORPHOLOGY attribute with a value of 128305008 |Abnormally opaque structure (morphologic abnormality)| and a FINDING SITE attribute withe a value of 78076003 |Structure of lens of eye (body structure)|. The other should have an ASSOCIATED MORPHOLOGY attribute with a value of 13018008 | Neovascularization (morphologic abnormality) | and FINDING SITE attribute of 81745001 | Structure of eye proper (body structure) |.

3.4.6.14 Immature cortical cataract

• The Cataract Pattern Report suggests that the definition of 311789006|Immature cortical cataract (disorder)| be modified by adding an FINDING SITE attribute having a value of 33347001|Structure of cortex of lens (body structure)|. This attribute has been added in the January 2016 International Release. The concept remained primitive in the January 2016 release but is fully defined in the January 2017 release.

• Recommended action as of the January 2017 release: None.

3.4.6.15 Cortical senile cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 33347001|Structure of cortex of lens (body structure)| to the definition of 78875003|Cortical senile cataract (disorder)|. This attribute has been added in the January 2016 International Release, and the concept remains primitive.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.16 Cortical cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 33347001|Structure of cortex of lens (body structure)| to the definition of 193576003|Cortical cataract (disorder)|. This attribute has been added in the January 2016 International Release, and the concept is now fully defined.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.17 Immature cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 33347001|Structure of cortex of lens (body structure)| to the definition of 446474007|Immature cataract (disorder)|. This attribute has been added in the January 2016 International Release, and the concept remains primitive.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.18 Nuclear senile cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 56707006|Structure of nucleus of lens (body structure)| to the definition of 193589009|Nuclear senile cataract (disorder)|. This attribute has been added in the January 2016 International Release, and the concept is now fully defined.

• Recommended action as of the January 2017 release: None.

3.4.6.19 Nuclear sclerotic cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute with a value of 56707006|Structure of nucleus of lens (body structure)| to the definition of 359766000|Nuclear sclerotic cataract (disorder)|. This attribute has been added in the January 2016 International Release, and the concept remains primitive.
  
  
• Recommended action as of the January 2017 release: Move the FINDING SITE attribute into a new role group with an ASSOCIATED MORPHOLOGY attribute having a value of 43846000| Sclerosis (morphologic abnormality)| to fully define the concept.

3.4.6.20 Traumatic cataract

• The Cataract Pattern Report suggests the addition of an ASSOCIATED MORPHOLOGY attribute with a value of 19130008|Traumatic abnormality (morphologic abnormality)| to the definition of 34361001|Traumatic cataract (disorder)|. In the January 2016 International Release, however, this concept has an ASSOCIATED MORPHOLOGY attribute with a value of 128306009|Cataract (morphologic abnormality)| and a DUE TO attribute with a value of 262755005|Injury of the lens (disorder)|, which captures the meaning or “traumatic.” The concept is fully defined, and it appears that its current state is preferable to the suggestion in the Cataract Pattern Report.
  
  
• Recommended action as of the January 2017 release: None.

 3.4.6.21 Total Traumatic cataract

• The Cataract Pattern Report suggests the addition of an ASSOCIATED MORPHOLOGY attribute with a value of 19130008|Traumatic abnormality (morphologic abnormality)| to the definition of 8656007 |Total traumatic cataract (disorder)|. In the January 2016 International Release, however, this primitive concept is a direct child of 34361001|Traumatic cataract (disorder)| and consequently inherits all of its attributes. 
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.22 Concussion cataract

• 231967008|Concussion cataract (disorder)| was discussed in Section 3.4.1.3. The Cataract Pattern Report suggests the addition of an ASSOCIATED MORPHOLOGY attribute with a value of 19130008|Traumatic abnormality (morphologic abnormality)| to the definition of this concept. However, the definition follows the same pattern as 34361001|Traumatic cataract (disorder)|, in that it has an ASSOCIATED MORPHOLOGY attribute with a value of 128306009|Cataract (morphologic abnormality)| and a DUE TO attribute with a value of 262755005|Injury of the lens (disorder)|.
  
  
• Recommended action as of the January 2017 release: None.

 3.4.6.23 Localized traumatic opacity

• The Cataract Pattern Report suggests the addition of an ASSOCIATED MORPHOLOGY attribute with a value of 19130008|Traumatic abnormality (morphologic abnormality)| to the definition of 43972005|Localized traumatic opacity (disorder)|. In the January 2016 International Release, however, this primitive concept has two role groups. One role group pairs a FINDING SITE attribute having a value of 78076003|Structure of lens of eye (body structure)| with an ASSOCIATED MORPHOLOGY attribute having a value of 19130008|Traumatic abnormality (morphologic abnormality)|. The other role group pairs a FINDING SITE attribute having a value of 78066003|Structure of lens of eye (body structure)| with an ASSOCIATED MORPHOLOGY attribute having a value of 128306009|Cataract (morphologic abnormality)|. In addition, there is an IS-A relationship to 262755005|Injury of the lens (disorder)|. Note that this is a different pattern from that used in 34361001|Traumatic cataract (disorder)| and 8656007 |Total traumatic cataract (disorder)|. From a semantic standpoint, it seems preferable to say that a traumatic cataract or opacity is due to an injury to the lens instead of saying that it is a kind of injury to the lens.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.24 Partial resolved traumatic cataract

• The Cataract Pattern Report suggests the addition of an ASSOCIATED MORPHOLOGY attribute with a value of 19130008|Traumatic abnormality (morphologic abnormality)| to the definition of 193598007|Partial resolved traumatic cataract (disorder)|. In the January 2016 International Release, however, this concept has an ASSOCIATED MORPHOLOGY attribute with a value of 128306009|Cataract (morphologic abnormality)| and a DUE TO attribute with a value of and |Injury of lens (disorder)|. The concept remains primitive, but its current state appears to be preferable to the suggestion in the Cataract Pattern Report.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.25 Cataract in degenerative disorder

• The Cataract Pattern Report suggests the addition of an ASSOCIATED WITH attribute having a value of 62585004|Degenerative disorder of eye (disorder)| to the definition of 21818003|Cataract in degenerative disorder (disorder)|, and it also raises the question of whether adding this attribute could make the concept fully defined. This attribute is present in the January 2016 International Release, but the concept remains primitive.

