摘要:This study was aimed to compare visual performance in eyes having femtosecond laser-assisted keratoplasty (FLAK) for grade 4 keratoconus and keratoconic eyes according to the Amsler-Krumeich classification. We comprised 15 eyes of 15 patients undergoing FLAK for grade 4 keratoconus and 69 of 69 keratoconic patients (grade 1; 26 eyes, 2; 17 eyes, 3; 10 eyes, and 4; 16 eyes), and compared best spectacle-corrected visual acuity (BSCVA), corneal astigmatism (CA), corneal densitometry (CD), and corneal higher-order aberrations (CHOAs) using the Scheimpflug rotating camera. BSCVA in the post-FLAK group was significantly better than that in grade 3 or 4 group, but not than that in grade 1 or 2 group. CA was significantly lower than that in grade 3 or 4 group, but not than that in grade 1 or 2 group. CD was significantly higher than that in grade 1, 2, and 3 group, and significantly lower than that in grade 4 group. CHOAs were significantly lower than that in grade 3 or 4 group, but not than that in grade 1 or 2 group. FLAK showed significantly better BSCVA, and less CA and CHOAs, than grade 3 or 4 keratoconus, and showed less CD than grade 4 keratoconus.