Laser iridotomy is generally a safe and effective procedure for
narrow-angle glaucoma. However, since surgical success with the
argon laser depends on a focal thermal effect, a corneal
burn is a possible complication. I describe five patients with occludable anterior chamber angles and bilateral corneal guttata who developed uniocular progressive
corneal edema with visual loss following
argon laser iridotomy. These five patients underwent iridotomy with a total
laser energy of 63, 48.5, 7, 25, and 25 J, respectively, and began to lose vision due to
corneal edema immediately, and 5, 2, 4, and 2 years later, respectively. Following
penetrating keratoplasty with
cataract surgery, histopathology of the corneal buttons showed generalized endothelial cell loss in all five. Microstructural findings of guttata and thickened Descemet's membrane implied that prior endothelial dystrophy had predisposed these patients to
laser-induced damage. Risk factors for immediate or delayed-onset bullous keratopathy after
argon laser iridotomy include prior angle closure, preexisting endothelial guttata, and high
laser energy with multiple applications. Recognizing the potential of this complication offers opportunities for preventive strategies.