Ultrasound pupillometry for the detection of a relative afferent pupillary defect (RAPD): Systematic evaluation in patients with optic neuritis and comparison with infrared video pupillometry

• DOI: 10.1371/journal.pone.0315712
• Publication Date: 2025-01-10T19:47:52Z
• Authors: Franziska Siebald; Ulrike Grittner; Carolin Otto; Charlotte Bereuter; Hanna G. Zimmermann; Lutz Harms; Jan Klonner; Stephan J. Schreiber; Friedemann Paul; Klemens Ruprecht; Felix A. Schmidt
• Keywords: Pupillometry; Optic neuritis

Purpose A relative afferent pupillary defect (RAPD) is a characteristic clinical sign of optic neuritis (ON). Here, we systematically evaluated ultrasound pupillometry (UP) for the detection an RAPD in patients with ON, including comparison infrared video (IVP), gold standard objective pupillometry. Materials and methods We enrolled 40 acute (n = 9) or past 31) ON (ON+), 31 multiple sclerosis (MS) without prior 50 healthy controls (HC) cross-sectional observational study. Examinations comprised swinging flashlight test, B-mode UP, IVP, autorefraction to assess best-corrected visual acuity, optical coherence tomography determine peripapillary retinal nerve fiber layer thickness, 51-item National Eye Institute-Visual Function Questionnaire vision-related quality life. Results While UP IVP measurements pupil diameter (PD) at rest correlated ON+ eyes 52, r 0.56, 95% CI: 0.35; 0.72) HC 100, 0.60, 0.47; 0.72), PD was smaller than (difference, mean (SD) eyes: 0.44 (0.87) mm, 0.69 (0.80) mm). assessment by sharply discriminated AUC 1, 95%CI: 1; 1). detected 5/31 (16%) MS who had not exhibited during test. In 52), showed stronger correlations acuity ( 0.66, 0.50; 0.78) life 0.47, 0.24; 0.66) 0.52, 0.36; 0.67 0.27, 0.03; 0.51). Conclusions allows quantification performance characteristics similar IVP. may detect subclinical damage MS. propose standardized protocol that can be used routine evaluation other neuropathies.