We thank the reader for showing interest in our article, “Pars plana vitrectomy versus three intravitreal injections of bevacizumab for nontractional diabetic macular edema. A prospective, randomized comparative study.”
As they have correctly mentioned, our study concluded that posttreatment decrease in central macular thickness (CMT) was more in pars plana vitrectomy (PPV) group and vision improvement more in intravitreal bevacizumab group. However, no statistically significant difference between the two methods was found. We have reported in our study, a better CMT after PPV, however, did not record corresponding better vision in the same group. Our study was not powered to analyze microstructural changes (e.g., Muller cell damage) and/or to document retinal sensitivity by way of microperimetry. Hence, we hypothesized that one of the reasons for not attaining better vision could be because of damage to photoreceptors during internal limiting membrane (ILM) peeling. We thank the reader for mentioning other reasons documented in published studies which reiterate our hypothesis and the fact that ILM peeling does cause anatomical and visual disturbances. However, there are contradictory reports published in scientific literature. A recent meta-analysis published by Nakajima et al. concluded that the visual acuity outcomes using PPV with ILM peeling versus no ILM peeling were not significantly different in diabetic macular edema. Kumagai et al. also reported that ILM peeling does not affect the postoperative best-corrected visual acuity significantly. Hence, we feel there is a need for larger randomized prospective studies to adequately address the effectiveness of PPV with ILM peeling on visual acuity outcomes in diabetic macular edema.
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1. Raizada S, Al Kandari J, Al Diab F, Al Sabah K, Kumar N, Mathew S. Pars plana vitrectomy versus three intravitreal injections of bevacizumab for nontractional diabetic macular edema. A prospective, randomized comparative study Indian J Ophthalmol. 2015;63:504–10
2. Nakajima T, Roggia MF, Noda Y, Ueta T. Effect of internal limiting membrane peeling during vitrectomy for diabetic macular edema: Systematic review and meta-analysis Retina. 2015;35:1719–25
3. Kumagai K, Hangai M, Ogino N, Larson E. Effect of internal limiting membrane peeling on long-term visual outcomes for diabetic macular edema Retina. 2015;35:1422–8