Ultrasound biomicroscopic assessment of the cornea following excimer laser photokeratectomy.

Excimer laser photokeratectomy is used as a refractive tool and in the treatment of superficial corneal disease. Ultrasound biomicroscopy is a new method of ultrasound imaging developed in our laboratories that allows subsurface imaging of ocular structures at microscopic resolution. We used this imaging method to examine 12 patients following excimer laser keratoablation. Following treatment, the normal appearance of a highly reflective Bowman's membrane below the epithelial echo was absent in the treatment zone. Corneal thinning was also noted. Postoperative scarring in the treatment area could be imaged as highly reflective regions in the superficial stroma. In therapeutic cases, corneal opacities could be imaged pretreatment and their depth assessed. The degree of opacity removal could be analyzed post-treatment. Ultrasound biomicroscopy helped assess corneal changes secondary to excimer laser photokeratectomy.