• Recommended action as of the January 2017 release:
  • Assuming the degeneration is systemic rather than specifically involving the eye, change the single defining superconcept from 193600001 | Cataract secondary to ocular disease (disorder) | to 193570009 | Cataract (disorder) |.
  • Change the ASSOCIATED WITH attribute having a value of 62585004|Degenerative disorder of eye (disorder)| to a DUE TO attribute having a value of 362975008 | Degenerative disorder (disorder) |.
  • Change the value of the existing ASSOCIATED MORPHOLOGY attribute to 128305008|Abnormally opaque structure (morphologic abnormality)|.
  • Create a new relationship group having an ASSOCIATED MORPHOLOGY attribute with a value of 33359002 | Degeneration (morphologic abnormality) | and a FINDING SITE attribute with a value of 78076003 | Structure of lens of eye (body structure) | to this new role group.
  • Finally, change the FSN to “Cataract due to degenerative disorder.”
  • Attempt to make the concept fully defined.

3.4.6.26 Calcified cataract

• The Cataract Pattern Report suggests the addition of an ASSOCIATED MORPHOLOGY attribute having a value of 18115005|Pathologic calcification, calcified structure (morphologic abnormality)| to the definition of 10970008|Calcified cataract (disorder)|. This attribute is present in the January 2016 International Release, and the concept is now fully defined.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.27 Posterior subcapsular polar senile cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute having a value of 77952006|Structure of posterior pole of lens (body structure)| to the definition of 5318001|Posterior subcapsular polar senile cataract (disorder)|. This attribute is present in the January 2016 International Release, and the concept is now fully defined.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.28 Posterior subcapsular polar cataract

• The Cataract Pattern Report suggests the addition of a FINDING SITE attribute having a value of 77952006|Structure of posterior pole of lens (body structure)| to the definition of 34533008| Posterior subcapsular polar cataract (disorder)|. This attribute is present in the January 2016 International Release, and the concept remains primitive.

• Recommended action as of the January 2017 release: None.

3.4.6.29 Cataract in eye inflammatory disorder

• The Cataract Pattern Report suggests the addition of an ASSOCIATED WITH attribute having a value of 128295000|Inflammatory disorder of the eye (disorder)| to the definition of 193602009|Cataract in eye inflammatory disorder (disorder)|. This attribute is present in the January 2016 International Release, and the concept remains fully defined.

• Recommended action as of the January 2017 release: Change the ASSOCIATED WITH attribute to a DUE TO attribute. Consider changing the FSN to “Cataract concurrent with and due to inflammatory disorder.”

 3.4.6.30 Congenital cataract

• The Cataract Pattern Report suggests that the definition of 79410001|Congenital cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains fully defined.

• Recommended action as of the January 2017 release: In keeping with IHTSDO-89, both of 609587005|Congenital cataract (morphologic abnormality)| and 16301006|Congenital opacity (morphologic abnormality)| will presumably be retired because they are both descendants of 21390004|Developmental anomaly (morphologic abnormality)|. In the stated view, change the value of the  ASSOCIATED MORPHOLOGY attribute in the role group to 128305008|Abnormally opaque structure (morphologic abnormality)| and leave the OCCURRENCE and FINDING SITE attributes as they are. 

3.4.6.31 Congenital cataract and lens anomalies

• The Cataract Pattern Report suggests that the definition of 268159001|Congenital cataract and lens anomalies (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group :
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|.

3.4.6.32 Total and subtotal congenital cataract

• The Cataract Pattern Report suggests that the definition of 204130004|Total and subtotal congenital cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|

 3.4.6.33 Congenital blue dot cataract

• The Cataract Pattern Report suggests that the definition of 204138006| Congenital blue dot cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|

3.4.6.34 Congenital sutural cataract

• The Cataract Pattern Report suggests that the definition of 253226005|Congenital sutural cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|

3.4.6.35 Congenital total cataract

• The Cataract Pattern Report suggests that the definition of 29590001|Congenital total cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains fully defined.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|

The concept can remain fully defined as it is distinguished from 79410001|Congenital cataract (disorder)| by the presence of 849000|Mature cataract (disorder)| as an additional parent.

3.4.6.36 Congenital membranous cataract

• The Cataract Pattern Report suggests that the definition of 204139003|Congenital membranous cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|

• The concept should remain primitive.

3.4.6.37 Cataract following rupture of capsule

• The Cataract Pattern Report suggests the addition of an AFTER attribute having a value of 95718009|Rupture of lens (disorder)| and an ASSOCIATED MORPHOLOGY attribute having a value of 19130008|Traumatic abnormality (morphologic abnormality)| to the definition of 231968003|Cataract following rupture of capsule (disorder)|. It also questions whether the addition of these attributes could make the concept fully defined. In the January 2016 International Release, however, this concept has an ASSOCIATED MORPHOLOGY attribute with a value of 128306009|Cataract (morphologic abnormality)| and a DUE TO attribute with a value of and 262755005|Injury of lens (disorder)|. The concept remains primitive, but its current state appears to be preferable to the suggestion in the Cataract Pattern Report.
• Recommended action as of the January 2017 release: The 19130008|Traumatic abnormality (morphologic abnormality)| concept is problematic because it implies a cause (trauma) without specifying the anatomic structure involved. A better choice for the value of the ASSOCIATED MORPHOLOGY attribute is 125671007 |Rupture (morphologic abnormality)|. Currently, the stated view has only one attribute, which is an AFTER attribute with a value of 95718009|Rupture of lens (disorder)|. In keeping with the current “zero-based” editorial policy, the following additions should be made:
  • A DUE TO attribute with a value of 95718009|Rupture of lens (disorder)|
  • A role group with containing the an ASSOCIATED MORPHOLOGY attribute with a value of 95718009|Rupture of lens (disorder)| and a FINDING SITE attribute with a value of 77155007|Structure of lens capsule (body structure)|.

