Table 2.

Selected secondary studies* “systematic reviews and meta-analysis” discussing novel coronavirus 2019 and eye

Author (s)	Study design	Results
Ulhaq and Soraya52	Letter to the editor	A meta-analysis was conducted The prevalence of ocular manifestations among COVID-19-infected patients ranged from 2% to 32%
Liu et al.53	Letter to the editor	A meta-analysis of 62 studies Significant increased probability of conjunctivitis in non-severe stages of COVID-19 compared to severe subjects
Lawrenson and Buckley54	Letter to the editor	A meta-analysis of selected 9 studies Conjunctivitis is a rare complication of COVID-19, with an estimated pooled prevalence of 4% or less. Virus presents in approximately 3% of tear/conjunctival swab samples
Aiello et al.55	Systematic review of 11 studies	Conjunctivitis was demonstrated to be as high as 32% in one study, three patients had conjunctivitis with a positive tear-PCR, 8 patients had positive tear-PCR in the absence of conjunctivitis, and 14 had conjunctivitis with negative tear-PCR The majority of the available data regarding SARS-CoV-2 colonization of ocular tissues and secretions have to be considered controversial

*Secondary studies mean studies on secondary results and involve the analysis of research which have already been performed and published. COVID-19: Novel coronavirus 2019, SARS-CoV: Severe acute respiratory syndrome coronavirus, SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus-2, PCR: Polymerase chain reaction