Better stromal bed quality with Zyoptix XP

The Zyoptix XP (Bausch & Lomb) microkeratome achieved increased stromal bed quality when compared with both standard and zero compression Hansatome heads (Bausch & Lomb), Thomas Hammer said.

Dr Hammer of the University Eye Hospital, Wittenberg, Germany, conducted an electron microscope evaluation of cutting edge and cut surface after lamellar keratotomy using both the XP and Hansatome.

The study evaluated both microkeratomes on freshly enucleated porcine eyes. There was a trial series of eight cuts with each model/head. After flap removal, an individualized score system was used to evaluate the cutting edge and stromal bed.

"The Hansatome is one of the most commonly used microkeratomes," said Dr Hammer. He added that the new Zyoptix XP is a new generation microkeratome developed from the Hansatome device and is based on the same pivoting principle as the Hansatome.

"Since the configuration of the cutting edge and the creation of the stromal bed has a potential impact on the refractive results, we examined those parameters," he said.

The cutting edge created by the Zyoptix XP microkeratome was steeper, leading to a shorter intraepithelial wound compared with the Hansatome. The demarcation of the cutting edge, or 'sharpness', was comparable to the Hansatome. But because the Zyoptix is 15% slower (4.6 mm/s) than the Hansatome with an equal oscillation of 1400 rpm/s, the stromal bed quality was smoother.

Dr Hammer concluded that increased stromal bed quality is achieved because of the changed oscillation and forward speed. The steeper cutting angle also decreases the risk of epithelial implantation.

Ophthalmology Times Europe reporting from the XXIV Congress of the ESCRS, London, 9-13 September, 2006.