340 likes | 517 Views
Accommodative Arching. Eyeonics Briefing 2 February 2005 Kevin L. Waltz, OD, MD Eye Surgeons of Indiana Indianapolis, IN. Outline of Briefing. Background Measurement limitations Historical assumptions Fortuitous patient Archeological evidence Theory fit with known data.
E N D
Accommodative Arching Eyeonics Briefing 2 February 2005 Kevin L. Waltz, OD, MD Eye Surgeons of Indiana Indianapolis, IN
Outline of Briefing • Background • Measurement limitations • Historical assumptions • Fortuitous patient • Archeological evidence • Theory fit with known data
Background for AA Theory • KLW’s interest in refractive lens surgery • Tracey experience since summer 2002 • i Trace experience since fall 2003 • Experience with capsular effects on IOL’s • KLW’s frustration with initial AT-45 outcomes • Extensive wavefront testing of distance and near vision with IOL’s, including AT-45 pts
Experience with Capsular/YAG Effects on Multifocal Optics 10 minutes Pre-YAG Post-YAG 20/20 & J3 20/20 & J1
Measurement Limitations • Original Tracey 64 sequential spots • i Trace sequential 256 spots • Variable spot positioning on Tracey • Tracey can readily measure wavefront at near • Shack-Hartmann simultaneous spots • NIPEK OPD simultaneous topo and wavefront • COAS direct imaging
Historical Assumptions • Near wavefront ignored • Near wavefront assumed to be the same as distance with some amount of uniformly increased power • Reading glasses = accommodation • Low HOA @ distance = low HOA @ near • Low HOA @ near is good
Zachary Waltz 13 yo OD – 5 D accommodation OD – No accommodation
Successful College Student 19yo OS – 5 D accommodation OS – No accommodation
Successful Medical Student S/P LASIK 23 yo OD – 5 D accommodation OD – No accommodation
Fortuitous Patient • 72 year old white male cataract pt • Desired to be less dependent on glasses • Uneventful cataract surgery • PO: Little to no near vision and myopic • Repositioned IOL in bag at 7 weeks to decrease myopia, rotated IOL 90° • Improved distance and near vision
Accommodation with CrystalensS/P IOL Rotation by 90° Distance refractive mapNear refractive map 0.186 rms total error 0.464 rms total errror 0.69+0.36X078 -2.37+0.92x008
Archeologiccal Evidence“The aberrations in some Tracey images are not compatible with high quality vision.”
AA Theory Fit With Known Data • Images are almost certainly real • Axial movement of 0.3 mm needed for 10 D of AA flexing over 2mm diameter • Variations in Crystalens orientation relative to power axis in eye would create inconsistent measured near vision in patients • Capsule effects might change with time
AA Theory Fit With Known Data Variations in IOL power with AA and emerging concept of neuroplasticity could explain inconsistency in measured accommodation vs observed near vision