The reliability of the Pelli-Robson contrast sensitivity chart.
Normative contrast sensitivity (CS) data were obtained using the commercially available Pelli-Robson chart from the dominant eye of 30 young (mean (+/- SD) age 22.5 +/- 4.3 years) and 42 older (mean (+/- SD) age 70.2+/- 6.7 years) subjects with normal healthy eyes. The majority of young subjects were found to have a CS of 1.80 log units or above. The majority of the older subjects were found to have a CS of 1.65 log units or above. CS results were obtained using both sides (A and B) of the Pelli-Robson chart from 30 (15 young and 15 older) of these subjects. These measurements were repeated under identical conditions, 2 weeks later. There was no significant difference between the results from sides A and B of the chart. The CS scores were shown to be repeatable to within +/- 0.15 log units or +/- 1 step. Therefore a significant change in CS score is +/- 2 steps or 0.30 log units. Slight improvements in reliability could be obtained by more careful permutation of letters on each step and a smaller step size. The restriction against these changes is the ensuing increased chart size.
Elliott
D B
DB
Clinical Vision Research Unit, University of Bradford, West Yorkshire, UK.
Sanderson
K
K
Conkey
A
A
D000328:Adult; D000368:Aged; D015350:Contrast Sensitivity; D006801:Humans; D015203:Reproducibility of Results; D014787:Vision Tests / Q000295:instrumentation*