Table 1.
Summary of main clinical studies on ICRS types.
| ICRS type | Study (author, year) | Patients (eyes) | Mean age | Baseline UDVA (logMAR) | Baseline CDVA (logMAR) | Kmax (preop/postop) | Corneal thickness (min) | Visual outcome (CDVA gain) | Complications |
|---|---|---|---|---|---|---|---|---|---|
| INTACS | Warrak et al., 2020 | 932 eyes | 27.4 ± 6.5 years | 0.75 | 0.27 | Not stated/−3.8 D | ⩾400 µm | +1.8 lines | 0.4% extrusion, halos/glare (~10%–15%) |
| KeraRing | Coskunseven et al., 2008 | 50 eyes | 29.3 years | Not specified | 0.41 | 50.63 → 47.56 D | ⩾400 µm | +1–4 lines | 6% migration, no extrusions |
| Ferrara Ring | Costa et al., 2021 | 124 eyes | Not specified | 0.91 | 0.40 | 55.23 → 53.43 D | ⩾400 µm | +0.18 logMAR | 4.8% extrusion, 12.9% required ICRS exchange |
| MyoRing | Naderi et al., 2021 | 48 eyes | Not specified | 1.20 | 0.63 | Not specified/−6.51 D | ⩾400 µm | +2 lines | 15.8% reoperation rate |
| CAIRS | Jacob et al., 2023 | 20 patients (24 eyes) | Not specified | Not specified | Not specified | Reduced (not quantified) | ⩾400 µm | +1.29 ± 1.33 lines | No major complications; 7 with opacification |
CDVA, corrected distance visual acuity; ICRS, intrastromal corneal ring segments; UDVA, uncorrected distance visual acuity.