Retina-related missing terms in SNOMED

I know the initial focus of the CRG is on glaucoma, but Cindy Cai and I were hoping we could maybe at least initiate some conversation about some retina terms that have been found to be missing from SNOMED. This is work coming out of the OMOP Retina group that Cindy leads. One of the workgroup members extracted all of the diagnosis/condition terms from the Ryan Retina Atlas, one of the premier information resources in retina that has an international set of editors. Presumably these conditions/terms should be represented in standardized vocabularies. The following terms were felt by the majority of the workgroup (which includes retina specialists from several academic centers in the US) to be important for representation but are currently not codified in SNOMED: 

• Nonexudative neovascular age-related macular degeneration
• Paracentral acute middle maculopathy
• Glaucoma drainage implant endophthalmitis
• Lamellar macular hole
• Nonproliferative sickle retinopathy
• Submacular hemorrhage
• Choroidal granuloma
• Eales disease
• Pachychoroid neovasculopathy
• Pachychoroid pigment epitheliopathy
• Peripheral exudative hemorrhagic chorioretinopathy
• Nongeographic atrophy

Elaine Wooler , we just wanted to put this forward for discussion... are the above fairly straightforward to codify? What information would you need? That way we can work on assembling that information among the retina group and and can have that ready for you, even if need to wait until after we do the glaucoma-related work first. Thanks!

I think it would be good to tackle some important missing terms in other fields as we go along, if possible.  Some important ones in that list!  Thanks

Agree, definitely worth adding any obvious missing terms. 

FYI, there is an existing term Eales' disease (disorder) SCTID: 54122009. Some others might also already exist with slightly different but essentially synonymous terms and would be easy enough to add additional synonyms, but am sure Elaine or one of her SNOMED colleagues would be able to check and advise.

"Glaucoma drainage device related endophthalmitis" once created would be a nice addition to our preferred glaucoma disorder terms!

Thank you Sally Baxter  Anthony Khawaja  Ian Rodrigues 

To be able to add any that are gaps a peer-reviewed reference source published within the last 10 years is helpful or definition of the disorder or consensus on the disorder by any expert groups, colleges or academies for example which might include reference to the body structure or structures involved.  Reference to classifications such as ICD-11 also useful and helps with our cross-maps to the classifications.

The following exist:

1. 1222665003 |Paracentral acute middle maculopathy (disorder)| - only added to the international edition in May 2022
2. Choroid granuloma - is this the same as 95683004 |Granulomatous choroiditis (disorder)|
3. 54122009 |Eales' disease (disorder)|
4. Pachychoroid neovasculopathy - worth looking at the subtypes under 75971007 |Choroidal retinal neovascularization (disorder)| as there may be a synonymous concept I don't have the expertise to find.
5. Nongeographic atrophy does not exist but wanted to check that the synonym of geographic atrophy of the macular is correct on the concept 414875008 |Nonexudative age-related macular degeneration (disorder)| 

Great, thank you Elaine Wooler for this info. We have a retina subgroup in our OMOP workgroup and tagging Cindy Cai here so she is aware since she is the retina subgroup lead. We will bring this to our retina subgroup and collect the information/references you mentioned, as well as review the existing terms. Our next meeting for that group is in early May I believe, so it may be a few weeks until we get the info back to you, but we will work on it! 

Excellent thanks Sally Baxter .  We have monthly releases so can add the content when it is ready.

Great! We are working on organizing definitions, references, ICD mappings etc. and will circle back in a few weeks' time.

Hi Elaine Wooler we have organized some definitions and references as follows – let me know if this is along the lines of what you were looking for.  Thanks!

Ryan’s Retina (7th edition) Concepts

1. Nonexudative neovascular age-related macular degeneration

Definition/Description: Nonexudative (or quiescent or asymptomatic) MNV is defined as treatment-naïve type 1 neovascularization detected with dye-based angiography or OCTA that is not associated with clinical evidence of exudation.

Literature review: https://doi.org/10.1016/j.ophtha.2020.01.040 (Ophthalmology) https://doi.org/10.1016/j.oret.2020.02.016 (Ophthalmology Retina)

DOI: 10.1097/IAE.0000000000003598 (Retina)

2. Paracentral acute middle maculopathy

SNOMED Code: 1222665003 (May 2022) – not found in Athena OHDSI platform

Definition/Description: An ischemic lesion caused by impaired perfusion of deep retinal vascular complex.

Literature review: https://doi.org/10.1016/j.ophtha.2018.07.006 (Ophthalmology) https://doi.org/10.1016/j.oret.2021.01.003 (Ophthalmology Retina)

DOI: 10.1097/IAE.0000000000003339 (Retina)

3. Glaucoma drainage implant endophthalmitis

Definition/Description: In most cases of endophthalmitis related to GDI, there is tube exposure present with injected conjunctiva, purulence from the implant site and hypopyon.

