Clinical outcomes after implantation of a combination of intrastromal corneal ring segments in different optical zones in advanced keratoconus

PURPOSE: To evaluate the efficacy and safety of combined intrastromal corneal ring segment (ICRS) implantation in different optical zones for advanced keratoconus. METHODS: This retrospective study analyzed 32 eyes from 30 patients who underwent combined implantation of an ICRS (320° arc, 200 µm) in the 5-mm zone and a high-myopia ICRS (400 µm) in the 6-mm zone. Pre- and postoperative (6 months) assessments included best-corrected distance visual acuity (BCVA), manifest refraction spherical equivalent (MRSE), keratometry (K), and asphericity (Q-value). RESULTS: A total of 32 eyes from 30 patients (mean age: 31.1 ± 10.43 years) were analyzed. Significant postoperative improvements were observed in BCVA ( P = 0.002), MRSE ( P < 0.001), K1, K2, mean K ( P < 0.001), maximum K, tomographic astigmatism, and Q-value ( P < 0.001). No intraoperative or postoperative complications were reported. CONCLUSIONS: Combined ICRS and high-myopia ICRS implantation improves visual acuity, reduces refractive error, and enhances corneal topography in advanced keratoconus. Further studies are needed to confirm long-term stability and safety.