Paper | Design | Regimen | Mean (SD) GA | Mean (SD) BW (g) | Sample Size | Efficacy | Safety |

Alshafei (2017)6 | Observational prospective | P 2.5%, T 5% (3 d) | 24–31 | – | 42 | R | |

Bolt (1992)7 | Quasi-RCT | P 2.5% (1d), T 0.5% (2 d) | 32.3 (±3.3) weeks | 1544 (±761) | 20 | ✓ | C |

C 0.5% (1d), T 0.5% (2 d) | 34.6 (±3.6) weeks | 1831 (±645) | 19 | ✓ | C | ||

Bonthala (2000)8 | Non-randomised intervention | P 1%, C 0.2% (2 d) | 29–33 | 1340 (±82) | 11 | C | |

Caputo (1982)9 | Quasi-RCT | P 2.5%, C 0.5%, T 0.5% (1 d) | 26–42 weeks | 880–3440 | 10 | ✓ | |

P 2.5%, C 0.5%, T 0.5% (2 d) | 26–42 weeks | 880–3440 | 10 | ✓ | |||

Chew (2005)20 | RCT | P 2.5%, C 1% (3 d) | 29.92 (±2.66) weeks | – | 13 | ✓ | G |

P 2.5%, T 1% (3 d) | 29.23 (±1.59) weeks | – | 13 | ✓ | G | ||

P 1%, C 0.2% (3 d) | 29.15 (±2.54) weeks | – | 13 | ✓ | G | ||

Elibol (1997)17 | Quasi-RCT | C 1% (2 d or 2 microd) | 39.68 (±34.33) days | – | 16 | ✓ | C, D |

P 10% (2 d or 2 microd) | 22.83 (±21.39) days | – | 18 | ✓ | C, D | ||

T 0.5% (2 d or 2 microd) | 28.78 (±26.89) days | – | 19 | ✓ | C, D | ||

Isenberg (1985)15 | RCT | C 0.25% (2 d) | 31 (±2) weeks | 1233 (±390) | 6 | G | |

C 0.5% (2 d) | 31 (±2) weeks | 1233 (±390) | 8 | G | |||

Saline 0.9% | 31 (±2) weeks | 1233 (±390) | 6 | ||||

Isenberg (1984 March)18 | Non-randomised intervention | C 0.5% (2 d) | – | 1198 (±220) | 10 | ✓ | C |

C 0.5%, T 0.5% (2 d) | – | 1227 (±220) | 10 | ✓ | C | ||

P 1%, C 0.2% (2 d) | – | 1273 (±251) | 10 | ✓ | C | ||

Isenberg (1984 July)40 | Non-randomised intervention | C 0.5% (2 d) | – | 1178 (±208) | 12 | ✓ | C |

P 1%, C 0.2% (2 d) | – | 1282 (±207) | 12 | ✓ | C | ||

P 2.5%, T 0.5% (2 d) | – | 1135 (±282) | 12 | ✓ | C | ||

Saline | – | – | 6 | ✓ | C | ||

Jiang (2016)10 | Observational retrospective | P 0.5%, T 0.5% (3 d) | – | – | 1254 | C, R | |

Khoo (2000)16 | RCT crossover | P 1%, C 0.2% (3 d) | 26.2 weeks (test 1) 35.8 weeks (test 2) | – | 28 | ✓ | C |

P 2.5%, T 0.5% (3 d) | 26.2 weeks (test 1) 36.1 weeks (test 2) | – | 28 | ✓ | C | ||

Laws (1996)11 | Observational prospective | P 2 5% (2d), C 0.5% (4 d) | 27.1 (±2.4) | 1003 (±332) | 56 | C | |

Lees (1981)12 | Observational prospective | P 2.5%, T 0.5% (1 d) | 31 (±3.12) | 1450 (±464) | 7 | C | |

Luo (2014)21 | RCT crossover | P 0.5%, T 0.5% (3 d) | 26–37 weeks | – | 88 | ✓ | |

P 0.25%, T 0.25% (3 d) | 26–37 weeks | – | 88 | ✓ | |||

Lux (2016)27 | RCT | T 0.5% (3 d) | – | – | 30 | ✓ | |

P 5% (1 d), T 0.5% (2 d) | – | – | 30 | ✓ | |||

Merrit (1981)45 | RCT | P 2.5%, T 1% (3 d) | 32 (±0.5) | 1569 (±98.7) | 52 | C | |

