Three year follow-up of subjective vault following myopic posterior chamber phakic Implantable Collamer Lens (ICL) implantation. Fernandes P 1, Alfonso JF 2,3, Meijome JG 1, Jorge J 1, Montés-Micó R 4, Physic Departmen (Optometry), University of Minho, Portugal. Fernández-Vega Ophthalmological Institute, Oviedo, Spain. 3 Surgery Department, School of Medicine, University of Oviedo, Spain. 4 Optics Department, Faculty of Physics, University of Valencia, Spain. 1 2
Purpose: To evaluate changes of subjective vault during a period of 36 months after implantation of phakic posterior chamber Implantable Collamer Lens (ICL) for myopia correction. Setting: Fernández-Vega Ophthalmological Institute. Oviedo. Spain Methods: 964 myopic eyes of 531 patients, 353 females (66.5%) and 178 (33.5%) males, who received a Visian ICL (model V4, Staar Surgical Inc.) implantation, were included in the study. Subjective vault was assessed at each of the follow-up during a period of 36 months, using an optical section during routine slit-lamp examination and classified in five levels(0, 1, 2 3 and 4) by comparing the separation between the lens anterior surface and the posterior surface of the ICL to the corneal thickness (CT). Results: Mean vault decreased from 2.30±0.87 immediately after surgery to 2.10±0.92 at 12 months and to 2.06±1.05 at 36 months. For patients presenting vault 2, 3 and 4 post-operatively, there was a decrease with time, with changes becoming statistically significant (p<0.05) after 1 month. The few eyes developing anterior subcapsular cataract (ASC) were older, had vault 2 or lower post-operative, shallower anterior chamber depth, smaller ICL size or smaller difference between ICL size and white-to-white distance. Eyes with acute increase in intraocular pressure (IOP) were significantly more myopic, had smaller white-to-white diameter and had larger photopic pupil diameters. Conclusions: Decrease in subjective vault after ICL implantation become statistically significant between 1 to 3 months post-operatively. Several patient-related and lens-related factors have been identified as potential predictors of ASC or acute increase in IOP. A tight follow-up during the critical post-operatively period should be considered in those particular cases.