International Journal of Keratoconus and Ectatic Corneal Diseases

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VOLUME 10 , ISSUE 1--2 ( January-December, 2023 ) > List of Articles

Original Article

Variable Thickness Intracorneal Ring Segment for the Treatment of Keratoconus

Adel Barbara, Joseph Pikkel, Jorge L Alio, Ramez Barbera, Michael Mimouni

Keywords : Intracorneal, Keratoconus, Ring, Segment, Thickness, Variable

Citation Information : Barbara A, Pikkel J, Alio JL, Barbera R, Mimouni M. Variable Thickness Intracorneal Ring Segment for the Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2023; 10 (1--2):8-12.

DOI: 10.5005/jp-journals-10025-1198

License: CC BY-NC 4.0

Published Online: 23-04-2024

Copyright Statement:  Copyright © 2023; The Author(s).


Aim: To report outcomes of a new variable thickness intracorneal ring segment (VT-ICRS) for the treatment of keratoconus. Methods: This was a retrospective interventional case series of consecutive keratoconus eyes that underwent VT-ICRS implantation from January 2018 to December 2020 with a minimum follow-up time of 3 months. Primary outcomes included best spectacle-corrected visual acuity (BSCVA), uncorrected distance visual acuity (UCVA) and adverse events. Secondary outcomes included keratometry and manifest refraction. Results: Overall, 9 eyes of 7 patients with a mean age of 30.22 ± 8.58 (range, 21–49 years) of which 85.7% (n = 6) were of male gender were included. The mean follow-up time was 9.0 ± 5.3 (range, 4–17) months. No intraoperative or postoperative adverse events were identified during the follow-up period of these patients. At final follow-up, there was significant improvement in logMAR UCVA (from 0.95 ± 0.21 to 0.34 ± 0.31, p < 0.001), manifest sphere (from 1.11 ± 1.69 to −0.13 ± 0.35 D, p = 0.05), manifest cylinder (from −6.61 ± 2.83 to −2.44 ± 2.26 D, p < 0.001), K2 (51.94 ± 5.43 to 49.20 ± 5.78 D, p = 0.01), and logMAR BSCVA (from 0.35 ± 0.10 to 0.15 ± 0.14, p = 0.002). The mean safety index was 1.68 ± 0.53 (range, 1–2.50) and the mean efficacy index was 1.24 ± 0.69 (range, 0.39–2.25). Alpins refractive vector analysis revealed a mean surgically induced astigmatism (SIA) of 4.99 ± 1.20 D (range, 3.79–7.12 D) with a mean SIA axis of 96.3 ± 42.5° (range, 25.1–142°). Conclusion: The initial results of VT-ICRS for the treatment of keratoconus are encouraging. Future studies should compare VT-ICRS to classic ICRSs for the treatment of keratoconus.

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