Bilateral Simultaneous Optic Neuritis Following Envenomations by Indian Cobra and Common Krait

Abstract

In India, most snakebite envenomation (SBE) incidents are caused by the “Big Four” snakes which include Russell’s viper, common krait, Indian cobra, and saw-scaled viper. Their common envenomation effects include neurotoxicity, myotoxicity, and coagulopathy. However, they also induce rare complications such as priapism, pseudoaneurysm, and sialolithiasis. Ocular manifestations such as optic neuritis develop rarely following envenomations by non-spitting snakes and they may cause temporary vision changes and blindness if untreated. While optic neuritis following Indian cobra envenomation has been reported previously, this was not encountered in victims of common kraits. Hence, for the first time, we report optic neuritis developed in a victim following envenomation by a common krait and compare its clinical features and diagnostic and therapeutic methods used with another case of optic neuritis in a victim of an Indian cobra bite. Both patients received antivenom treatment and made an initial recovery; however, optic neuritis developed several days later. The condition was diagnosed using ophthalmic examination together with computed tomography and/or magnetic resonance imaging methods. Due to very similar clinical features, both patients received intravenous corticosteroids which restored their vision and successfully treated optic neuritis. This case report suggests that the optic neuritis developed in a common krait envenomation is comparable to the one developed following a cobra bite, and therefore, the same diagnostic and therapeutic approaches can be used. This study also raises awareness of this rare complication and provides guidance for the diagnosis and treatment of SBE-induced optic neuritis.

Comment on Senthilkumaran et al. Bilateral Simultaneous Optic Neuritis Following Envenomations by Indian Cobra and Common Krait. Toxins 2022, 14, 805

“…It is with interest that I read the case report by Senthilkumaran et al [ 1 ], in which the authors described two cases of severe optic neuropathy following envenomation by an Indian cobra ( Naja naja ) and a common krait ( Bungarus caeruleus ). Both patients were treated with antivenom due to systemic envenomation, but developed bilateral optic neuropathy four and five days after the bite regardless.…”

Reply to Jalink, M.B. Comment on “Senthilkumaran et al. Bilateral Simultaneous Optic Neuritis Following Envenomations by Indian Cobra and Common Krait. Toxins 2022, 14, 805”

“…We thank the author for showing interest in our article [ 1 ] and proposing antivenom as a potential cause for the snakebite-induced bilateral optic neuritis that we reported in two snakebite victims [ 2 ]. Our primary aim of this article was to report the “polo mint” appearance that we observed using MRI in those patients and to emphasise the necessity for early diagnosis using sophisticated techniques such as MRI and treatment with corticosteroids to promptly tackle this condition.…”