Double intrastromal corneal ring segment implantation: a new approach for improved clinical outcomes in keratoconus patients

AIM: To evaluate the clinical outcomes after subsequent implantation of a new intrastromal corneal ring segment (ICRS) model followed by an additional short-arc ICRS implant in keratoconus patients.<br /> METHODS: This retrospective single-arm cohort study evaluated 25 eyes of 21 keratoconus patients implanted with the new ICRS followed by 140-arch length ICRS (140ICRS) implantation. Uncorrected distance visual acuity (UDVA, logMAR), corrected distance visual acuity (CDVA, logMAR), sphere, astigmatism, keratometry, spherical equivalent (SE), and asphericity were compared preoperatively and postoperatively after both ICRS implantation. RESULTS: The average follow-up time after 140-ICRS implantation was 6.40 +/- 2.20mo. The mean preoperative UDVA improved from 1.27 +/- 0.14 preoperative to 0.52 +/- 0.26 after both ICRS implantation (P=0.03). The mean sphere value reduced from-5.34 +/- 2.74 preoperatively to-2.06 +/- 1.84 postoperatively (P<0.001) after the first ICRS implantation and decreased to-0.59 +/- 1.54 postoperatively (P<0.00 1) after 140-ICRS implantation. The mean preoperative astigmatism was-3.72 +/- 1.56 and improved to-2.82 +/- 1.08 after the first ICRS implantation, and following the 140-ICRS implantation, the mean astigmatism was-1.37 +/- 0.67 (P=0.001). The SE and asphericity changes were statistically significant (P<0.001). The researchers did not find intraoperative or postoperative complications for both procedures.<br /> CONCLUSION: The combination of 2 different ICRSs can efficiently regularize the cornea, reduce the SE, and improve visual acuity in selected keratoconus patients.