Role of gut microbiomes in different ocular pathologies: A systematic review

Table 2 Quality of evidence of studies examined

Ref.	Type of study	Quality of evidence (NIH tool for observational studies) (ROBINS-I for non-randomized trial) (ROB2 for RCT)
Jayasudha et al[38], 2019	Case-control	8
Kalyana Chakravarthy et al[39], 2018	Case-control	6
Huang et al[40], 2018	Case-control	8
Morandi et al[41], 2024	Case-control	8
Wang et al[42], 2023	Case-control	8
Ye et al[43], 2020	Case-control	8
Tecer et al[44], 2020	Case-control	8
Kim et al[45], 2021	Case-control	8
Yasar Bilge et al[46], 2020	Cohort	9
Ye et al[47], 2018	Case-control	8
Zysset-Burri et al[48], 2019	Case-control	8
Zhang et al[49], 2023	Case-control	8
Zysset-Burri et al[50], 2020	Case-control	8
Xue et al[51], 2023	Case-control	6
Huang et al[52], 2021	Cross-sectional	8
Moubayed et al[53], 2019	Case-control	8
Ye et al[54], 2021	Case-control	8
Das et al[55], 2021	Case-control	8
Jayasudha et al[56], 2020	Cohort study	9
Khan et al[57], 2021	Case-control	8
Omar et al[58], 2024	Cohort	8
Sun et al[59], 2024	Case-control	8
Skondra et al[60], 2021	Cross-sectional	8
Chang et al[61], 2024	Case-control	7
Berkowitz et al[62], 2022	Case-control	8
Gong et al[63], 2020	Case-control	8
Kalyana Chakravarthy et al[64], 2018	Case-control	8
Jayasudha et al[65], 2018	Case-control	8
Mendez et al[66], 2020	Case-control	8
Moon et al[67], 2020	Case-control	8
Watane et al[68], 2021	Non-randomized clinical trial	Low risk of bias
Filippelli et al[69], 2021	Randomized control Trial	Low risk of bias
Filippelli et al[70], 2022	Randomized control trial	Low risk of bias
Yang et al[71], 2024	Case-control	8
Zhang et al[72], 2024	Case-control	8
Zhang et al[73], 2023	Case-control	8

RCT: Randomized controlled trial; NIH: National institutes of health; ROB2: Revised Cochrane Risk-of-Bias Tool for Randomized Trials; ROBINS-I: Risk of Bias in Non-Randomized Studies-of Interventions.