Implantation Of Intracorneal Ring Segments Using Manual Technique In The Management Of Keratoconus: Long-Term Results
Published 2026 - 44th Congress of the ESCRS
Reference: PP14.10 | Type: Free paper | DOI: 10.82333/bb8t-js09
Authors: Dr Francisca Teixeira da Costa Maia* 1 , Dr Ana Mendes da Silva 1 , Dr Marta Vaz Pereira 1 , Dr Ana Margarida Sampaio 1 , Dr Rui Silva 1 , Dr Christophe Pinto 1 , Prof. Dr Tiago Monteiro 2
1Ophthalmology,Hospital de Braga,Braga,Portugal, 2Ophthalmology,Unidade Local de Saúde São João,Porto,Portugal;Faculdade de Medicina da Universidade do Porto,Porto,Portugal
Purpose
The implantation of intracorneal ring segments (ICRS) has proven to be an effective approach for managing keratoconus (KC). However, long-term outcomes and its effect on the natural progression of the disease are not yet fully understood. This study aims to evaluate the efficacy, safety, and long-term stability (10 years) of Ferrara-type ICRS by manual surgery implantation.
Setting
A tertiary referral hospital in Braga, Portugal
Methods
A longitudinal retrospective single-center study was conducted, evaluating a cohort of patients who underwent Ferrara-type ICRS implantation surgery using the manual technique at Braga Hospital between 2010 and 2014. The parameters assessed included visual parameters (uncorrected visual acuity - UCVA and best-corrected visual acuity - BCVA), refractive parameters (sphere, cylinder, and spherical equivalent), and topographic variables (keratometry, asphericity, coma, and pachymetry). Evaluations were performed preoperatively, at 6 months, 12 months, 5 years, 8 years, and 10 years after surgery.
Results
Of 130 eyes treated, 124 were followed for 5 years, 81 for 8 years, and 61 for 10 years. Mean age was 29±11 years, 60% male, and 75% had KC stage 1–2 (Amsler-Krumeich). At 10 years, UCVA was 0.49±0.32 logMAR (pre: 0.95±0.39; p<0.001) and BCVA 0.23±0.22 logMAR (pre: 0.41±0.29; p<0.001); 80% maintained or improved UCVA. Safety and efficacy indices were 2.05 and 1.10. Sphere, cylinder, and spherical equivalent improved and remained stable. K1, K2, and Kmax decreased and remained stable; asphericity changed from -0.88±0.40 to 1.75±1.38 (p<0.01); coma did not change significantly. ICRS explantation for refractive rehabilitation was required in 5 patients (8%). Ring extrusion and intraoperative tunnel perforation occurred in 1 case each (1.6%).
Conclusions
The implantation of ICRS significantly improved visual, refractive, and topographic parameters and the results remained stable during a long-term follow-up. This study highlights the advantages of ICRS as a surgical treatment of keratoconus; having demonstrated that the procedure is safe and effective, minimally invasive, and reversible, with very good and stable long-term results.