Isolated optic neuritis from an identified Gnathostoma spinigerum

Ocular Gnathostomiasis Presenting as Branch Retinal Artery Occlusion

PURPOSE

To report a case of ocular Gnathostomiasis presenting as branch retinal artery occlusion.

METHOD

Observational case report.

RESULT

A 22-year-old Asian woman presented to her ophthalmologist with redness, tearing, and decreased vision in her left eye. Examination revealed anterior uveitis and branch retinal artery occlusion associated with both intra-retinal and vitreous hemorrhage. The patient was treated with topical corticosteroids and cycloplegics. After 3 weeks, she presented in our emergency, with further decrease in vision and worsening pain in the left eye. Slit lamp examination revealed a brown colored live worm on the posterior corneal surface, anterior uveitis, multiple iris holes, and vitreous cells. Indirect ophthalmoscopy showed focal retinal hemorrhages, subretinal tracts, and vitreous hemorrhage. Surgical removal of the worm from anterior chamber was done immediately.

CONCLUSION

Branched retinal artery occlusion with intraretinal and vitreous hemorrhage, panuveitis, and multiple iris holes may suggest the presence of an intraocular parasite.

Zoonotic helminths affecting the human eye

Nowaday, zoonoses are an important cause of human parasitic diseases worldwide and a major threat to the socio-economic development, mainly in developing countries. Importantly, zoonotic helminths that affect human eyes (HIE) may cause blindness with severe socio-economic consequences to human communities. These infections include nematodes, cestodes and trematodes, which may be transmitted by vectors (dirofilariasis, onchocerciasis, thelaziasis), food consumption (sparganosis, trichinellosis) and those acquired indirectly from the environment (ascariasis, echinococcosis, fascioliasis). Adult and/or larval stages of HIE may localize into human ocular tissues externally (i.e., lachrymal glands, eyelids, conjunctival sacs) or into the ocular globe (i.e., intravitreous retina, anterior and or posterior chamber) causing symptoms due to the parasitic localization in the eyes or to the immune reaction they elicit in the host. Unfortunately, data on HIE are scant and mostly limited to case reports from different countries. The biology and epidemiology of the most frequently reported HIE are discussed as well as clinical description of the diseases, diagnostic considerations and video clips on their presentation and surgical treatment.