• These changes may be enough to make the concept fully defined.

 3.4.6.38 Corticosteroid induced cataract

• The Cataract Pattern Report suggests that the definition of 404647000|Corticosteroid induced cataract (disorder)| be changed by adding two CAUSATIVE AGENT attributes, one with a value of 304275008|Corticosteroids and derivatives (substance)| and another with a value of 410942007|Drug or medicament (substance)|. Both of these attributes are present in the January 2016 International Release. It is worth noting that 410942007|Drug or medicament (substance)| is not an ancestor of 304275008|Corticosteroids and derivatives (substance)|. Although 404647000|Corticosteroid induced cataract (disorder)| is shown as primitive in the Cataract Pattern Report, the concept is now fully defined.

• Recommended action as of the January 2017 release: None at present, although the values of the CAUSATIVE AGENT attributes may eventually need to be changed as a result of the Substance Hierarchy Redesign (SHR) project.

3.4.6.39 Congenital subtotal cataract

• The Cataract Pattern Report suggests that the definition of 63912009|Congenital subtotal cataract (disorder)| be changed by adding an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and an ASSOCIATED MORPHOLOGY attribute having a value of 65828003|Congenital partial opacity (morphologic abnormality)|. In the January 2016 International Release, both of these attributes are present but the ASSOCIATED MORPHOLOGY attribute has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.
• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|.

• 3.4.6.40 Congenital lamellar cataract
• The Cataract Pattern Report suggests three additions to the definition of 204128001|Congenital lamellar cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • Another ASSOCIATED MORPHOLOGY attribute having a value of 128306009|Cataract (morphologic abnormality)|.

In the January 2016 International Release, the recommended OCCURRENCE attribute is present, but there is a single ASSOCIATED MORPHOLOGY attribute having a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive.

• • Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, put the following three attributes into a relationship group in the stated view:
  • The existing OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|.

3.4.6.41 Bilateral cataracts

• The Cataract Pattern Report suggests that the definition of 95722004| Bilateral cataracts (disorder)| be changed by adding two FINDING SITE attributes, one with a value of 88258005|Structure of lens of left eye (body structure)| and another with a value of 72345007| Structure of lens of right eye (body structure)|. Both of these FINDING SITE attributes are present in the January 2016 International Release. Furthermore, these FINDING SITE attributes are in two separate role groups, each containing an ASSOCIATED MORPHOLOGY attribute with a value of 128306009|Cataract (morphologic abnormality)|. Additionally, 95722004| Bilateral cataracts (disorder)| is now fully defined.

• Recommended action as of the January 2017 release: None.

3.4.6.42 On examination - lens - early opacity (disorder)

• The Cataract Pattern Report suggests that the definition of 162820002|On examination - lens - early opacity (disorder)| be changed by adding a FINDING INFORMER method with a value of 420158005|Performer of method (person)| and a FINDING METHOD attribute of 5880005|Physical examination procedure (procedure)|. Both of these attributes are present in January 2016 International Release. Although the Cataract Pattern Report questions raises a question of whether adding these attributes could make concept fully defined, it remains primitive.
  
  
• Recommended action as of the January 2017 release: None.

3.4.6.43 Congenital polar cataract

• The Cataract Pattern Report suggests three additions to the definition of 253223002|Congenital polar cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 253223002|Pole of lens (body structure)|

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. Although the concept is shown as primitive in the Cataract Pattern Report, 253223002|Congenital polar cataract (disorder)| is now fully defined.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to its 128305008|Abnormally opaque structure (morphologic abnormality)|. The concept can remain fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s inferred parent, 79410001|Congenital cataract (disorder)|.

3.4.6.44 Congenital capsular cataract

• The Cataract Pattern Report suggests three additions to the definition of 28550007|Congenital capsular cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The Cataract Pattern Report raised a question about whether the concept should remain primitive after addition of the suggested attributes, and 28550007|Congenital capsular cataract (disorder)| is now fully defined.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. The concept can remain fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s inferred parent, 79410001|Congenital cataract (disorder)|.

3.4.6.45 Acquired anterior capsular pigmentation

• The Cataract Pattern Report suggests three additions to the definition of 95720007|Acquired anterior capsular pigmentation (disorder)|:
  • An ASSOCIATED MORPHOLOGY attribute having a value of 51083003|Structure showing abnormal deposition of pigment (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 244501000| Anterior lens capsule (body structure)|
  • Another FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|

All three of these suggested changes are present in the January 2016 International Release. It is worth noting that the FSN of 51083003|Structure showing abnormal deposition of pigment (morphologic abnormality)| has apparently changed, since it is referred to as “Pigment deposition” it the Cataract Pattern Report and this phrase is now a synonym. Furthermore, the two FINDING site attributes are now in separate role groups. The first role groups contains an ASSOCIATED MORPHOLOGY attribute having a value of 51083003|Structure showing abnormal deposition of pigment (morphologic abnormality)| and the second role group contains an ASSOCIATED MORPHOLOGY attribute having a value of128306009|Cataract (morphologic abnormality)|.This second relationship group with a FINDING SITE of 77155007|Structure of lens capsule (body structure)| and an ASSOCIATED MORPHOLOGY of 128306009|Cataract (morphologic abnormality)| is inferred from the parent concept 72180004|Vossius' ring|. Although the Cataract Pattern Report raised a question about whether addition of these new attributes could make the concept fully defined, 95720007|Acquired anterior capsular pigmentation (disorder)| remains primitive in the January 2016 and January 2017 International Releases.

• Recommended action as of the January 2017 release: None.

3.4.6.46 Embryonal nuclear cataract

• The Cataract Pattern Report suggests three additions to the definition of 5361003|Embryonal nuclear cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 35538005|Structure of substance of lens (body structure)|

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The Cataract Pattern Report raised a question about whether the concept should remain primitive after addition of the suggested attributes, and 5361003|Embryonal nuclear cataract (disorder)| is now fully defined.

