Ocular Symptoms as a Marker of Dysautonomia in Long-COVID Patients: A Cross-Sectional Analysis

Background/Objectives: Post-coronavirus syndrome (long-COVID) refers to a multi-systemic range of symptoms that follows acute SARS-CoV-3 infection. Long-COVID has been linked with autonomic neuropathy as well as dry-eye disease (DED), an umbrella term that includes a variety of ocular symptoms and signs. Despite these associations, little is known about the co-occurrence of DED and dysautonomia symptoms in individuals with long-COVID. This study aims to examine relationships between dysautonomia and ocular symptoms in a long-COVID patient population. Methods: Cross-sectional study of 162 veterans with long-COVID. The Composite Autonomic Symptom Score-31 (COMPASS-31) assessed dysautonomia symptoms, and the NASA lean test and heart-rate variability metrics captured dysautonomia signs. Dry-eye disease (DED) symptoms were measured with the 5-Item Dry-Eye Questionnaire (DEQ5) and the Ocular Surface Disease Index (OSDI), while ocular pain intensity and neuropathic pain descriptors were evaluated using a Numerical Rating Scale (NRS) and select questions from the Neuropathic Pain Symptom Inventory modified for the Eye (NPSI-Eye), respectively. Results: Most participants (78%) reported DED symptoms (DEQ5 ≥ 6). Nearly all COMPASS-31 domains were associated with DED symptoms, with the strongest correlation observed between the OSDI and pupillomotor scores (r = 0.67, p < 0.001). Among the autonomic signs, the strongest associations were observed between the change in systolic and diastolic blood pressure from baseline to 8 min and ocular pain triggered by temperature (r = -0.44 and r = -0.48, respectively, p < 0.01 for both). On linear regression analyses, pupillomotor and secretomotor symptoms remained positively associated with DED symptoms, while autonomic signs were most closely related to ocular pain metrics, with fluctuating blood pressure changes during orthostasis relating to neuropathic symptoms. Conclusions: DED symptoms, including ocular pain intensity, relate to autonomic symptoms in a long-COVID cohort. While associations with autonomic signs were less consistent, these data suggest that subtle autonomic variability relates to ocular pain in the long-COVID setting.