Acuity Comparison Methods via Timed Test-Retest Precision of Matching-Card e-ETDRS Compared to PDI Check in Treated Amblyopes and Superb Normals.

Purpose: Existing and emerging visual acuity methods like dynamic and dichoptic presentation, preferential looking and eye tracking promise to afford better and earlier assessment in children with and without amblyopia so we propose methods needed to easily evaluate and compare their metrics.

Subjects and methods: Patients older than 8 years with treated amblyopia and superb vision (logMAR -0.1 to -0.3) normals performed timed, patched eETDRS with Sloan matching card at 3.00 m and PDI Check dichoptic near rivalry dynamic test to demonstrate test re-Test and compared disparate acuity with intraclass correlation (ICC) and Bland Altman 95% limits of agreement (LOA) to generate a simple method of qualifying acuity test matching.

Results: 26 amblyopic patients and 11 superb-vision normals performed eETDRS retest, PDI Check retest and combined ICC of 0.98, 0.60 and 0.27, respectively, and Bland Altman LOA of 0.24, 2.06 and 2.28 logMAR. The time to test one eye with eETDRS had median (interquartile range; IQR) duration of 280 (205 to 346) seconds, while the PDI Check autostereoscopic dichoptic for both eyes only took 39 (30 to 47) seconds. Optimum ICC and LOA for visual acuity comparison should be >0.95 and <0.3 logMAR, whereas "good" ICC and should be 0.75-0.89 ICC and 1.0-1.49 logMAR LOA.

Conclusion: Superb vision subjects (logMAR < -0.1) and treated amblyopic patients confirmed optimum comparable eETDRS, and fair test re-Test PDI Check but suppression on near dichoptic testing confirmed disparity compared to optimized eETDRS distance acuity.