["Oligocone" trichromasy, a rare form of incomplete achromatopsia]

Ophthalmologe. 1997 Nov;94(11):801-6. doi: 10.1007/s003470050207.
[Article in German]


Patients and methods: An 11-year-old girl presented because of reduced visual acuity while color vision was almost normal. Besides a general ophthalmological examination, special psychophysical tests, such as perimetry, color vision tests using pseudoisochromatic plates, arrangement tests, the Nagel anomaloscope and spectral sensitivity measurement, and electrophysiological tests (electroretinogram and electrooculogram) were conducted.

Results: The tests yielded the following: congenital nystagm, normal results at ophthalmoscopy, best visual acuity of 0.1 monocular and 0.2 binocular. Perimetry revealed a relatively central scotoma. All color vision tests showed only mild dysfunction of the blue-sensitive cones. Findings at photopic electroretinogram were almost completely lacking. There was no sign of progression in the last 6 years.

Conclusion: Differential diagnosis includes all diseases associated with congenital nystagm, such as aniridia, diseases of the optic nerve, albinism and all forms of hereditary cone dysfunction, cone dystrophies and complete and incomplete congenital stationary monochromatism. In the present case the findings are most congruent with oligocone trichromasy.

Publication types

  • Case Reports
  • English Abstract
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Color Perception Tests
  • Color Vision Defects / diagnosis
  • Color Vision Defects / genetics*
  • Color Vision Defects / physiopathology
  • Diagnosis, Differential
  • Female
  • Humans
  • Nystagmus, Pathologic / diagnosis
  • Nystagmus, Pathologic / genetics
  • Nystagmus, Pathologic / physiopathology
  • Retinal Cone Photoreceptor Cells / abnormalities*
  • Retinal Cone Photoreceptor Cells / physiopathology
  • Vision, Binocular / physiology
  • Visual Acuity / physiology
  • Visual Field Tests