Night Blindness, Ring Scotoma, and a Nonrecordable Electroretinogram in an Elderly Woman

A woman in her 70s and of Korean descent reported difficulty seeing in dimly lit settings for the past 6 years and was referred for evaluation. Her medical history was remarkable for long-standing hypertension, diabetes, and mixed connective tissue disease. On examination, the best-corrected visual acuity was 20/40 OD and 20/25 OS. Slitlamp examination showed prominent nuclear sclerosis and a posterior subcapsular cataract in the right eye and a well-positioned intraocular lens in the left eye. Ophthalmoscopic examination revealed bilateral pigment mottling with extensive peripheral depigmentation of the retinal pigment epithelium, sparing the central fovea bilaterally. Spectral-domain optical coherence tomography showed complete loss of photoreceptors outside the fovea, with retinal pigment epithelial atrophy, irregular proliferation, and some remodeling (Figure, A). Fundus autofluorescence showed a ring of parafoveal hypofluorescence and hyperfluorescence, with speckled hypofluorescence peripherally (Figure, B). Goldmann perimetry of both eyes (Figure, C) revealed significant constriction of the V-4-e isopter with an extensive ring scotoma between approximately 10° and 30° eccentricity. Central vision with the I-4-e isopter was constricted to 5° to 7°. A multifocal electroretinogram (ERG) showed profound signal attenuation throughout the examined area. The full-field electroretinogram was nonrecordable under both scotopic and photopic conditions.