Visual acuitiy after ICL implantation: Comparison of clinical outcomes and calculations of image magnifications

Abstract

Abstract: : Purpose: Implantation of an implantable contact lens (ICL) to correct myopia or hyperopia causes an increase or decrease of retinal image size, depending on preoperative refraction, corneal curvature, location of the ICL and postoperative refraction. Clinical change of visual acuity was compared with computerized image size calculations. Methods: In 65 eyes of 37 patients an ICL was implanted. Preoperative distance visual acuity with best refraction, preoperative keratometry, corneal pachymetry and preoperative anterior chamber depth were determined. Postoperatively the distance visual acuity with best refraction was determined and compared with the preoperative values. The distance of the posterior surface of the ICL to the anterior surface of the crystalline lens was evaluated by means of the Jaeger advice for the Haag Streit slit lamp. Based on these results the change of the pre– and postoperative retinal image size of a distance object was calculated and compared with the evaluated change of clinical visual acuity. Results: Postoperatively in myopic eyes an increase and in hyperopic eyes a decrease of visual acuity according to the extent of the preoperative ametropia was evaluated. Calculating the retinal image size after ICL implantation a change of 1.5 % per diopter of the preoperative ametropia was found. Changes of visual acuity after ICL implantation were 7.1 % higher for the 62 myopic eyes and 9.8 % higher for the 3 hyperopic eyes than in the computation. Conclusions: The found changes of visual acuity after ICL implantation because of changes of retinal image size were more distinct in the clinical outcomes than expectected due to theoretical computation.

Keywords: refractive surgery: phakic IOL • refractive surgery • refraction