Inferior peripheral iridectomy in patients receiving silicone oil. Rates of postoperative closure and effect on oil position.

BACKGROUND

Silicone oil tamponade is used in treating retinal detachments, but silicone-associated complications remain frequent. Keratopathy and acute pupillary block glaucoma are related to migration of silicone oil into the anterior chamber. Since 1985, many surgeons have created an inferior peripheral iridectomy (PI) at the time of surgery to prevent forward migration of the oil, but the rate of postoperative closure of the PI and the effect on oil position have not been well defined.

METHODS

The charts of 292 patients undergoing silicone oil surgery were reviewed. The status of the PI and the oil position were determined throughout the postoperative period.

RESULTS

Postoperative closure of the PI occurred in 40 (33%) of 121 aphakic eyes in the early postoperative period. Forward migration of the oil was highly associated with closure of the PI (32/40, 80%). Conversely, forward oil migration occurred in only 11% (9/81) of eyes with patent PIs. The rate of PI closure was significantly greater for patients with proliferative diabetic retinopathy (21/40, 52%) than for patients with proliferative vitreoretinopathy (11/58, 19%).

CONCLUSION

Postoperative closure of the PI occurred in a significant fraction of eyes undergoing silicone oil surgery, was highly correlated with forward oil migration, and occurred most frequently in eyes with proliferative diabetic retinopathy.