Clinical research on movement of intraocular contact lens during accommodation

Abstract

To study the movement of intraocular contact lens (ICL) during accommodation. Forty one eyes of 41 consecutive patients implanted ICL to correct high myopia were collected. The visual acuity and accommodation power were checked before and after the surgery. The movement of both the ICL and the lens was measured separately at nonaccommodated state and pilocarpine induced accommodation. The uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) improved 3 months after surgery. The mean accommodation power before surgery was (2.12 + or - 1.06) D, and was (4.46 + or - 2.11) D 3 months after surgery. Accommodation power was improved significantly (t = 2.312, P = 0.022). The distance from the posterior surface of ICL to the anterior surface of the lens was (0.48 + or - 0.27) mm at nonaccommodated state, and (0.34 + or - 0.19) mm at drug induced accommodation, the difference was significant (t = 2.104, P = 0.038). The position from corneal endothelium to the anterior surface of ICL had no significant difference at nonaccommodated state and drug induced accommodation (t = 1.165, P = 0.149). Depth of the anterior chamber (from the posterior surface of the cornea to the anterior surface of the lens) between nonaccommodated and drug-induced accommodation had no statistically significant difference (t = 1.821, P = 0.071), but the anterior pole of the lens actually moved forward at drug induced accommodation checked with slit lamp. With ultrasound biomicroscopy we could see that in several surgical eyes, ICL loop contacted with periphery lens both in nonaccommodated state and drug induced accommodation condition. Although the constriction of pupil induced by pilocarpine decreases the distance from the posterior surface of ICL to the anterior lens surface significantly, there still has enough space to avoid the occurrence of subcapsular cataract. The contact between ICL loop and periphery lens might be one of the causes for periphery lens opacification, but the influence of this contact to the occurrence of central subcapsular opacification still requires further investigation.