Fun prescription question

**Jstanfast** · 03-27-2015, 11:34 AM

Ok, we had a great kid come in yesterday for an eye exam. He has a finalized script of :

+1.00 -0.25 x 031
-4.00 -2.25 x 138

PDs- 30.5/26.5 with OC measured at the mechanical center. Frame PD is 64 B of about 25.5 ED of about 48.5

So the question is would you do or recommend even attempting to minimize the magnification issues. If so, any ideas on having that done without creating to truly ugly lens? Kid is 6 and not mentally ready for contacts so contacts are out for now and he is showing symptoms that the magnification difference is an issue.

frame chosen is a Nike 4677 size 47-17
at 7% magnification difference any ideas?

**Robert Martellaro** · 03-27-2015, 12:01 PM

Minimize back vertex distance, minimize VI, and instruct the client and parents that the chin should be lowered slightly, and raise the book slightly when reading (usually self-correcting).

If Iseikonic lens are prescribed, expect to see a +8 BC with about an 8mm CT in the left. A smaller (narrower 'A') frame will be needed. Zyl with pads is ideal. Don't try to eliminate all of the image size difference; get it down to 3% or 4% in the strongest meridian.

**drk** · 03-27-2015, 12:40 PM

That's brutal.

I'd like to hear what his issues are.

**Uilleann** · 03-27-2015, 01:25 PM

C-o-n-t-a-c-t.
L-e-n-s-e-s.

He can learn. I find the kids far easier most of the time than teaching "responsible" adults. And worst case scenario, teach mom and dad, and have them insert and remove for a while, till Jr. gets the hang of it. Our exec. director here did that for three years with his infant daughter from 2 months old on till her 3rd birthday. (Sadly, she passed away now.) But it certainly can be done with proper training - and just isn't that hard in almost every case like this.

**AngeHamm** · 03-27-2015, 01:32 PM

Originally Posted by Uilleann

C-o-n-t-a-c-t.
L-e-n-s-e-s.

+1!

**Robert Martellaro** · 03-27-2015, 02:01 PM

Originally Posted by jstanfast

Nt.

**Jstanfast** · 03-27-2015, 05:28 PM

We have put 2 year old's in necessary contacts, but like I said the child is not mentally ready for contacts. Doc, nor myself are comfortable using contacts yet for him. Optically we know this is not an amazing option.

Optically what is going to happen with his visually acuity when I throw best fit rules out the window and and put his -4 on an 8 base? With his OS with a 5mm CT and an 8 base with a 50/50 bevel to decrease the vertex from 10.2 to 7.7 the magnification is about 3% difference.

Will using a true Free form SV help with the acuities on the incorrect base curves?

**Paul Smith LDO** · 03-27-2015, 06:50 PM

What is the youngster's current Rx. If they are exhibiting some issues with image size, any chance the prescribing Dr can reduce the Rx in the OS, perhaps a more gradual increase over a period of time.

**obxeyeguy** · 03-27-2015, 07:48 PM

Originally Posted by Jstanfast

Ok, we had a great kid come in yesterday for an eye exam. He has a finalized script of :

+1.00 -0.25 x 031
-4.00 -2.25 x 138

PDs- 30.5/26.5 with OC measured at the mechanical center. Frame PD is 64 B of about 25.5 ED of about 48.5

So the question is would you do or recommend even attempting to minimize the magnification issues. If so, any ideas on having that done without creating to truly ugly lens? Kid is 6 and not mentally ready for contacts so contacts are out for now and he is showing symptoms that the magnification difference is an issue.

frame chosen is a Nike 4677 size 47-17
at 7% magnification difference any ideas?

Forget the magnification/minification for now. What are the acuities? What's the course of treatment for what I would think is an amblyopic child. A six year old with a 30.5 mono PD? " Showing symptoms that the magnification is an issue"? How?? What magnification? Very confused on this.

**Robert Martellaro** · 03-27-2015, 08:12 PM

Originally Posted by Jstanfast

Optically what is going to happen with his visually acuity when I throw best fit rules out the window and and put his -4 on an 8 base? With his OS with a 5mm CT and an 8 base with a 50/50 bevel to decrease the vertex from 10.2 to 7.7 the magnification is about 3% difference. Will using a true Free form SV help with the acuities on the incorrect base curves?

Theoretically it would, but it's out of range for every decent FF/optimized software that I know of. Don't worry about the off-axis vision, as OBX says, the child is probably amblyopic. Fill the Rx as written, and consult with the doc WRT suspected aniseikonia.

**mshimp** · 03-29-2015, 10:55 AM

First thing I would do is recheck that pupillary distance. Use a confrontational method. Also the Canthus method. The left monocular looks odd. Or maybe its the right eye that is odd.

**MakeOptics** · 04-01-2015, 02:40 PM

Originally Posted by Uilleann

C-o-n-t-a-c-t.
L-e-n-s-e-s.

He can learn. I find the kids far easier most of the time than teaching "responsible" adults. And worst case scenario, teach mom and dad, and have them insert and remove for a while, till Jr. gets the hang of it. Our exec. director here did that for three years with his infant daughter from 2 months old on till her 3rd birthday. (Sadly, she passed away now.) But it certainly can be done with peoper training - and just isn't that hard in almost every case like this.

Nailed it, without correction suppression occurs and amblyopia becomes a real issue. We used to just have parents put contacts in for kids like this, it's a pain but it can help preserve good vision for the future.