Experimental globe rupture after excimer laser photorefractive keratectomy
Y. Burnstein, D. Klapper and P. S. Hersh
Cornea Consultation Service, Montefiore Medical Center, Bronx, NY, USA.
OBJECTIVE: To assess corneal weakening after photorefractive keratectomy.
METHODS: 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. RESULTS: 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.
CONCLUSION: Excimer laser photorefractive keratectomy does not weaken the
cornea after degrees of ablation commonly used in the clinical setting.
