[Live epikeratophakia and deep lamellar keratoplasty for I-III stage-specific surgical treatment of keratoconus].

BACKGROUND

Perforating keratoplasty (PKP) for the treatment of keratoconus is a temporary procedure that sacrifices the healthy recipient endothelium. As an alternative to PKP we perform live-epikeratophakia (L-EPI) in keratoconus I-II and deep lamellar keratoplasty (DLKP) in keratoconus II-III.

PATIENTS AND

METHODS

20 patients with keratoconus were operated on either with L-EPI for keratoconus I-II (n = 10) or DLKP for keratoconus II-III (n = 10) respectively. In all cases, corneal tissue eligible for corneal transplantation was used. L-EPI: The corneal lenticule was prepared by means of the Barraquer-Krumeich-Swinger (BKS) set. The recipient cornea was trephined to a depth of 0.3 mm with the Guided-Trephine-System (GTS). The incision was extended manually (inner diameter 7.0 mm, outer diameter 9.0 mm). No keratectomy was performed. The lenticule was fixed with a 10 x 0 nylon double-running anti-torque suture (DRA). DLKP: The recipient cornea was trephined with the 8.0 mm GTS to a depth of 0.68 mm. A lamellar removal of the upper layers was performed by hand. After mechanical removal of the graft endothelium, the remaining full thickness donor cornea was sutured into the bed with a 10 x 0 nylon DRA suture.

RESULTS

L-EPI: Within this series, there was no disturbance of the healing process. Spherical equivalent and corneal astigmatism remained stable from the first month on. Visual acuity of 20/40 or better was obtained in 40% of the cases at 1 month, 53% at 6 months, and 100% at 1 year and 2 years. We did not observe any late decline of VA. Two patients with kerato-conus borderline stage II did not reach useful VA due to insufficiently reduced pre-existing irregular corneal astigmatism. These patients successfully underwent DLKP at 8 and 10 months respectively. DLKP: Except for 1 case (neurodermatitis), all lenticules remained stable with respect to refraction and radii up to the longest follow-up of 2 years. Starting from the first month on, refraction was stable. Visual acuity of 20/40 or better was reached in 33% of the cases at 1 month, in 56% at 6 months, and in 89% at 1 and 2 years. We did not administer systemic cyclosporine-A in either group. In the lamellar techniques presented, we did not observe any graft rejection. According to corneal topography, corneal astigmatism, spherical equivalent, and keratometry we did not observe any late re-onset of a progression of the cone.

CONCLUSION

In patients with keratoconus stage I to III, L-EPI or DLKP appeared to be very useful therapies. Both procedures seem to end progression of the disease and allow to preserve the healthy recipient endothelium. If unsuccessful, either procedure may be repeated. Neither procedure precludes possibly later needed PKP.