Abstract
Abstract: :
Purpose: To evaluate corneas of patients with ultrasound biomicroscopy (UBM) before and after the conductive keratoplasty procedure for the correction of presbyopia. Methods: CK is a procedure that utilizes radiofrequency energy delivered through a fine probe to create localized heat and shrink corneal collagen. We evaluated eleven consecutive patients (11 eyes) pre- and post-CK as part of the US FDA Phase III study for the correction of presbyopia. UBM was done with 50 mHz transducer with a physical axial resolution of 25 µm and a lateral resolution of 50 µm. UBM graphics were analyzed for shape of the corneal footprint (depth and width), central corneal thickness, anterior chamber angle and anterior chamber depth. Results: Foot print size and shape were similar with each treatment spot in the same eye and similar to spots in other patients. At 1 month postop, the foot print mean depth was 0.507 0.06 mm and width, 0.280 0.05 mm. The foot print faded with time. Central corneal thickness, anterior chamber depth, and anterior chamber angle averaged 0.556 mm, 2.50 mm and 16.31º, respectively, and did not show any significant changes postoperatively. Conclusion: UBM evaluation of corneas post-CK demonstrates repeatable cylindrical foot prints within the peripheral cornea, with consistent shape and size that may corroborate clinical findings of stable refractive changes. Despite peripheral flattening with the procedure, the anterior chamber angle appeared normal postoperatively and correlated with clinical postoperative IOP measurements.
Keywords: 544 refractive surgery