• Recommended action as of the January 2017 release: Move the OCCURRENCE attribute into the role group in the stated view. Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. The concept can remain fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s stated parent, 79410001|Congenital cataract (disorder)|.

3.4.6.47 Congenital subcapsular cataract

• The Cataract Pattern Report suggests three additions to the definition of 76562003|Congenital subcapsular cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 35538005|Structure of substance of lens (body structure)|.

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The Cataract Pattern Report raised a question about whether the concept should remain primitive after addition of the suggested attributes, but 76562003|Congenital subcapsular cataract (disorder)| remains primitive in January 2017 release.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. It appears that the concept could be fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s inferred parent, 79410001|Congenital cataract (disorder)|.

3.4.6.48 Congenital anterior polar cataract

• The Cataract Pattern Report suggests three additions to the definition of 253224008|Congenital anterior polar cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 28993004|Structure of anterior pole of lens (body structure)|.

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|.  The Cataract Pattern Report raised a question about whether the concept should remain primitive after addition of the suggested attributes, and 253224008|Congenital anterior polar cataract (disorder)| is now fully defined.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. The concept can remain fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s inferred parent, 79410001|Congenital cataract (disorder)|.

3.4.6.49 Nance-Horan syndrome

• The Cataract Pattern Report suggests four additions to the definition of 445257004|Nance-Horan syndrome (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • Another ASSOCIATED MORPHOLOGY attribute having a value of 107656002| Congenital anomaly (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 38199008|Tooth structure (body structure)|.

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attributes, however, have slightly different values from those suggested in the Cataract Pattern Report.  One ASSOCIATED MORPHOLOGY attribute has a value of 21390004|Developmental anomaly (morphologic abnormality)|, which is the direct parent of 107656002|Congenital anomaly (morphologic abnormality)|. This ASSOCIATED MORPHOLOGY attribute appears in a role group that also contains an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and a FINDING SITE attribute having a value of 38199008|Tooth structure (body structure)|.  The other ASSOCIATED MORPHOLOGY attribute has a value of 609587005| Congenital cataract (morphologic abnormality)| , which is a direct child of both 16301006| Congenital opacity (morphologic abnormality)| and 128306009| Cataract (morphologic abnormality)| This second ASSOCIATED MORPHOLOGY attribute appears in a different role group that also contains an OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)| and a FINDING SITE attribute having a value of 78076003|Structure of lens of eye (body structure)|. The Cataract Pattern Report raised a question about whether the concept should still be designated as primitive after addition of the suggested attributes, but that designation remains unchanged in the January 2017 release.

• Recommended action as of the January 2017 release: In keeping with the current “zero-based” editorial policy, add the following two role groups to the stated definition:
  • One role group containing:
    • An OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
    • An ASSOCIATED MORPHOLOGY attribute with a valule of 49755003 | Morphologically abnormal structure (morphologic abnormality) |. Note that this change from a value of 21390004|Developmental anomaly (morphologic abnormality)| is in keeping with IHTSDO-89.
    • A FINDING SITE attribute with a value of 38199008 | Tooth structure (body structure) |.
  • Another role group containing:
    • An OCCURRENCE attribute with a value of 255399007|Congenital (qualifier value)|
    • An ASSOCIATED MORPHOLOGY attribute with a valule of 128305008|Abnormally opaque structure (morphologic abnormality)|.
    • A FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|.

3.4.6.50 Congenital cortical cataract

• The Cataract Pattern Report suggests three additions to the definition of 66499004|Congenital cortical cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 57321004|Congenital punctate opacity (morphologic abnormality)|
  • A FINDING SITE attribute with a value of 33347001|Structure of cortex of lens (body structure)|.

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. Note that 57321004|Congenital punctate opacity (morphologic abnormality)| is a sibling of 609587005|Congenital cataract (morphologic abnormality)| and a direct child of 16301006|Congenital opacity (morphologic abnormality)|. The concept remains fully defined.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. The concept can remain fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s inferred parent, 79410001|Congenital cataract (disorder)|.

3.4.6.51 Congenital zonular cataract

• The Cataract Pattern Report suggests three additions to the definition of 21590003|Congenital zonular cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 609587005|Congenital cataract (morphologic abnormality)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 57321004|Congenital punctate opacity (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 33347001|Structure of cortex of lens (body structure)|.

In the January 2016 International Release, the suggested OCCURRENCE and FINDING SITE attributes are present. The ASSOCIATED MORPHOLOGY attribute, however, has a value of 609587005|Congenital cataract (morphologic abnormality)|, which is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. Note that 57321004|Congenital punctate opacity (morphologic abnormality)| is a sibling of 609587005|Congenital cataract (morphologic abnormality)| and a direct child of 16301006|Congenital opacity (morphologic abnormality)|. The concept remains primitive in the January 2017 release.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. It appears that the concept should remain primitive to distinguish it from 66499004|Congenital cortical cataract (disorder)|, which is fully defined.

3.4.6.52 Osteogenesis imperfecta, recessive perinatal lethal, with microcephaly AND cataracts

• The Cataract Pattern Report suggests five changes to the definition of 15552004|Osteogenesis imperfecta, recessive perinatal lethal, with microcephaly AND cataracts|:
  • An OCCURRENCE attribute having a value of 255399007 | Congenital (qualifier value) |
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|
  • Another ASSOCIATED MORPHOLOGY attribute having a value of 25283002|Congenital dysplasia (morphologic abnormality)|
  • A FINDING SITE attribute having a value of 12738006|Brain structure (body structure)|
  • Another FINDING SITE attribute having a value of 272673000|Bone structure (body structure)

In the January 2016 International Release, all of the suggested attributes are present but one of the ASSOCIATED MORPHOLOGY attributes has a value of 609587005|Congenital cataract (morphologic abnormality)| instead of 16301006|Congenital opacity (morphologic abnormality)|. As previously noted, 609587005|Congenital cataract (morphologic abnormality)| is a direct child of both 16301006|Congenital opacity (morphologic abnormality)| and 128306009|Cataract (morphologic abnormality)|. The concept remains primitive in the January 2017 release.

