Annual change of corneal endothelial cell density (ECD) in normal eyes
| Study | Study site | Study type | Number of eyes/subjects | Age (years) | Follow-up (years) | ECD change/year |
| Cheng et al 26 | UK | Longitudinal | 103 eyes | 11 participants were <65 years; 53 were between 65 and 74 years and 39 were ≥75 years | 2 | −1% |
| McGill, Liakos27 | UK | Longitudinal | 48 subjects | Not mentioned | 2 | −0.6% |
| Werblin28 | USA | Longitudinal | 5 eyes | 69.3±8 | 5 | −0.80% |
| Numa et al29 | Japan | Longitudinal | 9 subjects | 67.4±7.7 | 5 | −0.26%±1.32% (−8.36 to 17.4 cells/mm2) |
| Bourne et al 30 | USA | Longitudinal | 42 subjects | 59.5±16.8 (range 30–84, at the recent follow-up) | 10.6±0.2 | −0.6%±0.5% (−16 cells/mm2) |
| Yee et al 31 | USA | Cross-sectional | 60 eyes | Range 12–85 | – | −9.45 cells/mm2 |
| Rao et al 32 | India | Cross-sectional | 537 eyes | 48±16.5 (range 20–87) | – | −0.30% |
| Hashemian et al 33 | Iran | Cross-sectional | 525 eyes | 52.7±19.1 (range 20–85) | – | −0.60% |
| Yunliang et al 34 | China | Cross-sectional | 1329 eyes | 44±21 (range 10–98) | – | −0.30% |
| Niederer et al 35 | Auckland | Cross-sectional | 85 subjects | 38±16 (range 18–87) | – | −0.50% |
| Higa et al 36 | Japan | Cross-sectional | 2602 eyes | 59.1±14.9 | – | −0.25% (−7.43 cells/mm2) |
| Islam et al 37 | Pakistan | Cross-sectional | 464 eyes | 39.52±18.09 (range 12–80) | – | −0.28% |
| Abdellah et al 38 | Egypt | Cross-sectional | 568 eyes | 49±15.2 (range 20–85) | – | −0.30% |