Conductive Keratoplasty With Corneal CXL for Keratoconus and Corneal Ectasia
Purpose
Prior studies of conductive keratoplasty (CK) for keratoconic irregular astigmatism showed marked regression at 1-3 months. This study evaluated improvement in vision after CK combined with a proprietary, transepithelial corneal crosslinking (CXL) procedure to lock in the effect in patients with keratoconus or corneal ectasia.
Methods
This was a non-randomized, prospective, noncomparative case series. 155 eyes of 113 patients were studied. Exclusion criteria included corneal apex thickness less than 350 microns, prior CK or CXL, rigid contact lens use within 4 weeks of CK, or patients content with their current vision. CK was performed using intraoperative keratometry, a new spot nomogram; CXL was performed within 36 hours. CK spots were applied either superiorly, apically, or both. Uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BCVA) were analyzed at preoperative and postoperative month (POM) 1, 2-4.5, 4.5-10, and 10-15.
Results
Mean improvement in logMAR UCVA and logMAR BCVA at POM4.5-10 were 0.105 (p-value 0.038) and 0.068 (p-value 0.003), respectively. Mean logMAR UCVA and logMAR BCVA at POM10-15 improved by 0.053 (p-value 0.619) and 0.066 (p-value 0.029), respectively. A subgroup analysis of 63 eyes with a preoperative BCVA of 20/40 or worse revealed greater mean improvement in logMAR UCVA and logMAR BCVA at POM 4.5-10 of 0.284 (p-value 0.005) and 0.219 (p-value <0.001), respectively. The subgroup mean logMAR UCVA and logMAR BCVA at POM10-15 improved by 0.146 (p-value 0.333) and 0.189 (p-value 0.016), respectively. No adverse events occurred.
Conclusion
This new non-invasive method of CK combined with proprietary Epi-on CXL for corneas with keratoconus or ectasia is a safe and effective way to improve vision up to 15 months after the procedure. Patients with worse preoperative vision had greater benefit from the procedure.