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.

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 (140-ICRS) 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 (=0.03). The mean sphere value reduced from -5.34±2.74 preoperatively to -2.06±1.84 postoperatively (<0.001) after the first ICRS implantation and decreased to -0.59±1.54 postoperatively (<0.001) 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 (=0.001). The SE and asphericity changes were statistically significant (<0.001). The researchers did not find intraoperative or postoperative complications for both procedures.

Conclusion: The combination of 2 different ICRSs can efficiently regularize the cornea, reduce the SE, and improve visual acuity in selected keratoconus patients.