Clinical outcomes after femtosecond laser-assisted implantation of an intrastromal corneal ring segment with a 340-degree arc length in postkeratoplasty patients: 12-month follow-up

Purpose: To assess the clinical outcomes after implantation of a new 340-degree arc length intrastromal corneal ring segment (ICRS) aided by the femtosecond laser in postkeratoplasty patients after a 12-month follow-up. Setting: Private practice, Brasilia, Brazil. Design: Prospective case series. Methods: Eyes with previous keratoplasty had ICRS implantation assisted by femtosecond laser. The primary outcome measure was the change in the uncorrected distance visual acuity (UDVA) 12 months postoperatively. The secondary outcome measures were the corrected distance visual acuity (CDVA), refraction, and corneal tomography 1, 3, 6, and 12 months postoperatively. The astigmatism results were analyzed using vector analysis through the double-angle polar plot. Results: Of the 18 patients, 7 (38.9%) were men, and 11 (61.1%) were women. The mean UDVA was 20/250 (1.15 logarithm of the minimum angle of resolution [logMAR]) before implantation and 20/70 (0.54 logMAR) at the last follow-up (P < .001). The mean CDVA improved from 20/35 (0.26 logMAR) to 20/25 (0.10 logMAR) (P < .001). The mean spherical equivalent and astigmatism components were significantly reduced after ICRS implantation. The mean corneal astigmatism decreased from 5.55 +/- 2.29 D preoperatively to 3.92 +/- 1.82 D postoperatively (P < .001). The CDVA remained the same or improved in 19 of 20 eyes and decreased by 1 line in 1 patient. There were no surgical complications. Conclusion: A new ICRS with a 340-degree arc length was effective in treating postkeratoplasty eyes, improving visual acuity and reducing corneal astigmatism. Copyright (C) 2019 Published by Wolters Kluwer on behalf of ASCRS and ESCRS