Combined femto laser, excimer laser procedure allows correction of high cylinder and sphere

Issue: May 2016

PARIS — A technique combining deep intrastromal arcuate keratotomy with LASIK allows correction of high ametropia beyond the normal range of LASIK.

The technique is performed in two steps, Ora Levy, MD, said at the meeting of the French Society of Ophthalmology. First, arcuate incisions are performed with a femtosecond laser on an optical zone varying between 6.5 mm and 7 mm. A LASIK flap is then performed with the same laser, 100 µm deep, with a diameter of 9.5 mm.

Ora Levy

“The flap is lifted to let the surgeon reopen the incisions and then put back into place,” Levy said.

After refractive stabilization, 1 month later, the flap is lifted again, and the residual ametropia is treated with an excimer laser.

In a study, a significant reduction of congenital astigmatism was achieved, with 80% of the patients within 1 D of residual cylinder after the procedure. Efficacy was good, with 93% of the patients achieving uncorrected visual acuity of 20/25 or better. In 93% of the patients, refraction was within 1 D, and 66.6% of patients were within 0.5 D. The spherical equivalent was stable between 1 month and 6 months. No patient lost best corrected visual acuity lines, and no surgical complications occurred. The safety index was 1.02.

“This procedure allowed us to spare an average of 15 µm of tissue compared with conventional LASIK that could have been performed with undercorrection in this group of patients. This is not a negligible quantity,” Levy said.

A larger series of patients and a longer follow up are needed to confirm the results and the long-term benefits of this technique, she said. – by Michela Cimberle

Reference:

Levy O. Intrastromal arcuate keratotomy under a LASIK flap. Presented at: Meeting of the French Society of Ophthalmology; May 7-10, 2016; Paris.

Disclosure: Levy reports no relevant financial disclosures.