Barbara Parolini, MD (Verona, Italy), Giacomo Panozzo, MD (Verona, Italy), Fabio Patelli, MD (Milan, Italy)


This is a three-centers prospective clinical trial on diffuse, non-tractional diabetic macular edema comparing the effects of simple vitrectomy (core PPV with PVD creation if necessary; no ILM peeling, no triamcinolone, no laser) with natural history in a matched control group of eyes. Study design and one year preliminary results will be discussed.


Enrollment started in January 2005 and will close in June 2006. Patients will be followed for two years. We excluded eyes with any ophthalmic treatment in the previous eight months and eyes with macular edema associated with traction or foveolar hard exudates. A complete ophthalmic evaluation, OCT test and blood samples for basic glycemia, Hb1Ac, creatininemia and microalbuminuria were performed every three months. Fluorescein angiography with evaluation of amplitude of foveal avascular zone was tested at baseline and every six months. Eyes with VA =?40 letters at ETDRS chart at two meters were followed without any therapy, and below this value were randomized to vitrectomy or follow-up.


107 eyes of 76 patients have been recruited at 01.31.2006. Patients enrollment and data processing are not complete yet, but several issues are already available for the one-year follow-up. 1. Natural history. VA, retinal thickness and volume did not worsen in the vast majority of eyes. Among the group of eyes with low VA at baseline, 37% demonstrated a spontaneous significant improvement in VA. 2. Glycemia is strongly linked to the progression of the disease. Hba1c > 9% seems to be the cut off value associated with major visual and anatomic impairment. 3. Vitrectomy without any retinal manipulation or intravitreal steroid had no effect compared to natural history at one year, but higher numbers of eyes will be provided to confirm these data.


At one year follow-up, non-tractional diffuse DME demonstrates to be a fairly stable condition, sometimes leading to spontaneous improvement and tightly related to glycemic control. Given the small numbers of data processed at this moment, simple vitrectomy does not seem to improve the natural course of the disease. Follow-up will be prolonged for up to two years.