• Recommended action as of the January 2017 release: Change the FSN to “Osteogenesis imperfecta, recessive perinatal lethal co-occurrent with microcephaly and cataracts” and change the value of the ASSOCIATED MORPHOLOGY attribute to 128305008|Abnormally opaque structure (morphologic abnormality)|.

3.4.6.53 Anterior capsule opacification

• The Cataract Pattern Report suggests three additions to the definition of 410568009|Anterior capsule opacification (disorder)|:
  • An HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|
  • A FINDING SITE attribute having a value of 244501000|Anterior lens capsule (body structure)|

In the January 2016 International Release, all of the suggested attributes are present, and the concept remains fully defined.

• Recommended action as of the January 2017 release: Change FSN to “Anterior capsule opacification following extraction of cataract” and remove the HAS DEFINITIONAL MANIFESTATION attribute, which has been deprecated.

3.4.6.54 Posterior capsule opacification

• The Cataract Pattern Report suggests three additions to the definition of 410567004|Posterior capsule opacification (disorder)|:
  • A HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|
  • A FINDING SITE attribute having a value of 244502007|Posterior lens capsule (body structure)|

In the January 2016 and 2017 International Releases, all of the suggested attributes are present, and the concept remains fully defined.

• Recommended action as of the January 2017 release: Change FSN to “Posterior capsule opacification following extraction of cataract” and remove the HAS DEFINITIONAL MANIFESTATION attribute, which has been deprecated.

3.4.6.55 After-cataract with vision obscured

• The Cataract Pattern Report suggests three additions to the definition of 193615000|After-cataract with vision obscured (disorder)|:
  • Addition of a HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|
  • A FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|

In the January 2016 International Release all of the suggested attributes are present, and the concept remains primitive in the January 2017 release.

• Recommended action as of the January 2017 release: Change the FSN to “After-cataract with vision obscured following extraction of cataract.”

3.4.6.56 Elschnig's pearls

• The Cataract Pattern Report suggests three additions to the definition of 231974003|Elschnig's pearls (disorder)|:
  • An HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|
  • A FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|

In the January 2016 International Release all of the suggested attributes are present. The concept remains primitive in the January 2017 release.

• Recommended action as of the January 2017 release: Remove the HAS DEFINITIONAL MANIFESTATION attribute, which has been deprecated.

3.4.6.57 Capsular fibrosis

• The Cataract Pattern Report refers to the FSN of SCTID 47337003 as "Capsular fibrosis." This phrase is a synonym of 47337003|After-cataract (disorder)| in the January 2016 International Release. Three changes to the definition of this concept are suggested:
  • A HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|
  • A FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|

All of these suggested changes are present in the January 2016 International Release, and 47337003|After-cataract (disorder)| was primitive in that release but is fully defined in the January 2017 release.

• Recommended action as of the January 2017 release: Although all the changes proposed by the Cataract Pattern report have been made, the stated definition of this concept could arguably be improved by making the following changes:
  • Make 247075009 | Lens capsule opacity in pseudophakia (finding) | a parent of 47337003 | After-cataract (disorder) | and remove the HAS DEFINITIONAL MANIFESTATION attribute, which has been deprecated.
  • Add an AFTER attribute with a value of 54885007 | Extraction of cataract (procedure) | to the stated definition of 247075009 | Lens capsule opacity in pseudophakia (finding) |. Additionally, put the existing FINDING SITE attribute into a new role group with an ASSOCIATED MORPHOLOGY attribute having a value of 128305008 | Abnormally opaque structure (morphologic abnormality) |.

3.4.6.58 After-cataract not obscuring vision

• The Cataract Pattern Report suggests three additions to the definition of 51044000|After-cataract not obscuring vision (disorder)|:
  • A HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|
  • A FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|

All of these suggested changes are present in the January 2016 International Release, and the concept remains primitive in the January 2017 release.

• Recommended action as of the January 2017 release: Change the FSN to “After-cataract not obscuring vision following extraction of cataract” and and remove the HAS DEFINITIONAL MANIFESTATION attribute, which has been deprecated.

 3.4.6.59 Soemmerring's ring

• The Cataract Pattern Report suggests three additions to the definition of 65720003|Soemmerring's ring (disorder)|:
  • A HAS DEFINITIONAL MANIFESTATION attribute having a value of 247075009|Lens capsule opacity in pseudophakia (finding)|,
  • An AFTER attribute having a value of 54885007|Extraction of cataract (procedure)|,
  • A FINDING SITE attribute having a value of 77155007|Structure of lens capsule (body structure)|.

All of these suggested changes are present in the January 2016 International Release, and the concept remains primitive in the January 2017 release.

• Recommended action as of the January 2017 release: Remove the HAS DEFINITIONAL MANIFESTATION attribute, which has been deprecated.

3.4.6.60 Congenital posterior polar cataract

• The Cataract Pattern Report suggests five additions to the definition of 253225009|Congenital posterior polar cataract (disorder)|:
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 107656002|Congenital anomaly (morphologic abnormality)|
  • Another ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|,
  • A FINDING SITE attribute having a value of 77952006|Structure of posterior pole of lens (body structure)|
  • Another FINDING SITE attribute having a value of 280630009|Pole of lens (body structure)|

All of these suggestions have been addressed in the January 2016 International Release, but the following points are notable:

• • There is only one FINDING SITE attribute, however, and it has a value of 77952006|Structure of posterior pole of lens (body structure)|. This seems quite reasonable because 77952006|Structure of posterior pole of lens (body structure)| is a direct child of 280630009|Pole of lens (body structure)| and there is no apparent reason to use the more general concept.
  • A single ASSOCIATED MORPHOLOGY attribute with a value of 609587005|Congenital cataract (morphologic abnormality)| provides the needed semantics because it is a direct child of 16301006|Congenital opacity (morphologic abnormality)| and a descendant of 21390004|Developmental anomaly (morphologic abnormality)|.

