Routine clinical measurement of spectral contrast sensitivity is hampered by the time consumption of current methods.
We are developing a system that allows instantaneous measurement of spectral contrast sensitivity.
The UCST system consists of custom software running on an iPad connected to a calibrated TFT-monitor. Twenty
healthy subjects were consecutively randomized to have their spectral contrast sensitivity measured with the UCST
strategy or with a Vistech VCTS 6500 chart. The examination time and the spectral contrast sensitivity, respectively,
were recorded for each eye in each subject.
The Vistech strategy resulted in a more extended mean examination time (CI-Vistech:± (0.95) = 87 ±27 s, d.f. = 9) than the UCST strategy (CI-UCST:μ (0.95) = 13 ±4 s, d.f. = 9), and the estimated mean difference between the two strategies
indicated a difference in examination time (CI-difference:μ (0.95) = [47;106] s, d.f. = 18).
The overall contrast sensitivity for each group was estimated as the contrast sensitivities for the spatial frequencies
sampled, integrated over the spatial frequency band sampled. The Vistech strategy resulted in a higher estimated mean
overall contrast sensitivity (CI-Vistech:μ (0.95) = 116±24 log rel.·log [c.·deg-1], d.f. = 9) than the UCST strategy (CIUCST:
μ (0.95) = 74±14 log rel.·log [c.·deg-1], d.f. = 9), and the estimated mean difference between the two strategies indicated a difference in overall contrast sensitivity (CI-difference:μ (0.95) = [15;68] log rel.·log [c.·deg-1]), d.f. = 18). It is concluded that the UCST strategy measures spectral contrast sensitivity on the order of 7 times faster than the
Vistech strategy. The slightly lower overall contrast sensitivity recorded for the UCST strategy appeared to be due to a
limitation in dynamic range that can be overcome with improved design.