Abstract
Abstract: :
Purpose:To report lamellar graft diameter and thickness in an artificial anterior chamber obtained with the Moria ALTK microkeratome, which creates free flaps by rotational excursion. Methods: Free lamellar flaps were cut from human corneoscleral rims mounted in an artificial anterior chamber. Maximal sized caps (11 mm) were attempted at each thickness--150, 200, 250, and 300 um heads. Three corneoscleral rims were cut per head. Interchamber pressure of 65 mmHg was confirmed with Barraquer tonometry. Flap diameter was measured with calipers. Flap thickness was calculated by the subtraction method (corneal thickness minus remaining bed thickness). Ultrasound pachymetry was used to measure corneal thickeness. Results: Results are reported as an average and range in microns. See table below. Flap thicknesses were within -31 and +66 microns of predicted thickness. All flap diameters were less than predicted but within 1.5 mm of predicted. Conclusions: The 150, 200, and 250 micron heads cut flaps thicker than predicted while the 300 micron head cut them thinner. All heads cut within 70 microns of predicted. All flap diameters were less than 11 mm but were predictably 1-2 mm less than anticipated. Visual success in lamellar keratoplasty depends on a smooth interface between donor and host, and a good match of recipient bed and lamellar graft dimensions. The Moria ALTK microkeratome cuts free flaps within a predictable range but this range should be checked by each individual surgeon. Results
Keywords: anterior segment • cornea: clinical science