Abstract
Purpose :
Testing for contrast sensitivity (CS) loss is valuable given its impact on visually-mediated tasks and to monitor ocular disease progression. The Pelli-Robson (PR)(a gold standard CS test) requires an in-person visit and that patients know the English alphabet. The SpotChecks (SC) CS test does not require this and may be feasible to complete remotely. SC has not been widely evaluated in people with visual impairment (VI). We evaluated the agreement between CS measurements on the PR and SC charts across a range of VI levels.
Methods :
Better-eye distance visual acuity (VA) and binocular logCS measurements with the PR and SC tests were obtained using standard protocols in 25 subjects with VI due to various ocular diseases (mean age 70 years; range 55-89) enrolled in the Community Access Through Remote Eyesight (CARE) study. 95% limits of agreement (LoA; +/-1.96xSD) between the PR and SC tests were assessed according to subgroups for VA and age.
Results :
As expected, the SC test overestimated logCS across all subjects when compared to the PR test since SC does not require optotype discrimination. Mean differences in logCS between tests were -0.16 (95% LoA:-0.64,+0.35; p=0.01) for VA <0.55 logMAR (n=13) and -0.12 (95% LoA:-0.43,+0.24; p=0.004) for VA 0.55-1.00 logMAR (n=7), these between-test differences were significant. For 5 subjects with VA >1.0 logMAR, the mean difference of -0.45 and LoA were larger (95% LoA:-1.31,+0.41; p=0.03). Mean differences between CS tests also increased significantly with age. The mean difference was -0.12 logCS (95% LoA:-0.40,+0.15; p=0.01) for ages 55-65 years (n=9), -0.20 (95% LoA:-0.80,+0.38; p=0.04) for ages 66-75 (n=8), and -0.25 (95% LoA:-1.10,+0.59; p=0.05) for ages 77+ (n=8). Age and VA were not significantly related (p=0.78).
Conclusions :
The LoA between the PR and SC tests were largest in those with severe VI or the oldest subjects with VI. The 95% LoA between the PR and SC tests in all VI groups were larger than those of normally-sighted young adults in prior literature, reported as −0.24 to 0.09 right eye and −0.23 to 0.14 left eye. SC could be valuable in remote assessment and in patients with language barriers, illiteracy and aphasia, but SC results are not comparable to the PR. Future directions include evaluation in a larger sample (enrollment ongoing), assessment of test-retest repeatability and examining differences by ocular diagnosis.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.