Six Months Results Of Custom Fast Epi-On Keratoconus Cross Linking Using Riboflavin-Vitamin E Tpgs As A Penetration Enhancer

Epi-on cross linking (CXL) has the limitation of effective riboflavin penetration into the corneal stroma. Recently, riboflavin-vitamin E TPGS is proposed as a penetration enhancer for epi-on CXL. The purpose of the study is to present a short term (6 months) result of custom fast epi-on CXL using riboflavin-vitamin E TPGS.

Retrospective, single center study

18 patients (M : F = 12 : 6, mean age = 30.1 ± 8.6 y) were enrolled in the study. The treated eyes were first soaked for 15 min. with either Ribocross or Ribofast, followed by irradiation with CFX-Linker (SERVImed) for 15 min., with a beam diameter of 5.0-5.5 mm, UV light intensity 2.8 mW /cm2. The pre- and post-op 6 months CDVA in logMAR, Kmax, thinnest thickness, and refractometer cylinder were compared. DA ratio, integrated radius, ARTh, and SP-A1 of the Vinciquerra screening report of the Corvis ST examinations were also compared.

At post-op 6 months, the mean CDVA improved from 0.30 ± 0.17 to 0.22 ± 0.24 (p = 0.0754), and refractometer cylinder decreased from 7.4 ± 3.8 to 6.5 ± 3.5 D (p = 0.4061). Kmax was significantly reduced from 60.1 ± 8.5 to 59.1 ± 8.4 D (p = 0.0322), and changes in thinnest thickness were insignificant (457.1 ± 38.1 vs 453.2 ± 35.5 um, p = 0.375). For Corvis ST examinations, except changes in DA ratio was significant (5.5 ± 0.9 vs 7.5 ± 3.9, p = 0.02977), changes in integrated radius, ARTh, and SP-A1 were insignificant.

During the short-term observation, no KC progression was noted in any patients. This, along with significant reduction in averaged Kmax suggest that custom fast epi-on keratoconus cross linking using riboflavin-vitamin E TPGS as a penetration enhancer is an effective technique to prevent keratoconus progression, however, long term validation is still needed.