Does EyeKinetix pupillometry clarify RAPD detection?

purposeTo evaluate variability observed in pupil light response with the EyeKinetix pupillometer in healthy non-dark-adapted individuals.

methodsWe performed objective pupillometry in 440 non-dark-adapted patients with 20/20 corrected visual acuity, normal visual fields, and no ophthalmic disease who presented for routine exam. EyeKinetix was performed as part of the routine exam screening protocol. Metrics reviewed were RAPDx amplitude scores, latency scores, and quantitative metrics of pupil dynamics measured by the EyeKinetix. Sequential retesting was analyzed for repeatability. Statistical analyses included normality testing, confidence intervals, t-tests, and Intraclass Correlation Coefficient (ICC) calculations for repeated measures.

resultsAmplitude and latency scores exhibited significant variability. The mean amplitude score was 0.0249 ± 0.247, with 5% of patients >  = 2 standard deviations [> 0.51 log unit (LU)]. Latency scores showed low reliability (ICC = 0.165), whereas amplitude, constriction velocity, and release velocity demonstrated moderate to high reliability (ICC = 0.472-0.966).

conclusionObjective pupillometry without dark adaptation using the EyeKinetix device displays substantial variability and identifies a number of relative afferent pupil defects (RAPDs) in this cohort of healthy patients. These findings indicate that, in healthy populations, reliance on RAPDx scores alone could generate false positives. Establishing robust normative cutoffs and validating them in disease cohorts will be necessary before reliable use as a screener. Further optimization may be necessary for more clinical confidence in a primary care setting.