Comparison of the effect of capsular bend on the rotational stability between 2 toric intraocular lenses

Purpose:To compare the effect of capsular bend on the rotational stability between 2 toric intraocular lenses (IOLs). Setting:Eye Hospital of Wenzhou Medical University, Hangzhou, Zhejiang Province, China. Design:Prospective study. Methods:Patients with preexisting astigmatism received AcrySof IQ (SN6AT) or TECNIS (ZCT/ZMT) toric IOL during cataract surgery. CASIA2 was used to record the toric IOL axial orientation and capsular bend index (CBI) at the 1-day, 1-week, 1-month, and 3-month interval postoperatively. The postoperative rotational stability and CBI of both models were compared. Results:A total of 58 eyes from 58 patients were enrolled in this study. The total misalignment of the TECNIS (ZCT/ZMT) group (6.96 +/- 5.10 degrees, 7.41 +/- 5.19 degrees, 6.93 +/- 5.29 degrees, and 6.86 +/- 5. 27 degrees) was significantly higher than that of the AcrySof IQ (SN6AT) group (3.55 +/- 2.21 degrees, 4.00 +/- 2.74 degrees, 3.72 +/- 2.72 degrees, and 3.52 +/- 2.50 degrees) at all follow-up intervals (P < .05). The mean rotation of the TECNIS (ZCT/ZMT) group (2.66 +/- 2.18 degrees) was significantly greater than that of the AcrySof IQ (SN6AT) group (1.65 +/- 1.47 degrees) from 1 day to 1 week postoperatively (P < .05). The capsular bend formation in the TECNIS (ZCT/ZMT) group was delayed compared with the AcrySof IQ (SN6AT) group (P < .05, at the 1-week, 1-month, and 3-month interval). The TECNIS (ZCT/ZMT) group showed fibrosis in the peripheral anterior capsule, leading to its stretching away from the IOL surface, while the AcrySof IQ (SN6AT) group exhibited gentle adherence of the anterior capsule to the IOL surface. Conclusions:The AcrySof IQ toric IOL (SN6AT) exhibited greater rotational stability than the TECNIS toric IOL (ZCT/ZMT), which may partially result from the delay in capsular bend formation of TECNIS at the 1-day to 1-week follow-up postoperatively.