The use of cellphone based automated pupillometry to quantify opioid withdrawal in patients receiving treatment for opioid use disorder.

INTRODUCTION

Overdose deaths attributed to opioid misuse resulted in over 50,000 deaths in 2024. Opioid agonist therapies such as methadone and buprenorphine are effective for the treatment of opioid use disorder (OUD). Yet, patient retention is an issue due to the challenges of stabilizing patients on an appropriate dose during the initial phase of treatment (induction). Accurate and objective quantification of opioid withdrawal can better optimize dose titration during induction. The study goal was to validate the use of cellphone-based pupillometry for assessing withdrawal in OUD.

METHODS

Forty-five patients, currently engaged in methadone or buprenorphine treatment for OUD, were recruited from a local clinic. Participants were interviewed daily for fourteen consecutive days and reported on their drug use, their perceived craving and withdrawal (via the clinical opioid withdrawal scale (COWS) and completed an automated pupillary light reflex examination prior to receiving their daily dose. Pupillometry measures and self-reported craving and withdrawal measures were compared against time since last opioid dose (TSLD) to evaluate the sensitivity of measures to withdrawal. A multilevel modeling approach was conducted to account for the nested data.

RESULTS

The pupillary light reflex was significantly associated with TSLD in those receiving methadone, and amongst those receiving high morphine equivalent doses. Opioid withdrawal as measured by the Clinical Opioid Withdrawal Scale (COWS) failed to demonstrate a significant relationship with TSLD.

CONCLUSIONS

These findings suggest that pupillometry measures may be superior to commonly used self-report measures for assessing withdrawal in the context of MOUD for OUD.