RESIDUAL REFRACTIVE ERROR AFTER CATARACT EXTRACTION

Title RESIDUAL REFRACTIVE ERROR AFTER CATARACT EXTRACTION
Author, Co-Author Asfa Afsar, Fiona Rogan, Sudi Patel, William Wykes
Topic
Year
1996
Day
Monday
Program Number
Poster 102
Room
Southern Hem I,II
Affiliation
Department Vision Sciences
Abstract PURPOSE: To determine clinically if the SRK/SRK-T regression formulae are good predictors of the final refraction after phakoemulsification extracapsular cataract extraction.

METHODS: 26 patients with mature cataracts (age range between 45-85 years) were recruited prior to lens implantation. These were carefully selected to exclude any ocular disease other than the presence of the cataract. Their axial length and keratometer readings, taken using the Storz biometer and Bausch and Lomb keratometer, were entered into a Storz biometer pre-programmed to calculate the implant power required for the desired post-operative refraction using the SRK/SRK-T regression formulae. The patients then had phacoemulsification cataract extraction combined with intraocular lens implantation using an intraocular lens with the back vertex power as close to the desired, within the limits of availability. In all 26 patients the lens used was a foldable lens and the incision either left to self-seal or sealed by one cross-over suture. Only one eye of each patient was operated upon.The patients were seen 1-2 months post-operatively and a routine eye examination was carried out including the determination of their refraction. This was then transformed into the equivalent sphere form to enable a comparison between the expected sphere and the actual post-operative refraction.

RESULTS: 19 eyes (73%) had a final refractive error between ±0.50 to 1.25D of the predicted result. In 6 eyes (23%) the final refractive error fell between ±1.25D to 2.00D. Only 1 eye (3.8%) had a post-operative refraction greater than ±2.00D of the predicted sphere. CONCLUSION: Although the SRK/SRK-T regression formulae are the choice for most ophthalmic surgeons, the results suggest that they could be further refined to give more predictable post-operative refractive errors. [supported by a grant from the College of Optometrists].
Affiliation of Co-Authors Department Vision Sciences, Department of Ophthalmology, Department Vision Sciences
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