Table 1. Characteristics of included randomized controlled trials.

Study	Participants	Participants’ characteristics	Interventions	Measurement Method for MPOD	Trial Duration
Yurong Gao et al. (2018)[29]	48 AMD patients; 52 eyes	24 dry AMD patients;24 wet AMD patients F 20; M 28 age 61.9±11.24	1.20mg/d lutein 2.blank	Fundus autofluorescence	3 months
Chan Li et al.(2017)[30]	200 early AMD patients	F101; M 99 age 70.22±7.13	1.20mg/d lutein 2.placebo	not given	12 months
Richer, S. P. et al.(2011)[31, 32]	60 mild-to-moderate AMD patients	F 3; M 57 age 74.9±10	1.8mg/d Z 2.8mg/d Z plus 9mg/d L 3.placebo	HFP	12 months
Weigert, G. et al.(2011)[33]	126 AMD patients (stages 2,3,and 4)	age 71.6±8.6 F66; M50	1.20mg/d/ L 2.placebo	Spectral fundus reflectance	6 months
Arnold, C. et al(2013)[34]	145 dry AMD patients	age 69.1±9.7 F79;M 66 BMI 27.8±4.34	1.10 mg L, 1 mg Z, 100 mg DHA, 30 mg EPA 2. 20 mg L, 2mg Z, 200 mg DHA, 60 mg EPA 3.placebo	1-wavelength reflection method	12 months
Garcia-Layana, A. et al.(2013)[35]	44 early AMD patients	F18; M26 age 68.53±8.43 BMI 25±1.45	1.12mgL 0.6mg Z 280mgDHA 2.placebo	HFP	12 months
Murray, I. J. et al(2013)[36]	72 AMD patients	age 70.5±8.7 F35; M37	1.10mg L 2.placebo	HFP	12 months
Huang, Y. M. et al.(2015)[37–39]	81 early AMD patients	F 47; M34 age 69.33±7.32 BMI24.67±3.22	1.10mgL 2.20mgL 3.placebo	Fundus autofluorescence	24 months
Azar, G. et al.(2017)[40]	126 AMD patients	F74; M52 age 75.3±7.61 BMI 25.69±4.68	1.5mgL1mgZ 2.placebo	Fundus autofluorescence	12months

Abbreviations: HFP, heterochromic flicker photometry; F, female; M, male; BMI, body mass index; Z: zeaxanthin; L: lutein.