A modified technique of keratoleptynsis ("letter-box") for treatment of canine corneal edema associated with endothelial dysfunction.

Abstract

To describe a modified keratoleptynsis procedure, as a method of preserving central corneal function, and evaluate the outcome in vision, reduction of corneal thickness and treatment of epithelial corneal ulcers in cases with endothelial cell dysfunction. Forty-four dogs (72 eyes) were affected by progressive corneal edema, with or without ulcerative keratitis. All patients were treated with a dorsal and ventral superficial keratectomy followed by conjunctival flaps, maintaining a clear central cornea. Corneal thickness measurements were obtained via ultrasound biomicroscopy. All eyes showed resolution of ocular discomfort postoperatively, with a median time to resolution of 35days. Two years post-surgery, vision had been lost in 2 of 29 eyes (7%). From the initial population, 23 dogs (39 eyes) had follow-up evaluations of corneal thickness. The mean central corneal thickness was 1359±251μm prior to surgery. Thickening of the central cornea was observed one week after surgery to 1559±263μm. Decreased corneal thickness was reported, at 1month, 4months, 10months and 2years postoperatively (1285±267μm, 1102±150μm, 1121±288μm, 1193±283μm, respectively). All eyes showed a similar trend of increasing and then decreasing corneal thickness. This surgical technique provided statistically significant reduction in central corneal thickness and sustained relief of ocular pain. Reduction in corneal thickness appeared to be maintained 2years post-surgery, and all patients remained comfortable. Superficial corneal pigmentation and fibrosis resulted in vision loss in two eyes.