Intraocular lens power calculation in clear lens exchange for extreme hyperopia

Session Details

Session Title: Premium IOLs: Multifocal, EDOF & Toric

Session Date/Time: Tuesday 25/09/2018 | 16:30-18:00

Paper Time: 17:16

Venue: Room A4

First Author: : G. Shkolnik RUSSIA

Co Author(s): :    Y. Batkov   N. Pashtayev   V. Mikhaylova              

Abstract Details

Purpose:

Accuracy of intraocular lens (IOL) power calculation in short eyes is inferior to emmetropic eyes. Most studies focus on relatively standard eyes. The purpose of this study was to assess the accuracy of IOL power calculation in eyes undergoing refractive lens exchange for extreme hyperopia and to compare available formulas based on their predictive capacity.

Setting:

S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary

Methods:

Results of 13 implantations involving IOLs > 40 diopters (D) in power were retrospectively evaluated. IOL power calculation was performed using five formulas: Haigis, HofferQ, HolladayI, SRKII, SRK/T. Mean numerical refractive prediction error (RPE) and mean absolute refractive prediction error (ARPE) were back calculated. Mean and median ARPE were computed after zeroing out mean numerical RPE for each formula. Proportion of eyes within certain RPE limits for each formula was calculated.

Results:

Mean RPE ranged from 1.43 to 11.71 D before adjustment and from 1.08 to 5.34 D after adjustment (p <0.0001). Haigis formula produced the least RPE, while SRKII the most. Pairwise comparison by mean ARPE after adjustment revealed no statistically significant difference between Haigis and HofferQ formulas. Comparison of formulas by percentage of eyes with minimal RPE identified Haigis and HofferQ as the most accurate, while the difference between the two was not statistically significant.

Conclusions:

Prediction errors in IOL power calculations in extremely short eyes are relatively frequent (only 31-46% of eyes are within ± 0.5D) and require reduction. Among the evaluated formulas, Haigis and HofferQ are the most accurate. Personalized constants are necessary to improve calculation accuracy.

Financial Disclosure:

... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented