Vitrectomy results in diabetic macular oedema without evident vitreomacular traction

Purpose: To determine the effectiveness of vitrectomy in eyes with diabetic macular oedema without evident traction from a thickened vitreous membrane . Methods: Twenty-one consecutive eyes from 19 patients with diabetic macul ar oedema that had undergone vitrectomy were analysed retrospectively. All eyes had an attached posterior hyaloid membrane in the macular region, but without thickening and without evident traction on the macula. A standard p ars plana vitrectomy with the creation of a posterior vitreous detachment w as performed. Results: Median duration of macular oedema at the time of vit rectomy was approximately 11.0 months (range 2-36 months). The median preop erative best-corrected visual acuity of 0.08 (range hand motions/0.003 to 0 .4), improved by 5 lines to a median final postoperative best-corrected vis ual acuity of 0.25 (range 0.025-0.5) (P=0.001). Seven eyes without preopera tive macular photocoagulation had a median visual acuity improvement of 77% , range 32-400%, while 12 eyes with preoperative macular laser treatment ha d a median visual acuity improvement of 14.8%, range 0-66.1% (P=0.02, CI 95 %, after multivariate regression analysis). In all 21 eyes, macular oedema was no longer visible on microscopic examination after a median period of 3 .0 month's (range 1-9 months) after vitrectomy. Conclusions: In eyes with d iabetic macular oedema without evident macular traction front a thickened v itreous membrane, vitrectomy resulted in the resolution of macular oedema, with an improvement in visual acuity in the majority of cases. Eyes without preoperative macular photocoagulation had a significantly higher percentag e visual improvement than eyes without preoperative macular laser treatment . A randomised controlled prospective trial of primary vitrectomy versus ma cular photocoagulation is needed to determine the role of vitrectomy as tre atment modality fur diabetic macular oedema.