A new rapid epi-on corneal crosslinking method is showing promise for treating keratoconus patients.
Known as custom fast crosslinking, this treatment algorithm features no epithelial disruption, 15 minutes of corneal presoaking with a riboflavin-vitamin E TPGS solution and a 370nm ultraviolet A radiation beam centered on the most highly curved corneal region. Italian and US researchers, in their study published in Cornea, report that their technique is different from the current protocol since their method involves significantly less ultraviolet A radiation beam fluence, total energy and exposure time.
The study enrolled 81 patients whose refraction, spectacle-corrected distance visual acuity, Kmax and corneal hysteresis were monitored for seven years after treatment.
Researchers found the average refractive cylinder magnitude was reduced by 26.1% at one month postoperatively and by 44.2% at seven years. Additionally, they noted best spectacle-corrected distance visual acuity improved from +0.26 ± 0.34 (20/36.4) to +0.15 ± 0.23 (20/28.25) at one month, +0.05±0.20 (20/22.4) at one year and +0.06±0.20 (20/22.96) at seven years following surgery.
The investigators also reported best spectacle-corrected distance visual acuity improved post-surgery in 54.3% of patients at one month, 74.1% at three months, 84% at six months, 87.7% at 12 months, 84% at 48 months and 82.7% at 84 months.
Also of note: Kmax did not increase in 96.3% of patients at one month, 97.5% at one year and 98.8% at seven years postoperatively, with average corneal apex flattening at one month and seven years (-2.79±1.70D and 4.00±2.40D, respectively).
“Custom fast crosslinking, 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,” the researchers wrote in their paper.
|Caruso C, Epstein RL, Troiano P, et al. Topography and pachymetry guided, rapid epi-on corneal crosslinking for keratoconus: 7-year study results. Cornea. July 24, 2019. [Epub ahead of print].|