Manual trephination of mushroom keratoplasty in advanced keratoconus

Purpose: To evaluate the technique of mushroom keratoplasty for patients with advanced keratoconus, with respect to postoperative astigmatism, visual improvement and stability, and endothelial cell count. Methods: Sixteen eyes of 15 patients with advanced keratoconus received a mushroom keratoplasty at the Erasmus Medical Centre a Rotterdam between April 2003 and May 2006. The donor cornea ha a larger anterior stromal lamella (9.0 mm) and a smaller posterior part (7.0 mm). Visual acuity and keratometry were measured at 6, 12, 24, and 36 months. Specular microscopy was performed annually. Results: Best-corrected visual acuity improved significantly (P = 0.003) from 0.25 +/- 0.20 preoperatively to 0.62 +/- 0.22 at 6 months postoperatively. Visual acuity remained stable with a best-corrected visual acuity of 0.70 +/- 0.22 from 1 year onward. At all follow-up periods, mean postoperative astigmatism remained <3.5 D. Mean postoperative astigmatism at 1, 2, and 3 years measured 2.67 +/- 1.95 (n = 15), 2.54 1.86 (n = 6), and 3.30 +/- 2.12 D (n = 5). The average endothelial cell count at 1 and 2 years was 1755 678 (n = 12) and 1573 +/- 546 cells/mm(2) (n = 5), respectively At the end of follow-up, all transplants remained functional and clear. Conclusions: The mushroom-shaped graft can combine the benefits of a good visual acuity, a low astigmatism, and rapid postoperative healing. The short-term results of our limited series of patients are encouraging. Further research is necessary to draw stronger conclusions regarding the long-term effects.