Sustained 7–9-Year Stability After Sequential Icrs Implantation Combined With Corneal Cross-Linking In Progressive Keratoconus

To evaluate long-term functional and structural stability following sequential intrastromal corneal ring segment (ICRS) implantation combined with corneal cross-linking (CXL) in progressive keratoconus over 7–9 years.

Retrospective single-centre study conducted at the Department of Ophthalmology, First Faculty of Medicine, Charles University and Central Military Hospital – Military University Hospital Prague, Czech Republic.

Twenty-nine eyes with progressive keratoconus (mean age 31.2 ± 10.2 years; baseline Amsler–Krumeich stage 2.75; Kmax 58.6 ± 5,28 D; minimal pachymetry 452 ± 29 µm) underwent Ferrara ICRS implantation followed by standard accelerated transepithelial CXL. Baseline UCDVA was 0.33 ± 0.24 logMAR, BCDVA 0.49 ± 0.23 logMAR, , sphere −4.80 ± 3.29 D, and cylinder −4.34 ± 3.98 D. Outcomes were assessed at baseline, 1 year, and 7–9 years using paired t-tests (p<0.05 considered significant).

At 1 year after ICRS implantation cylinder decreased from −4.34 ± 3.98 D to −2.65 ± 1.36 D (p=0.031). Kmax decreased from 58.6 ± 5.3 D to 57.0 ± 4.7 D (p=0.19). UCDVA (logMAR) changed from 0.33 ± 0.24 to 0.40 ± 0.18 (p=0.11), while BCDVA remained stable (0.56 ± 0.16 logMAR, p=0.10). Pachymetry remained unchanged (p=0.99). At 7–9 years after surgery, Kmax further decreased to 56.3 ± 4.3 D (p=0.031). UCDVA showed no significant long-term change (0.39 ± 0.23 logMAR, p=0.24). BCDVA remained stable (0.51 ± 0.22 logMAR, p=0.61). Pachymetry decreased to 443 ± 26 µm (p=0.011). Mean keratoconus stage decreased from 2.75 ± 0.45 to 2.37 ± 0.60.

Sequential ICRS implantation combined with CXL provides early refractive modification and durable long-term stabilization in progressive keratoconus. Visual function remains preserved up to 9 years, supporting this combined reshaping and biomechanical strengthening strategy as an effective long-term treatment option.