Topography and Pachymetry Guided, Rapid Epi-on Corneal Cross-Linking for Keratoconus: 7-year Study Results

To evaluate custom fast cross-linking (cfCXL) treatment of keratoconus.

"Custom fast cross-linking" or "cfCXL" is a keratoconus treatment algorithm featuring no epithelial disruption, 15 minutes of corneal presoaking with a riboflavin-vitamin E TPGS solution, and a 370-nm ultraviolet A radiation beam centered on the most highly curved corneal region. Ultraviolet A radiation beam fluence, total energy, and exposure time are significantly less than those in the Dresden protocol. In this study, refraction, spectacle-corrected distance visual acuity, Kmax, and corneal hysteresis were monitored in 81 eyes of 81 patients for 7 years with 100% follow-up. Pretreatment Kmax and patient age averaged 53.01 ± 4.87 D and 25.9 ± 4.7 years, respectively.

Average refractive cylinder magnitude was reduced by 26.1% at 1 month postoperatively and by 44.2% at 7 years postoperatively. Logarithm of the minimum angle of resolution average spectacle-corrected distance visual acuity (best spectacle-corrected distance visual acuity) improved from +0.26 ± 0.34 (20/36.4) to +0.15 ± 0.23 (20/28.25), +0.05 ± 0.20 (20/22.4), and +0.06 ± 0.20 (20/22.96) at 1 month, 1 year, and 7 years postoperatively, respectively. Best spectacle-corrected distance visual acuity improved in 54.3%, 74.1%, 84.0%, 87.7%, 84.0%, 84.0%, and 82.7% of patients at postoperative months 1, 3, 6, 12, 24, 48, and 84, respectively. Kmax did not increase in 96.3% of patients at 1 month, 97.5% at 1 year, and 98.8% at 7 years postoperatively, with average corneal apex flattening at 1 month and 7 years of -2.79 ± 1.70 D and -4.00 ± 2.40 D, respectively.

Custom fast cross-linking, epi-on, rapid, narrowed beam apex-centered treatment of keratoconus with riboflavin-vitamin E TPGS produced a significant, rapid, and lasting cone progression stoppage, astigmatism reduction, and visual acuity improvement.