Abstract
Purpose :
To adapt crosslinking fluence according to corneal pachymetry and evaluate its safety and efficacy when treating thin corneas using an epi-off accelerated-pulsated protocol.
Methods :
We performed a retrospective longitudinal study in which data from 16 eyes (14 patients) with keratoconus was obtained. They were treated with a customized epi-off accelerated-pulsated crosslinking protocol in March-May 2023. Patients had a minimum age of 18 years, and thinnest stromal thickness between 250-399 microns. Keratometries and corneal pachymetries were obtained by corneal tomography (Pentacam, Oculus), stromal thickness was obtained by subtracting epithelial thickness measured by anterior segment OCT (Triton, Topcon). During the procedure, corneal epithelium was removed using 30% ethylic alcohol solution and cellulose sponges. The stroma was soaked with a 0.1% isotonic riboflavin solution for 10 minutes and UVA light was applied (KXL System, Glaukos) using an irradiance of 15 mW/cm2 and a customized total fluence (based on a trial published by Hafezi et al.) in a pulsated fashion (1 second on – 1 second off). Bandage contact lenses were placed and antibiotic and corticosteroid drops were administered. Follow-up was performed at 72 hours, 1 week, 3 and 6 months. Demarcation line depth was evaluated at 1 week and stability was evaluated 6 months postoperatively. Variables analyzed included flattest and steepest keratometries, thinnest point pachymetry, UCVA, endothelial cell density, complications and progression.
Results :
16 eyes from 14 patients (10 male) treated with customized cross-linking in March-May 2023 were included. Mean patient age was 24.1 years. Mean preoperative keratometries were 52.99 ± 6.1, 58.34 ± 6.7 and 55.51 ± 6.34 D for flattest, steepest and mean, respectively. Mean preoperative pachymetries were 400.8 ± 27.82. Mean preoperative UCVA was 1.24 ± 0.5 LogMAR. Mean preoperative endothelial cell count was 2846 cells/mm2. There was no statistically significant difference between any of these variables and their postoperative 6 month values. Progression was observed in one eye at the 6 month consult.
Conclusions :
Our results suggest that the epi-off accelerated-pulsated protocol is a safe and effective treatment option for corneas thinner than 400 microns. Nevertheless, patients must be followed up for longer periods for stability to be appropriately documented.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.