Purpose: To report the clinical outcome and complications of intravitreal injections of crystalline cortisone in patients undergoing pars plana vitrectomy for treatment of proliferative diabetic retinopathy.
Methods: The prospective, interventional case series study included 29 consecutive patients (29 eyes) who underwent pars plana vitrectomy for treatment of complicated proliferative diabetic retinopathy associated with central retinal traction detachment. All patients received an intravitreal injection of 15 to 20 mg of crystalline triamcinolone acetonide at the end of surgery, and were operated on by the same surgeon. Mean follow-up time was 1.4 +/- 1.1 months (median, 1 month; range, 0.30 to 4.9 months).
Results: At the end of the follow-up period, the retina was attached in 26 of the 29 patients (89.7%). In three of the 29 patients (10.3%), a retinal redetachment had occurred. None of the patients developed iris neovascularization, and the iris neovascularization, present preoperatively in 12 patients, slightly to markedly regressed in all 12 patients. Preoperative and postoperative intraocular pressure values (P =.72) and blood glucose measurements did not vary significantly. A pseudohypopyon consisting of cortisone crystals in the inferior anterior chamber angle was detected in one patient and resolved spontaneously within 4 days.
Conclusions: The present clinical study suggests that intravitreal injection of crystalline cortisone with most of the vehicle removed seems to be well tolerated by eyes undergoing pars plana vitrectomy for treatment of complicated diabetic proliferative retinopathy. In view of the antiphlogistic and antiproliferative effect of cortisone, future randomized clinical trials may be indicated to investigate further the role of intravitreal injection of crystalline cortisone in the treatment of proliferative diabetic retinopathy.