drk
08-19-2005, 03:16 PM
Had another episode of a recurrent problem with yet another patient. I doubt it's my pupillometer, but I'm open to anything...
Patient returns after dispensing of his first progressive,Complaint: OS near vision blurry unless turns head to right (has to look nasally). Distance vision has same effect, although less. OD is "perfect".
Rx: -0.25-0.75x163/ -0.25-1.75x 177, +0.75 add OU. PD is 29.5/29.5. Fit in Panamics. Refraction was double-checked, as was PD measurement and placement of fitting cross. The lenses were not rotated in the frame. The adjustment was as correct as adjustments get.
As I sometimes do, I viewed a vertical line (doorframe) while looking through the lens, and shook the lens to visualize the increased skew when the peripheral astigmatism was encountered in the near portion, but with the low add I couldn't outline the corridor and near portion as well as with a higher add.
Instead, I drew a "vertical" line down the lens along the image of the visualized doorframe in order to find the "optical center-line" of the corridor and near portion and distance portion (not unlike what used to be done to visualize the OC of an exec.) What I found is that the asymptomatic eye had a pretty much vertical, not inset, line from top to bottom of the lens. The symptomatic eye's lens had a line that tilted nasally, from top to bottom, as you would expect for an inset corridor and near portion.
Despite what looks more reasonable on the symptomatic left side, I concluded that somehow the lens has more inset than the patient needs, and reordered with 1.5 mm less inset.
Questions:
1.) What does my method really prove? Nothing?
2.) Can the inset be wrong on one eye? I know the OS Rx is different, and that the French like their segs inset more than we'd expect.
3.) Is the right lens the "wrong" lens, and he just prefers it?
Help, if you can!
Patient returns after dispensing of his first progressive,Complaint: OS near vision blurry unless turns head to right (has to look nasally). Distance vision has same effect, although less. OD is "perfect".
Rx: -0.25-0.75x163/ -0.25-1.75x 177, +0.75 add OU. PD is 29.5/29.5. Fit in Panamics. Refraction was double-checked, as was PD measurement and placement of fitting cross. The lenses were not rotated in the frame. The adjustment was as correct as adjustments get.
As I sometimes do, I viewed a vertical line (doorframe) while looking through the lens, and shook the lens to visualize the increased skew when the peripheral astigmatism was encountered in the near portion, but with the low add I couldn't outline the corridor and near portion as well as with a higher add.
Instead, I drew a "vertical" line down the lens along the image of the visualized doorframe in order to find the "optical center-line" of the corridor and near portion and distance portion (not unlike what used to be done to visualize the OC of an exec.) What I found is that the asymptomatic eye had a pretty much vertical, not inset, line from top to bottom of the lens. The symptomatic eye's lens had a line that tilted nasally, from top to bottom, as you would expect for an inset corridor and near portion.
Despite what looks more reasonable on the symptomatic left side, I concluded that somehow the lens has more inset than the patient needs, and reordered with 1.5 mm less inset.
Questions:
1.) What does my method really prove? Nothing?
2.) Can the inset be wrong on one eye? I know the OS Rx is different, and that the French like their segs inset more than we'd expect.
3.) Is the right lens the "wrong" lens, and he just prefers it?
Help, if you can!