Post COVID-19 visual impairments and symptoms are common sequelae following SARS-CoV-2 infection and may include less efficient saccadic eye movements, binocular dysfunction, and difficulty dealing with visual noise, according to research published in Clinical and Experimental Optometry.
Researchers evaluated post COVID-19 visual impairments and symptoms among 38 non hospitalized patients who were consecutively recruited from a regional rehabilitation unit between January and December 2022 (76% women; mean age, 47 years). The team assessed visual and oculomotor function, and tested both saccadic eye movements and the participants’ sensitivity to visual motion. Study participants underwent Brain Injury Vision Symptom Survey (BIVSS), Convergence Insufficiency Symptom Survey (CISS), Developmental Eye Movement Test (DEM), and Visual Motion Sensitivity Clinical Test Protocol assessments to determine general symptoms, near symptoms, saccadic eye movements, and environmental movement sensitivity, respectively.
An analysis of BIVSS data revealed a mean total symptom score of 46.2. Overall, all but 3 study participants scored above 31 — a cutoff value considered useful for symptom screening in patients with traumatic brain injury. A total of 73.7% of participants reported difficulty tolerating visually busy places.
An analysis of CISS data shows that frequent rereading, trouble remembering, slow reading, and loss of concentration while reading (71.1%–86.8%) were common post COVID-19 visual impairments and symptoms. Overall, 29 patients had between 1 and 3 clinical signs indicating reduced visual acuity, visual field, eye movements, or accommodative or binocular functions (Table 2). A total of 7 patients met the criteria for convergence insufficiency and 2 patients demonstrated accommodative insufficiency, according to the report.
Overall, participants had high symptom scores (26–60%). Increased symptom score was associated with less efficient saccadic eye movements (P <.001) and binocular dysfunction (P=.029). Patients who reported severe symptoms in visually busy places scored significantly higher on the Visual Motion Sensitivity Clinical Test Protocol (P =.029).
“Based on findings regarding basic oculomotor dysfunctions in post-COVID-19 patients and other patient groups, it may be necessary to consider oculomotor inefficiency as part of the underlying reasons for reading-related symptoms,” according to the study authors. “If so, these problems could be targeted with appropriate spectacle correction, guidance on visual ergonomics, or vision therapy.”
Study limitations include a small sample size and the possibility that some reported post COVID-19 visual impairments were actually present before SARS-CoV-2 infection.
Johansson J, Möller M, Markovic G, Borg K. Vision impairment is common in non-hospitalised patients with post-COVID-19 syndrome. Clin Exp Optom. Published online May 18, 2023. doi:10.1080/08164622.2023.2213826