Similar Findings?

Tue, 27 Jul 2021 21:10:41 GMT

Has anyone seen a similar variation of RP? Curious what the dark gray demarcation could be?

Any insight would be appreciated.

Wed, 28 Jul 2021 12:31:23 GMT

We see mostly RP as we do research on genetic eye diseases and see this ever so often. However, looking at the pictures with the damage to the macula area, I would guess this patient has the conerod dystrophy (CR) variant, which is often confused with the traditional RP. In CR, the central vision is the primary problem with the peripheral vision taking loss later. These two conditions used to be lumped together but over the last 10-15 years, we have separated them into two different conditions. Mutations in the same gene can cause either of the two, especially if it is x-linked and in the RPGR gene.

Thu, 29 Jul 2021 14:01:04 GMT

Correct me if I'm wrong, seriously please. with Conerod Dystrophy the OCT shows a different presentation as well doesn't it? Usually RPE thinning centrally whereas RP commonly has RPE thinning peripherally working its way centrally making a smaller "island" of normal RPE?

Thu, 29 Jul 2021 21:25:00 GMT

I just attached OCT scans through the fovea. I was not able to scan through the dark gray demarcation before the patient left. Would you expect the darker gray area shown on the FAF pictures to indicate early GA from RPE thinning? If true then I would expect the damage to trend worse toward the fovea. I am wondering what is causing the darker gray coloring as I have seen a similar view in a patient with fan guttering that also resulted in atrophy.

Thu, 29 Jul 2021 21:25:38 GMT

OCT

Fri, 30 Jul 2021 14:54:20 GMT

I think this is one where a 55 degree OCT might show some really helpful information. The scan width on this looks like it's about the 20 degree view, and just at the edges the RPE OU it a little more present than it is between the very edge and the central macula. I think even the 30 degree view might expand out just enough to catch more of the RPE. This is one of those times when being able to get a volume scan out of the central vision can be helpful.

This of course is from the imager perspective, I can't speak for physicians perspectives outside of the first 4 I worked for who preferred having peripheral scans when there was something to be shown by OCT peripherally.

Technical: Isn't it a 6mm view on 20 degree, 8mm view on 30 degree, and I think 15mm on 55 degree?

Fri, 30 Jul 2021 18:19:23 GMT

I had time to consult our practices senior provider. It turns out the darker gray pigmentation is her version of normal. She has peripheral damage as well as arcade. I'll be sure to scan through farther out in her periphery on the next visit. Thanks.