Abstract
Abstract: :
Purpose: 1) To evaluate whether vitrectomy has any benefit over Argon grid laser in improving visual acuity and resolving retinal thickening in patients with diabetic macular edema (DME) and no macular traction, and 2) to determine the feasibility of further trials in this population in terms of rate of recruitment and loss to follow up. Methods: A randomised controlled feasibility study. Patients with DME and a visual acuity of 0.3 logMAR or worse after one or more laser grid treatments were randomised on a 1:1 basis to either pars plana vitrectomy with ILM peeling (PPV) or further grid laser. Patients with a posterior vitreous detachment or biomicroscopic evidence of retinal traction, or a taut thickened posterior hyaloid were excluded. Primary outcome measures were 1) best–corrected logMAR visual acuity, 2) mean central foveal thickness on Optical Coherence Tomography and 3) rate of recruitment and loss to follow up. Analysis was on an intention to treat basis. Results: From a potential population of 2.3 million individuals, 117 patients were referred over the course of 18 months for consideration of inclusion in the trial. 40 patients were found to be eligible and 33/40 (82.5%) of these patients were followed up to 12 months. 19 patients were randomised to PPV and 21 to more grid laser.The mean baseline logMAR visual acuity (SD) was 0.65 (0.28) for the group randomised to PPV and 0.60 (0.23) for the group randomised to laser. At 12 months follow up the mean logMAR visual acuity (SD) was 0.72 (0.33) for the group randomised to PPV and 0.57(0.33) for the group randomised to laser. The mean baseline (SD) retinal thickness was 415(111)um for the group randomised to PPV and 394 (157)um for the group randomised to laser. At 12 months follow up the mean (SD) retinal thickness was 348 (210)um for the group randomised to PPV and 359 (154)um for the group randomised to laser. Conclusions:1)These data provide little evidence of any benefit of vitrectomy over macular laser in patients with DME and no macular traction in terms of visual acuity and macular thickness. 2)Randomised controlled trials are feasible in this population.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • diabetic retinopathy • vitreoretinal surgery