IOP-related codes to add

Hi everyone, I am creating discussion pages for categories of topics arising from our meeting on 3/23/2023. My apologies for the delay in posting; just returned from spring break. I will put the IOP-related ones here, and then a separate one for gonioscopic grading.

Here are some of the intraocular pressure (IOP)-related codes that the group thought would be useful to add to SNOMED (based on survey of glaucoma specialists and discussion at the last meeting): 

• Maximum IOP
• Maximum untreated IOP 
• Presenting IOP
• Target IOP

Laterality: These would apply to each eye (left eye, right eye). Unlike diagnosis codes there isn't a bilateral situation for this one.

Range of Observed Values: In terms of the range of observed values, we expect these to be positive integers.

Associated Units: The associated units would be mm Hg for each value. 

Method of tonometry: Another associated code to develop is the ability to denote the method of tonometry used, which is currently not represented completely in SNOMED (there is a code for non-contact tonometry but otherwise the specifications for other forms are lacking). Here is a suggested list for methods of tonometry from one of our group members in the survey that was administered: 

• Goldman applanation
• Rebound (iCare)
• Non-contact 
• Pneumatonometer
• Mackay-Marg (Tonopen)
• Dynamic contour
• Indentation
• Tactile
• ORA

Elaine Wooler Let me know if additional info is needed. Happy to provide and/or solicit additional info from the group, and of course appreciate everyone's input here. It would be great to advance this toward incorporation into the vocabulary and thanks in advance for your help!

Thanks Anthony Khawaja I am not super familiar with ORA so this is very helpful! Seems reasonable to include Corvis as well.

Hi Elaine Wooler I think the subtype framework would work, similar to the target diastolic blood pressure one you shared (but instead being target introacular pressure, as one example).

Thanks for sharing the Google doc on the tonometry concepts. I didn't realize methods of measurement were listed as "procedures", so that is really helpful to know. I added some comments there, and added some terms that are not currently represented (i.e. the gaps), but I think it would be helpful perhaps to also discuss as a group at our next CRG meeting as well.  

This is great. From my point of view target IOP and maximum untreated IOP would be really useful to have. 

Have also added a column on the spreadsheet with my comments.

I am working on the tonometry procedures and there was a suggestion to merge 392338001 |Indentation tonometry (procedure)| and 389149000 |Schiotz tonometry (procedure)|.  In SNOMED these are also separate devices - 391955007 |Schiotz tonometer (physical object)| and 392340006 |Indentation tonometer (physical object)|  So would 389149000 |Schiotz tonometry (procedure)| be a subtype of 392338001 |Indentation tonometry (procedure)| rather than the same thing?  Also based on this section IOP and Tonometry - EyeWiki (aao.org)

I agree with Michael.  Just circling back a bit - does this influence how we handle the other methods of IOP measurement?  E.g. iCare tonometer for Rebound Tonometry (there is another one available now or soon by Reichert).  I.e. should we be adding in all devices?

Thanks Elaine Wooler I agree with Eric Brown ... we are meaning palpation/tactile. Agree the electronic applanation would be an erroneous synonym.