Outcomes of femtosecond laser-assisted mushroom-configuration keratoplasty in advanced keratoconus

Purpose To evaluate the long-term outcomes after femtosecond laser (FSL)-assisted mushroom-configuration keratoplasty in advanced keratoconus.Patients and methods Thirteen eyes with Amsler-Krumeich stage IV keratoconus underwent FSL-assisted mushroom-configuration penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) at a tertiary referral centre. Preoperative risk factors included low orneal thickness, high keratometry measurements, previous hydrops, and central stromal scarring. Main outcome measures were visual acuity and refractive outcome.Results The median follow-up was 33 months (range: 4-43). Preoperatively, the mean corrected distance visual acuity (CDVA) was 1.22 +/- 0.47 LogMAR (range: 0.5-1.9 LogMAR), mean minimum corneal thickness was 282 +/- 100.8 mu m (range: 147-478 mu m), and mean average keratometric (K) value was 63.4 +/- 7.63 dioptre (D; range: 57.0-75.7 D). Four patients underwent PKP and nine underwent DALK (two converted to PKP). Five patients subsequently underwent a modified arcuate mushroom interface dissection (AMID) procedure for astigmatic correction. At the final follow-up, the mean CDVA was 0.05 +/- 0.13 LogMAR (range: -0.10 to 0.20 LogMAR), mean spherical equivalent was -3.21 +/- 3.21D, mean cylindrical refractive error was 3.23 +/- 2.20 D, and mean average K was 43.1 +/- 1.53 D. Complications included early graft dehiscence, corneal vascularisation, stromal rejection, and sclerokeratitis. Sutures were completely removed at the mean 18.4 months for PKP and 9.1 months for DALK postoperatively.Conclusion FSL-assisted mushroom-configuration keratoplasty is feasible and safe in patients with stage IV keratoconus. AMID could further enhance the refractive outcome safely.