Effect of Keratoconus Severity on Clinical Outcomes After Deep Anterior Lamellar Keratoplasty.

PURPOSE: To evaluate the effect of keratoconus severity on the visual and refractive outcomes and complications after deep anterior lamellar keratoplasty (DALK).

DESIGN: Consecutive interventional case series.

METHODS: This study enrolled 227 keratoconus-affected eyes that underwent DALK. Amsler-Krumeich keratoconus classification was used to categorize the patients: stage II, 47 eyes; stage III, 60 eyes; and stage IV, 120 eyes. The outcome measures, including postoperative best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, mean keratometry, keratometric astigmatism, and complications, were analyzed and compared based on keratoconus stage.

RESULTS: The mean patient age was 27.6 ± 8.0 years, and the mean follow-up period was 38.0 ± 19.8 months. No significant differences were observed in postoperative BSCVA (P = .55), spherical equivalent refraction (P = .27), mean keratometry (P = .09), and keratometric astigmatism (P = .14) among the groups. Improvement in BSCVA were significantly greater in stage III and stage IV compared with stage II (P = .04 and P < .001, respectively). The decrease in spherical equivalent was significantly greater in stages III and IV compared with stage II (P = .04 and P = .001, respectively). Mean keratometry decreased to a greater degree in stage IV compared with stages II and III (P < .001 for both comparisons). The study groups were comparable with respect to intraoperative Descemet membrane perforation, the rate of successful big-bubble formation, suture-related complications, and graft rejection.

CONCLUSIONS: DALK is a safe and effective procedure for the treatment of all stages of keratoconus. This technique of corneal transplantation is more effective in eyes with severe keratoconus compared with those with moderate keratoconus.