The Cataract Pattern Report raised a question about whether the designation of 253225009|Congenital posterior polar cataract (disorder)| as primitive could be changed as a result of adding the suggested attributes, and the concept is now fully defined.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| to 128305008|Abnormally opaque structure (morphologic abnormality)|. The concept can remain fully defined because the value of the FINDING SITE attribute is more specific than the value of this attribute in the concept’s inferred parent, 79410001|Congenital cataract (disorder)|.

3.4.6.61 Rubella cataract

• The Cataract Pattern Report suggests five additions to the definition of 253227001|Rubella cataract (disorder)|:
  • A HAS DEFINITIONAL MANIFESTATION attribute having a value of 238812004|Exanthematous disorder (disorder)|
  • An OCCURRENCE attribute having a value of 255399007|Congenital (qualifier value)|
  • A CAUSATIVE AGENT attribute having a value of 5210005|Rubella virus (organism)|
  • A PATHOLOGICAL PROCESS attribute having a value of 441862004|Infectious process (qualifier value)|
  • An ASSOCIATED MORPHOLOGY attribute having a value of 16301006|Congenital opacity (morphologic abnormality)|

The HAS DEFINITIONAL MANIFESTATION attribute is considered to be deprecated, but the other suggestions have been addressed in the January 2017 release.

Cataract Pattern Report also raised a question about whether the designation of |Rubella cataract (disorder)| as primitive could be changed as a result of adding the suggested attributes. The concept was primitive in the January 2016 International Release but is fully defined in the January 2017 release.

• Recommended action as of the January 2017 release: Change the value of the ASSOCIATED MORPHOLOGY attribute from 609587005|Congenital cataract (morphologic abnormality)| 128305008|Abnormally opaque structure (morphologic abnormality)| and and remove the HAS DEFINITIONAL MANIFESTATION attribute.

3.4.7 Analysis of the Current Structure of the Cataract Sub-Hierarchy

There are 113 concepts in a SNOMED CT subset consisting of 193570009|Cataract (disorder)| and all of its descendants. The 39 direct children of 193570009|Cataract (disorder)| are shown in Figure 1. As noted in Section 3.5, IHTSDO-819 suggests that the sub-hierarchy defined as 62585004|Degenerative disorder of eye (disorder)| and its descendants be reorganized based on anatomy and etiology. For the purposes of this project, the question is whether to apply this suggestion to the cataract sub-hierarchy.

The current editorial policy on grouper concepts is focused on ensuring that they are clinically useful. The goal is not simply to add more structure to a given sub-hierarchy in hopes of making it easier to query or navigate. There is nothing inherently wrong with a flat hierarchy, especially if modeling consistency can be improved by fully defining as many concepts as possible. With fully defined concepts, groupers can “emerge” from in the inferred view from the classification process.

At present, the two main requirements for grouper concepts are (1) they should be fully defined, not intermediate primitives, and (2) they should be clinically useful, where "clinically useful" means that a typical clinical user might want to perform a subsumption query on the grouper of view the descendants of the grouper in a browser because doing so could help answer a question of clinical interest.

Moreover, the cataract disorder subhierarchy is relatively small, which means that it is less likely to benefit from adding more grouper concepts.

In view of these considerations, it is recommended that no attempt should be made to reorganize the cataract sub-hierarchy based on anatomy and etiology, in keeping with IHTSDO-819. It is worth pointing out that organizing a sub-hierarchy by etiology is difficult because there is no single attribute in the SNOMED CT concept model that precisely corresponds to the meaning of the word “etiology.”

Although it is outside the scope of this project, IHTSDO-891 should arguably be reviewed in light of the current editorial policy on grouper concepts. Even at the level of the sub-hierarchy rooted at 62585004|Degenerative disorder of eye (disorder)|, there may be little need to add more grouper concepts in an attempt to reorganize the sub-hierarchy on an anatomical and etiological basis. If that proves to be the case on further review, then IHTSDO-819 should presumably be deleted as an active item in the Content Tracker.

Figure 1: List of the direct child concepts of "Cataract (disorder)," where concepts having descendants are designated by a "+" sign

3.5 Subsidiary and interrelated problems

Although the scope of this project is limited to 193570009|Cataract (disorder)|and its descendants, four related JIRA items have been identified:

• IHTSDO-811 (artf222415) requests review of|39450006|Senile cataract (disorder)|for completeness, based on the observation that Steadman’s Medical Dictionary lists several types of cataracts that do not appear as siblings or descendants of “Senile cataract.” It should be noted that the phrase “Senile cataract” does not appear as a Fully Specified Name (FSN) in the International Edition 20160131 Release of SNOMED CT. Rather, it currently appears as a description of 39450006|Age-related cataract (disorder)|, indicating that the FSN has been changed. As noted in Section 3.4.1.1, JIRA item IHTSDO-811 has been retired because it is being addressed by this project (i.e., IHTSDO-791). See Section 3.4.1.1 for further details.
• IHTSDO-819 (artf222535) requests a sub-hierarchy review of 62585004|Degenerative disorder of eye (disorder)|, suggesting that the descendants of this concept be organized based on etiology and anatomy. For the reasons described in Section 3.4.7, it is not recommended that the requested reorganization in IHTSDO-819 not be applied to the cataract sub-hierarchy.
• IHTSDO-424 (artf220828) proposes considering retirement of 128306009|Cataract (morphologic abnormality)|in order to “redefine cataract procedures currently using cataract morphology with morphology opacity and finding site lens to be consistent with modeling of cataract disorders.” Strictly speaking, IHTSDO-424 is out of scope for this project because it deals with procedures instead of disorders. Nevertheless, it seems clear that the same concept should be used as the value of the PROCEDURE MORPHOLOGY/DIRECT MORPHOLOGY attribute for cataract procedures and as the value for the ASSOCIATED MORPHOLOGY attribute for cataract disorders. As described in Section 3.4.3, the quality and consistency of the cataract sub-hierarchy can be improved by replacing the current 128306009|Cataract (morphologic abnormality)| values of ASSOCIATED MORPHOLOGY attributes with 128305008|Abnormally opaque structure (morphologic abnormality)|. Making this change would allow 128306009|Cataract (morphologic abnormality)| to be retired, which would arguably remove any possible confusion arising from having “cataract” as both a disorder and a morphologic abnormality.
• IHTSDO-89 proposes major changes to the representation of congenital disorders by using the OCCURRENCE attribute instead of using congenital morphologic abnormality concepts (which will ultimately be retired). Although this JIRA item is not specifically linked to IHTSDO-791, it has had a significant impact on recommendations about how congenital cataracts should be modeled.

