Precisely Controlled Side Cut in Femtosecond Laser-Assisted Deep Lamellar Keratoplasty for Advanced Keratoconus.

PURPOSE: To evaluate the outcomes of femtosecond laser-assisted deep lamellar keratoplasty (FDLK) in treating advanced keratoconus.

METHODS: In the management of keratoconus in advanced stages, 89 patients (94 eyes) received FDLK, and 100 patients (100 eyes) underwent vacuum trephine-assisted deep anterior lamellar keratoplasty (DALK). Visual acuity, corneal curvature, and central corneal thickness were measured. The follow-up duration was 1 year.

RESULTS: The best-corrected visual acuity (logMAR) was 0.23 ± 0.15 at 6 months and 0.08 ± 0.07 at 1 year in the FDLK group, which was significantly better than that in the vacuum trephination group (0.30 ± 0.10 and 0.13 ± 0.08, respectively). The mean curvature was 43.24 ± 5.25 D in the eyes treated by FDLK and 48.31 ± 3.68 D in the eyes treated by vacuum trephine-assisted DALK at 1 year. The mean astigmatism in the FDLK group was lower as compared with the vacuum trephination group. In the FDLK group, the graft adhered well with the recipient, which was 72 ± 17 μm in thickness. In the vacuum trephination group, the remaining peripheral corneal thickness was 153 ± 25 μm. The epithelium healed at 3 ± 2 days and 6 ± 2 days in both groups, respectively.

CONCLUSIONS: The vacuum trephine remains as a major surgical tool for deep lamellar keratoplasty. The precise control of side cut in the diameter and depth in the FDLK procedure can help to accelerate the healing of epithelium and the improvement of visual acuity early after surgery for advanced keratoconus, compared with vacuum trephine-assisted DALK.