Visual Performance of People With Albinism Assessed With Generalizable and Adaptive AIM and FInD Methods.

Purpose: People with albinism (PwA) are known to have visual impairments; however, little is known about whether these functions are disrupted across earlier and later stages of the visual pathway. We investigated distinct perceptual functions and fixation stability within each observer and compared the data with age- (±5 years) and sex-matched controls. Methods: Twenty-one self-reported PwA and twenty-one controls were recruited. Angular-indication measurement (AIM) and foraging-interactive-D-prime (FInD) psychophysical methods were deployed to measure OS, OD, and OU near visual acuity, spatial contrast sensitivity function (CSF), temporal contrast sensitivity (tCS; 0.5 c/°; horizontal grating: 0, 1, 2, 4, and 8 Hz), OU glare acuity, threshold-versus-contrast (2c/° vertical grating), long, medium, and short wavelength cone-isolated color detection, color discrimination, stereoacuity across spatial frequencies (1c/°, 2c/°, 4c/°, 8c/°), horizontal, circular, radial pattern and motion coherence, and equivalent-noise motion detection. Thresholds were determined by AIM and FInD and compared using N-ANOVAs, t-tests, planned multi-comparisons, correlations, and unsupervised, agglomerative hierarchical cluster analysis for each group. Results: We found significant differences between groups for most visual functions except for simple and complex form-coherence (two way-ANOVAs, P > 0.05) and complex motion coherence. Correlations between outcomes revealed more significant correlations for PwA and differences in the specific correlates between groups. Unsupervised hierarchical clustering revealed different functional clusters between groups. Conclusions: AIM and FInD successfully interrogated visual deficits in PwA. Overall, PwA showed impaired performance in achromatic, chromatic, temporal, and binocular functions, and had higher intrinsic noise levels. Midlevel vision was comparable between groups. Unsupervised cluster analysis and correlation between outcomes revealed a difference in functional outcome clusters between groups. The results may help to increase the efficiency of screening and identify target deficits for rehabilitation.

A new, adaptive, self-administered, and generalizable method used to measure visual acuity.

SIGNIFICANCE: Angular Indication Measurement (AIM) is an adaptive, self-administered, and generalizable orientation-judgment method designed to interrogate visual functions. We introduce AIM Visual Acuity (VA) and show its features and outcome measures. Angular Indication Measurement VA's ability to detect defocus was comparable with that of an Early Treatment of Diabetic Retinopathy Study (ETDRS) letter chart and showed greater sensitivity to astigmatic blur. PURPOSE: This proof-of-concept study introduces Angular Indication Measurement and applies it to VA. METHODS: First, we compared the ability of AIM-VA and ETDRS to detect defocus and astigmatic blur in 22 normally sighted adults. Spherical and cylindrical lenses in the dominant eye induced blur. Second, we compared repeatability over two tests of AIM-VA and ETDRS. RESULTS: A repeated-measure analysis of variance showed a main effect for defocus blur and test. For the astigmatism experiment, an interaction between blur and orientation was found. Pairwise comparisons showed that AIM was more sensitive to astigmatic-induced VA loss than ETDRS. Bland-Altman plots showed small bias and no systematic learning effect for either test type and improved repeatability with more than two adaptive steps for AIM-VA. CONCLUSIONS: Angular Indication Measurement VA's ability to detect defocus was comparable with that of an ETDRS letter chart and showed greater sensitivity to induced astigmatic blur, and AIM-VA's repeatability is comparable with ETDRS when using two or more adaptive steps. Angular Indication Measurement's self-administered orientation judgment approach is generalizable to interrogate other visual functions, e.g., contrast, color, motion, and stereovision.

AIM (Angular Indication Measurement)- Visual Acuity: An adaptive, self-administered, and generalizable vision assessment method used to measure visual acuity.

This proof-of-concept study introduces Angular Indication Measurement and applies it to VA (AIM-VA). First, we compared the ability of AIM-VA and ETDRS to detect defocus and astigmatic blur in 22 normally-sighted adults. Spherical and cylindrical lenses (±0.00D, +0.25D, +0.50D, +0.75D, +1.00D, +2.00D and +0.50D, +1.00D, +2.00D each at 0°, 90°, 135°, respectively) in the dominant eye induced blur. Second, we compared repeatability over two tests of AIM-VA and ETDRS. A 2-way-ANOVA showed a main effect for defocus-blur and test with no interaction. A 3-way-ANOVA for the astigmatism experiment revealed main effects for test type, blur, and direction and with no interactions. Planned multiple comparisons showed AIM had greater astigmatic-induced VA loss than ETDRS. Bland-Altman plots showed small bias and no systematic learning effect for either test type and improved repeatability with >2 adaptive steps for AIM-VA. AIM-VA's ability to detect defocus was comparable with that of an ETDRS letter chart and showed greater sensitivity to astigmatic blur, and AIM-VA's repeatability is comparable with ETDRS when using 2 or more adaptive steps. AIM's self-administered orientation judgment approach is generalizable to interrogate other visual functions, e.g., contrast, color, motion, stereo-vision.