320º Intracorneal Ring Segments Implantation For Advanced Keratoconus
Published 2024 - 42nd Congress of the ESCRS
Reference: PO809 | Type: Free paper | DOI: 10.82333/mb5e-bg22
Authors: Pablo Morales* 1 , Geraldine Kohn 2 , Ambrosio Márquez 3 , Rodrigo Castillo 4 , Nayud Jara 5 , Claudio Catalán 5 , Sergio Eguiza Rubi 1 , María Micaela Scorsetti 1 , Antonio Cano 6 , Juan Durán de la Colina 1
1Cornea and Refractive Surgery,Instituto Clínico Quirúrgico de Oftalmología (ICQO),Bilbao,Spain, 2Ophthalmology,Universidad Católica,Santiago,Chile, 3Cornea and Refractive Surgery,Instituto David Bitrán,Santiago,Chile, 4Cornea and Refractive Surgery,Clínica de Especialidades Oftalmologicas (CEOFT),Rancagua,Chile, 5Ophthalmology,Instituto David Bitrán,Santiago,Chile, 6Cornea and Refractive Surgery,Hospital la Arruzafa,Córdoba,Spain
Purpose
To evaluate the clinical outcomes after implantation of a 320° arc length Ferrara intrastromal corneal ring segment (320 ICRS) in eyes of patients with advanced (Km >53 D) central keratoconus with at least 6 months follow-up.
Setting
Cornea and Refractive Surgery department at Instituto David Bitrán in Santiago de Chile.
Methods
A retrospective study in which a 320-ICRS was placed in 19 eyes of patients with advanced central (nipple or bowtie phenotypes) keratoconus. All surgeries were performed by 2 surgeons (P.M, and A.M). The Alcon FS200 Femtosecond laser was used for tunnel creation, and the new AJL nomogram was used as guide for implantation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), mean keratometry (Kmean), Asphericity (Q), Aberrometry readings at 4.5 mm, and lines of vision gain/loss, were assessed preoperatively and at the final follow-up visit after the procedure.
Results
Mean preoperative Km changed from 55.1 D (±2.61) to 52.0 D (±3.35), Mean UDVA (LogMAR) improved from 1.58 (±0.61) to 0.51 (±1.76), and mean preoperative Q decreased from -1.64 (±0.47) to -1.26 (±1.26). All these changes proved to be statistically significant (p<0.05). All patients gained lines of UDVA, and mean UDVA lines gained was 9.6 (± 1.75). 1 case of perforation was observed, in which the implant was explanted with no clinical repercussions. In 4 patients using scleral contact lenses preoperatively with unsatisfactory visual acuity, a new postoperative scleral lens fitting improved vision up to LogMAR 0 (20/20). All parameters stabilized at 3 months follow-up.*PRELIMINARY RESULTS.
Conclusions
The 320 ICRS implantation is a safe, reversible and efficient procedure in cases of advanced central keratoconus and should be considered in order to avoid/delay corneal transplantation in such cases. Bowtie phenotypes are benefitted the most from this procedure. In patients using scleral contact lenses preoperatively, vision improved after a new contact lens fitting, demonstrating a better corneal profile, which translates in a better quality of vision. Close follow-up and contact lens fitting should be advised in order to achieve the final visual outcome.