Experimental globe rupture after excimer laser photorefractive keratectomy.

Abstract

To assess corneal weakening after photorefractive keratectomy. Photorefractive keratectomy was performed in 16 human eye-bank eyes by means of a 193-nm excimer laser (range, 6 to 54 diopters [D]). Porcine eyes underwent either photorefractive keratectomy procedures (range, 30 to 93 D) with a 5-mm beam diameter or deep 5-mm plano disc ablations. Intraocular pressure was increased gradually with the use of nitrogen gas until the globe ruptured. Human eyes with less than 42 D of correction ruptured at the limbus or behind the insertions of the extraocular muscles. Two eyes showed initial leakage at the 42-D ablation site. Ablations greater than 46 D entered the anterior chamber during treatment. One porcine eye ruptured at the ablation site after a 42-D treatment. Other eyes ruptured at the equator with treatments up to 78 D. Excimer laser photorefractive keratectomy does not weaken the cornea after degrees of ablation commonly used in the clinical setting.