FDA parameter

[mauroventura]

Hello Opticians,
It's an emotion for me to open a new thread after so much time.
Just one question i'm involved to understand the corneal topograph utility to determine a possible Keratoconus.
Is there someone who can explain the meaning of FDA parameter??

Thanks in advance for the help.

Mauro

[jpways]

I have to say I've never seen any term associated with keratoconus that can be associated with that acronym. So that maybe the answer can be figured out through context, is there someone asking for this parameter, if so who? Also, seeing as where you are from, is the form in English? Because, I can't help wondering if this acronym might be in Italian (or some other language) and if we can figure out the translation, the term might make sense.

[SharonB]

Ciao Mauro!
If you are using a corneal topographer, the steep zones will stand out clearly in red and orange. On some systems you need to look closely at the dioptric "key."
Some will give you "relative" dioptric differences in the various corneal zones, but most will give you the true dioptric values. If you see orange or red zones below the corneal center, allora, you may have a positive diagnosis. I have never seen or read U.S.A. FDA criteria for keratoconus. Have you tried to use a keratometer? Lo so... e un' technologica vecchia...ma funzione bene. If you cannot get an accurate reading on the keratometer, and need to use a range extension lens, you may also have a confirmed diagnosis. Please P.M. me for further discussion.
Buona Fortuna
Sharon

[SharonB]

Hi Mauro!
I have done some further research, and I can only find FDA (US Food and Drug Administration) information on devices to treat keratoconus... Contact lenses, hybrid contact lenses, Intacs, etc. There appears to be no other information on using corneal measurements, or what the critera are.
Ancora, Buona Fortuna
Sharon

[mauroventura]

HI Jpways ,
thank you very much for you reply.

Hi Sharon,
many thanks for your help (it's pleasant to see Italian words on Optiboard ).
You're right .This was my mistake ( As explained in the thread i'm looking to understand if topograph make the difference for a correct contact lens application . looking Numeric index AK, AGK for determination of keratoconus , I found also FDA as reference for devices to treat keratoconus (exactly as you write in your second post).Many thanks again.

Mauro.

[Dr. Bill Stacy]

Keratoconus is a tricky diagnosis, and topography certainly helps, along with changes in K readings, changes in refractive and corneal astigmatism (both regular and irregular), changes in corneal thickness, and changes in best corrected acuity with spectacle Rx. With all those things evaluated, some diagnoses are still questionable. I think the current trend is, when in doubt, go for the keratoconus diagnosis. At least that can bring some medical insurance money to the table. But be ready to back it up with some numbers.

[CNG]

We suspect of keratoconus when the script is high, has a lot of corneal cyl, has the munsoon (Sp?) corneal view and usually do not see good with glasses. We put everyone in the topographer and the picture is pretty obvious. We are starting to measure corneal sensitivity and doing OCT of cornea. As our board certified opticians fits these people, we tend to use the topographer to confirm only diagnosis and get an idea of where to start with the lenses. When fitting it pretty much is the ability to read the flourecein pattern and perform an over refraction. The topographer it really is not that crucial if you know how to modify the GP lens from the patterns.

CNG