Novice question: Patient with hi+ and hi cyl.

[Flux3r]

So i have a patient who had corneal erosion and sees an ophthalmologist.

the Rx i received from the outside doctor reads as:

-3.00+5.50x95
-3.00+6.50x79

i currently have him in 1.70 hi index, but he says there is distortion outside of the 45degree nystagmus (idk the optometry term for this point so ill use the law enforcement term.) now my 50 yr veteran optician says this is as good as its going to get due to his Rx. My doctor/boss says i might try a better Abbe value material, which i think could help. i have two weeks to gather information and advice before we make a decision. i wear trivex myself and suggested it and it was greenlit, and i know cr39 and of course glass would be better abbe-wise. the patient doesn't care much about thickness, but i doubt hes ever seen his Rx in a normal material.

Thoughts, comments, or advice?

Any help for the new guy greatly appreciated.

[drk]

FFSV in any material would help greatly. Trivex is a good choice.

[huskypaul]

I have had good success with digital lenses with high cyls. such as this RX. Either trivex or 1.60 should work well.

[Flux3r]

I have had good success with digital lenses with high cyls. such as this RX. Either trivex or 1.60 should work well.

we originally tried to use 1.60 and had the same issue, though to a lesser extent.

[Slim]

Id def go FF on this one. Trivex too. Shouldnt be to thick either do to axis being near 90, lab could thin them quite a bit.

[uncut]

I would like to suggest that this person would benefit from a slight tint in their lens to counter bouts of light sensitivity. I would use 1.6 UV blocking tintable material for the lens, with a careful control on lens shape and size.

[drk]

Uncut sees the job cut. Good point on frame choice: rectangle, but not over, say, a 50 eye.

I think homey has keratoconus.

Another point: I CAN'T THINK in plus cylinder! It's: OD +2.50-5.50x005, OS +3.50-6.50x169.

[DanLiv]

Id def go FF on this one. Trivex too. Shouldnt be to thick either do to axis being near 90, lab could thin them quite a bit.

Yup the axes will conveniently keep the final thickness pretty manageable. And given that, I wouldn't even bother with half-measures on the Abbe and would go directly to FF CR-39. Trivex is only barely better Abbe than your currently problematic 1.70, so if chromatic aberration is the problem Trivex will no solve it. If you go FF CR-39 you know you have eliminated as much of that problem as possible, and if issues remain then you can truthfully say it's as good as it gets, or you've isolated some other issue.

[kat]

+1 for FF and Trivex

[DanLiv]

What's with the Trivex love in this case? 1.70 with Abbe 39 already failed, is the bump to Trivex Abbe 43 going to make the difference? If we are worrying about Abbe, why not knock it out of the equation with 58 Abbe CR-39? Trivex is only negligibly thinner anyway.

[drk]

It's lighter.
It's probably not an abbe issue, anyway.
Betcha he's about 20-30 y.o. with keratoconus (which, actually would make a case for CR39 since we'd like MORE UV for a cone), and he rides a motorcycle. (Those astigmats are a wild bunch.)
But your point is valid.

[Flux3r]

It's lighter.
It's probably not an abbe issue, anyway.
Betcha he's about 20-30 y.o. with keratoconus (which, actually would make a case for CR39 since we'd like MORE UV for a cone), and he rides a motorcycle. (Those astigmats are a wild bunch.)
But your point is valid.

haha close drk
hes 26 and, like me former law enforcement and drives a dune buggy around town!

[Flux3r]

Thanks for the advice folks i will take it under advisement!

[Jacqui]

CR-39 and Free Form. If that doesn't help, suggest psychiatrist.

[Robert Martellaro]

So i have a patient who had corneal erosion and sees an ophthalmologist.

the Rx i received from the outside doctor reads as:

-3.00+5.50x95
-3.00+6.50x79

i currently have him in 1.70 hi index, but he says there is distortion outside of the 45degree nystagmus (idk the optometry term for this point so ill use the law enforcement term.) now my 50 yr veteran optician says this is as good as its going to get due to his Rx. My doctor/boss says i might try a better Abbe value material, which i think could help. i have two weeks to gather information and advice before we make a decision. i wear trivex myself and suggested it and it was greenlit, and i know cr39 and of course glass would be better abbe-wise. the patient doesn't care much about thickness, but i doubt hes ever seen his Rx in a normal material.

Thoughts, comments, or advice?

Any help for the new guy greatly appreciated.

Sorry for the late response. Take a look at the base curve- if it's less than +6.00, even if aspheric, there will be a small amount of oblique astigmatism on the 180 meridian. In general, the oblique astigmatism at 180 in left lens is about .50 D with a +6 BC, and about .75 D with a +4 BC. A lower refractive index material will also reduce the oblique astigmatism slightly at 180 using the same BCs.

For best results, use an atoric design to minimize this aberration.

[huskypaul]

Diminished optical zone, increased peripheral distortion. I've had outstanding results with the FF trivex SV. Perhaps like many others I am drawn too it, much like the moth to the flame(yet to be burned) Not with standing the obvious frame criteria I would have tried it first, if it did not work for the patient then I would have tried CR 39.

[sharpstick777]

I would recommend Free-form SV Ice-Tech for that high of a cyl, He probably will never see 20/20 even with FFSV if he has cones, so make sure you acquire his Best Corrected DVA's before dispense. Cyl GREATLY reduces usable zones, Free-form will gain some of that back, but not all. He will NEVER see edge to edge clear in any lens, even with Free-form. Its a much better solution, not a perfect one.

RGP Contacts or Vaulted Sclerals will give Cone patients their best vision, but the fit and lenses are enormously expensive.

His options and and expected outcomes should be clearly explained before ordering, esp with DVA's.

[sharpstick777]

I would personally go round and small, but centration is the most important key for the best frame choice,