Background: A pigment epitheliopathy that resembles ophthalmomyiasis interna occurs in approximately 10% of a large sample of the Chamorro population of Guam age 39 years or older; the rate is approximately 50% among those who have amyotrophic lateral sclerosis or Parkinsonism-dementia complex (lytico bodig).
Methods: Since publication of an earlier clinical report of affected patients, several of them have died of their neurologic disease, and their eyes were obtained for pathologic study. This is the first pathologic report of the retinal pigment epitheliopathy seen in the setting of amyotrophic lateral sclerosis/Parkinsonism-dementia complex of Guam and is based on examination of 13 eyes from 7 patients.
Results/conclusion: Focal areas of attenuation of the retinal pigment epithelium in association with a reduced amount of intracellular pigment correlated with the funduscopic and gross appearance. No larvae were seen, and there was no evidence of inflammation. The pathogenesis of this pigment epitheliopathy remains undetermined.