Microkeratome creates high-quality, predictable flaps and smoothbeds, studies show

Studies evaluating the new Zyoptix XP microkeratome (Bausch & Lomb) indicate that it performs safely and reliably to cut LASIK flaps of a reproducible thickness with a standard deviation that matches or exceeds results reported for the femtosecond laser (IntraLase).

At the recent American Society of Cataract and Refractive Surgery annual meeting, Dr. Maloney presented the results of a retrospective study analyzing flap thickness and variability achieved with the Zyoptix XP in a series of 50 patients who underwent bilateral flap creation using the same blade for both eyes. The microkeratome was equipped with the 120-μm plate, and the results showed it created first-eye flaps of an average thickness that was very close to the nominal thickness with a very low variability. The mean ± SD for flap thickness was 123 ± 14.8 μm. Flaps in the second eye were thinner on average, but also close to the nominal thickness and with a reasonably low standard deviation (112 ± 18 μm).

Compared with laser technology

Hung Ming Lee, MD, of the Refractive Surgery of the Eye Institute, Tan Tock Seng Hospital, Singapore, directly compared the Zyoptix XP microkeratome with the 15-kHz femtosecond laser in a prospective, bilateral study including 50 patients with comparable spherical equivalent (SE) and best-corrected visual acuity (BCVA) levels in fellow eyes. Intended parameters were 120 μm for thickness and 8.5 mm for diameter using both flap creation devices. Dr. Lee was operating with the Zyoptix XP as a novice while he was an experienced user of the femtosecond laser.

Variability in flap thickness was similar for the two techniques. Standard deviation (SD) for ultrasound pachymetry-measured flap thickness was 16.1 μm for the Zyoptix XP and 16.2 μm for the femtosecond laser. Using OCP, the corresponding SD values were 14.4 μm and 15.9 μm, respectively.