[Transepithelial corneal collagen crosslinking in patients with progressive keratoconus]

To assess the effectiveness of transepithelial collagen crosslinking (CXL) in patients with keratoconus.

The study involved 44 patients (44 eyes) with stage I-II progressive keratoconus. Patients were divided into two groups. The 1^st group included 22 patients that had underwent transepithelial CXL. The 2^nd group included 22 patients that had underwent traditional CXL.

All patients of the group 2 all patients had corneal syndrome, which lasted 2-4 days. In the 1^st group, 98% of the patients did not have corneal syndrome and their visual acuity (VA) was same as preoperative on the next day after the surgery. In the 2^nd group, the mean level of postoperative pain was 1.7 times higher than in group 1 (p<0.05). Six months after the treatment, uncorrected VA (UCVA) in the 1^st group has increased by 52%, the best corrected VA (BCVA) - by 17%, in the 2^nd group UCVA increased by 53%, BCVA - by 20% (p<0.05). The demarcation line in the 2^nd group was 2.2 times deeper than in the 1^st group (p<0.05). Six months after the treatment in the 1^st group mean K1, K2 and K_m decreased by 1.5%, 2.3% and 1.7% respectively (p>0.05); in the 2^nd group - by 3.6%, 3.9% and 4.1% (p<0.05) compared with the data before the surgery. One year after the treatment, mean K_max in the 1^st group decreased by 2.1%, in the 2^nd group - by 3.9%. Differences with preoperative values were statistically significant only in the 2^nd group.

Transepitelial CXL is a safe procedure well tolerated by patients and leading to a rapid restoration of visual function. Transepithelial CXL proved to have reduced effectiveness in inducing improvement in keratometric values, its effect on visual acuity was likely to be similar to that of epithelium-off CXL.