Near-Infrared OCT Imaging for the Assessment of Anisocoria

BACKGROUND: Assessment of anisocoria in clinical settings can be very challenging, particularly for young children and patients with dark irises. In some instances, a smartphone camera is used to capture an image of the pupils to aid in accurate assessment. This study aims to assess and compare the inter and intra-rater reliability of assessment of anisocoria using near-infrared optical coherence tomography (NI-OCT) and smartphone photographs. METHODS: In this prospective cross-sectional study, binocular photographs of thirty participants, aged eight months to sixty-eight years, were taken at four time points using smartphone and NI-OCT cameras after the application of Tropicamide 0.5% to create varying amounts of anisocoria. The 240 photographs were presented in random order to three optometrists for measurement of pupil diameter in each photograph, as well as 118 photographs that were randomly selected to be measured twice by each rater for a total of 358 photographs. Study outcome measures were inter and intra-rater reliability of anisocoria measurements in each photograph, and inter and intra-rater agreement on the presence of anisocoria of one millimetre (mm) or more. RESULTS: The reliability of anisocoria measurements and agreement on the presence of anisocoria of one mm or more was excellent using the NI-OCT photographs (ICC=0.93-0.99, k=0.83-1.0), and decreased considerably using the smartphone photographs (ICC=0.84-0.90, k=0.53-0.74), especially for photographs of participants with dark irises (ICC=0.36-0.82, k=0 11-0.47). CONCLUSIONS: Using NI-OCT photographs allows for reliable measurement of anisocoria and can aid in the detection of pathological anisocoria, especially in patients with dark irises and children.