The relationship between capsulorhexis size and anterior chamber depth relation.

Abstract

Background and objective: To determine whether the diameter of the capsulorhexis has an effect on anterior chamber depth (ACD) following phacoemulsification surgery.

Patients and methods: Fifty-one consecutive patients were selected for cataract extraction by phacoemulsification with intraocular lens (IOL) implantation. Twenty-two of 51 patients underwent 4 mm capsulorhexis, while the rest underwent 6 mm. All were implanted with a multi-piece polymethyl methacrylate posterior chamber IOL with 5.0 mm diameter biconvex optic and flexible haptic. They were followed 3 months postoperatively. The width of the capsulorhexis was assured according to the IOL optic implanted intraoperatively, and by the help of slit-lamp measurement after dilatation of the pupil on the first postoperative day. ACD and axial length (AL) of patients was obtained by ultrasonography on both the days before surgery, and the first and seventh postoperative days, and after 30, 60 and 90 days.

Results: Early significant increase of ACD and ACD/AL ratios were observed in only the 6 mm capsulorhexis group on the first day postoperatively (P = .012, and P = .018). On the 90th postoperative day, ACD increased significantly both in the 4 mm (P = .002) and the 6 mm capsulorhexis groups (P = .049) when compared to preoperative values. For the same period, meaningful increase in ACD/AL ratio in the eyes with both 4 mm and 6 mm capsulorhexis groups was also noted compared with preoperatively (P = .002 and P = .019). There was a statistical difference between the 90th day ACD values of 4 mm (3.73 +/- 0.32 mm, mean +/- standard deviation) and 6 mm capsulorhexis groups (3.50 +/- 0.33 mm) (P = .028). For the same period, ACD/AL ratio was also significantly different for both groups (0.152 +/- 0.01, and 0.142 +/- 0.01 respectively) (P = .004). The refractive error changes followed the ACD changes and showed meaningful differences between 1st and 90th days postoperative values of each group (P = .029, and P = .014, respectively).

Conclusion: A 4 mm capsulorhexis results in a longer postoperative ACD than does a 6 mm capsulorhexis for the IOL type used in this study.