Abstract
Purpose:
The ability to accurately monitor the disease status or improve the visual function of low vision patients requires reliable and repeatable vision tests. It is generally accepted that measures of visual function in the low vision patient population are more variable than normally sighted individuals. This may decrease the reliability of standard visual tests when applied to a population such as albinism. The purpose of our study is to determine whether one such test of visual function, contrast sensitivity, could reliably be measured in this population both in the presence of glare and without.
Methods:
CS was tested with Vector Vision CSV-1000 LV which is a low vision letter chart and the CSV-1000HGT (halogen glare test) which tests CS in the presence of glare. Thirteen subjects with albinism with best corrected logMAR visual acuity (VA) ranging from 0.4 to 0.9, participated in this study. LogMAR VA was tested using the EDTRS chart. Dependent variables including CS under normal test condition and CS with glare, were tested at two different visits, 3 months apart. The CSV-1000LV chart was used to measure CS while the CSV1000HGT was utilized to measure the effect of glare on CS. Test-retest reliability was assessed with the intraclass correlation coefficient (ICC).
Results:
A significant test-retest reliability was determined according to the ICC values calculated for both CS measured without and with glare (ICC=0.864, p<0.001; ICC=0.455, p= .048) respectively.
Conclusions:
CS in patients with albinism, as tested with Vector Vision CSV-1000LV and CSV-1000HG is repeatable and consistent, indicating that this test is a reliable tool for measuring visual function in this particular low vision population.
Keywords: 584 low vision •
478 contrast sensitivity