Evaluation of the SpotChecks contrast sensitivity test in healthy adults

Abstract Purpose SpotChecks is a new contrast sensitivity (CS) test designed for self‐monitoring of vision. This study assessed the test–retest repeatability of take‐home SpotChecks, in‐office SpotChecks and near Pelli–Robson charts in healthy adults. Methods One eye of 61 healthy adults with near visual acuity (VA) of 6/9 or better (age range 22–84, mean 49 18 years) was tested during two office visits (mean 10 8 days apart). Each visit included high‐contrast VA, then 12 randomly ordered CS tests (6 different SpotChecks and 6 different Pelli–Robson) under the same lighting (luminance 110 cd/m 2 ), all at near in the same eye with habitual correction. The same eye was self‐tested with take‐home SpotChecks once a day on 6 days between the office visits. SpotChecks was scored by the logCS at the highest line with ≥2 errors. Pelli–Robson was scored by 0.05 × number of letters read correctly − 0.15. Repeatability of logCS was defined as 1.96 S w , S w representing within‐subject standard deviation. Comparison for repeatability was performed with Bootstrap hypothesis test. Results SpotChecks and Pelli–Robson showed similar intra‐session or inter‐visit repeatability ( p = 0.14–0.81). Inter‐day repeatability for take‐home SpotChecks was 0.18 logCS, the same as that from the first measurements of two office visits with SpotChecks or Pelli–Robson. Inter‐visit repeatability improved to 0.15 by using the average of two repeated measurements for SpotChecks ( p = 0.02) or three repeated measurements for Pelli–Robson ( p = 0.04). Age showed a small effect on logCS (−0.015/decade, p = 0.02) for both SpotChecks and Pelli–Robson. Mean logCS was 0.05 lower in those ≥50 years (SpotChecks 1.84 0.10 and Pelli–Robson 1.77 0.10) compared with those <50 years of age (SpotChecks 1.89 0.07 and Pelli–Robson 1.83 0.07). Conclusions SpotChecks showed good repeatability with take‐home and in‐office testing in healthy adults, making it a promising tool for monitoring disease progression at home.