Effect of large positioning holes on capsule fixation of plate-haptic intraocular lenses

Purpose: To compare the centration and fixation of silicone plate-haptic in traocular lenses (IOLs) with different-sized positioning holes. Setting: Eye Clinic of the Johannes Gutenberg-University Mainz, Mainz, Germ any. Methods: In a prospective randomized study, 51 Chiroflex C10 and 58 Chirofl ex C11 IOLs were implanted under standardized conditions by the same surgeo n. The IOL position was documented at the end of surgery and by retroillumi nation on the first day and 5 months postoperatively. The positioning-hole area was evaluated by ultrasound biomicroscopy (50 MHz)5 months postoperati vely. Results: One day postoperatively, no IOL in either group was decentered mor e than 1.0 mm. After 5 months, 33% of the C10 and 42% of the C11 IOLs were decentered between 0.5 and 1.0 mm, and 11% of the C10 and 8% of the C11 IOL s were decentered more than 1.0 mm (maximum 1.23 mm and 1.41 mm, respective ly). Up to the first postoperative day, 20% of the C10 and 22% of the C11 l enses were rotated more than 15 degrees. At 5 months, an additional 15% of the C10 and 19% of the C11 lenses were rotated. Ultrasound biomicroscopy sh owed no tissue or capsule adhesion in the holes in most cases (85% C10 grou p; 71% C11 group); No difference was statistically significant. Conclusions: Larger positioning holes did not prevent IOL decentration or r otation; thus, this IOL design appears unsuitable for correcting astigmatis m. Because tissue in the positioning hole was rare with both lens types, it is doubtful that enlarged plate-haptic perforations will prevent IOL luxat ion into the vitreous cavity after capsulotomy. J Cataract Refract Surg 200 0; 26:1778-1785 (C) 2000 ASCRS and ESCRS.