Experimental studies of capsular equator rings of soft latex

To determine the efficacy of wide equatorial rings of various materials in reducing posterior capsule opacification (PCO) and maintaining the circular contour of the capsular equator in a rabbit model.

Laboratory for Intraocular Microsurgery and Implants, Goldschleger Eye Research Institute, Tel-Aviv University, Sheba Medical Center, Tel-Hashomer, Israel.

Closed rings made of poly(methyl methacrylate), Teflon(R), polyurethane, and latex were introduced into the capsular bags of rabbit eyes after removal of the lens material. The soft latex rings were deemed the only practical rings for atraumatic implantation through a small incision. Latex rings of 2 dimensions with rectangular edges were implanted in 8 rabbits. One eye served as a control after lens removal and no ring implantation. The eyes were followed for up to 5 months and then evaluated by light microscopy.

Posterior capsule opacification was minimal or absent in all animals implanted with the latex rings. Mild to moderate inflammatory reaction was noted in most eyes. It was caused by the ring material or secondary to long-standing pressure on the ciliary tissue. The rings also maintained well the circular contour of the capsular bags.

Equatorial rings of soft latex with sharp rectangular edges were effective in minimizing PCO and maintaining the shape of the capsule after lens removal in rabbits. Soft rings made of a biocompatible material may be effective in humans.