DARK-ADAPTATION IN PATIENTS WITH BEST VITELLIFORM MACULAR DYSTROPHY

Psychophysical dark adaptation studies were performed in six patients with Best vitelliform macular dystrophy (BVMD) using a Goldmann-Weeker s dark adaptometer. Prebleach thresholds were determined before obtain ing a postbleach full recovery curve. Unlike patients with Stargardt m acular dystrophy, all patients with BVMD showed a normal time to reach their baseline dark adapted thresholds after bleaching of their rod v isual pigment when tested in clinically normal appearing retina. Altho ugh a lipofuscin material accumulates within retinal pigment epithelia l cells in patients with either Best or Stargardt dystrophy, functiona l findings pertaining to recovery of rod dark adaptation thresholds as well as electro-oculogram light peak to dark trough ratios are differ ent in these two disorders.