Ocular sequelae of snakebite envenoming: a review of the indirect effects of snakebite envenoming on the eye

Snakebite envenoming is a major public health issue in developing, often agricultural-based, tropical countries, which causes substantial mortality and morbidity. Most studies have been conducted on well-known toxic effects such as neurotoxicity, cytotoxicity, and hemotoxicity, however, there is scarce information on their indirect effects on the eye. In this review, we provide an overview of ocular pathologies caused by snakebite envenoming. In total, 65 cases, described in 42 case reports and series, were identified in the PubMed and Embase databases. Most reported ocular toxicities/disorders after snakebite envenoming were ophthalmoplegia (12 cases), intra- and peri-ocular hemorrhages (9 cases), and acute glaucoma (13 cases). We also discuss the possible mechanisms for these ocular pathologies. Interestingly, optic neuropathy might be an adverse effect of antivenom instead of directly being caused by envenoming. We prompt recognition of this largely overlooked topic within the field of snakebite, and further stress the need to combat this neglected tropical disease.