Combined rhegmatogenous and traction retinal detachment in proliferative diabetic retinopathy: clinical manifestations and surgical outcome.

BACKGROUND: Combined rhegmatogenous and traction retinal detachment (combined detachment) is a serious complication in proliferative diabetic retinopathy. The common clinical findings and surgical results of this complication were investigated.
METHODS: Forty eyes of 36 consecutive patients with combined detachment undergoing pars plana vitrectomy at a teaching hospital in a 4.5-year period were retrospectively reviewed. All cases had been followed up for at least 6 months.
RESULTS: Only 10 of the 40 cases had a preoperative visual acuity better than finger counting vision. Extensive proliferation with multiple, thickened, plaque-like vitreoretinal adhesions and large areas of detachment were noted in 38 cases, 19 cases showing predominantly fibrous tissue and 19 cases presenting with predominantly active fibrovascular proliferation. Two cases had minimal fibrovascular proliferation. Retinal breaks were identified in 7 eyes (17.5%) before surgery and in 33 eyes (82.5%) during surgery. Thirty-seven eyes (92.5%) achieved long-term retinal reattachment. Silicone oil was used in 23 eyes (57.5%). Visual acuity improved in 28 eyes (70%), was unchanged in 6 (15%), and became worse in 6 (15%). In 19 eyes postoperative vision was better than 20/400. Multiple regression analysis showed preoperative visual acuity as the single factor associated with postoperative visual outcome.
INTERPRETATION: Combined retinal detachment in proliferative diabetic retinopathy may occur during the stage of active fibrovascular proliferation or as a late complication. It is frequently associated with tightly adherent preretinal tissue and extensive detachment. Preoperative visual acuity best predicts visual prognosis.