P 2.5%, T 0.5%, C 0.5% (3 d) | 30.2 (±0.4) | 1250.7 (±61.6) | 30 | C | |||

Mirmanesh (1992)22 | Non-randomised Intervention | P 2.5% (3 d) | 27 (±2) | 840 (±200) | 21 | R | |

Mitchell (2016)28 | RCT | P 1%, C 0.2% (3 d) | 28.5 (±2.8) | 1148 (±523) | 25 | G, R | |

Mitchell (2011)46 | Observational prospective | P 1%, C 0.2% (3 d) | 28.24 (±2.62) | 1161 (±352) | 50 | R, C, G, N | |

Neffendorf (2015)43 | Observational retrospective | P 2.5%, C 0.5% (3 d) | 29 (no SD) | 1234 (no SD) | 138 | ✓ | R, C, other |

Ogut (1996)26 | Non-randomised intervention | P 2.5%, C 0.5%, T 0.5% (1 d) | 39.4 weeks | 3150 | 10 | ✓ | |

P 2.5%, T 1% (1 d) | 39.4 weeks | 3150 | 10 | ✓ | |||

P 2.5%, C 1% (2 d) | 39.4 weeks | 3150 | 10 | ✓ | |||

C 1%, T 1% (1 d) | 39.4 weeks | 3150 | 10 | ✓ | |||

P 2.5% (2 d) | 39.4 weeks | 3150 | 10 | ✓ | |||

C 1% (2 d) | 39.4 weeks | 3150 | 10 | ✓ | |||

T 1% (2 d) | 39.4 weeks | 3150 | 10 | ✓ | |||

Saline 0.9% | 39.4 weeks | 3150 | 10 | ✓ | |||

Phamonvaechavan (2012)23 | RCT crossover | P 2.5%, T 0.75% (2d) | 30.5 weeks | 1241.9 | 21 | ✓ | C |

P 2.5%, T 0.75% (2 d) | 30.5 weeks | 1241.9 | 21 | ✓ | C | ||

Punyawattanaporn (2009)41 | RCT | P 1%, C 0.2% (1 d) | 30.49 (2.34) | 1368 (438.99) | 70 | ✓ | R |

P 1%, C 0.2% (3 d) | 30.49 (2.34) | 1368 (438.99) | 70 | ✓ | R | ||

Rosales (1981)24 | Observational prospective | P 2.5%, T 0.5% (3 d) | – | – | 10 | C | |

Rush (2004)25 | Observational prospective | P 2.5%, T 0.5% (3 d) | – | – | 30 | R, C | |

Sindel (1986)19 | RCT | P 2.5%, T 1% (2 d) | 28.0 (1.9) weeks | 1022 (226) | 10 | ✓ | C |

P 2.5%, T 0.5% (2 d) | 28.3 (1.6) weeks | 1115 (281) | 10 | ✓ | C | ||

P 1%, T 1% (2 d) | 29.0 (2.4) weeks | 1110 (317) | 10 | ✓ | C | ||

Vicente (2012)42 | RCT | P 1%, C 0.2% (1 d) | 28.7 (2.6) weeks | – | 5 | ✓ | |

P 1%, C 0.2% (2 d) | 28.7 (2.6) weeks | – | 10 | ✓ | |||

P 1%, C 0.2% (3 d) | 28.7 (2.6) weeks | – | 15 | ✓ | |||

Wheatcroft (1993)1 | Non-randomised intervention | P 2.5%, C 0.5%, (2 d) | 29.8 weeks | 1238 | 26 | ✓ | |

P 2.5%, C 0.5%, (2 microd) | 29.8 weeks | 1238 | 26 | ✓ |

Efficacy was identified if authorsmeasured pupil dilation or successful retinopathy of prematurity eye examinations. Safety was determined if physiological measurements were taken.

BW, birth weight;C, cardiovascular;C, cyclopentolate;D, dermal; G, gastrointestinal; GA, gestational age;P, phenylephrine;R, respiratory;RCT, randomised controlled trial;T, tropicamide;d, standard drop;microd, microdrop.