Purpose
To recognize dysfunctions in the autonomic nervous system (ANS) with changes in dynamic and static pupillary responses in patients who recovered from coronavirus disease-2019 (COVID-19)
Methods
One month after recovery from COVID-19, patients were subjected to eye examinations. Pupillary responses were measured using a pupillometry system. Dynamic pupil parameters (i.e., pupil contraction amplitude, pupil dilatation latency, pupil contraction latency, pupil dilatation duration, pupil dilatation velocity, pupil contraction duration, pupil contraction velocity, resting pupil diameter [PD]) and static pupil parameters (i.e., mesopic PD, scotopic PD, high photopic PD, and low photopic PD) were registered.
Results
Although high photopic and scotopic PDs were significantly higher in patients recovering from COVID-19 than in healthy controls (
P
= 0.04 and
P
= 0.002), no statistically significant difference was found in mesopic and low photopic PD (
P
= 0.19 and
P
= 0.41). Regarding dynamic pupillometry parameters, resting PD and pupil contraction velocity (
P
= 0.04 and
P
= 0.02, respectively) were significantly higher in patients recovering from COVID-19 than in healthy controls (
P
< 0.001 and
P
< 0.001, respectively), whereas pupil dilatation latency and pupil contraction duration were lower in these patients than in healthy controls (
P
= 0.01 and
P
= 0.008, respectively). No significant differences in pupil contraction amplitude, pupil dilatation duration, pupil contraction latency, and pupil dilatation velocity were found between the study groups (
P
= 0.93,
P
= 0.91,
P
= 0.42, and
P
= 0.48, respectively).
Conclusion
Pupil responses, which are controlled by the ANS, were impaired in patients recovering from COVID-19. Pupillometry shows promise as a non-invasive, easy-to-apply diagnostic technology for detecting autonomic dysfunction in patients recovering from COVID-19.
Clinical trial registration
Not applicable.
