Superior decentration of GP contacts

Anyone have any hints on solving issues with superior (high)
decentration?

information to keep in mind:

pupils are around 8-8.5mm in mid dark conditions. so this limits the
minimum size of my contacts.

prescription is -2.25 and -2.5. very slight astigmatism in my right
eye and none in my left.
Slightly dry eye but good tear film.

My lenses are centering very high, even with fairly large lenses I am
consistently looking through the transition area at night (and in the
day to some extent).

When I push my lenses down using my eyelisds just a bit they "snap"
into position over the center and my vision is perfect, even at
night. At least until I blink the next time. Then the lid attach is
re-established and they get pulled up and out of the center.

My lenses have been getting progressively larger with the optic zone
gettng closer and closer to the edge, but no real improvement (in fact
it might be slightly worse).

What do you all think?

 

Try a semi-scleral or cornea-scleral lens. Those cannot become
decentered.

 

How is lens comfort on the semi-scleral type lens? So far the larger
my lenses get the more uncomfortable they are even with what shows to
be a perfect fit (combo of edge awareness and dry eyes).

Thanks for the advice, I will be trying another set of lenses in a
couple days and will ask about the sclerals.

 

I get about 4-5 hours before they become incredible uncomfortable.
Tried.. I would guess 15-20 different types. Silicon hydro (o2optix
and oasis), acuvue, pro something along with a ton of other lenses.
The best was the oasis, but the quality of vision was poor compared to
rgp. I could read something if I looked at it long enough, if that
makes any sense, but nothing was "sharp". Just always kinda fuzzy.

With the RGP lenses, while they are centered, everything is rock solid
and super easy to see, better than my glasses even.

 

The comfort is as good and sometimes better than soft lenses. I
prescribe them quite often these days and just published a paper on
them in Eye & Contact Lens.

 

now that it is clear that you were describing the fit your your RGP's
in your initial posting as opposed to SCL (right?) I will chime in and
try to help.

Asumming we are talking about RGPs, if I was the doc trying to refit
you to get better centration of the lens, I would put you in as small
a lens as possible, with a steeper base curve than the pair you were
describing. Larger RGPs, and ones with flatter base curves, tend to
fit just as you describe-- "lid-controlled" which characteristically
has the lens stuck-up under the upper lid and moving with it when you
blink. So without examining you, that's my $0.02 cents. What does
your doc say? It really isn't rocket science to a decently-trained
optometrist.

 

Understood, they are making another set right now but I don't know
what the specs are though I did tell her how a previous set was much
more comfortable at a smaller size, though that could also have been
because they were made with a good distance between the edge and the
optical zone. The newer ones I am now wearing have a fairly narrow
space there (basically they made the OZ as large as possible without
making the lens much larger supposedly). They are currently making
another pair which should be here today or tomorrow and I asked that
centration be the major fix.

As for why it cant be small they have been keeping it a bit larger
than normal due to my large pupils, demonstrated some issues there
before, though that could also have been centration issues. You know
how it is, when you are a patient you don't know enough to be able to
accurately communicate the issue. I saw glare around everything at
night but I didn't know what to look for to give a better idea of my
specific issue. Now I can describe the issue quite a bit better so
hopefully the solution will be coming shortly.

Dr. Leukoma: Thanks for the response, I very much appreciate it. I'll
let my doctor know about your article and we will see. (hah..
*cough*... gotta love the bad puns.)

 

Well, he won't find it under "leukoma" but he will find it under
Gemoules.

The fitting of these lenses is not very widespread, so don't expect
your fitter to leap at the suggestion. For that he would have to
acquire a fitting set, and then basically start from scratch. I have
quite a few large pupil patients and this is how I have learned to
deal with their issues after basically doing everything else. Based
on a cost-benefit analysis you might very well decide that you will
accept some tradeoffs rather than go through so much trouble and
expense.

 

Is the article available on-line anyplace? Either way, can you give us
a title?

By the way, are your patients able to wear these lenses happily for a
full day in most cases?

--

 

A Novel Method of Fitting Scleral Lenses Using
High Resolution Optical Coherence Tomography

Eye & Contact Lens: Science and Clinical Practice
(formerly the CLAO Journal), March 2008.
Wolters Kluwer/Lippincott Williams & Wilkins publisher

In most cases. Not all cases.