Table 1.
Characteristics of the eligible randomized clinical trials.
| Authors (Year) | Study Participants | Trial Duration | No. of Groups | Lnterventions | Measurement Method for MPOD | Follow-Up Rates (%) | Quality Score * |
|---|---|---|---|---|---|---|---|
| Trieschmann et al. (2007) [20] | 130 AMD patients aged (71.4 ± 7.6) years in Germany | 6 months | 2 | 12 mg lutein and 1 mg zeaxanthin combined with other antioxidants; placebo | Fundus autofluorescence | 94.6 | 3 |
| Richer et al. (2007) [21] | 90 AMD patients aged (74.1 ± 7.5) years in the USA | 12 months | 3 | 10 mg lutein; 10 mg lutein combined with other antioxidants; placebo | HFP | 84.4 | 5 |
| Weigert et al. (2011) [30] | 126 AMD patients aged (71.6 ± 8.6) years in Austria | 6 months | 2 | 20 mg lutein daily in months 1 to 3 and 10 mg lutein daily in months 4 to 6; placebo | Spectral fundus reflectance | 87.3 | 3 |
| Arnold C et al. (2013) [31] | 20 AMD patients aged (66.0 ± 8.0) years in Germany | 10 weeks | 2 | 10 mg lutein plus 3 mg zeaxanthin; placebo | VISUCAM NM/FA | 100.0 | 5 |
| García-Layana et al. (2013) [32] | 44 AMD patients aged (68.5 ± 8.5) years in Spain | 12 months | 2 | 12 mg lutein plus 0.6 mg zeaxanthin combined with other antioxidants; placebo | HFP | NR | 3 |
| Dawczynski et al. (2013) [33] | 172 AMD patients aged (70.0 ± 10.0) years in Germany | 12 months | 3 | 10 mg lutein, 1 mg zeaxanthin combined with other antioxidants; 20 mg lutein, 2 mg zeaxanthin combined with other antioxidants; placebo | VISUCAM NM/FA | 84.3 | 3 |
| Murray et al. (2013) [34] | 72 AMD patients aged (70.5 ± 8.7) years in UK | 12 months | 2 | 10 mg lutein daily; placebo | HFP | 86.9 | 5 |
| Arnold C et al. (2013) [35] | 172 AMD patients aged (69.0 ± 10.0) years in Germany | 12 months | 3 | 10 mg lutein plus 1 mg zeaxanthin combined with other antioxidants; 20 mg lutein plus 2 mg zeaxanthin combined with other antioxidants; placebo | VISUCAM NM/FA | 84.3 | 5 |
| Huang et al. (2015) [36] | 112 AMD patients aged (69.1 ± 7.4) years in China | 24 months | 4 | 10 mg lutein; 20 mg lutein; 10 mg lutein plus 10 mg zeaxanthin; placebo | Fundus autofluorescence | 96.4 | 5 |
| Kvansakul et al. (2005) [37] | 92 healthy men in UK | 12 months | 4 | 10 mg lutein; 10 mg zeaxanthin; 10 mg lutein plus 10 mg zeaxanthin in months 1 to 6 and 20 mg lutein; 20 mg zeaxanthin; 10 mg lutein plus 10 mg zeaxanthin in months 7 to 12; placebo | MAP | 79.3 | 4 |
| Bone et al. (2007) [38] | 19 healthy subjects in the USA | 120 days | 2 | 14.9 mg of meso-zeaxanthin, 5.5 mg of lutein, and 1.4 mg of zeaxanthin; placebo | HFP | NR | 3 |
| Johnson et al. (2008) [39] | 57 healthy women in the USA | 4 months | 3 | 12 mg lutein plus 0.5 mg zeaxanthin;12 mg lutein plus 800 mg DHA; placebo | HFP | 86.0 | 4 |
| Bone et al. (2010) [40] | 100 healthy subjects in the USA | 140 days | 4 | 5 mg lutein; 10 mg lutein; 20 mg lutein; placebo | HFP | 87.0 | 4 |
| Connolly et al. (2011) [17] | 44 healthy subjects in Ireland | 6 months | 2 | 10.6 mg meso-zeaxanthin, 5.9 mg lutein, and 1.2 mg zeaxanthin; placebo | HFP | 79.5 | 5 |
| Nolan et al. (2011) [41] | 121 healthy subjects in Ireland | 12 months | 2 | 12 mg lutein, 1 mg zeaxanthin combined with other antioxidants; placebo | HFP | 62.8 | 4 |
| Landrum et al. (2012) [42] | 30 healthy subjects in the USA | 24 weeks | 3 | 20 mg lutein diacetate; 20 mg lutein; placebo | HFP | NR | 3 |
| Loughman et al. (2012) [22] | 36 healthy subjects in Ireland | 6 months | 3 | 20 mg lutein plus 2 mg zeaxanthin; 10 mg meso-zeaxanthin, 10 mg lutein plus 2 mg zeaxanthin; placebo | HFP | 88.9 | 5 |
| Yao et al. (2013) [43] | 120 healthy subjects in China | 12 months | 2 | 20 mg lutein; placebo | HFP | 82.5 | 4 |
| Bovier et al. (2015) [44] | 102 healthy subjects in the USA | 4 months | 3 | 20 mg zeaxanthin; 8 mg lutein plus 26 mg zeaxanthin combined with other antioxidants; placebo | HFP | 67.6 | 4 |
| Nolan et al. (2016) [45] | 105 healthy subjects in Ireland | 12 months | 2 | 10 mg lutein, 2 mg zeaxanthin, and 10 mg meso-zeaxanthin; placebo | Autofluorescence | 80.0 | 5 |
Abbreviations: AMD, age-related macular degeneration; HFP, heterochromatic flicker photometry; MPOD, macular pigment optical density; NR, not report. * Study quality was judged based on the Jadad scale.