ESCRS - POCOR035 - Variable Thickness Rings For Keratoconus: A Prospective Case Series On Visual, Refractive, And Corneal Topographic Outcomes

Variable Thickness Rings For Keratoconus: A Prospective Case Series On Visual, Refractive, And Corneal Topographic Outcomes

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR035 | Type: Case Report | DOI: 10.82333/jpnt-sh04

Authors: Dr Raluca Bievel Radulescu* 1 , Dr Cristina Monterosso 2

1Fondazione Banca Degli Occhi del Veneto,Venice,Italy, 2Ospedale Dell'Angelo,Mestre,Italy

Purpose

To evaluate the short-term clinical outcomes of variable thickness rings (VTR) in keratoconus patients, focusing on visual, refractive, corneal topographic, and aberrometric changes.

Setting

This prospective, noncomparative case series included 6 eyes with mild to moderate keratoconus treated with Mularoni-designed VTR (Ring&Co, Bologna, Italy). Preoperative and postoperative assessments at 1 and 3 months included:

  • (UDVA) and SCDVA 

  • Manifest refraction

  • Corneal topography 

  • Pachymetry

  • Higher-order aberrations

  • Corneal stability index 

All surgeries were performed under topical anesthesia using a femtosecond laser. VTR implants ranged from 200–400 μm in thickness and 120–160° in arc length

Report of case

  • Visual Acuity: UDVA improved from 0.65 ± 0.35 to 0.32 ± 0.08 logMAR; SCDVA improved from 0.46 ± 0.23 to 0.32 ± 0.08 logMAR (p < 0.001).

  • Refractive Outcomes: Mean spherical equivalent decreased, and cylindrical error improved from −3.62 ± 2.23 D to −3.47 ± 1.65 D.

  • Corneal Topography: Kmax decreased from 56.94 ± 5.30 D to 54.09 ± 4.18 D (p = 0.02); K1 and K2 showed flattening trends.

  • Corneal Thickness: Thinnest pachymetry increased slightly (337 μm → 362 μm), suggesting corneal remodeling.

  • Aberrometry: HOAs showed variable trends, with some patients improving and others showing mild increases postoperatively.

  • Stability: CSI improved in most cases (0.02–16.41 → 0.9–13.5).

  • Safety: No intraoperative complications; one patient developed postoperative corneal infiltrates. Endothelial cell density remained stable.

Conclusion/Take home message

VTR-ICRS implantation in keratoconus patients effectively improves visual and refractive outcomes while preserving corneal trophism due to reduced implant thickness. Customized segment design enables targeted corneal reshaping, offering a valuable tool for personalized keratoconus management, especially for patients planning future lens-based refractive interventions. Further studies with larger cohorts and longer follow-up are recommended to confirm long-term efficacy and corneal biomechanical stability.