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Updated: Aug 6, 2026
Three Different Protocols of Corneal Collagen Crosslinking in Keratoconus: Conventional, Accelerated and Iontophoresis
Published on: November 12, 2015
Precise Epithelium Removal for Ectatic Corneas Technique in Corneal Collagen Crosslinking (PERFECT-CXL): Technique
Jeffrey Desilets1, Kanika Agarwal1, Kathryn M Hatch2
1Comprehensive Ophthalmology Service, Massachusetts Eye and Ear, Boston, MA, USA.
Purpose:
To describe clinical outcomes of a hybrid collagen crosslinking technique, Precise Epithelium Removal for Ectatic Corneas Technique Collagen Crosslinking (PERFECT-CXL) using tomography-guided hybrid partial central epithelium removal with peripheral epithelial disruption in keratoconus.
Patients And Methods:
A retrospective chart review of all previously untreated eyes that underwent PERFECT-CXL for keratoconus (KCN) by one surgeon from June 2018 to January 2023 at a single, tertiary care center. PERFECT-CXL utilizes a two-stage epithelial approach involving diffuse, across the entire cornea, roughening with an Ultracell LASIK Disc in order to create epithelial microerosions, followed by 45 minutes of loading with hypo-osmolar 0.146% riboflavin. After loading, epithelial debridement of an approximately 4-5mm zone is performed, centered over the cone, based on Pentacam tomographic localization, and the cornea is treated with pulsed UV-A irradiation. This hybrid method aims to optimize oxygen availability and targeted biomechanical stabilization while also aiming to promote faster visual recovery and an earlier return to contact lens wear. In this retrospective chart review, 362 eyes underwent PERFECT-CXL, of which 150 were previously untreated non-contact lens wearing keratoconic eyes. Outcomes measured at 6 months, 1, 2 and 3 years post-operatively included best spectacle-corrected visual acuity (BSCVA), maximum keratometry (Kmax), and treatment-associated complications.
Results:
At six months, one, two, and three years post-op, BSCVA was stable in 97.5% (n = 120), 95.7% (n = 93), 94.2% (n = 69), and 94.9% (n = 39) of eyes, respectively. At one, two, and three years post-op, 80.3% (n = 117), 88.2% (n = 93), 84.1% (n = 69), and 84.6% (n = 39) of eyes experienced stabilization in Kmax, respectively. Of patients not lost to follow-up, 1.3% (2/150) demonstrated progression requiring retreatment within three years. There were no instances of treatment-associated complications.
Conclusion:
Preliminary, retrospective results suggest that PERFECT-CXL can be a safe and effective technique in halting progression of KCN and can be utilized in various stages of keratoconus.
