PurposeEvaluating the clinical results of trans-epithelial collagen cross-linking (CXL) and standard CXL in patients with progressive keratoconus.MethodsThis prospective study comprised 20 eyes of 20 patients with progressive keratoconus. Ten eyes were treated by standard CXL and ten by trans-epithelial cross-linking (TE-CXL, epithelium on) with 1 year of follow-up. All patients underwent complete ophthalmologic testing that included pre- and postoperative uncorrected visual acuity, corrected visual acuity, spherical error, spherical equivalent, corneal astigmatism, simulated maximum, minimum, and average keratometry, coma and spherical aberration, optical pachymetry, and endothelial cell density. Intra-and postoperative complications were recorded. The solution used for standard CXL comprised riboflavin 0.1% and dextran 20.0% (Ricrolin), while the solution for TE-CXL (Ricrolin, TE) comprised riboflavin 0.1%, dextran 15.0%, trometamol (Tris), and ethylenediaminetetraacetic acid. Ultraviolet-A treatment was performed with UV-X System at 3 mW/cm2.ResultsIn both the standard CXL group (ten patients, ten eyes; mean age, 30.4±7.3 years) and the TE-CXL group (ten patients, ten eyes; mean age, 28±3.8 years), uncorrected visual acuity and corrected visual acuity improved significantly after treatment. Furthermore, a significant improvement in topographic outcomes, spherical error, and spherical equivalent was observed in both groups at month 12 posttreatment. No significant variations were recorded in other parameters. No complications were noted.ConclusionA 1-year follow-up showed stability of clinical and refractive outcomes after standard CXL and TE-CXL.

Our pilot study suggests that customized PRK can be a safe and effective method for treating ametropia and irregular astigmatisms after PK. Future studies with larger samples and longer follow-ups should be performed to confirm these results.

A two-year follow-up showed that photorefractive keratectomy was an effective treatment for esotropia associated with mild to moderate hyperopia in young adults with purely refractive accommodative esotropia.

Our results showed efficacy, clinical and refractive stability after standard-CXL, TE-CXL and iontophoresis-CXL.