Visual impairment in Finnish Usher syndrome type III
Article first published online: 2 DEC 2005
Acta Ophthalmologica Scandinavica
Volume 84, Issue 1, pages 36–41, February 2006
How to Cite
Plantinga, R. F., Pennings, R. J. E., Huygen, P. L. M., Sankila, E.-M., Tuppurainen, K., Kleemola, L., Cremers, C. W. R. J. and Deutman, A. F. (2006), Visual impairment in Finnish Usher syndrome type III. Acta Ophthalmologica Scandinavica, 84: 36–41. doi: 10.1111/j.1600-0420.2005.00507.x
- Issue published online: 2 DEC 2005
- Article first published online: 2 DEC 2005
- Received on November 17th, 2004. Accepted on April 19th, 2005.
- Usher syndrome;
- retinitis pigmentosa;
- phenotype−genotype correlation;
- visual field deterioration;
- functional vision score
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.