An unusual retinal pigment epitheliopathy endemic to the island of Guam.

An unusual retinal pigment epitheliopathy resembling ophthalmomyiasis interna posterior (OMI) is endemic to Guam. Sixteen percent of a sample of the indigenous population were found to have the retinopathy. Fifty-two percent of a group of individuals suffering from amyotrophic lateral sclerosis/Parkinsonism-dementia complex (ALS/PDC) were found to have the same retinopathy. Although the retinal appearance is similar to that caused by a subretinal parasite, a definite etiology has not been identified. Three case reports are presented as samples of the clinical presentation of the condition.