Anterior capsule cover and axial movement of intraocular lens

Abstract

Purpose: To measure optic shift (OS) of a single piece monofocal intraocular lens (IOL) with varying relationships between anterior capsule cover and IOL optic. Methods: This is a prospective randomized masked study of 150 eyes undergoing phacoemulsification. Eyes received either option: 360° total capsule cover (group I); partial cover (group II); or no cover (group III). OS was calculated as difference in anterior chamber depth after administration of cyclopentolate 1% and pilocarpine 2% on IOLMaster® at separate visits at 6 months follow-up. Subsequently, using retro-illumination photographs, percentage area of capsule cover was calculated. OS within and between groups I and II was analyzed. The impact of one quartile change in area of capsule cover on percentage change in OS was measured for both groups. Unpaired t-test, correlation, and regression were applied. Results: In groups I, II, and III, mean age of patients was 56.68±6.38, 57.09±7.34, 59.15±6.35 years, respectively; mean OS (mm) was 1.25±0.28, 1.20±0.24; 0.95±0.26 (P = 0.013), respectively; and percentage area of capsule cover (%) was 47.35±10.48, 33.83±10.11, 0.16±0.13 (P = 0.001), respectively. Mean percentage area of capsule cover in group I vsgroup II was significant (P = 0.001). OS was 1.22±0.26mm in groups I and II (combined) vs0.95±0.26 mm in group III (P = 0.004, (0.06, 0.33)). OS in group I vsgroup II was not significant (P = 0.46). Correlation coefficient was r = 0.38 (P < 0.001). With every increment on quartile (a quartile is any of the three values which divide the sorted data set into four equal parts, so that each part represents one-fourth of the sample or population) class of area of capsule cover the OS increased by 0.12 mm. Conclusion: The OS differed significantly between total and partial cover groups combined vsno cover group.