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OK, my patient/aunt has some kind of progressive orbitopathy (that I have to farm out to someone who knows his/her/xe's stuff) with a wicked newer esotropia and vertical tropia. She's successfully been in prism along the way in her journey (about 6^ BO OD and OS--no vertical) but it's getting worse.
I need to deliver about 7 BO OD and OS, and now about 7 BU OD and 7 BD OS, in order to achieve binocular fusion.
Is this do-able? Any tips?
(Want a new outside Rx?)
(Want a new aunty?)
Should be do-able, but I certainly wouldn't want to be the one to surface it! Not sure if digital cutting allows that range or not, but of course small and ROUND would be the order of the day. The ability to rotate the lens in frame a few degrees will make the final fit that much more flexible. But I'm only preaching what yinz already know...
It's possible. It might need to go to a specialty lab like EPIC though.
I recently filled a
-10.25 -3.00 x 165 10 BO 3.5BU
-8.25 -3.25 x 021 10 BO 3.5BD
with the best part of course being a 52 pd, adjusted for prism meant a distance PD of 46!
What's aunties VA's?
It's time to loose the PALs- Rx separates or segmented (segs will be significantly different in heights).Quote:
Originally Posted by drk
Avoid low Abbe materials.
Avoid free-form even if the fabricators say it's doable.
Show prism samples to demo their inherent poor cosmesis at this level of prism.
Discuss press-on prisms.
Make sure bottom of OS lens clears the cheek, and the brow on the OD- use a heavy safety bevel or light roll.
Trial frame to gauge adaptability- wait until at home before wearing.
Hope this helps,
Robert Martellaro
So...
1. frame selection
2. no low abbe materials
3. avoid PAL
4. traditional surfacing
Thank you.
P.S. normal VAs
You will need to adjust the PD 2mm narrower for each eye, and the fitting heights 2mm down on the right and 2mm up on the left. If there is significant power to go along with the prism you may also need to adjust the prism amount, add prism for plus power, lower prism power for minus power.
So this pt went from zero vertical to a total of 14? Wow... there will be some adaptation. Definitely wouldn't recommend progressives.
Ryser's Rule?Quote:
Originally Posted by drk
First fresnel the vertical see if she can adopt with her current progressive?
I did that the other day with some older patient. It was 5 diopters. He said he couldn't tell much difference. I prayed when I saw him walking out of the building. He looked like he was drunk.Quote:
Originally Posted by Uncle Fester
Hey! Fester for the win. Brilliant suggestion. May take her out of the patch for the meanwhile, too.
Coincidently the guy I put the fresnel on just came in .... he's adapting quite well to the prism. Diplopia is gone but has a little depth perception issues. It hasn't been that long so he has been advised to wear a bit longer. He also has an appointment scheduled to see OMD regarding surgery.
Anyone with fusion so bad they need Fresnel prism cannot expect much in the way of stereoacuity, if even because of the blur (but it's really from the bare alignment).
The best to expect is no diplopia.