Effect of corneal collagen crosslinking on subsequent deep anterior lamellar keratoplasty (DALK) in keratoconus.

PURPOSE: The purpose was to investigate the impact of ultraviolet light corneal collagen crosslinking (UV-CXL) on the success rate and clinical outcome of subsequent deep anterior lamellar keratoplasty (DALK) in eyes with keratoconus (KC).

METHODS: Medical records of 101 consecutive eyes with KC scheduled for big-bubble DALK surgery were screened retrospectively for details of previously performed UV-CXL, as well as intra- and postoperative complications of DALK surgery. Main outcome measures were intraoperative success rates (big-bubble formation, conversion to penetrating keratoplasty (PK)), postoperative complications, best corrected visual acuity (BCVA), endothelial cell density (ECD), and central corneal thickness (CCT) within 18 months of follow-up.

RESULTS: Out of the 101 KC eyes, eight eyes (7.9%) had a history of previous UV-CXL. Surgical failure, defined as conversion to PK due to macroperforation, occurred in 17 eyes (16.8%) of 93 eyes without and in none with previous UV-CXL (P < .001). Failure to achieve a big-bubble occurred in 37 eyes (40.2%) without previous UV-CXL and in two eyes (25%) with previous UV-CXL. Microperforations of Descemet's membrane were observed in ten eyes (20.7%) without and in 14 eyes (15.2%) with previous UV-CXL (P = .16). No significant differences could be detected for either the postoperative complication rate (P ≥ .18) or the clinical outcome parameters at 18 months follow-up, including BCVA, ECD and CCT (P ≥ .08) for eyes with or without UV-CXL.

CONCLUSIONS: In DALK surgery, prior UV-CXL does not seem to affect the rate of intra- or postoperative complications, the success rate, or its clinical outcome.