Visual impairment in Finnish Usher syndrome type III

Acta Ophthalmol Scand. 2006 Feb;84(1):36-41. doi: 10.1111/j.1600-0420.2005.00507.x.


Purpose: To evaluate visual impairment in Finnish Usher syndrome type 3 (USH3) and compare this with visual impairment in Usher syndrome types 1b (USH1b) and 2a (USH2a).

Methods: We carried out a retrospective study of 28 Finnish USH3 patients, 24 Dutch USH2a patients and 17 Dutch USH1b patients. Cross-sectional regression analyses of the functional acuity score (FAS), functional field score (FFS*) and functional vision score (FVS*) related to age were performed for all patients. The FFS* and FVS* were calculated using the isoptre V-4 test target instead of the usual III-4 target. Statistical tests relating to regression lines and Student's t-test were used to compare between USH3 patients and the other genetic subtypes of Usher syndrome.

Results: Cross-sectional analyses revealed significant deterioration in the FAS (1.3% per year), FFS* (1.4% per year) and FVS* (1.8% per year) with advancing age in the USH3 patient group. At a given age the USH3 patients showed significantly poorer visual field function than the USH2a patients.

Conclusions: The rate of deterioration in visual function in Finnish USH3 patients was fairly similar to that in Dutch USH1b or USH2a patients. At a given age, visual field impairment in USH3 patients was similar to that in USH1b patients but poorer than in USH2a patients.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Cross-Sectional Studies
  • Finland
  • Genotype
  • Humans
  • Middle Aged
  • Phenotype
  • Retrospective Studies
  • Usher Syndromes / genetics
  • Usher Syndromes / physiopathology*
  • Vision Disorders / physiopathology*
  • Visual Acuity / physiology*
  • Visual Field Tests
  • Visual Fields / physiology*