Manual trephination of mushroom keratoplasty in advanced keratoconus

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.

Sixteen eyes of 15 patients with advanced keratoconus received a mushroom keratoplasty at the Erasmus Medical Centre at Rotterdam between April 2003 and May 2006. The donor cornea had 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.

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/mm2 (n = 5), respectively. At the end of follow-up, all transplants remained functional and clear.

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.