Ten-year outcomes of microkeratome-assisted lamellar keratoplasty for keratoconus

Background/Aims To report the 10-year outcomes of modified microkeratome-assisted lamellar keratoplasty (LK) for keratoconus. Methods In this single-centre interventional case series, 151 consecutive eyes with keratoconus underwent modified microkeratome-assisted LK. Eyes with scars extending beyond the posterior half of the corneal stroma and preoperative thinnest-point pachymetry value of less than 300 μm were excluded. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), endothelial cell density, immunological rejection, ectasia recurrence and graft failure rates. Results Baseline BSCVA (0.89±0.31 logarithm of the minimum angle of resolution (logMAR)) significantly improved to 0.10±0.12 logMAR at year 3 (p<0.001), and remained stable up to 10 years. At 10 years, 94% of eyes saw ≥20/40, 61% saw ≥20/25 and 24% saw ≥20/20 Snellen BSCVA. At final follow-up, RA exceeding 4.5 dioptres was observed in 5 cases (4%). Endothelial cell loss was 25±17% at 1 year with an annual decline of 2% over 10 years. The 10-year cumulative risk for immunological rejection and graft failure was 8.5%, and 2.4%, respectively. No case developed recurrent ectasia at 10 years. Conclusion Modified microkeratome-assisted LK results in stable visual and refractive outcomes with low rates of immunological rejection and graft failure in the absence of recurrence of ectasia for at least 10 years.