Ophthalmic Screening in Patients with Coronavirus Disease 2019: A Prospective Cohort Study

Retinal Findings in Hospitalized COVID-19 Patients, Is Routine Ophthalmological Examination Required after Discharge? Prospective Case-Control Study

OBJECTIVES

To investigate retinal findings by comparing patients hospitalized for COVID-19 with the control group.

METHODS

In this prospective study, 188 eyes of 94 recovered COVID-19 patients and 108 eyes of 54 healthy participants as a control group were evaluated. Patients were divided into three groups, those with mild, moderate, and severe COVID-19. Refractometry, tonometry, optical biometry, optical coherence tomography (OCT) measurements, and complete ophthalmological examinations were performed on healthy volunteers and COVID-19 patients on average 2 weeks after discharge. Pulse O₂ and vital parameters were also assessed. Primary outcomes were evaluated, such as retinal findings, and secondary outcomes as retinal thickness, choroidal thickness (CT), retinal nerve fiber layer thickness, and ganglion cell layer thickness.

RESULTS

There was no difference between the groups in terms of demographic data, ocular biometry, and intraocular pressure (p > 0.05). Pulse O₂ was lower in the study group (p < 0.001). Retinal findings were detected in 68 (36.1%) of 188 eyes in the study group and 28 (25.9%) of 108 eyes in the control group (p = 0.07). The two most common retinal findings were hypertensive retinopathy and retinal pigment epithelium alterations and/or drusen in both groups. In OCT measurements, significant thinning was observed in nasal macular thickness and superior 2 mm CT in the study group compared to the control group (p < 0.05). In patients divided into subgroups according to disease severity, no significant difference was found between the groups in any OCT parameter (p > 0.05).

CONCLUSION

It has been observed that COVID-19 infection does not cause a specific and sensitive finding in the ocular tissues, especially the retina, and does not produce a reproducible measurement result. Recommending routine eye exam after COVID-19 does not seem cost-effective.

Visual perception alterations in COVID-19: a preliminary study

AIM

To compare the visual perception (color and chromatic-achromatic contrast vision) of a small cohort of COVID-19 patients at the time of infection and after 6mo with that of a healthy population matched for sex and age.

METHODS

A total of 25 patients (9 females, 16 males, mean age: 54±10y) with COVID-19 hospitalized in the COVID-19 Unit of the University Clinical Hospital of Valladolid were recruited for this preliminary study. Visual perception, as determined by monocular measurement of contrast sensitivity function (CSF) and color vision was assessed in each patient using the Optopad test. The results obtained were then compared with those of a sample of 16 age- and sex-matched healthy controls (5 females, 11 males, mean age: 50±6y) in which the same measurement procedure was repeated. Statistically significant differences between groups were assessed using the Mann-Whitney U test. Measurements were repeated after a minimum follow-up period of 6mo and statistically significant differences between the two time points in each group were assessed using the Wilcoxon signed rank test.

RESULTS

Discrimination thresholds (color and chromatic-achromatic contrast vision) and their corresponding sensitivity, calculated as the inverse of the discrimination threshold, were evaluated. Analysis of the data revealed higher contrast threshold results (i.e., worse contrast sensitivity) in the COVID-19 group than in the control group for all spatial frequencies studied in the Optopad-CSF achromatic test and most of the spatial frequencies studied in the Optopad-CSF chromatic test for the red-green and blue-yellow mechanisms. In addition, color threshold results in the COVID-19 group were also significantly higher (i.e., worse color sensitivity) for almost all color mechanisms studied in the Optopad-Color test. At 6mo, most of the differences found between the groups were maintained despite COVID-19 recovery.

CONCLUSION

The present results provide preliminary evidence that visual perception may be impaired in COVID-19, even when the infection has passed. Although further research is needed to determine the precise causes of this finding, analysis of CSF and color vision could provide valuable information on the visual impact of COVID-19.

Ocular surface disturbance in patients after acute COVID-19

Background

We investigated the ocular surface disturbances in COVID‐19 patients discharged from the hospital.

Methods

One hundred and seventy‐nine eyes of 109 healthy participants and 456 eyes of 228 post‐COVID‐19 patients received comprehensive eye examinations; the latter were interviewed with questionnaires on ocular symptoms before and after COVID‐19 diagnosis. Associations of ocular surface manifestations with virological and ophthalmic parameters were evaluated by multivariable mixed linear or logistic regression models.

Results

Mean interval between COVID‐19 diagnosis and ophthalmic evaluation was 52.23 ± 16.12 days. The severity of meibomian gland dysfunction (MGD) based on clinical staging was higher in post‐COVID‐19 than healthy eyes (1.14 ± 0.67 vs. 0.92 ± 0.68, p = 0.002) and so was ocular surface staining score (0.60 ± 0.69 vs. 0.49 ± 0.68, p = 0.044). Patients requiring supplementary oxygen during hospitalisation had shorter tear break‐up time (β −1.63, 95% CI ‐2.61 to −0.65). Cycle threshold (Ct) value from upper respiratory samples (inversely correlated with viral load) at diagnosis had an OR = 0.91 (95% CI 0.84–0.98) with new ocular surface symptoms 4 weeks after diagnosis. The presence of ocular surface symptoms 1 week prior to COVID‐19 diagnosis showed an OR of 20.89 (95% CI 6.35–68.66) of persistent or new ocular symptoms 4 weeks afterward.

Conclusions

MGD and ocular surface staining are more common and severe in post‐COVID‐19 patients. Patients with higher viral loads have greater risks of ocular surface symptoms. Patients requiring supplementary oxygen are more likely to show tear film instability. Ocular surface evaluation should be considered 1–3 months following hospital discharge for any COVID‐19 patient.