Response to comment on: Intravitreal anti-vascular endothelial growth factor with and without topical non-steroidal anti-inflammatory in centre-involving diabetic macular edema.

Dear Editor,

We would like to thank the authors for their interest and comments on the article ‘Intravitreal anti-vascular endothelial growth factor with and without topical non-steroidal anti-inflammatory in centre-involving diabetic macular edema.’[12]

The role of topical Non-steroidal anti-inflammatory drugs (NSAIDs) in preventing macular edema after cataract surgery in patients with diabetes is well established.[3] Likewise, there is evidence that topical NSAIDS can minimize macular edema and stabilize visual acuity following pan retinal photocoagulation (PRP) for diabetic patients.[4] Its role as an alternative to the current standard of care, which is intravitreal anti-VEGF, has been explored in a few pilot studies, with conflicting results.[56] Even the role in non-center-involving diffuse macular edema (DME) has not been established with certainty.[7]

We agree with the authors that a prospective, randomized control trial would undoubtedly be more ideal. Even the studies suggested by the authors to suggest topical NSAIDS are conference proceedings, small pilot studies, and retrospective design studies.[89]

We thank the authors for pointing out problems regarding the sample size. We did a post hoc analysis for the power calculation regarding the sample size and a post hoc power of 97.2% was obtained. The minimum sample size required to gain 80% power was 16 in group 1 and 32 in group 2 and we had more than that in both groups.

Due to the inherent retrospective design of our study with limited systemic data availability, we could not analyze the systemic confounders which could influence the study results. The sub-group analysis of intravitreal biosimilar and ranibizumab was not possible as dividing them into subgroups led to smaller samples in the groups to give a meaningful result.

We agree that in a developing country like India, we need a more cost-effective option for managing CI-DME. Based on the existing body of literature, topical NSAIDS cannot be used as an alternative. We demonstrated that its role as an adjuvant to the existing standard of care is also questionable. Laser photocoagulation remains an alternative option in resource-limited settings.[10]

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Conflicts of interest

There are no conflicts of interest.