Epi-LASIK safe, effective 1 year postop with low patient discomfort

October 15, 2005

Lisbon, Portugal—Epi-LASIK is a safe and effective alternative refractive procedure to treat patients with low and moderate levels of myopia, according to Vikentia Katsanevaki, MD, PhD. One-year data indicate that patients have good refractive results and stable vision.

An important finding is that patient discomfort is low after the procedure. Dr. Katsanevaki reported the findings at the European Society of Cataract and Refractive Surgeons meeting.

"As we realized at the beginning of our research, the big advantage of mechanical separation was the preservation of the basement membrane and a small portion of Bowman's layer at the bottom of the epithelial layer," Dr. Katsanevaki said. She is a refractive specialist with Vardinoyannion Eye Institute, University of Crete, Greece.

Dr. Katsanevaki and colleagues performed almost 400 procedures with only a small percentage in which the epithelial separation was incomplete. The epithelial separation was performed with the use of Centurion Epikeratome (Norwood Abbey Eyecare) and the laser correction with the Allegretto laser platform (WaveLight Laser Technologie AG). The authors analyzed data from 234 eyes that had been followed for at least 1 year. The patients' preoperative refractive error ranged up to –8 D of myopia. The investigators also scored the pain levels reported by the patients based on corneal sensitivity testing using a Cochet Bonnet aesthesiometer.

"There are two important issues with Epi-LASIK. The first is safety. We found that at 1 year after treatment, 53% of patients gained at least one line of vision," Dr. Katsanevaki reported. "The second issue is the development of corneal haze. We found that 90% of patients had either clear corneas or clinically insignificant haze."

The results with haze also applied to 20 patients who had reached the 2-year follow-up evaluation.

The Epi-LASIK procedure also demonstrated a great deal of visual stability within the first year.

She reported that in a small subgroup of patients with 24-month follow-up there was a change of more than 0.5 D in 10% of the eyes from the first to the third month, and no change from the 6-month to the 24-month visit.

Postoperative pain also is a consideration with Epi-LASIK. In this series of patients, the mean pain score, which the patients rated on a scale of 0 to 4, in more than 200 eyes remained below the threshold of burning; almost 10% of patients reported pain that was worse than discomfort during the first couple of hours after the procedure. That decreased to 7% after the first 24 hours, Dr. Katsanevaki explained.

Visual rehabilitation is the biggest problem with a surface procedure, she pointed out. The mean visual acuity during the first postoperative days was 20/40. Re-epithelization was complete in all patients by the sixth postoperative day (average, 4.5 days), and the mean visual acuity was 20/32.

Seven patients had penetration of Bowman's membrane. The patients were treated based on the location of the penetration. If the penetration was outside of the visual axis, the patients were treated during the same session; in two eyes the penetration was within the optical zone and they were treated at a later date with LASIK, she explained. None of these eyes had visual loss.

"Epi-LASIK provides a safe and effective alternative for treating our patients. The visual results were excellent 1 year after treatment. Visual rehabilitation remains a problem," she concluded. "However, this procedure offers the advantage of a less invasive procedure compared with other refractive surgeries."