Table 2.
Data extracted from eligible RCTs in qualitative systematic review
| Study | Design | Subjects/ sample size | Age (yr) | Sex | Supplement | Duration (month) | Dosage | Indicator | Main results | Quality Score |
|---|---|---|---|---|---|---|---|---|---|---|
| Bo-Jie Hu et al. 2011 [29] | Quasi-Experimental |
Total 90 (30 healthy, 30 non-PDR with treatment, 30 non-PDR non-treatment) |
59 | M/F | lutein + zeaxanthin | 3 | 6 mg + 0.5 mg | BCVA, CS, OCT |
After medication: -Improvement of VA -↑Sig CS -↓Sig Foveal thickness |
3 |
| Garcia-Medina et al. 2011 [30] | RCT |
Total 105 (62 T2DM with non-PDR with treatment, 43 T2DM with non-PDR without treatment) |
30–65 | M/F | Mixture: | 60 | 2tablets/day |
MDA, TAS, aBCVA, DR score |
-↓Sig MDA in both groups -↓Sig TAS in placebo and ↑NS in treatment group -NS change in aBCVA -↑Sig DR score in placebo and ↑NS in treatment group |
3 |
| VC, | 60 mg | |||||||||
| Alpha-Tocopherol | 10 mg | |||||||||
| Niacin | 10 mg | |||||||||
| b-Carotene | 3 mg | |||||||||
| Lutein, | 3 mg | |||||||||
| Zn | 13.5 mg | |||||||||
| Cu | 1 mg | |||||||||
| Se | 10 mcg | |||||||||
| Manganese | 1 mg | |||||||||
| Proteins | 130 mg | |||||||||
| CH | 60 mg | |||||||||
| Fat | 230 mg | |||||||||
| Nebbioso et al. 2012 [31] | RCT |
Total 32 (16 pre-DR in treatment, 16 pre-DR in placebo) |
57 | M/F |
Mixure: ALA, genistein, VC,VE, B complex |
1 | 400 + 80 + 30 + 5 + 15 mg |
FORT, d-ROM BAP |
-↑Sig. BAP by treatment -↑Sig. OP by treatment |
3 |
| Domanico et al. 2015 [32] | RCT |
Total 68 (34 Non-PDR with/without supplements) |
40–79 | M/F |
A mixture: Pycnogenol, Coenzyme Q10, VE |
6 |
1 tablet/ day (50+ 20+ 30 mg) |
CMT FORT |
-↑NS BCVA in both groups -↓Sig. FORT at 3 mo, ↓NS at 6 mo treatment -↓Sig. CMT at 3 mo, ↓NS at 6 mo treatment -NS correlation between FORT and CMT |
2 |
| Roig Revert et al. 2015 [33] |
RCT (Community-Based Study Design) |
Total 208 (68T2DM with DR, 62 T2DM without DR, 78 healthy) | 25–80 | M/F |
Mixture: DHA, vitamins E, C, B1, B2, B3, B6, B9, B12, lutein, zeaxanthin, glutathione, hydroxytyrosol, Se, Mn, Zn, Cu |
18 | Not clear |
MDA, TAS, HbA1C, BS, lipid profile, BCVA, retinal thickness, IOP |
At baseline: -↑Sig. Oxidative stress,inflammatory, vascular risk markers in T2DM + DR vs. others -↓Sig.TAS in T2DM + DR vs. others After treatment: -↓Sig MDA in T2DM+ DR -↑Sig TAS in T2DM + DR -↑Sig HbA1C in T2DM + DR -NS changes in lipid profile in T2DM ± DR -↓NS BCVA -↓NS IOP in T2DM + DR -↑Sig IOP in T2DM-DR -↑Sig RNFL in T2DM ± DR -↑NS MT in T2DM+ DR -↓NS MT in T2DM- DR |
2 |
| Rodríguez-Carrizalez et al. 2016 [34] | RCT |
Total 60 (20 Non-PDR in each group) |
60 | M/F |
Group 1: Coenzyme Q10 |
6 | 400 mg |
HbA1c, FBS, Lipid profile, LPO, Nitrites/ Nitrates, TAC, CAT, GPX, CVA, LEP |
-↓NS HbA1C, FBS, Tchol, LDL, TG by treatment -↑NS HDL by treatment -↓Sig. LPO, Nitrites/ Nitrates, CAT, GPx by treatment -↑Sig. TAC by treatment -NS change in CVA in all groups -NS decraese in LEP in all groups |
2 |
|
Group 2: Mixture of lutein, astaxanthin, zeaxanthin,VC,VE, Zn, Cu |
10 + 4 + 1 + 180 + 30 + 20 + 1 mg | |||||||||
| Group 3: placebo | ||||||||||
| Chatziralli et al. 2017 [35] | Quasi-experimental |
Total 282 (282 Insulin-dependent T2DM + DR in different stages) |
50–70 | M/F | VE | 3 | 300 mg | MDA, DR degree, HbA1C |
-↓Sig. MDA in all DR stages -↑Sig response to VE in PDR by treatment naïve vs. prior laser photocoagulation |
0 |
CMT Central macular thickness, FORT Free oxygen radical test, MDA Malondialdehyde, TAS Total antioxidant status, aBCVA Average best corrected visual acuity (average of both eyes of each patient on a decimal scale), LPO Lipo-peroxidation products, NS Non significant, d-ROM reactive oxygen metabolites, BAP Biological antioxidant potential, OP oscillatory potential, CS Contrast sensitivity, OCT optical coherence tomography, PDR proliferative diabetic retinopathy, MT Macular thickness, IOP Intraocular pressure, RNFL Retinal nerve fiber layer thickness, CAT Catalase, TAC total antioxidant capacity, LEP Left eye pressure, CVA Corrected visual acuity, CH Carbohydrate