Ophthalmomyiasis interna posterior. Report of a case with optic atrophy.

PURPOSE: The prognosis for patients with ophthalmomyiasis Interna posterior is variable. In many patients the larva remains in the eye for years without inducing inflammation or loss of vision. Sometimes, however, the migrating larva involves the macula and optic nerve and results in permanent visual loss or even blindness. METHODS: Our patient presented with sudden painless loss of vision in the right eye that was caused by ophthalmomyiasis interna posterior. Hemorrhage of the optic nerve head suggested that the fly larva had entered the vitreous cavity from the optic nerve head. Subretinal tracts were sequelae of the subretinal migration of the organism. Sequential photographs documented the fly larva migration into the optic nerve head head from the vitreous cavity. The organism was removed by pars plana vitrectomy and retinectomy. RESULTS: In spite of the successful removal of the first stage fly larva, the visual acuity remained poor because of optic nerve atrophy. CONCLUSION: We suggest early removal of fly larvae to prevent damage and visual loss in cases of ocular myiasis interna posterior.

Onchocerciasis in Ecuador: ocular findings in Onchocerca volvulus infected individuals.

Little is known of the epidemiology and clinical picture of ocular onchocerciasis in South America. A survey of onchocercal eye disease was performed in the hyperendemic area of a rain forest focus of onchocerciasis in Esmeraldas Province in Ecuador. A total of 785 skin snip positive individuals from black and Chachi Amerindian communities were examined. The blindness rate attributable to onchocerciasis was 0.4%, and 8.2% were visually impaired. Onchocercal ocular lesions were seen in a high proportion of the study group: 33.6% had punctate keratitis, microfilariae in the anterior chamber and cornea were seen in 28.9% and 33.5% respectively, iridocyclitis was seen in 1.5%, optic atrophy in 5.1%, and chorioretinopathy in 28.0%. Sclerosing keratitis was not seen. The prevalence of all ocular lesions increased with age. Punctate keratitis was strongly associated with microfilarial counts in the cornea and chorioretinopathy was correlated with infection intensities in the cornea and anterior chamber. Chachi Amerindians had higher anterior chamber microfilarial counts and a greater prevalence of punctate keratitis than blacks though blacks had a greater prevalence of iridocyclitis and optic nerve disease. The pattern of ocular disease resembled rain forest onchocerciasis in west Africa with few severe ocular lesions in the anterior segment and all blinding lesions attributable to posterior segment disease.

Unilateral optic atrophy presumed secondary to schistosomiasis of the optic nerve.

BACKGROUND: Schistosomiasis, a parasitic disease, is endemic in many parts of the world. Schistosomal eggs may be found in almost any organ or tissue in the body, including the eye. The presence of schistosomal eggs in the eye can produce granuloma formation and inflammatory sequelae. METHODS: A 63-year-old male had contracted schistosomiasis 40 years earlier while on active military service in the Philippines. Schistosoma japonicum eggs were isolated from his stools and military records indicated that the disease responded well to treatment with antimony potassium tartrate. The patient has gradually lost vision with his left eye over 15 years without the benefit of a complete optometric and medical diagnosis. RESULTS: CT scan suggested the likelihood of "subtle changes in the left optic nerve medially, possibly related to tumor invasion." Further evaluation and coordinated clinical thinking with other eye and medical practitioners led to the suspected diagnosis of schistosomal granuloma in the left optic nerve. In addition, the patient was legally blind from the consequences of glaucoma and its surgical intervention in his fellow eye. CONCLUSIONS: Although over 200 million people are infected with schistosomiasis, the United States is not an area where schistosomiasis is endemic. It is, however, endemic in parts of South America, Africa, Asia and the Caribbean Islands. Patients who have been in endemic areas with unexplained ophthalmic findings or systemic findings that could be related to granuloma formation or inflammatory sequelae of disease should have schistosomiasis included in their differential diagnosis.