Decreasing outer retina traumatism of ILM peeling in diabetic eyes with foveal sparing technique

Purpose: To evaluate the effect on outer retina integrity of foveal sparing internal limiting membrane (ILM) peeling compared to standard ILM peeling on proliferative diabetic retinopathy (PDR) eyes affected by diabetic macular edema (DME) and epiretinal membrane (ERM). Materials and methods: Eyes diagnosed with PDR, DME and ERM eligible for vitrectomy were prospectively recruited and randomly assigned to either foveal sparing (FS) group and no foveal sparing (nFS) group. Ellipsoid zone (EZ) lesion size, EZ reflectivity and external limiting membrane (ELM) integrity and angular sign of Henle Fiber Layer Hyperreflectivity (ASHH) were assessed preoperatively and 1 year postoperatively. Results: Twelve (12) eyes and fifteen (15) eyes were included in FS and nFS group respectively. The two groups showed no differences in terms of EZ lesion size (p=0.549), EZ reflectivity (p=0.657) and ELM integrity (0.999) at preoperative examination. A significant increase in EZ lesion size was noted in nFS group between preoperative and postoperative examination (p=0.040) which was not present in FS group (p=0.862). Moreover, nFS group showed a higher prevalence of ASHH and a lower EZ reflectivity at follow up compared to FS group (respectively p=0.047 and p=0.041). Conclusions: Vitrectomy with FS ILM peeling may result in a better preservation of the Muller-photoreceptors complex in PDR complicated with DME and ERM.