The next LASIK Flap

Horizontally oval flaps match the shape of the most common ablation pattern for astigmatic correction. And while the conventional round flap works well, oval flaps represent an opportunity to improve the LASIK procedure. They better conform to the natural anatomical shape of the cornea and allow for better alignment of the flap. The horizontally oval flap matches the horizontally oval ablation pattern that is created for the majority of myopic corrections.

In a study conducted the average outermost horizontal measurement was 12.0 ±0.5 mm, and the average outermost vertical measurement was 11.1 ±0.4 mm. These dimensions demonstrate that the cornea is an 8{0730eed075b45d9e50c00d6cd42dd08773e0164f29a45151808bf89051290974} horizontal ellipse and that oval flaps are a better anatomical match for the cornea, because they symmetrically fit into the horizontally oval shape of the normal cornea. Round flaps can rotate when they are repositioned, causing striae. In contrast, because oval flaps can only fit into one orientation, the possibility of rotation is eliminated and ensures perfect alignment.

Round flaps invade a greater degree of peripheral vital lamellar fibers and nerves superiorly and inferiorly compared with oval flaps, which preserve peripheral fibers and nerves symmetrically. Also, fewer cuts are made vertically on the cornea with oval flaps. Because it is equidistant to the limbus from all locations, an oval flap lends itself to more symmetrical healing than a round flap. The hinge can be made along the long axis of an oval flap. This creates a wider hinge and better exposure of the stromal bed compared with round flaps, and with an oval flap, the hinge need not be ablated.

The iFS Femtosecond Laser to create a flap that is 100 μm deep with inverted 110º side cuts. My preference for making an oval flap is a 5{0730eed075b45d9e50c00d6cd42dd08773e0164f29a45151808bf89051290974} “oversized” flap set with an 8.2-mm vertical default. I find that the setting provides an 8.6-mm horizontal measurement that fits the average cornea well. I place the pocket in the superior location, as this puts both the pocket and the hinge in the visually insignificant area of cornea masked by the upper eyelid.

Based on the research the iFS Femtodecond Laser was used to treat the vast majority of LASIK patients , and they will greatly benefit from horizontally oval flaps, which correspond to horizontally oval ablation patterns for the treatment of WTR and oblique astigmatism. Oval flaps are anatomically compatible with the cornea, and they allow refractive surgeons to achieve perfect alignment of the flap.

At Laser Locators we carry the top name surgical and diagnostic ophthalmic equipment manufacturers you can trust, like Acon, Nidek, Lumenis and more for preforming all of your precise ophthalmic procedures. Contact us at  or call 1-877-924-2020 and let one of our expert equipment locators help you today.