Vitrectomy with peeling retinal limiting membrane (ILM) in eyes with diabetic macular edema

Purpose
to evaluate the efficacy of pars plana vitrectomy with retinal internal limiting membrane (ILM) peeling in eyes with diabetic macular edema.

Material and methods
Twenty five eyes of 25 patients with diabetic macular edema. All eyes underwent a pars plana vitrectomy including separation of the posterior hyaloid, ILM peeling and air endotamponde. Preoperatively visual acuity (VA), funduscopic examination and the presence or absence of posterior vitreous detachment, were evaluated. Fluorescein angiography was performed in all patients prior to surgery. Eyes with cystoid macular edema or macular ischaemia were excluded. Postoperative VA, anatomic results, and complications were recorded. The follow-up was 7 to 27 months (mean 17).

Results
Intraoperatively, thick posterior hyaloid was found to be attached to the posterior pole in 20 cases. The mean postoperative VA (0.2) was significantly better than the preoperative VA (0.08) (p=0.0001). VA improved postoperatively in 21 eyes (84%), at least two lines on the Snellen chart in 8 eyes (32%). It remained unchanged in 4 eyes (16%). Confluent hard exudates in fovea were present significantly more frequently in eyes without VA improvement (p=0.004). The postoperative VA was better in eyes that had not undergone photocoagulation (improvement by 0.14 line) than in others (improvement by 0.11 line) but the difference was non-significant. Reduction of macular exudates was noted in every case in the follow-up over 6 months. Postoperative complication included retinal detachment were treated by re-vitrectomy with oil endotamponade. Cataract has been noted in six eyes.

Conclusions
Vitrectomy including removal of ILM in diabetic macular edema, leads to improvement of visual acuity and longterm stabilization of visual function.