Risk factors for postoperative hemorrhage after vitrectomy for diabetic retinopathy

To identify the potential risk factors for postvitrectomy diabetic vitreous hemorrhage (PDVH).

A matched case-control nested into a retrospective follow-up study was done to review the surgical results in 68 consecutive eyes undergoing primary pars plana vitrectomy for vitreous hemorrhage. The eyes were divided into two groups based on the presence of PDVH (19 cases and 49 controls) and were matched on surgeon and the date of surgery. Twenty-three factors related to the preoperative examination and eight factors related to the operative procedure were analyzed. Statistical analysis was based on conditional logistic regression models with PDVH as the dependent variable. The mean follow-up interval was six months.

The factors associated with the incidence of PDVH were iris neovascularization (OR = 9.8, P = 0.03), lower extremity amputations (OR = 8.3, P = 0.02) and the use of antihypertensive agents within three months before vitrectomy (OR = 0.2, P = 0.04). Phakic and aphakic eyes of diabetic patients with lower extremity amputations would have a 70% probability of developing PDVH. This probability would have dropped to 30-40% had they been taking antihypertensive treatment.

Iris neovascularization and lower extremity amputations increase the risk of PDVH. Antihypertensive treatment before vitrectomy decreases this risk.