Prognostic indicators of success and failure in vitrectomy for diabetic retinopathy.

Results of pars plana vitrectomy for complications of diabetic retinopathy were analyzed by logistic regression analysis in 1007 eyes to determine the preoperative and intraoperative factors associated with visual success or failure. Preoperative factors associated with a poorer visual outcome (final visual acuity less than 5/200) include preoperative iris neovascularization, cataract, visual acuity less than 5/200 and traction or rhegmatogenous retinal detachment. Intraoperative factors associated with a greater chance of a poor visual result include use of intravitreal gas or air and creation of an iatrogenic retinal break or detachment. The presence of any one of these factors resulted in a 1.5 to 3.9 times greater risk of a poor final visual result. The regression coefficients may be combined to predict the likelihood of obtaining final acuity greater than or equal to 5/200 in eyes with various preoperative characteristics.