A comparative study of bowman layer transplantation results without and after ultraviolet crosslinking in advanced keratoconus

Abstract

Aim. A comparative study of Bowman layer transplantation (BLT) after its ultraviolet (UV) crosslinking and BLT without preliminary UV crosslinking in patients with advanced keratoconus (KC) stages III to IV.
 Materials and methods. There were 30 patients aged 14 to 37 years with KC IIIIV stages. The first group included 15 patients who underwent BLT without prior UV crosslinking. The second group included 15 patients who underwent BLT after UV crosslinking. The criteria for inclusion of patients in the study were: progressive KC, with corneal thinnest point (CTP) without epithelium of 400 m or less, a maximum keratometric index (Kmax) of 58 D and more, with patient satisfied by his visual acuity in a scleral contact lens (SCL) and refusing keratoplasty.
 Results. In comparison with preoperative data in both groups, Kmax decreased by an average 0.6 0.5 D, and CTP increased in the first group by an average of 41.5 16.3 m, and in the second group by an average of 31,9 9.2 m. Best corrected visual acuity (BCVA) did not change.
 Conclusion. During the follow-up of 26.6 6.2 (from 6 to 36) months, CTP and Kmax indices remained stable in operated patients, which indicates the arrest of KC progression after BLT with crosslinking and without it. The preservation of endothelial cell density and BCVA values indicates the safety of both methods.