How would you fill this?

[jpways]

I just had a walk in that's has me questioning myself

The patient is a 9 year old girl with cerebral palsy. She is ambulatory so there is a high risk of her falling. The ocular history includes surgery for a phoria (the mother didn't remember if it was exo or eso and also didn't remember which eye) as well as nystagmus, however nystagmus is still present though the mother said it is a lot less severe.

New RX is
-15.75 -1.25 x 45
-14.00 -3.00 x 135
Add +3.00
Doctor order of a progressive

Old rx neutralized at
-15.50 -1.50 x 43
-14.25 -3.00 x 136
I know the lens is Transitions with AR, my best guess of material (based on thickness, color, and sound) is polycarbonate

My best guess of her distance PDs is R: 28.5 L: 27.5 (I measured at the point that looked like the center of rotation)
The new frames has measurements of
A: 47.0 B: 28.5 ED 49.1 DBL: 15

SH is 15

POW:
VD: R: 11 L: 10 Wrap: 7 Panto: 3

The patient's only requirement on the lenses is she really wants to stay in Transitions

And this job is being done under VSP

I've talked to my lab and we've reached the conclusion that because of needing Transitions we're looking at Shamir Digitals, so I'm leaning towards the Autograph III

Due to lens blank limitations my choices of materials are 1.50 and 1.67 (I can get 1.74 but even if didn't have a high risk of falling I'm extremely hesitant to fit a child in 1.74).

Here's where I'm not sure which way to go, which material is going to give me the best impact resistance (even at the cost of edge thickness) the lab is telling me that if I want 1.67 the minimum CT they would make is 3.0, I would assume it would be a similar CT for 1.50 as I'm assuming Z87.1 standards for the 1.50 lens.

[iD]

the Shamir Attitude III isn't compatible with that rx right?

[jpways]

correct, Attitude 3 is a high base curve variation(s) of the Autograph III, power range is -6.50 to +6.00 in 1.67

[optical24/7]

Consider 1.60 (MR8). In static load testing it is way stronger than 1.67 or 1.74. You may have difficulty getting that power in a digital design with 1.60 but she will have less CA than the poly she's used to.

[Jubilee]

With the wicked back curve that will have, isn't their more danger with the edges ? Thinking a 2.0 CT should be sufficient..

[ml43]

With the wicked back curve that will have, isn't their more danger with the edges ? Thinking a 2.0 CT should be sufficient..

Correct, not only that, but a lens made to Z87.1 standards means nothing if it isn't mounted in a Z87.1 or ASTM frame.

She could easily fall and have the lens unmount from the groove and still end up taking out her whole eye.

for this power, a lenticular lens will definitely help with both weight and edge thickness.
If the frame chosen is relatively flat, a biconcave lens and facets is also an option.

also, pretty sure with that power, it's just out of range for the the auto II/III, cut off is -16.75 in 1.67

[jpways]

Correct, not only that, but a lens made to Z87.1 standards means nothing if it isn't mounted in a Z87.1 or ASTM frame.

I really should know better I was trying to justify in my head why the lab would want a 3.0 center without finishing the thought.

for this power, a lenticular lens will definitely help with both weight and edge thickness.
If the frame chosen is relatively flat, a biconcave lens and facets is also an option.

Is there such a thing as a lenticular progressive lens? Granted I've never even had to think about doing a lenticular, but I thought those were limited to SV and lined multifocals.

also, pretty sure with that power, it's just out of range for the the auto II/III, cut off is -16.75 in 1.67

I'm worried about this too, I have a call into my Shamir rep to confirm it is -16.75 sphere with -8.00 cylinder and not -16.75 total power. But I seem to remember I asked this in the past and I was told I was correct. Plus, I've already been told by my lab that they can get a blank that's thick enough to edge this.

[optical24/7]

A 3.0mm c.t. will have more impact resistance than a 2.0 c.t. lens. A frame doesn't have to be stamped Z87 to put one in either. I wouldn't say it means nothing, you're still providing a more impact resistant lens.

