UK Keratoconus Self-Help and Support Association

Finally went in for another fitting on my sclerals. My doctor up and left the practice where I go i guess and now I have a new doctor. Apparently he didn't leave much as far as notes and such on my lenses and stuff so they are pretty much clueless now. I dont like my new doctor, she didnt even introduce herself to me, just sat me down and looked at my eyes and lenses and said my vision was better than she expected.

Then she went on to tell me that these lenses are different and that they are not RGP's because they are sclerals. She said my old lenses are but they were corneal lenses, which i already know. But im like, these new ones are RGP's, I'm the one who gave the company info to my old doc to have them make em for me, but shes insisiting that they are hybrids. Are hybrids not a mix between soft and hard lenses? These things are plastic, they don't flex etc.

Anyhow, the one in my left eye didn't feel comfortable and i tld her this, she said it takes time to get used to, i agree to an extent, the right one seemed fine. Also, teh vision in the left eye seemed a tad off, i told her that they might be in the wrong eyes as when i went in for my last fitting, the doc told me that he talked to the company that made em and they suggested that he reverse them to see if they fit better that way, which they did, and to then send em back to tweak the presription. I told her this but she said that if i grabbed them from the right and left marked side of the case that they are in the right eyes.

I put a deposit down and asked if i could try them out for a week to see how they are. I put the right one in my left eye when i got home and i could see well out of it, but it hurt so i took it out, which was hard to do in itself. I wil put the left one in my right eye tomorrow to see what happens, although i had asked how would i be able to tell which was which because there are no markings to distinguish which side is which. I hope that i was right and they fit better and offer better vision in teh other eye, if not, i will go back and have her measure them to tell me which side is for which. I'm really not hapy with her though.

In the UK sclerals are made with a rigid material that is gas permeable.

I had always thought that hybrids are a mixture of hard and soft material.

If we are wrong somebody will help us both out.

Not happy with your practitioner? Is it possible to change?

Andrew

DJ

My understand, like Andrew's, is also that Hybrids are like Softperms, part soft, centre gp material......

Do you have a choice of other fitters?......

J

Ok, i think i was right, these lenses are definatly hard all the way, i dunno what shes talking about and I'm not very impressed at all.I mean the lenses themselves are good, but i think i need the left one tweaked some more as i can kind of see beter through that eye with my glasses on, its supposed to be the other way around.

I have the option of trying to get back with my old doctor, they just have to tell me where he has gone and i will call them. It would probably be best to stick wih the one whos been with me the past few years as he knows my case better than the new one.

heres a link for those who may be interested in reading up on what i have as it differs from KC but is related. Also because i to was diagnosed early on as having KC but it was changed to PMD.

http://www.emedicine.com/oph/topic551.htm

I always thought that Pellucid Marginal Degeneration was a synonym of Keratoconus.

Is it something different?

Andrew

To confirm:
the scleral lenses I have now are made of RGP (=rigid gas permeable) plastic, which is one of the same types of RGP plastic as are used for the smaller, conrneal, lenses. (I gather there are various, slightly different, "recipes" for making the RGP plastics.)

Previously, I had scleral lenses made out of PMMA. That's an abbreviation for the chemical name of another, non-gas permeable type of plastic, more often known as "Perspex" (which is a brand name). I don't know if anyone is still maing lenses from PMMA - nor if anyone has tried to make a pMMA/RGP mixture. (The reason they might try to do so is to get a material which has some gas permeability, and can also be moulded, eg. to casts of patients' eyeballs, in the way PMMA lenses were made when I first got them. RGP materials can't be moulded very well, hence the practice of using "fitting sets" where you try to find the best fit from a set of pre-shaped trial lenses.

As I understad it, PMD relates to the parts of the cornea that change shape, and the shape that results.
Thus, in very approx imate form:

( Normal eye
< KC eye with central cone
fill in the "droopy boob" for yourselves!
[ PMD
C keratoglobus

No doubt one of the speicalists will fill in some Latin and greek words for these.
Rosemary

Pellucid is "new Latin" and means "translucently clear:. The original application of the word was more poetic than indicative, as in mountains reflected in the pellucid waters

Marginal means at the margin or edge and degeneration means what it means.

PMD is therefore a description of a symptom of Keratoconus where the lens bulges from the centre and sags reducing the lucidity of the lens and compromizing its visual accuity. I had always thought that PMD was used in some jurisdictions as a synonym for KC, and checking on the www, I see that this is indeed the case.

Whether there is an other, discrete condition that also bears this name remains a mystery to me. I remember some years ago on the old style forum somebody posted that she had been redesignated PMD, but I think that her situation was more to do with hospital politics and budget allocation than any serious diagnostic variation.

Andrew

If I've understood what was said in one of the conference talks last year, PMD is not a synonym for KC, but a type of KC where the thinning is at the periphery or margin of the cornea, rather than being somewhere near the middle of the cornea which is more usual in KC.
Anne

That would be consistent with, but not identical to my understanding of the condition. Kamiya K, Hirohara Y, Mihashi T, Hiraoka T, Kaji Y, Oshika T. of the Division of Ophthalmology, National Tokyo Hospital, Tokyo, Japan, report PMD as if it were distinct from KC, but others use PMD, KC and corneal ecstasia as if they were just different terms for the same thing.

It would make sense, if there is such a plethora of terms around, to sort them out into sub categories.

Andrew

When looking at my computer monitor, when i have my lenses in, it looks like the right side of the screen is higher than the left, like the left side slants down. I don't have that issue when i wear my glasses so i am not sure if my glasses are to blame or my lenses. If i close my right eye, it goes back to normal. So it seems that my left lens may be to blame. I'l mention it to the doc when i go back next week.