Asymmetric Intrastromal Corneal Ring Segments with Progressive Base Width and Thickness for Keratoconus: Evaluation of Efficacy and Analysis of Epithelial Remodeling

Abstract

Purpose: The aim of this study is to describe visual outcomes and epithelial remodeling following the implantation of asymmetric intracorneal ring segments (ICRSs) of variable thickness and base width for the management of duck-type keratoconus. Methods: A prospective observational study of patients with duck-type keratoconus was conducted. All patients received one ICRS AJL PRO + implant (AJL Ophthalmic). We analyzed demographic and clinical data, anterior segment optical coherence tomography (AS-OCT) data and Scheimpflug camera images obtained with a Placido disc MS-39 (CSO, Firenze, Italy) one and six months after surgery to determine keratometric and aberrometric outcomes and epithelial remodeling. Results: We studied 33 keratoconic eyes. ICRS implantation significantly improved both corrected distance visual acuity (CDVA) and uncorrected distance visual acuity at six months, as assessed with the logMAR (minimum angle of resolution) system, from 0.32 ± 0.19 to 0.12 ± 0.12 (p < 0.001) and from 0.75 ± 0.38 to 0.37 ± 0.24 (p < 0.001), respectively. Overall, 87% of implanted eyes gained ≥ 1 line of CDVA, and 3% of patients (n = 1) lost one line of CDVA; 55% of eyes attained a manifest refraction spherical equivalent between +1.50 and −1.50 D. Epithelial remodeling was greater at the wider and thicker end (+11.33 µm ± 12.95; p < 0.001 relative to the initial value) than at the narrower and thinner end (+2.24 µm ± 5.67; p = 0.01). Coma aberration was significantly reduced from 1.62 ± 0.81 µm to 0.99 ± 0.59 µm (p < 0.001). Conclusions: AJL-PRO + ICRS implantation for duck-type keratoconus improves refractive, topographic, aberrometric and visual parameters and induces progressive epithelial thickening along the segment.

A new technique to implant intracorneal ring-segments from the perilimbal region: one-year prospective pilot study report

“…Comparing our findings with existing literature proves challenging due to the absence of studies employing a similar technique. Nonetheless, for reference, Fernandez-Vega et al [ 21 ] reported a safety index of 1.13 in a cohort of 409 patients with six months of follow-up, while Benlarbi et al [ 22 ] more recently reported a value of 1.45, also with a six-month follow-up. It’s important to note that these studies differ from ours in various aspects, with the primary commonality being the evaluation of the safety index in keratoconus patients undergoing ICRS implantation.…”

Епітеліальний Профіль Рогівки І стабільність Рефракції Після Ексимерлазерної Корекції Аметропії, Виконаної На Різних Платформах

“…Гіперметропічний профіль ексимерлазерної абляції призначений для збільшення кривизни центральної ділянки, який створює морфологію, подібну до кератоконічної рогівки. Як відомо з джерел літератури, при кератоконусі фіксують стоншення епітелію в ділянці найбільшого вигину рогівки [20][21][22][23][24][25]. Тому можна припустити, що профіль товщини епітелію після гіперметропічної абляції буде подібним до того, що спостерігається при кератоконусі.…”