What to do for different image sizes

[Freebird]

Greetings!

I am troubleshooting a patient I inherited, who purchased 2 new pairs with us a couple weeks ago. His Rx is not much different than his old one, but he is having massive troubles with the new lenses.

Old Rx:
R: -9.50 +1.50 x109
L: -4.75 +2.00 x80
Add: +2.75
PAL: Comfort 1.67

New Rx:
R: -10.00 +1.75 x122
L: -5.25 +1.00 x68
Add: 3.00
PAL: Varilux X Design 1.74

With his old ones, he doesn't get any swim or distortion, and he says he doesn't get any difference in depth perception or image sizes. With the new ones, he feels that his right eye pushes objects out much farther than his left eye. I spoke with our lab's help desk, and they suggested doing the OD on a 1.74 and the OS on a 1.67, as well as adding 1.9 diopters to the base to the OS. Chalking this up to synaptic flatulence (because I cannot remember to which lens we would add more curvature to the base) is this the best course of action? We are not going to keep him in the X Design, but rather an IOT lens where we can select base curves.

Would you recommend something else?

Thank you very much!

[Tallboy]

Are the problems in distance viewing, within the add corridors or both?

[drk]

That axis shift is pretty brutal.

I mean, yeah, the anisometropia is cray cray, but it's not worse than before.

But turning his astigmatism oblique is a cardinal sin.

Prescriber needs notified...or you can get a trial frame, elicit the symptom, and shave off five degrees towards the old axis until he gets his sea legs.

[Robert Martellaro]

Retinal detachment OD? Cataracts?

Post BCVAs. If degraded, describe the event that caused the vision loss and/or the anisometropia. Is the client binocular, and is there suppression. I'm guessing suppression if they can read w/o diplopia or fatigue.

Note the roughly 1.25 D increase in sphere equivalent OS. The 13/12 degree axis change isn't in the best direction, but probably isn't the primary cause of visual distress.

Decreasing the refractive index increases the image size, although the difference is inconsequential. Don't assume that they are aniseikonic.

I don't have any experience yet with the VAL X, however, the traditionally surfaced Comfort sure works well for me when the going gets tough, especially for binocular disorders.

Consider dropping the refractive index to 1.60 for less chromatic aberration, especially if the right eye is the good eye.

Hope this helps,

Robert Martellaro

[AngeHamm]

Consider dropping the refractive index to 1.60 for less chromatic aberration, especially if the right eye is the good eye.

Eek. That patient is NOT going to be happy with that lens thickness.

[Kwill212]

Eek. That patient is NOT going to be happy with that lens thickness.

Only if they were fit in a bad frame to begin with. Thickness difference is going to be small if a good frame selection was made. I find it almost never necessary to go above 1.60.

[Prentice Pro 9000]

That axis shift is pretty brutal.

I mean, yeah, the anisometropia is cray cray, but it's not worse than before.

But turning his astigmatism oblique is a cardinal sin.

Prescriber needs notified...or you can get a trial frame, elicit the symptom, and shave off five degrees towards the old axis until he gets his sea legs.

I'm betting these are two different RXs from two ODs.

[Quince]

Greetings!

I am troubleshooting a patient I inherited, who purchased 2 new pairs with us a couple weeks ago. His Rx is not much different than his old one, but he is having massive troubles with the new lenses.

With his old ones, he doesn't get any swim or distortion, and he says he doesn't get any difference in depth perception or image sizes. With the new ones, he feels that his right eye pushes objects out much farther than his left eye. I spoke with our lab's help desk, and they suggested doing the OD on a 1.74 and the OS on a 1.67, as well as adding 1.9 diopters to the base to the OS. Chalking this up to synaptic flatulence (because I cannot remember to which lens we would add more curvature to the base) is this the best course of action? We are not going to keep him in the X Design, but rather an IOT lens where we can select base curves.

Would you recommend something else?

Thank you very much!

Yes, different base curves makes sense, but I have never heard of anyone suggesting separate indexes. Is this not a cardinal sin??

[Kwill212]

Yes, different base curves makes sense, but I have never heard of anyone suggesting separate indexes. Is this not a cardinal sin??

I don't think so. The odd cases I have done it, I have never encountered a problem. Off axis is going to be so wonky in this Rx having differing indexes is not going to matter.

[Tallboy]

I always thought when you were doing different indexes for aniseikonia You put the lower index on the lens with the most power and the higher index on the one with the lower power. Its been a long time since I have done this but that is what I thought I did. Could be wrong.

EDIT: I just reread that chapter in System for Dispensing, I was wrong! Ignore this.

[Prentice Pro 9000]

I like to mess with the calculator on opticampus sometimes

[Tallboy]

I like to mess with the calculator on opticampus sometimes

Those calculators are one reason I think of Darryl probably every day!

[waynegilpin]

That axis shift is pretty brutal.

I mean, yeah, the anisometropia is cray cray, but it's not worse than before.

But turning his astigmatism oblique is a cardinal sin.



Prescriber needs notified...or you can get a trial frame, elicit the symptom, and shave off five degrees towards the old axis until he gets his sea legs.

I used to tell the techs I worked with that I don't care if you increase or decrease the power, but when you start rotating the axis I will: Steal your lunch, slash your tires and still take you out back and beat you with a stick.