Literature review:

DOI: 10.1097/IAE.0000000000001329 (Retina) doi: 10.1038/s41433-021-01462-9 (Eye)

4. Lamellar macular hole

Definition/Description: Thinning of the foveal tissue, leaving the RPE and photoreceptor layers intact but causing partial loss of the inner nuclear layer

Literature review: https://doi.org/10.1016/j.ophtha.2014.10.014 (Ophthalmology) https://doi.org/10.1016/j.oret.2022.07.009 (Ophthalmology Retina)

DOI: 10.1097/IAE.0000000000003665 (Retina)

5. Nonproliferative sickle retinopathy

Definition/Description: The retinal changes in NPSR occur secondary to vaso-occlusion and local ischemia. Occlusion of retinal vasculature first appears in the peripheral retina as “salmon patches”, which represent retinal hemorrhage from superficial blood vessels.

Literature review:

DOI: 10.1097/IAE.0000000000000309 (Retina) 10.1016/j.ajoc.2022.101329 (American Journal of Ophthalmology Case Reports)

6. Submacular hemorrhage

Definition/Description: Subretinal hemorrhage is an accumulation of blood between the neurosensory retina and the Retinal Pigment Epithelium (RPE) arising from the choroidal or retinal circulation

Literature review: https://doi.org/10.1016/j.ophtha.2016.01.035 (Ophthalmology) https://doi.org/10.1016/j.oret.2020.07.028 (Ophthalmology Retina)

DOI: 10.1097/IAE.0000000000003725 (Retina)

7. Choroidal granuloma

Definition/Description: Granulomas are nodular collection of immune cells formed by the immune system to confine pathogens and inflammatory agents that cannot be eliminated.

Literature review:

DOI: 10.1097/IAE.0000000000002864 (Retina) 10.3390/diagnostics13071296 (Diagnostics)

8. Pachychoroid neovasculopathy

Definition/Description: Described the occurrence of type 1 MNV lacking aneurysmal dilations (polyps) in eyes with pachychoroid disease

Literature review: https://doi.org/10.1016/j.ophtha.2016.06.060 (Ophthalmology) https://doi.org/10.1016/j.oret.2022.04.004 (Ophthalmology Retina)

DOI: 10.1097/IAE.0000000000002980 (Retina)

9. Pachychoroid pigment epitheliopathy

Definition/Description: Characterized by the presence of RPE disruption within the posterior pole over regions of choroidal thickening in eyes showing no evidence of active or prior CSC

Literature review:

DOI: 10.1097/IAE.0000000000001773 (Retina) 10.1136/bjo-2022-322457 (British Journal of Ophthalmology)

10. Peripheral exudative hemorrhagic chorioretinopathy

Definition/Description: Uncommon degenerative process of the retina with subretinal or sub-RPE hemorrhage and exudative mass outside of the macular region

Literature review:

DOI: 10.1097/IAE.0000000000003636 (Retina) 10.3760/cma.j.cn112142-20221024-00527 (Chinese Journal of Ophthalmology)

11. Nongeographic atrophy

Definition/Description: May be thought of as incipient atrophy as it may immediately precede GA in the same location | (other definition from a paper) Nongeographic atrophy was defined as retinal pigment disturbances including hypopigmentation and hyperpigmentation in CFPs that typically corresponded to hyperfluorescence and hypofluorescence in FA images within or overlapping areas previously occupied by CNV.

Literature review: https://doi.org/10.1016/j.ophtha.2018.11.020 (Ophthalmology) 10.1001/jamaophthalmol.2020.0437 (Journal of American Medical Association Ophthalmology)

Amazing, thank you!

Sally Baxter and Cindy Cai I am authoring these now and may have a few questions along the way in terms of modelling the body structures involved and also any relation to existing content.  Shall I ask these questions here or email you directly?

Thanks Elaine Wooler agree with Cindy, we can do it here. It will be informative for all of us to understand the process for adding terms. Thanks!

Hi Sally Baxter and Cindy Cai 

Re:  Submacular hemorrhage.

There is an existing concept - 13937002 |Subretinal hemorrhage (disorder)| defined with the body structure 41275009 |Structure of retinal pigment epithelium (body structure)|.  Would this be the parent concept for submacular hemorrhage and what would the body structure be for submacular hemorrhage?

The current structure is below as I would also like to rule out any existing concept that might be the same as submacular hemorrhage:

• 13937002 |Subretinal hemorrhage (disorder)|
  • 247161000 |Macular subretinal hemorrhage (disorder)|
    • 421328004 |Subfoveal hemorrhage (disorder)|
  • 678081000119100 |Subretinal hemorrhage of left eye (disorder)|
  • 678101000119107 |Subretinal hemorrhage of right eye (disorder)|

Many thanks

Elaine

Hi Cindy

Thank you and hope I can explain.  The key to the hierarchy structure of these concepts is the body structure involved.  As authors we may expect a new concept to have particular parents but that hard work on finding the correct parents is done by the classifier using the logic in the model we build on the concepts based on the body structure hierarchy and any other modeling present.  The link to the Retinal body structure hierarchy can be found here.  

The  image will show this in more detail and shows the additional parent of retinal hemorrhage:

Hi Elaine,

Thanks for explaining and for the link.

In looking at the list you originally sent, submacular hemorrhage should be the same thing as macular subretinal hemorrhage.

I don't think we need an additional term.

Would love for others to weigh in as well.

Cindy