Pupillographic Analysis of COVID-19 Patients: Early and Late Results After Recovery

We aimed to investigate the short- and long-term static and dynamic pupillary responses of patients recovered from coronavirus disease-19 (COVID-19) using quantitative infrared pupillography.

This study included patients who recovered from COVID-19 (Group 1) and age- and gender-matched controls (Group 2). A detailed ophthalmic examination was performed at 1 month and 6 months after the diagnosis of COVID-19. Photopic, mesopic, and scotopic pupil diameters (PDs) were measured using a quantitative infrared pupillography which was integrated into Scheimpflug/Placido photography-based topography system. PDs at 0, 2^nd, 4^th, and 6^th seconds, and average pupil dilation speeds at 2^nd, 4^th, 6^th, and 8^th seconds were recorded.

Eighty-six eyes of 86 patients (Group 1: n=42; Group 2: n=44) were included. While the mean photopic, mesopic, and scotopic PDs were significantly larger in the COVID-19 group than the control group in the 1^st month (p=0.035, p=0.017, p=0.018, respectively), no statistically significant difference was found in the 6^th month. Besides, average pupil dilation speeds and PDs at the 0, 2^nd, 4^th, and 6^th seconds were not statistically significantly different between the two groups in the 1^st month and 6^th month.

PDs were significantly larger in COVID-19 patients in all light intensities in the 1^st month after COVID-19. However, pupillary dilation was transient, and no significant difference was found in the 6^th month. We suggest that the transient pupillary dilation may be secondary to the autonomic nervous system dysfunction and/or optic nerve and visual pathways alterations following COVID-19.