Evaluation of Macular Function after Vitrectomy in Diabetic Macular Edema

Purpose: To document the effects of successful vitrectomy on retinal function and anatomy in diabetic patients. Methods: Three-port pars plana vitrectomy with detachment of posterior vitrous face was performed in 30 eyes of 25 patients with diabetic macular oedema DME (11 male, 14 Female).For each patients, visual acuity (VA) examination, measurement of retinal thickness using optical coherence tomography (OCT), full field electro-retinogram (ERG) and multifocal eletroretinogram (MF-ERG) were performed before and 1week,1month and 3months after vitrectomy. Results: Mean postoperative visual acuity was significantly improved (P<0.05); mean retinal thickness was significantly (P=0.001 ) decreased after 3monthes of surgery (from 450±150 into 220±50 micron ) .b-wave amplitudes of all cone and rod responses of ERG were significantly decreased in all vitrectomized eyes after 1 week. At one month, rod response was still unimproved but improved after 3months. Reduction in foveal Function as well as in para-foveal areas detected in the MF-ERG within 1st month. Then, mean P1 wave amplitude of MF-ERG of central ring increased and mean P1 wave implicit time decreased. These changes of MF-ERG parameters observed 3 months after vitrectomy. Conclusion: Multifocal electroretinogram can be useful to provide objective criteria for functional evaluation before and after vitrectomy in diabetic oedema.