Abstract
Purpose :
To evaluate whether various scoring methods can improve repeatability of SpotChecks and the effect of age on repeatability and contrast sensitivity (CS) measured by Spot-Checks and near Pelli-Robson (PR) tests.
Methods :
61 healthy adults (age 22-84, mean 49±18, M:F=32:29) were tested in one eye using habitual correction during two office visits (mean 10±8 days apart). Each visit included a high-contrast acuity, then in random order, 6 different SpotChecks and 6 different PR charts under the same lighting (luminance 110 cd/m2). SpotChecks consists of 24 lines of 5 gray round spots (9 mm size) on a white paper. The contrast decreases 0.01 per spot (logCS ranges 0.90-2.09). Subjects marked all visible spots with guessing encouraged at habitual reading distance. Five scoring methods were used to determine the logCS: the highest line with ≥2 errors (S1), the 2nd, 3rd, or 4th incorrectly marked spot for S2, S3, S4, respectively, and two consecutive errors (S5). PR charts were tested at 40 cm and scored as [0.05*number of correct letters-0.15]. Repeatability is defined as the within-subject standard deviation (Sw) calculated with one-way analysis of variance. The effect of age on repeatability and scores of logCS was evaluated with linear regression.
Results :
Compared to S1, scoring methods S2, S3 and S4 showed better intravisit repeatability (Sw=0.048 to 0.057) but only Sw of S4 visit2 reached statistical significance. Results below were based on S1. Intravisit repeatability was similar for SpotChecks (0.061 visit1, 0.060 visit2) and PR (0.058 visit1, 0.055 visit2). Standard deviation of 6 logCS measurements was not associated with age for SpotChecks or PR in both visits (p>0.3 for all). Linear regression of logCS on age showed a slope of -0.0015/year (p<0.05) for both SpotChecks and PR. Mean logCS was 0.06 lower (p<0.05) in those ≥50 years (n=31, SpotChecks 1.84±0.10, PR 1.77±0.10) than those <50 years (n=30, SpotChecks 1.90±0.07, PR 1.83±0.07). Intervisit repeatability improved (p < 0.05) by averaging 4 or more trials in each visit: Sw=0.063 (1 trial) vs 0.045 (4 trials) for SpotChecks, 0.066 (1 trial) vs 0.051 (4 trials) for PR.
Conclusions :
Intervisit repeatability of SpotChecks and PR is similar and improves by averaging repeated measurements at each visit. Age in healthy adults did not show clinically significant effect on the repeatability or contrast sensitivity measured by SpotChecks or PR tests.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.