Preliminary Evaluation of a Mobile Device for Dark Adaptation Measurement.

PURPOSE: We evaluated the feasibility of a smartphone application-based dark adaptation (DA) measurement method (MOBILE-DA).
METHODS: On a Samsung Galaxy S8 smartphone, MOBILE-DA presented a 1.5° flashing stimulus (wavelength = 453 nm) between -1.15 and -4.33 log candela (cd)/m2 at 8° eccentricity using an adaptive staircase, and logged timing of user response (tapping on the screen) whenever the stimulus became visible (monocularly). In a dark room, the smartphone was placed ≈40 cm from the subject, and a white smartphone screen at maximum brightness (≈300 cd/m2) for 120 seconds was used for bleaching before testing. MOBILE-DA was evaluated in normally-sighted (NV) subjects (n = 15; age, 22-82 years). Additionally, a subject with myopic retinal degeneration (MRD; VA, 20/100; age, 62 years) and another with optic nerve atrophy (ONA; visual acuity [VA], 20/500; age, 40 years) were measured. Maximum test timing was capped at 20 minutes. Linear regression was performed to determine age-effect on DA parameters: rod-cone break time (tRCB ) and test-time (tterm ). Use of the normalized area under the DA characteristics (AUC) as an outcome measure was explored.
RESULTS: For NV, the repeatability coefficients for tRCB , tterm , and AUC were ±2.1 minutes, ±5.4 minutes, and 4.4%, respectively, and aging-related delays were observed (tRCB , R 2 = 0.47, P = 0.003; tterm , R 2 = 0.34, P = 0.013; AUC, R 2 = 0.41, P = 0.006). Compared to ONA and NV, DA was greatly prolonged in the MRD subject (52% larger AUC than the NV mean).
CONCLUSION: The age-effect was verified for MOBILE-DA measurements in NV subjects; impaired DA in a case with retinal-degeneration was observed. TRANSLATIONAL RELEVANCE: This study establishes feasibility of the smartphone-based DA measurement method as a potential accessible screening tool for various vision disorders.