Table 1.

Characteristics of observational studies

Study	Design	Patients (n)			PCR positivity rate			Treatment for ocular manifestation
		All	Ocular manifestation	Systemic manifestation	PCR tears/ocular manifestation	PCR tears/all COVID-19-related patients	PCR positivity rate other than tears sample
Guan et al7	Cross-sectional	1099	9	1099	n/a	n/a	100% NP+; 4/1099 (0.36%) stool+; 4/1099 (0.36%) rectal+	n/a
Wu et al8	Cross-sectional	38	12	38	0.17	0.05	28/38 NP+	n/a
Xia et al43	Prospective observational	30	1	30	1.00	0.03	30/30 NP+	n/a
Zhang et al15	Cross-sectional	102	2	n/a	1.00	0.02	72/102 NP+	Ganciclovir eye drops
Xie et al44	Retrospective	33	0	33	n/a	0.06	100% NP+	n/a
Chen et al45	Cross-sectional	535	27	535	n/a	n/a	343/535 NP+	Ofloxacin, tobramycin, ganciclovir eye drops, artificial tear
Kumar et al46	Cross-sectional	45	0	31	n/a	0.02	100% NP+	n/a
Zhou et al47	Cross-sectional	121	8	121	0.13	0.02	100% NP+	n/a
Deng et al41	Cross-sectional	114	0	114	n/a	0	90/114 NP +	n/a
Karimi et al48	Cross-sectional	43	1	43	1.00	0.07	30/43 NP +	n/a
Grimaud et al49	Retrospective	20	6	20	n/a	n/a	10 NP+ (and 15 serology+)	n/a
Valente et al30	Prospective observational	27	4	23	0.25	0.11	100% NP+	n/a
Seah et al24	Prospective observational	17	1	14	0	0	17/17 (100%) NP+	n/a
Fang et al50	Cross-sectional	32	0	28	n/a	0.16	32/32 (100%) NP+, 25/32 (78,1%) saliva+	n/a

n/a, not applicable; NP, nasopharyngeal.