Pars plana vitrectomy versus three intravitreal injections of bevacizumab for nontractional diabetic macular edema: A prospective, randomized comparative study.

Dear Sir,

We read with interest the paper “Pars plana vitrectomy versus three intravitreal injections of bevacizumab for nontractional diabetic macular edema (DME). A prospective, randomized comparative study” written by Raizada et al.[1] They found that both 3 monthly injection of bevacizumab and vitrectomy with internal limiting membrane (ILM) peeling is equally effective in vision gain and macular thickness reduction. They did not observe any serious adverse effects in both study arms. Interestingly, they showed that macular thickness reduction is more profound in the vitrectomy group with an earlier maximum visual gain than bevacizumab group. They mentioned that ILM peeling may cause further photoreceptor damage which we think needs further elaboration. Recently, Ripandelli et al. evaluated the functional outcomes of ILM peeling in patients with idiopathic epiretinal membrane in a comparative study and showed that mean retinal sensitivities on microperimetry in 4° and 12° central subfields were significantly lower in ILM peeled group.[2] Moreover, they demonstrated significantly higher number of absolute microscotomas in 12° central subfield during the 12-month follow-up. Romano et al. reported that ILM peeling may cause further damage to Müller cells, and collapse of intraretinal scaffold which can be seen as submacular atrophy in nontractional DME) cases.[3] Yoshikawa et al. investigated topographical changes after ILM peeling in DME patients and showed macular displacement toward the optic disc.[4] This may have some functional implications such as impaired fixation characteristics or stereopsis. All these observations prove that not only distance visual acuity but also other components of the visual function need to be considered.

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