Calculation of a diffractive extended-depth-of-focus intraocular lens after myopic laser in situ keratomileusis

Session Details

Session Title: Moderated Poster Session: Focus on Multifocal IOLs and Cataract Surgery
Session Date/Time: Friday 21/02/2020 | 14:00-15:00
Paper Time: 14:32
Venue: Poster Area


First Author: T.Kohnen GERMANY
Co Author(s): M. Adas  L. Henzelmann  K. Pawlowicz  C. Lwowski        

Abstract Details

Purpose:

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

Setting:

Department of Ophthalmology, Goethe-University, Frankfurt, Germany

Methods:

Case records of patients of cataract surgery or refractive lens exchange with implantation of a diffractive EDOF IOL (Symfony, J&J) were screened for history of myopic LASIK. Preoperative measurements were taken by the IOL Master 500 & 700 (Carl Zeiss). Subjective refraction (SE) was performed by an optician at least 4 week 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:

25 eyes matched our inclusion criteria with a mean SE of -0.81D ± 0.69, the mean pre-LASIK SE was -6.4D ± 3.63. The formulas ranked by MAE were Shammas (0.7D ± 0.75), Haigis L (0.72D ± 0.57), Average (0.79D ± 0.8), Barrett True K (1.14D ± 0.89), mod. Masket (1.4D ± 1.15), Barrett no History (1.45D ± 0.7), and Masket (1.64D ± 1.27). The formulas with the most eyes within ±0.5D were Average (52%), Shammas (48%), and Haigis L (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:

None