We thank the reader for showing interest in our article titled: “Pars Plana Vitrectomy versus three intravitreal injections of bevacizumab for nontractional diabetic macular edema. A prospective, randomized comparative study.”
Probably, the reader is unaware that Indian Journal of Ophthalmology is a well-reputed scientific journal, and all the articles published in the journal have to undergo a rigorous and well-structured peer review, which is been done by leaders in that particular subspecialty. Our manuscript also underwent peer review, and it was assessed on scientific and ethical parameters. Hence, we take exception of the reader labeling our methodology as “unscientific” and “conclusion questionable.”
Having said that we will attempt to answer some questions and points raised by the reader. The main point raised by the reader is regarding the inclusion of cases labeled as “refractory macular edema.” The reader is correct in his statement that there is no consensus or international definition for nontractional refractory diabetic macular edema (DME). The reader probably missed reading carefully our inclusion criteria which were very well laid down. The following inclusion criteria were applied: “(1) A confirmed diagnosis of diabetes mellitus, (2) clinical and angiographic evidence of DME refractory to laser photocoagulation (last laser session at least 3 months before being enrolled).” Hence, our cases of macular edema were refractory to laser.
The reader also missed to note a statement in our article (discussion section, para 1) which disclosed that “Only 4 eyes included in the study received anti-VEGF injections previously. All 4 eyes received only one anti-VEGF injection. They got this injection elsewhere (not in our hospital) and that also more than 3 months before being enrolled in the study.” Any retina physician would know that one isolated injection of antivascular endothelial growth factor (VEGF) does not change the course of diabetic retina disease.
The reader probably also missed our exclusion criteria which stated that we excluded cases with vitreomacular traction (VMT) syndrome evident on biomicroscopic examination and optical coherence tomography, and cases with a history of receiving laser or intravitreal injection of any anti-VEGF agent or steroids within last 3 months.
Hence, we feel that reader is not correct in his/their assumption and understanding of refractory macular edema cases enrolled in our study.
The reader is right to note that we excluded patients with VMT. The reader may not know this, but this was done on purpose. As we know that cases with VMT do not respond well with anti-VEGF and pars plana vitrectomy (PPV) is a definitive option in these cases. Including VMT cases in our study would have titled the results favorably toward the PPV group. Hence, to have a fair scientific comparison VMT cases were excluded.
We agree with the reader that indocyanine green (ICG) can be toxic, but at the time of planning this study, our institute was using ICG for the internal limiting membrane (ILM) peel. Although there are contradictory reports published in the literature regarding the use of ICG, we acknowledged the fact that ICG can influence final result in discussion section. The reader probably missed reading our discussion carefully regarding the use of Indocyanine dye. We have clearly mentioned in our discussion section that “…. the final visual result is affected by many variables like the dexterity of surgeon, dye used for ILM peel, the extent of ILM peel and cataract progression.”
The reader commented on intraoperative breaks in our PPV group. We encountered peripheral breaks in seven cases in PPV group and honestly reported that in our results. Probably, because our team of retina surgeons’ belief in extensive vitreous excision up to the periphery has something to do with that.
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Conflicts of interest
There are no conflicts of interest.
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