Long-Term Outcome after Vitrectomy for Diabetic Macular Edema

Abstract
To determine the benefit of vitrectomy on eyes with diabetic macular edema. A retrospective institutional case series was used including 66 patients (69 eyes) who had undergone pars plana vitrectomy for diabetic macular edema between 1992 and 2000. Prior to surgery, the patients had been treated with laser coagulation as recommended by the Early Treatment Diabetic Retinopathy Study. In the case of persistent macular edema, vitrectomy with removal of the posterior hyaloid in all cases and the inner limiting mem brane in 51 (74%) of all cases was performed. The mean preoperative best-corrected visual acuity improved from 20/320 to 20/80 at the time of best postoperative best-corrected visual acuity (p < 0.0001). The mean increase in Snellen lines was 2.7 +/- 7.9. In 90% of eyes, the macular edema improved. A persistence of the edema was observed in 10%. All eyes had at least 12 months of follow-up with a mean of 55 months and a maximum of 120 months. Our findings confirm that vitrectomy might represent a therapeutic alternative in the case of persisting diabetic macular edema after laser photocoagulation.