Evaluation of cone‐mediated dark adaptation using a smartphone app (MOBILE_DA) in healthy subjects

• Published in: Acta ophthalmologica (Oxford, England) Vol. 103; no. S284
• Main Authors: Gavilán, Beatriz Sánchez, Marin, Maria Cinta Puell, Pundlik, Shrinivas
• Format: Journal Article
• Language: English
• Published: Malden Wiley Subscription Services, Inc 01.01.2025
• Subjects: Acuity; Adaptation; Bleaching; Cones; Macular degeneration; Smartphones; Threshold limits; Visual thresholds; Young adults
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/aos.17273

Purpose: There is evidence of the role of dark adaptation (DA) as a functional biomarker in age‐related macular degeneration (AMD) where foveal cones are impacted during the initial stages of AMD. In this study we determine the repeatability of smartphone application (MOBILE DA) to evaluate the cone‐mediated dark adaptation (DA) in healthy young adults. Methods: Testing was done by placing a smartphone in front of the subject in a dark room. The App presented a 1.5° flashing stimulus at 3° eccentricity using an adaptive staircase. A 14800 lux white bulb was used for bleaching before testing. In two different sessions 1 week apart, the cone‐mediated dark adaptation was measured in 40 healthy subjects aged 21.4 ± 3.4 with good visual acuity (VA). Cone‐mediated DA recovery threshold was measured for 5 min. Threshold recovery functions were fitted to an exponential decay model to determine the time constant (τ, minutes) of cone sensitivity recovery and final cone luminance threshold (LTf). Repeatability was estimated by the Bland‐Altman method, whereby the mean difference (MD) and the 95% limits agreement were determinate as the coefficient of repeatability (COR). Results: Mean time constant (t) values was 1.28 ± 0.43 minutes in session 1 and 1.28 ± 5.4 for the session 2 and for the final luminance threshold the mean values were ‐2.12 ± 0.23 log cd/m2 for the session 1 and ‐2.13 ± 0.28 for the session 2. Mean differences in time constant measurements and LTf between session 1 and 2 were not significant. COR value for t was 1minute and COR value for LTf was 0.33 log cd/m2. Conclusions: The MOBILE‐DA offered repeatable measurements. The APP was able to detect rapid changes in light sensitivity that occur during cone‐mediated dark adaptation indicating the clinical potential of using mobile device based DA measurements.