Precision and accuracy of an artificial anterior chamber system in obtaining corneal lenticules for lamellar keratoplasty

Purpose: To determine the precision and accuracy of an artificial anterior chamber and a manual microkeratome in obtaining corneal lenticules for lamellar keratoplasty. Setting: Department of Ophthalmology, Cornea, External Diseases and Refractive Surgery Service, University of California Irvine, Irvine, California, USA. Methods: A lamellar keratectomy was performed in 47 human corneoscleral rims. Three lenticule thicknesses (180, 300, and 360 mum heads) and 3 diameters (7.0, 8.0, and 9.0 mm) were attempted. Diameters and thicknesses were measured by planimetry and pachymetry, respectively. Results: Peripheral lenticule thickness was more likely to be within +/- 50 mum of the intended depth in thinner cuts (180 mum, 9/15 corneas, 60%; 300 mum, 6/16 corneas, 40%; 360 mum, 3/12 corneas, 33.3%) (P = .045). Eighty percent (32/40 corneas) were within +/-0.5 mm of the expected diameter. Accuracy was best in the 8.0 mm group, with 47.1% (8/17 corneas) within 0.2 mm of the expected diameter. A thickness/diameter correlation was not observed (r(s) less than or equal to 0.28). Conclusions: The precision and accuracy of this system varied according to the attempted thickness and diameter. (C) 2001 ASCRS and ESCRS.