Title

AN UNUSUAL CASE OF MACULAR PATTERN DYSTROPHY

Summary

Purpose: to present a case of a 57 years old patient, with maternally inherited diabetes and deafness (MIDD), diagnosed after a routine eye exam. Methods: a female patient, with a macular scar seen in a routine eye exam were referred to the federal university of São Paulo. The patient had no visual acuity complaint, but had a familiar history of diabetes and hearing loss. A complete ophthalmologic exam, retinal autofluorescence, fluorescein angiography, optical coherence tomography and retinal color photos were performed. The patient presented with macular areas of atrophy, with no hemorrhages, resembling a macular pattern dystrophy in the left eye. Further investigation with genetic test found a substitution of Guanine(G) for Adenine(A) at position 3243 of leucine transfer RNA in the mitochondrial DNA. Compatible with a maternally inherited diabetes with a macular pattern dystrophy. Discussion: This type of diabetes is rare, comprising 1% of all diabetes. Not all of the patients present with diabetes symptoms or macular lesions. It`s an autosomal dominant inherited disease, and despite the macular lesions, most of the patients maintain a good visual acuity. The same 3243 mutation is responsible for other phenotype called MELAS (mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes). Probably the proportion of mutant and normal mitochondria could be a factor to these different phenotypes. The retinal damage is not fully comprehended, but it could be due to the retinal pigmented epithelium high energy demand. In conclusion, genetic counseling plays an important role to this patient and there still no effective treatment to the eye pathology, despite the diabetes clinical control.

Area

CLINICAL CASE

Authors

Murilo Ubukata Polizelli, Kim Kayat, Nathalia Corbelli, Octaviano Magalhaes Junior