4 Risks / Benefits

4.1 Risks of Not Addressing the Problem

The primary risk of not addressing the problem is that the cataract sub-hierarchy will not be consistent with the desired modeling patterns described in IHTSDO-791 and the accompanying Cataract Pattern Report. This risk is small because almost all of the recommended changes in the Cataract Pattern Report have already been made in the January 2016 International Release, as described in 3.4.6.

The Project Risk Profile assessment tool in the from the document entitled A Guide to Stakeholder Engagement (available at https://confluence.ihtsdotools.org/display/CONSULTANTTERMINOLOGISTGROUP/Stakeholder++Engagement++Resources ) was used to evaluate the risks of this project, as follows:

4.2 Risks of Addressing the Problem

The risks of addressing the problem mostly involve the use of resources that could potentially be applied to higher priority projects. Resource requirements, which are described in more detail in Section 9, are likely to be low in view the relatively small number of concepts involved. 

5 Requirements: criteria for success and completion

5.1 Criteria for success/completion

Released concepts in the cataract sub-hierarchy, defined as 193570009|Cataract (disorder)| and its descendants, are in scope for this content project and will:

• Be clearly and consistently represented in SNOMED CT, as noted in IHTSDO-791
• Have stated definitions consisting of IS-A relationships, attributes, and attribute values that have been assigned in a consistent manner to ensure that classification results in logical inferred relationships.
  
  

5.2 Strategic and/or specific operational use cases

• This content project aligns with the IHTSDO strategic direction of making SNOMED CT easier to use. This will be achieved by using consistent modeling patterns (as specified in IHTSDO-791) for the cataract sub-hierarchy. 

6 Solution Development

6.1 Initial Design

The proposed solution essentially consists of applying current editorial policies to each of the specific issues raised in IHTSDO-791 and the associated Cataract Pattern Report. Detailed recommendations for implementing this solution are described in Section 3.4.

6.1.1 Outline of Initial Design: Option 1

A number of the problems identified in Section 3.4 concern changing the status of concepts from primitive to defined. In some cases, IHTSDO-791 suggests that new attributes should be added to the concept definitions before these changes are made, but in other cases it suggests that the changes can be made without the addition of new attributes.

In any case, whenever the status of a concept is changed from primitive to defined, the classifier should be run to determine whether the change results in any equivalence errors. If equivalence errors are found, then the status of the concept should be changed back to primitive.

6.1.1.1 Inconsistent Use of the OCCURRENCE Attribute for Cataract Concepts Related to Periods of Life

As discussed in Section 3.4.1.1, the presence of “Senile cataract” as a synonym of for 39450006|Age-related cataract (disorder)| strongly suggests that the intended meaning of this concept is “Cataract related to old age.”

Accordingly, an OCCURRENCE attribute with a value of 271872005|Old age (qualifier value) |should be added to the definitions of 39450006|Age-related cataract (disorder)|. In keeping with the “zero-based” editorial policy, a role group containing an ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)| and a FINDING SITE attribute with a value of 78076003|Structure of lens of eye (body structure)|. The meaning of the concept should also be clarified by changing the FSN to either “Old-age related cataract” or “Senile cataract.”

With respect to the eight direct children of this concept, which are shown in Table 2, the same OCCURRENCE attribute and the same role group should be added to the stated definitions of each child concept. The same role group should also be added unless a FINDING SITE attribute with a more specific value than 78076003|Structure of lens of eye (body structure)| is present or can be added.

As shown in Table 2, three of these eight direct children are already fully defined. Two of the other five  primitive child concepts can be made fully defined. A more specific FINDING SITE attribute with a value of 33347001 | Structure of cortex of lens (body structure) | is already present in the stated definition of 78875003 | Cortical senile cataract (disorder) |. A role group containing an ASSOCIATED MORPHOLOGY attribute with a value of 128305008|Abnormally opaque structure (morphologic abnormality)| and a FINDING SITE attribute with a value of 28993004 | Structure of anterior pole of lens (body structure) | can be added to the stated definition of 111515007 | Anterior subcapsular polar senile cataract (disorder) | to make it fully defined.

Table 2: Direct children of 39450006|Age-related cataract (disorder)|

6.1.1.2 Toxic Cataract

Despite the suggestion in IHTSDO-791 that this concept be connected to 441952005|Poisoning caused by chemical substance (disorder)|, using a CAUSATIVE AGENT attribute with a substance value of is arguably more direct than using a DUE TO attribute having a disorder concept as its value. Specifically, the following changes should be made to the stated definition of 38583007 | Toxic cataract (disorder) |:

• Add 75478009 | Poisoning (disorder) | as a parent
• Add a CAUSATIVE AGENT attribute with a value of 35331000 | Toxic substance (substance) |
• Add a role group containing an ASSOCIATED MORPHOLOGY attribute with a value of 128305008 |Abnormally opaque structure (morphologic abnormality)| and FINDING SITE attribute with a value of 78076003 |Structure of lens of eye (body structure)|.

These changes can presumably make the concept fully defined.

6.1.1.3 Concussion Cataract

No relationship to 110030002|Concussion injury of brain (disorder)| should be added to 231967008|Concussion cataract (disorder)|, provided that expert clinical reviewers agree that concussion cataract is a type of traumatic cataract in which there is an injury to the lens itself and is not secondary to a concussion injury of the brain. (See Section 3.4.1.3.)

