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Calculation of diffractive extended depth of focus intraocular lenses after myopic laser in situ keratomileusis

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First Author: C.Lwowski GERMANY

Co Author(s):    M. Adas   K. Pawlowicz   T. Kohnen              

Abstract Details

Purpose:

To evaluate the formulas of the ASCRS calculator for calculation of diffractive extended depth of focus intraocular lenses (EDOF IOL) in patients with a history of myopic laser in situ keratomileusis (LASIK)

Setting:

Retrospective consecutive case series Department of Ophthalmology, Goethe-University, Frankfurt, Germany

Methods:

Case records of patients that underwent cataract surgery or refractive lens exchange with implantation of diffractive EDOF IOLs (Symfony and AT LARA) were screened for a history of myopic LASIK. Preoperative measurements were taken with IOL Master 500 & 700. Subjective refraction (SE) was performed by an optician at least 4 weeks postoperative. Mean prediction error (MPE), mean absolute prediction error (MAE), and the amount of eyes within ±0.5D, ±1.0D, ±1.5D, and ±2.0D was calculated for the Shammas, Haigis L, Barrett True K, Barrett no History, Masket, modified Masket and the average of those formulas (Average) using the ASCRS calculator.

Results:

36 eyes matched our inclusion criteria with a mean postoperative SE of -0.79D ± 0.75, the mean pre-LASIK SE was -6.26D ± 3.25. The formulas ranked by MAE were Haigis L (0.70D ± 0.58), Shammas (0.75D ± 0.61), Average (0.77D ± 0.7), mod. Masket (0.98D ± 1.12), Masket (0.99D ± 1.02), Barrett True K (1.13D ± 0.83), and Barrett no History (1.33D ± 0.73), The formulas with the most eyes within ±0.5D were Haigis L (47%), Shammas (46%), and Average (44%).

Conclusions:

Calculation of IOLs of eyes with a history of refractive surgery remains a challenge. In our collective the Shammas and Haigis L formula performed best in terms of MAE and number of eyes within ±0.5D. Alternatively the average of all given formulas can deliver reasonably results.

Financial Disclosure:

... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, ... receives consulting fees, retainer, or contract payments from a competing company