Deep anterior lamellar keratoplasty in eyes previously treated with collagen crosslinking for keratoconus: 3-year results

Abstract

Purpose: To evaluate the 3-year results of deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in keratoconus patients with previous corneal collagen crosslinking (CXL) treatment. Methods: Twenty eyes of 20 keratoconus patients who underwent DALK surgery using the big-bubble technique after CXL treatment between January 2011 and September 2015 were retrospectively reviewed. All patients completed 3 years follow-up. Intraoperative and postoperative complications were recorded. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), maximum keratometry, keratometric astigmatism and endothelial cell density (ECD) were analysed. Results: The mean interval between CXL and DALK surgery was 47.5 ± 24.0 months (mean ± SD). DALK was completed in all eyes. Big-bubble was successfully achieved in 16 eyes (80%), and manual dissection was performed in four eyes (20%). Microperforation occurred in three eyes (15%). Postoperatively, persistent epithelial defect occurred in three eyes (15%). The mean UCVA and mean BSCVA values were significantly improved preoperatively to all postoperative visits (p < 0.001). UCVA was 20/100 or lower in all eyes preoperatively and 20/100 or better in 18 eyes (80%) at 3 years; BSCVA was 20/40 or better in all eyes (100%) and 20/20 or better in three eyes (15%), and keratometric astigmatism was lower than 4 dioptres in 14 eyes (70%) at 3 years. The mean ECD loss was 6.3 ± 4.4% at 1 year, 9.0 ± 6.3% at 2 years and 11.2 ± 7.4% at 3 years. Conclusion: Previous CXL treatment in keratoconus patients did not cause a negative impact on the visual, refractive and surgical outcomes of DALK surgery using the big-bubble technique. DALK surgery seems to be a safe and effective surgical approach in these patients.