6.1.1.4 Concepts That Appear to be Defined but are Classified as Primitive

Table 3 lists 13 concepts from Table 1 that remain primitive in the January 2016 International Edition, even though IHTSDO-791 suggests that they are candidates for being made fully defined. All of these concepts are described in the Cataract Pattern Report. For each concept in Table 10, the third column  lists the section of this document where the recommendations in the Cataract Pattern Report are discussed in more detail.

There should be an attempt to make each of the concepts in Table 10 fully defined. This attempt consists of three steps: (1) changing the concept from primitive to fully defined in an editing tool, (2) running the classifier to determine whether any equivalence errors are detected, and (3) reverting the concept back to primitive if equivalence errors are detected by the classifier.

Table 3: Primitive concepts that may be changed to fully defined

6.1.1.5 Implementation of Changes Requested in the Cataract Pattern Report

Many of the changes requested in the Cataract Pattern Report have already been made, as described in Section 3.4.6. The vast majority of these changes were found to have already been implemented in the January 2016 International Release. In a few cases, current attribute values differ slightly from what was requested in the Cataract Pattern Report, but the current state addresses the issues raised and is arguably superior to the suggestions in the original request. However, many of the requested changes in the Cataract Pattern Report have now been superseded by changes needed to be consistent with IHTSDO-89 on modeling congenital disorders. Other changes are needed to make the modeling consistent with current editorial policy.

6.1.2 Significant design or implementation decisions / compromises

As noted previously, the implantation of the specific changes requested in IHTSDO-791 is straightforward, in that most of the changes have already been made as of the January 2016 International Release.

6.1.3 Evaluation of Design

The proposed design should be evaluated by determining whether it adequately address the specific changes requested in IHTSDO-791 and the accompanying Cataract Pattern Report in the context of current editorial policies.

6.1.4 Exceptions and Problems

The primary exceptions to complete resolution of IHTSDO-791 and its related problems (IHTSDO-811, IHTSDO-819, IHTSDO-414, and IHTSDO-89) may require input from other groups.

A common theme throughout this project is the need to make a concept fully defined, run a description logic classifier to determine whether making the concept defined produces equivalency errors, and then “undoing” the change to make the concept primitive again if such errors are found. While at least a subset of the proposed changes could be tested during the elaboration phase, this was not done because the author lacked access to a classifier that could perform such tests. It is expected that classifier software will become more widely available outside the IHTSDO core content teams in the relatively near future.

6.1.5 Design Strengths

The primary strengths of the design are that it proposes a careful implementation of the changes requested in IHTSDO-791 and the accompanying Cataract Pattern Report, subject to current editorial policies.

6.1.6 Design Weaknesses

There are no obvious design weaknesses in the proposal to implement changes requested in IHTSDO-791 and the accompanying Cataract Pattern Report, subject to current editorial policies.

Attempting to re-organize the cataract sub-hierarchy in terms of anatomy and etiology, as requested in IHTSDO-819, could have introduced substantial weaknesses into the proposal, because the added grouper concepts would have questionable clinical utility. For the reasons described in Section 3.4.7, it is recommended that no new grouper concepts be added.

6.1.7 Design Risks

7 Recommendation: Detailed design final specification

This section is intended to distill proposed changes described in earlier sections of this document into a succinct list that can be implemented in a straightforward manner.

• As described in Section 6.1.1.1, add an OCCURRENCE attribute with a value of 271872005|Old age (qualifier value)| to the definition of 39450006|Age-related cataract (disorder)| and change the FSN to reflect the meaning of “cataract related to old age.”
• Make the changes to the stated definition of 38583007 | Toxic cataract (disorder) | described in Section 6.1.1.2 to make make the concept fully defined.
• Attempt to change each concept listed in Table 10 from primitive to defined. After each change, the classifier should be run to determine whether any equivalence errors are detected. If such errors are found, the concept should be changed back to primitive. See Section 6.1.1.4.
• Implement a batch change process to replace 128306009 |Cataract (morphologic abnormality)| as the value of FINDING SITE attributes with 128305008 |Abnormally opaque structure (morphologic abnormality)|.
• Make of the changes recommended in Section 3.4.

8 Quality program criteria

8.1 Quality metrics

8.1.1 Quality metric 1

9 Project Resource Estimates

Estimated project size: Small.

The implementation and review of existing content could be undertaken over one release.

9.1 Scope of construction phase

The proposed solution is detailed in Section 6 of this document with recommendations detailed in Section 7. IHTSDO-791 and the accompanying Cataract Pattern Report were thoroughly reviewed, and the results of that review are described in Section 3.4. Thus, the scope of the construction phase should be small because most of the changes requested have already been made in the January 2016 International Release, or perhaps earlier. In fact, much of the work that might have gone into the construction phase of this project, had it been addressed earlier, consisted instead of verifying that most of the changes requested in the Cataract Pattern Report had already been made. As described in Section 7, the construction phase should consist primarily of adding attributes to a small number of existing concepts, testing whether a designated set of existing concepts can be made fully defined without introducing equivalence errors.

9.2 Projection of remaining overall project resource requirements

9.2.1 Expected project resource requirement category

As described in this document, the project can be accomplished by the content team and is not large enough to require project management.

9.2.2 Expected project impact and benefit

The implementation of this project can benefit users by ensuring that concepts in the cataract sub-hierarchy follows consistent modeling patterns in accordance with current editorial policy. 

9.2.3 Indicative resource estimates for construction, transition and maintenance:

Implementing batch change from FINDING SITE values of 128306009 |Cataract (morphologic abnormality)| to values 128305008 |Abnormally opaque structure (morphologic abnormality)| will affect all 113 concepts in the sub-hierarchy. Implementing the other changes recommended in Section 3.4 would affect approximately 40 concepts.

There currently are 25 SIRS requests containing the word “cataract,” and all but two of them are requests for lateralized content. Adding any lateralized body structures that may be necessary is likely to be a small task. The maintenance phase is likely to be extremely small, since it seems unlikely that more than a handful of new cataract concepts might be requested over the next few years.

Appendix: Cataract Pattern Report

See attached file: artf222563_SNOMED Pattern Cataract (193570009) Report.html