Table 1. Characteristics of studies included in the systematic review
| study | country | type of cases: number of cases (number of males) | controls (males) | age of cases mean(sd) | age of controls mean(sd) | diagnostic criteria | MMSE score in cases mean(sd) | method | eyes | NOS score |
| Kergoat 2001[33] | Canada | AD(mild-mod):30(NA) | 30(NA) | 70.0(1.3) | 72.1(1.3) | NINCDS-ADRDA, DSM-IV |
21.6(1.0) | NFA | monocular | 5.0 |
| Parisi 2001[10] | Italy | AD(mild):17(9) | 14(NA) | 70.4(6.1) | matched | NINCDS-ADRDA, DSM-III |
--- | OCT | monocular | 5.0 |
| Iseri 2006[29] | Turkey | AD(mild-mod):14(6) | 15(7) | 70.1(9.7) | 65.1(9.8) | NINCDS-ADRDA, DSM-IV |
18.5(6.3) | OCT | binocular | 5.0 |
| Berisha 2007[34] | United Kingdom | AD(mild-mod):9(NA) | 8(NA) | 74.3(3.3) | 74.3(5.8) | NINCDS-ADRDA, DSM-IV |
23.8(5.1) | OCT | binocular | 6.0 |
| Paquet 2007[32] | France | MCI:23(8) AD(mild):14(5) AD(mod-sev):12(6) |
15(2) | MCI:78.7(6.2) AD(mild):78.3(5.1) AD(mod-sev):78.8(4.9) |
75.5(5.1) | NINCDS-ADRDA 22.6 [range:20-25] | OCT | binocular | 3.5 | |
| Chi 2010[12] | China | AD(mild-mod):12(7) | 17(10) | 75.4(7.30) | 75.3(5.8) | NINCDS-ADRDA, DSM-IV |
21.4(5.0) | OCT | monocular | 7.0 |
| Kesler 2011[11] | Israel | MCI:24(NA) AD(mild-mod):30(NA) |
24(NA) | MCI:71.0(10.0) AD:73.7(9.9) |
70.9(9.2) | DSM-IV, Petersen criteria |
MCI:28.1(2.1) AD:23.6(4.3) |
OCT | binocular | 5.5 |
| Min 2012[24] | China | MCI:12(NA) AD(mild):10(NA) AD(mod):10(NA) AD(sev):7(NA) |
30(NA) | MCI:71.6(6.1) AD(mild):71.7(7.6) AD(mod):71.4(6.1) AD(sev):72.1(7.7) |
71.5(5.2) | NINCDS-ADRDA, Petersen criteria |
≤25 | OCT | binocular | 7.0 |
| Chen2013[13] | China | AD(mild-mod):38(16) | 26(11) | 73.1(8.5) | 70.2(9.8) | NINCDS-ADRDA | <28 | OCT | binocular | 7.0 |
| Kirbas 2013[9] | Turkey | AD(mild-mod):40(22) | 40(20) | 69.3(4.9) | 68.9(5.1) | NINCDS-ADRDA | 18-25 | OCT | monocular | 5.0 |
| Moreno- Ramos 2013[30] | Spain | AD(mild):10(6) | 10(6) | 73.0(6.5) | 70.2(5.5) | NINCDS-ADRDA | 16.4(1.5) | OCT | binocular | 5.0 |
| Ascaso 2014[31] | Spain | MCI:21(NA) AD:18(NA) MCI+AD:21(NA) |
41(21) | 72.1(8.7) | 72.9(7.9) | DSM-IV, Winblad criteria |
MCI+AD:19.3 | OCT | binocular | 5.0 |
| Ferrari 2014[28] | Italy | AD(mild-mod):53(20) | 23(11) | 71.5(6.6) | 66.7(7.4) | --- | --- | OCT | --- | --- |
| Garcia- Martin 2014[16] | Spain | AD(mild):20(8) | 28(9) | 79.3(4.1) | 72.1(5.1) | NINCDS-ADRDA, DSM-IV |
23.7(3.3) | OCT | monocular | 6.0 |
| Shen 2014[25] | China | MCI:23(10) | 52(31) | 74.4(3.2) | 74.1(2.6) | Petersen criteria | 22.2(1.5) | OCT | binocular | 8.0 |
| Zhu 2014[17] | China | MCI:47(14) AD:10(5) | 167(53) | MCI:76.1(8.2) AD:79.6(8.6) | 75.5(7.7) | CDR,ADL,DSM-IV,Petersen criteria | --- | OCT | --- | 7.5 |
| Cheung 2015[15] | Singapore | MCI:41(13) AD:100(43) |
123(67) | MCI:70.4(10.2) AD:73.5(6.23) |
65.7(3.8) | NINCDS-ADRDA, DSM-IV, Petersen criteria |
--- | OCT | monocular | 7.0 |
| Gao 2015[14] | China | MCI:26(16) AD(mild-mod):25(11) |
20(14) | AD:74.7 MCI:73.5 | 71.95 | NINCDS-ADRDA, Petersen criteria |
AD:23.6 MCI:28.1 |
OCT | binocular | 7.0 |
| Oktem 2015[18] | Turkey | MCI:35(15) AD:35(14) |
35(12) | MCI:74.1(6.3) AD:75.4(6.9) |
70.2(8.0) | DSM-IV, Petersen criteria |
AD:18 MCI:28 |
OCT | binocular | 6.0 |
| MCI, mild cognitive impairment | AD(mod-sev), moderate-to-severe Alzheimer’s disease | NFA, Nerve Fiber Analyzer | ||||||||
| AD, Alzheimer’s disease | NINCDS-ADRDA, National Institute of Neurologic and | NOS, Newcastle-Ottawa Scale | ||||||||
| AD(mild), mild Alzheimer’s disease | Communicative Disorders and Stroke-Alzheimer's Disease | CDR, Clinical Dementia Rating | ||||||||
| AD(mod), moderate Alzheimer’s disease | and Related Disorders Association | ADL, Activities of Daily Living | ||||||||
| AD(sev), severe Alzheimer’s disease | DSM, Diagnostic and Statistical Manual of Mental Disorders | NA, not available | ||||||||
| AD(mild-mod), mild-to-moderate Alzheimer’s disease | MMSE, Mini-Mental Status Examination | OCT, Optical Coherence Tomography | ||||||||