Posters

Intraocular lens constant optimization in cataract surgery before Descemet’s membrane endothelial keratoplasty and in triple DMEK

Poster Details

First Author: N.Lorenzana Blanco SPAIN

Co Author(s): G. Velarde Rodríguez   B. García Sandoval   I. Jiménez-Alfaro Morote   N. Alejandre           

Abstract Details

Purpose:

To analyse refractive results in patients who underwent cataract surgery and Descemet's membrane endothelial keratoplasty (DMEK) and to optimize the constants of the intraocular lenses (IOLs) that were implanted.

Setting:

Jiménez Díaz Foundation, University Hospital of Madrid (Spain).

Methods:

A retrospective observational study with a minimum follow-up of 6 months was carried out on 92 eyes of 85 patients with Fuchs´ dystrophy and cataract, of which 65 provided full filled inclusion criteria. Three types of IOLs were implanted: CT-Asphina-409M(Zeiss), Akreos-AO-MI60(Bausch&Lomb) and Acrysof-IQ-SN60WF(Alcon). Target refraction for the choice of IOL power was calculated using third generation formulas, an IOLMaster-700(Zeiss) and the constants supplied by the User group for Laser Interference Biometry. The absolute error of post-surgical spherical equivalent (SE), if the target had been plano, was used to propose optimized IOL constants for the different formulas and lens types.

Results:

A target of -0.23±0.25 diopters (D) was selected according to SRK/T formula. The resulting SE was 0.03±0.83D. Although 15.4% of patients showed a SE greater than 1D, none achieved a postoperative refraction greater than 2D. The group that underwent triple-DMEK (N=20) had a slightly more hypermetropic refractive result than the sequential-surgery-group (N=45), without reaching statistical significance (0.21Dvs-0.05D,p=0.254). Optimized IOL constants obtained for the SN60WF-IOL were 119.49 for SRK/T, 6.00 for Hoffer-Q, 2.19 for Holladay and 1.84 for Haigis; for the MI60-IOL were 119.33, 5.83, 2.04 and 1.70; and for the Asphina-IOL were 118.17, 5.15, 1.32 and 0.97 respectively.

Conclusions:

IOLs constants should be recalculated specifically for these surgeries. Further research is needed to allow us to identify clinic parameters that predict which patients need a different target (such as asphericity of the posterior corneal surface).

Financial Disclosure:

None