CASE REPORT: Two sisters of 54 and 60years old, with a history of diabetes and deafness, consulted for decreased visual acuity (VA). Funduscopic examination revealed patchy areas of chorioretinal atrophy with annular arrangement around the fovea. Genetic study identified the heteroplasmic mutation 3243A>G in mitochondrial DNA, which supports syndrome maternally inherited diabetes and deafness (MIDD) or Ballinger-Wallace disease.DISCUSSION: The finding of such macular disorders, especially in the presence of diabetes mellitus and deafness, should suggest the performing of a mitochondrial genome screening to identify this unusual syndrome.