Ocular angiostrongyliasis in Thailand: a retrospective analysis over two decades

PURPOSE: To elucidate the clinical manifestations, management, and visual outcomes of patients with ocular angiostrongyliasis. METHODS: This was a single-center retrospective study of patients with ocular angiostrongyliasis presenting between 1995 and 2017 at Srinagarind Hospital, Khon Kaen, Thailand. Cases were found based on a search of diagnostic codes. A total of 18 patients were diagnosed through identification of the Angiostrongylus cantonensis parasite within the eye. Medical records and ocular photography were reviewed. RESULTS: There were 18 cases, with a mean age of 40.7±14.2 years. All patients had a history of raw food ingestion, such as snails. Most of the patients presented with blurred vision: 13 cases (72.22%) had best-corrected visual acuity of 2/60 or worse. Only one living larva was detected in each case. The size of larvae varied widely from 2.6–12.6 mm in length. Larvae were commonly detected in the vitreous cavity. Although multiple treatment modalities were used, including focal laser, surgery, antihelminthic drugs, and steroid treatment, the majority of cases (70.6%) did not have visual improvement. CONCLUSION: Focal laser is recommended to eradicate subretinal angiostrongyliasis, while laser treatment prior to surgical removal is recommended to eliminate intracameral and intravitreal angiostrongyliasis. Pulse methylprednisolone therapy may be beneficial in cases of acute optic neuritis. The visual prognosis mainly depends on ocular pathology and parasitic migration pathway.