Blind Spot Enlargement Syndrome

We report five patients with unilateral blind spot enlargement. All patients had visual acuity of 20/25 or better, normal color vision (Ishihara plates), a relative afferent pupillary defect, and flat optic nerve heads. All five patients were young to middle-aged women seen prospectively by the author for painless loss of vision. Four patients had acute onset of symptoms, and the clinical course appeared to be nonprogressive. In the remaining patient, the onset was gradual, and the visual loss has continued to progress. Standardized electro retinogram (ERG) in these patients ranged from mild to severe unilateral reductions in rod and cone responses.