Adult vitelliform macular dystrophy: Morphology, Function and Follow–up

Abstract

Abstract: : Purpose: Adult vitelliform macular dystrophy (AVMD) was first described by Gass (1974) but is still often misdiagnosed. Large studies using recently developed morphological and functional diagnostic methods do not exist. Methods: The records of 67 consecutive AVMD patients (1994–2003) showing at least in one eye a central vitelliform lesion smaller than one disc diameter were reviewed regarding visual acuity, color vision, perimetry, RPE–autofluorescence, fluorescein angiography, EOG, full–field ERG and mfERG. Blood samples were taken for genetic analysis of the VMD2 and RDS/peripherin genes. Follow–up was available for 14 patients for a mean period of 3.6 years (1–6 years). Results: The mean age was 54.8 years. Visual loss was mild to severe. Color vision and visual field were normal in about half of the patients but presented defects with high variability in the other half of patients. Autofluorescence was increased centrally in 77% of the eyes. In the ERG recordings, the 30Hz flicker response was reduced in 71% of the eyes. MfERGs showed a marked central amplitude reduction in 62% of the eyes and a continual gradual normalization of the P1 amplitude towards the periphery. Mutational analysis in the VMD2 and RDS/peripherin genes revealed only in 1/24 patients a potentially disease–associated mutation in the RDS/peripherin gene in a single patient. The latter finding provides further evidence of genetic heterogeneity in AVMD. Conclusions: AVMD is characterized by late onset, slow progression, good prognosis and high variability of morphological and functional abnormalities resulting frequently in misdiagnosis. Findings from autofluorescence indicate lipofuscin accumulation in the yellow lesion. The electroretinographic recordings reveal a moderate generalized cone dysfunction with increased severity towards the fovea. Ophthalmoscopy, autofluorescence and recording of mfERG are prerequisites to correctly diagnose AVMD

Keywords: retinal degenerations: hereditary • retinal pigment epithelium • electroretinography: clinical