Review Article
An Update on the Safety and Efficacy of Corneal Collagen Cross-Linking in Pediatric Keratoconus
Table 1
Variability of the criteria used to define keratoconus progression in different studies.
| Study | Visual acuity | Refraction | Keratometry | Pachymetry | Topography | Considerations |
| Caporossi et al. [30] | UCVA/BSCVA decrease ≥ 1 Snellen line | ΔSph or ΔCyl > 0.5 D |
> 0.5 D | Decrease in thinnest pachymetry ≥ 10 μm | ΔSAI/SI > 0.5 D | At least 2 parameters in 3 months |
| Caporossi et al. [31] | UCVA/BSCVA decrease ≥ 1 Snellen line | ΔSph or ΔCyl > 0.5 D | > 1 D | Decrease in thinnest pachymetry ≥ 10 μm | ΔSAI/SI > 0.5 D | At least 3 parameters (1 clinical and 2 instrumental) in 3 months |
| Vinciguerra et al. [32] | | Change in Sph or Cyl ≥ 3 D | ≥ 1.5 D on 2 consecutive topographies | Decrease in CCT ≥ 5% on 3 consecutive tomographies | | Any parameter in 3 months |
| Zotta et al. [33] | | ΔSE > 0.75 D | of cone apex > 0.75 D | | | Any parameter in 6 months |
| Chatzis and Hafezi [34] | | | > 1 D | | | Follow-up period of maximum 12 months |
| Bakshi et al. [35] | | ΔCyl ≥ 1.5 D | ≥ 1.5 D | | | Any parameter at 3 time points in 12 months |
| Magli et al. [36] | | ΔCyl > 1 D | of cone apex > 1 D | | | Any parameter in 6 months |
| Shetty et al. [32, 37] | | | > 1–1.5 D with corresponding change in refraction | Decrease in thinnest pachymetry ≥ 5% | | Any parameter in 6 months |
|
Zotta et al. [33] | | ΔCyl ≥ 1 D and ΔSE ≥ 0.5 D | ≥ 1 D | | | All 3 parameters on consecutive examinations |
|
|
UCVA: uncorrected visual acuity, BSCVA: best spectacle corrected visual acuity, Sph: sphere, Cyl: cylinder, SAI: surface asymmetry index, SI: symmetry index, CCT: central corneal thickness, SE: spherical equivalent, and Δ: increase in.
|