Purpose: To assess pupillary light responses (PLRs) in eyes with high myopia and evaluate the ability of handheld chromatic pupillometry (HCP) to identify glaucomatous functional loss in eyes with high myopia. Design: Cross-sectional study with prospective data collection. Methods: Participants included 28 emmetropes (EM), 24 high myopes without glaucoma (HM), and 17 high myopes with confirmed glaucoma (HMG), recruited at the Singapore National Eye Center. Monocular PLRs were evaluated using a custom-built handheld pupillometer that recorded changes in horizontal pupil radius in response to 9 seconds of exponentially increasing blue (469.1nm) and red (640.1nm) lights. Fifteen pupillometric features were compared between groups. A logistic regression model (LRM) was used to distinguish HMG eyes from non-glaucomatous eyes (EM and HM). Results: All pupillometric features were similar between EM and HM groups. Phasic constriction to blue (P<0.001) and red (P=0.006) lights, and maximum constriction to blue light (P<0.001) were reduced in HMG compared to EM and HM. Pupillometric features of melanopsin function (PIPR AUC 0-12s (P<0.001) and PIPR 6s (P=0.01) to blue light) were reduced in HMG. Using only three pupillometric features, the LRM could classify glaucomatous from non-glaucomatous eyes with an AUC of 0.89 (95%CI: 0.77-1.00), sensitivity 94.1% (82.4%-100.0%) and specificity 78.8% (67.3%-90.4%). Conclusions: PLRs to ramping-up light stimuli are unaltered in highly myopic eyes without other diagnosed ocular conditions. Conversely, HCP can distinguish glaucomatous functional loss in highly myopic eyes and may be a useful tool to detect/confirm the presence of glaucoma in patients with high myopia.

RPN, DM and AT have a patent application based on the handheld pupillometer used in this study (PCT/SG2018/050204): Handheld ophthalmic and neurological screening device. The rest of the authors have no conflicts of interest to disclose.

This work was supported by the National Medical Research Council, Singapore (NMRC/CIRG/1401/2014) and the National Health Innovation Centre Singapore (NHIC-l2D-170818l) to DM, and the Singhealth Duke-NUS Academic Medicine Research Grant (AM/TP018/2018) to RPN. The funding organizations had no role in the design and conduct of the research.

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The study was approved by the SingHealth Centralized Institutional Review Board, and written informed consent was obtained from all participants. Research procedures adhered to ethical principles outlined in the Declaration of Helsinki.

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All data produced in the present study are available upon reasonable request to the authors.