Colour vision in a family with butterfly-shaped pigment dystrophy of the fovea

Abstract

Colour vision was examined in 11 members of a family in which three members had butterfly-shaped pigment dystrophy of the fovea in both eyes. Colour vision was tested with the Standard Pseudoisochromatic Plates part 2, the Farnsworth-Munsell 100-hue (FM 100) test, Nagel anomaloscope, and Color Vision Meter 712 anomaloscope. Eight members of the family had healthy eyes, normal visual fields and normal colour vision. Of the three members with butterfly-shaped dystrophy, one had slightly decreased visual acuity in both eyes (0.8), the two others had normal acuity in one eye but acuity of 0.4 and 0.5, respectively, in the other eye. All three had normal visual fields. During dark adaptation the rod threshold was slightly elevated in two members and normal in one. ERGs were measured in only one of the affected family members and they were normal. In all colour vision tests, the results of the three affected family members were within the normal ranges. However, in the FM 100 test, the error scores increased in all three patients during the 3-year follow-up period: two had error scores at the upper normal limit. The FM 100 test seems to be the best colour vision test for follow-up studies in slowly progressive foveal dystrophies such as butterfly-shaped dystrophy.KeywordsRetinal Pigment EpitheliumColour VisionError ScoreColour Vision DeficiencyNormal Visual FieldThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.