Customizing the Amadeus II microkeratome: evaluation of cut quality with various settings using electron microscopy.

PURPOSE

To evaluate the cut quality of keratectomy specimens created with the new Amadeus II microkeratome (SIS, Ziemer Ophthalmic, Port, Switzerland) using scanning electron microscopy (SEM). Methods. Corneal cuts were performed in 24 freshly enucleated porcine eyes using the Amadeus II microkeratome with combinations of cutting-head depth, oscillation rate, head-advance speed, and reuse of the blade. For the cutting trials, a 140-microm and 160-microm cutting head with three oscillation rates of 8,000, 10,000, and 13,000 rpm and two head-advance speed rates of 1.5 and 3.5 mm/s were chosen. In each setting, the blade was reused for a second time. All eyes were included, resulting in 4 groups with 6 eyes for each configuration. The surface and edge of the corneal cut was examined using SEM.

RESULTS

At fixed oscillation rates, an increase in head-advance speed led to lower quality cuts, higher surface roughness, and irregular cut edges for both cutting heads (140 microm/160 microm), especially when using the blade for a second time. At fixed head-advance speeds an increase in oscillation rates improved the cut quality for both cutting heads (140 microm/160 microm). This results in smoother surface characteristics and more regular cut edges, especially when using the blade for the first time.

CONCLUSIONS

Using the Amadeus II microkeratome for laser in situ keratomileusis procedures, the optimum oscillation rate, the optimum head-advance speed, and a single use of the blade will produce a very smooth and regular surface and cut edge for safe, comfortable, and improved customized refractive surgery.