Any minus lens can be lenticularized. It's simply a matter of putting a convex curve on the back, creating a bowl in the center. (We were doing this in the lab back in the 70's and I'm sure the practice pre-dates that.) You just need a lab that offers this.

Unless it's impossible to achieve a given Rx, bi-concave or bi-convex lenses should ALWAYS be avoided. The optics are terrible anywhere other than the OC. Plus, I know of no bi-concave PAL designs.

No offence, but this doctor has not done a ton of low vision if he's recommending a +3.00 add PAL for a child. The corridor is extremely narrow with that add. Even adults that have been in PAL's for years struggle with 3.00 adds. ( I unfortunately see a lot of 3.00 add AMD patients.)

A FF design would give the patient a tad better off axis viewing, but if I need to fill this Rx as written, I'd use a conventional grinder, considering the limitations on power/material choices (I'd stick with 1.60 for optics and impact resistance.)

[drk]

Unless it's impossible to achieve a given Rx, bi-concave or bi-convex lenses should ALWAYS be avoided. The optics are terrible anywhere other than the OC. Plus, I know of no bi-concave PAL designs. No offence, but this doctor has not done a ton of low vision if he's recommending a +3.00 add PAL for a child. The corridor is extremely narrow with that add. Even adults that have been in PAL's for years struggle with 3.00 adds. ( I unfortunately see a lot of 3.00 add AMD patients.) A FF design would give the patient a tad better off axis viewing, but if I need to fill this Rx as written, I'd use a conventional grinder, considering the limitations on power/material choices (I'd stick with 1.60 for optics and impact resistance.)

Man, this seems like a great post. 1. What's with the +3.00 add? 2. Why a progressive? Is someone with nystagmus really going to use that? 3. It causes a lot of unnecessary expense and trouble in this case. Easy to throw stones without all the information, though.

[Paul Smith LDO]

A 3.0mm c.t. will have more impact resistance than a 2.0 c.t. lens. A frame doesn't have to be stamped Z87 to put one in either. I wouldn't say it means nothing, you're still providing a more impact resistant lens.

Any minus lens can be lenticularized. It's simply a matter of putting a convex curve on the back, creating a bowl in the center. (We were doing this in the lab back in the 70's and I'm sure the practice pre-dates that.) You just need a lab that offers this.

Unless it's impossible to achieve a given Rx, bi-concave or bi-convex lenses should ALWAYS be avoided. The optics are terrible anywhere other than the OC. Plus, I know of no bi-concave PAL designs.

No offence, but this doctor has not done a ton of low vision if he's recommending a +3.00 add PAL for a child. The corridor is extremely narrow with that add. Even adults that have been in PAL's for years struggle with 3.00 adds. ( I unfortunately see a lot of 3.00 add AMD patients.)

A FF design would give the patient a tad better off axis viewing, but if I need to fill this Rx as written, I'd use a conventional grinder, considering the limitations on power/material choices (I'd stick with 1.60 for optics and impact resistance.)

Good call regarding the optics of a PAL design with a 3.00 Add. Also, there is no mention of an Add in the previous Rx. I hate to assume but if we are I would say that the Add is to aid with convergence and would fit high using a FT. Best to contact the POD and garner more information.

[Robert Martellaro]

The progressive is for cosmetic reasons (blame the parents). Tell the parents you need to use a smaller, rounder frame. Look for a base curve that is less than +1.00, which should come in a thick blank. Agree with optical24/7 WRT 1.60 refractive index. Agree with Paul to use a segmented multifocal. (I couldn't find a flat enough base in a round 24mm). This will most likely have to be surfaced on a traditional generator. Tough going, but this is as good as it gets until they're ready for CLs. Transitions will force polycarbonate, which will trash the near optics. Use a fitover sunglasses instead.

