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.
Methods: Nine hundred and sixty four 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 classified in five levels (0, 1, 2, 3 and 4) was assessed at each of the follow-up visits by a trained ophthalmologist during a period of 36 months.
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 the 3-month follow-up visit. The few eyes developing anterior subcapsular cataract (ASC) were older, had a tendency to vault 2 or lower post-operative, shallower anterior chamber depth and smaller ICL size. 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 became statistically significant after the third month postoperatively. Several patients 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-operative period should be considered in those particular cases.