Author's Reply.

Dear Sir,

We thank the authors for their interest in our study.[1] We agree with the comment made by the authors.

The incidence of hypoxic ischemic encephalopathy (HIE) is on the rise[2] and may be greater than that mentioned in our article, but our study looked at the prevalence of HIE amongst patients diagnosed to have optic atrophy and not in the general population, hence the overall estimation of incidence of HIE is beyond the scope of the current study.

We also agree that HIV infection is a known cause of optic nerve atrophy, but in our practice we do not routinely screen all patients with optic atrophy for HIV. Investigations for HIV are considered only if neuroimaging and second line investigations yield no results or if there are other systemic or ocular features, which may arouse a suspicion of HIV. Socioeconomic concerns also limit such investigations in many cases. The reasons mentioned above and the fact that our study was limited to children under the age of 16 years may partially explain the absence of any patients with HIV in our cohort.