Elliptical nonmechanical corneal trephination: intraoperative complications and long-term outcome of 42 consecutive excimer laser penetrating keratoplasties

Abstract

Purpose: To assess intraoperative complications and long-term outcome of elliptical excimer laser trephination for penetrating keratoplasties (EELPKs) performed at the Friedrich-Alexander University of Erlangen, between 1989 and 2002.

Methods: This was a retrospective, longitudinal, single-center, clinical, interventional case series. Forty-two eyes (14 Fuchs dystrophy, 11 corneal ulcer, 7 aphakic/pseudophakic bullous keratopathy, 9 corneal scars, 1 keratotorus) after EELPK were observed. Trephination was performed with a 193-nm Meditec excimer laser along metal masks with 0-8 orientation teeth/notches. Horizontal/vertical graft diameters ranged from 7.0/6.0 to 8.0/7.0 mm, and 12 to 24 interrupted sutures were used. Simultaneously, 11 eyes (26.2%) underwent cataract surgery, 3 (7.1%) underwent intraocular lens (IOL) exchange, and 1 (2.4%) underwent secondary IOL implantation. The main outcome measures included intraoperative complications, immune reactions, and final astigmatism/visual acuity at the end of follow-up.

Results: During surgery, 4 (9.5%) recipients had iris bleedings, and 10 (23.8%) ring-shaped superficial corneal thermal donor damages were detected. One (2.4%) immunologic graft rejection was seen in Fuchs dystrophy, and 3 (7.1%) in corneal ulcers occurred during follow-up (4.7 +/- 3.2 years). At the end of follow-up, corrected visual acuity (0.1/0.4; P < 0.001) and keratometric astigmatism (2.3 D/4.7 D, P = 0.001) increased significantly.

Conclusions: In EELPK, intraoperative disadvantages, such as the need for interrupted sutures and a tendency toward higher and more irregular astigmatism, may be expected. This study does not have the power to statistically confirm the tendency of EELPK toward a lower rate of immunologic graft rejections after normal-risk keratoplasty. However, EELPK may have advantages in deep or perforated elliptically shaped corneal ulcers (such as in acanthamoeba keratitis).