Long-term clinical outcomes of deep anterior lamellar keratoplasty in patients with keratoconus

Purpose To report long-term clinical outcomes of deep anterior lamellar keratoplasty (DALK) in patients with keratoconus. Design Retrospective noncomparative interventional study. Methods setting: Single center. patients: Total of 158 eyes/150 consecutive patients with keratoconus with postoperative follow-up time equal to or greater than 4 years. intervention: DALK. main outcome measure(s): Uncorrected and corrected distance visual acuity (UDVA, CDVA), mean refractive spherical equivalent (MRSE), keratometry, endothelial cell density (ECD). Results Mean postoperative follow-up was 76.9 ± 23.2 (range 48-120) months. Preoperative UDVA was 20/400 (1.5 ± 0.4 logMAR), CDVA 20/50 (0.7 ± 0.2 logMAR), MRSE -11.1 ± 5.6 diopters (D), mean keratometry 60.7 ± 6.1 D, topographic astigmatism 4.7 ± 2.6 D. At last postoperative follow-up visit, UDVA improved to 20/50 (0.5 ± 0.3 logMAR), CDVA to 20/25 (0.09 ± 0.1 logMAR), MRSE to -2.6 ± 3.5 D, mean keratometry to 44.4 ± 2.2 D, and topographic astigmatism to 2.9 ± 1.3 D. Postoperative ECD did not vary from preoperative values being 2070.5 ± 367.5 cell/mm² and 2198 ± 373 cell/mm², respectively, with 70% of eyes (111/158) showing ECD ≥2000 cells/mm². Eighteen eyes (11.3 %) developed stromal or epithelial rejection, 3 (1.8%) required regrafting. Eyes with successful big bubble showed greater CDVA than those that required manual dissection at follow-up equal to or less than 5 years but comparable results in the longer term. Conclusions DALK provides stable long-term visual and refractive outcomes. Risk of graft rejection, postoperative complication, and late ECD decay is reduced when compared to standard penetrating keratoplasty.