Phacoemulsification and lens implantation in rabbit eyes: capsular bag versus ciliary sulcus implantation and 4.0 versus 7.0 mm capsulorhexis.

PURPOSE

To compare the effects of intraocular lens (IOL) implantation in the capsular bag versus the ciliary sulcus and of a 4.0 versus 7.0 mm continuous curvilinear capsulorhexis (CCC) on postoperative inflammation and after-cataract formation.

SETTING

St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Trial 1 comprised 40 rabbits that had CCC, endocapsular phacoemulsification, and a poly(methyl methacrylate) IOL implanted in the capsular bag in one eye and the ciliary sulcus in the fellow eye. In Trial 2, 40 rabbits had a 4.0 mm CCC in one eye and a 7.0 mm CCC in the fellow eye followed by phacoemulsification and IOL implantation in the capsular bag. White blood cell (WBC) counts and prostaglandin E2 (PGE2) concentrations in aqueous humor were determined at 1, 3, 7(8), 28, and 56 days postoperatively. Wet mass of the dissected after-cataract was measured at day 56. In Trial 1, wet mass of the iris-ciliary body was measured at each observation.

RESULTS

In Trial 1, WBC counts at day 1 were higher with a sulcus-fixated IOL (P = .05). The median wet mass of the dissected after-cataract was 108.5 mg in eyes with a sulcus-fixated IOL and 62.5 mg in eyes with a capsule-fixated IOL (P = .01). In Trial 2, WBC counts at day 8 were significantly higher in eyes with a 7.0 mm CCC than in those with a 4.0 mm CCC (P < .05). There was no significant difference in the amount of after-cataract.

CONCLUSIONS

The results indicate that IOL implantation in the capsular bag causes less inflammation and after-cataract formation than sulcus fixation and that using a large CCC does not affect the total amount of after-cataract but may enhance the inflammatory response.