[Mizikal]

I would preach lined bifocal tell the cows come home. with a -15.75 the glasses are not going be aesthetic anyway so the goal should be best vision possible. I have not had good luck with kids that age in a PAL. How is her head control with the cerebral palsy? I have had kids with it in varying degrees and finding the "sweet spot" for reading can be a challenge. Good luck explaining that to parents. I usually say why we shouldn't give them the price difference and say " We can do a PAl if you really want to but I would rather you save your $ and go with something that will work the best". I think its odd the DR ordered a PAl,

[ml43]

The progressive is for cosmetic reasons (blame the parents). Tell the parents you need to use a smaller, rounder frame. Look for a base curve that is less than +1.00, which should come in a thick blank. Agree with optical24/7 WRT 1.60 refractive index. Agree with Paul to use a segmented multifocal. (I couldn't find a flat enough base in a round 24mm). This will most likely have to be surfaced on a traditional generator. Tough going, but this is as good as it gets until they're ready for CLs. Transitions will force polycarbonate, which will trash the near optics. Use a fitover sunglasses instead.

round frames always make high rx's easier, considering decentration is on the low side.

if the lens is to be lenticularized, round will be a huge benefit.

unless there's a software limitation, this rx isn't crazy enough to rule out digital generating. in any high minus, an aspheric/atoric back surface will reduce edge thickness, even when lenticularization is used, and it won't limit you as much on blank thickness and base curve selection.

pretty sure bill from fea wears a -14 in a 4-6 base, in blutech 1.56 I believe. I'll try to find the picture he posted.

the biggest hurdle is getting the lab to do it.

edit:
found the picture of his blue tech pair, they aren't on a 4-6 base, but I'm pretty sure I read he has some type of lenticularized pair on a 4-6 base.

reason I bring it up, is if they can be run on a 4 base, then they can be mounted in a sport safety frame, or maybe even goggles. Way easier to make sure the seg is positoned well.

[rbaker]

Man, this seems like a great post. 1. What's with the +3.00 add? 2. Why a progressive? Is someone with nystagmus really going to use that? 3. It causes a lot of unnecessary expense and trouble in this case. Easy to throw stones without all the information, though.

Yah . . . lets go back to square one and forget the progressive lenses and all the other bells and whistles. Forget the Add. Small zyle frame with a Hi Index SV lens.

[Robert Martellaro]

Man, this seems like a great post. 1. What's with the +3.00 add? 2. Why a progressive? Is someone with nystagmus really going to use that? 3. It causes a lot of unnecessary expense and trouble in this case. Easy to throw stones without all the information, though.

1. The key is the cerebral palsy.

2. Probably cosmetics, and no.

3. Unnecessary? Maybe. Maybe not.

"Accommodative dysfunction in CP patients can vary from 10-100%."

http://www.optometry.co.uk/uploads/a...Taub-10206.pdf

Yes.

[jpways]

I just called the OMDs office that wrote this prescription, I did have to speak with a nurse, but I was told that this is not an unusual for this doctor to order a +3.00 progressive for similar cases. Yes, this is really a doctor's preference and the doctor specializes in treating nystagmus (according to the website of the hospital at which the doctor works) so I'm guessing that his list of similar cases is relatively large.

[Robert Martellaro]

I just called the OMDs office that wrote this prescription, I did have to speak with a nurse, but I was told that this is not an unusual for this doctor to order a +3.00 progressive for similar cases. Yes, this is really a doctor's preference and the doctor specializes in treating nystagmus (according to the website of the hospital at which the doctor works) so I'm guessing that his list of similar cases is relatively large.

That's that then. Keep your fall-back position (segmented multifocals) handy.

Search http://lenslist.com for availability. Look for a short corridor PAL.

http://questopticallab.com/services.html might have a solution.

Watch for temple and nose pad/arm clearance, especially the latter, for the shortest vertex distance possible. Continue to consider a narrower and taller frame (rounder), and use a rounded safety bevel.

[ml43]

Came across this today, to give you guys an idea of what this Rx looks like.

This is a 1.74 auto III
-15.00 -2.25 22 +2.25 add

4.5 horizontal decentration, 0 veritical decentration.
A: 52, B: 35

[drk]

Hideous, but what would we expect?

[newguyaroundhere]

That lens looks like it could stop a bullet