How to interpret Oct scan in high myopia

[Littlechia]

Dear John Hagan
I recently had a 2nd Oct scan, the rnfl average were 93/93 (94/95 1.5 years ago); however the distribution is not reproducible



The gcc Gmap remained unchanged only 1 in yellow (superior inner nasal) which was same as last visit 1.5 year ago

There are papers say Oct rnfl results are problematic in myope :temporal shift fibre bundles, tilted disc, ocular mangificaton

How you deal with these problems?

Also, do you have any experience in using brunch membrane opening width for glaucoma diagnosis in high myope

I am -8.5 myope My pressure are 20/20 CCT 599/598

My doc said it's really hard to diagnose early glaucoma

[JohnHaganMD]

1. Your "eye doctor" should be an Eye MD ophthalmologist not an OD optometrist.  If there is any question get consult from glaucoma specialist Eye MD.
2. To make Dx of glaucoma need to go on IOP, visual field, NFL OCT and optic nerve appearce and family history. This is same as most people.
3. I don't have any experience in what you describe about Bruch's membrane.

[Littlechia]

Than you Dr Hagan
Again I am from Taiwan, I was seen by two different glaucoma specialists here and one of them is US trained.

We patients are lucky to have many opthonolologists here; you can literally go to a specialist without a referral
The doc looked at my discs and concluded that they maybe due to high myope not likely glaucoma and also suggested me to stick with one doc to monitor my eyes using the same Oct and vf as the results are more comparable in long term

Just out of curiosity, based on your experience, are Oct results reliable in high myope ? because I get a lot of fluctuations readings in rnfl quadrant s when comparing two scans done 1.5 years apart

Do you adjust axial length to reduce ocular mangificaton effect?

[JohnHaganMD]

Axial length is not a parameter that is used in OCT.  Myopic disks are hard to evaluate so takes a combination of tests to determine if glaucoma.  There are some newer algorithms for OCT that make it easier to evaluate.  

[JohnHaganMD]

In your case visual field may be more accurate than OCT

[Littlechia]

Thank you doc. I have been seen by 3 doctors and keep hearing the same advice  and I am scheduled to be tested for vf  I am in good hands now :)

[JohnHaganMD]

Good luck