title: Retention of central visual field in retinitis pigmentosa.
abstract: According to Kanski, roughly one in four patients with retinitis pigmentosa retains visual acuity adequate for reading, although the electroretinogram may be extinguished and the visual field constricted to 2 to 3 degrees (whether diameter or radius is not stated). Under the age of 20 years, an acuity as poor as 6/60 is relatively uncommon, whereas over the age of 50 years such an acuity becomes common. Heckenlively comments that by the end of the 4th decade of life, most males with X-linked retinitis pigmentosa have vision reduced to hand motion or light perception. Women tend to be less severely affected than men: in a study by Bird, only 3 of 48 female heterozygotes had an acuity of less than 6/9, whereas only 8 of 28 hemizygous males had an acuity of 6/9 or better. I thought it would be instructive to analyze the visual field data for a female patient who, although she had suffered considerable loss of peripheral vision, is continuing to function visually quite well.
authors.affiliation: School of Optometry, University of Waterloo, Ontario, Canada.
authors.forename: T D
authors.initials: TD
authors.lastname: Williams
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D012174:Retinitis Pigmentosa / Q000503:physiopathology*; D014792:Visual Acuity; D014794:Visual Fields / Q000502:physiology*