The Prevalence of ocular manifestations and ocular samples polymerase chain reaction positivity in patients with COVID 19 - a systematic review and meta-analysis

Objective: To estimate the prevalence of ocular manifestations and ocular samples polymerase chain reaction (PCR) positivity among COVID 19 patients. Methods: A systematic literature review was performed using search engines (PubMed, Google Scholar, Medrixv and BioRixv) with keywords SARS CoV 2, novel coronavirus, COVID 19, ocular manifestations, conjunctival congestion, Ocular detection, Polymerase chain reaction, and conjunctivitis. The measure of heterogeneity was evaluated with the I2 statistic. The pooled proportion of patients presenting with symptoms and ocular samples PCR positivity was estimated. Results: A total of 20 studies (14 studies and 6 case reports) were included in the systematic review and 14 studies were included in the metaanalysis. The pooled prevalence of conjunctivitis was 5.17% (95% CI: 2.90 to 8.04). Conjunctivitis was reported as an initial symptom of the disease in 0.858 % (95% CI: 0.31 to 1.67). Common associated features include itching, chemosis, epiphora. Seven patients (29 %) with conjunctivitis showed positive results in ocular samples, whereas 13 patients (54%) showed positive only in their nasopharyngeal samples (NPs) or sputum samples and 4 patients (16 %) were negative for both NPs and Sputum as well as ocular samples. The pooled prevalence of ocular PCR positivity was 2.90 % (95% CI: 1.77 to 4.46) vs. NPs 89.8% (95% CI: 78.80 to 79.0). Conclusion: The prevalence of conjunctivitis and ocular samples PCR positivity among COVID 19 patients was low indicating that the eye is a less affected organ. However, conjunctivitis may present as the first symptom of the disease making the patient seek medical care at the earliest.