Epi-LASIK offers good visual results compared with LASIK

Alexandria, Egypt-The debate over the efficacy of epi-LASIK and LASIK continues. Both procedures are safe, although the visual rehabilitation is slower in patients who undergo epi-LASIK. However, the visual results ultimately surpass those who had LASIK, according to Ahmed A. El-Massry, MD, who reported on a comparison study of the two procedures.

"The advantages of epi-LASIK, which requires mechanical separation of the corneal epithelium, are that it provides surface ablation for thin corneas, less postoperative haze compared with PRK, and maintenance of the corneal thickness," Dr. El-Massry said. "The disadvantages include postoperative pain similar to LASEK, a steep learning curve, postoperative medications, and long postoperative care."

In their comparative study, Dr. El-Massry, clinical professor of ophthalmology, Alexandria University, Alexandria, Egypt, and colleagues included 40 eyes of 40 patients who underwent ablations with a particular excimer laser using wavefront technology (Star S4 with CustomVue, Advanced Medical Optics/VISX); 20 patients underwent LASIK and 20 patients underwent epi-LASIK.

The preoperative refractions ranged from –2.0 to –6.0 D; the mean preoperative visual acuity levels were 1.09 in the epi-LASIK group and 1.05 in the LASIK group. "At 1 month postoperatively, the patients who underwent epi-LASIK had lower visual acuity compared with the patients who underwent LASIK," Dr. El-Massry reported. "After 3 months, the reverse was true, with the patients who underwent epi-LASIK having better visual acuity than those who underwent LASIK."

Thirteen of 20 epi-LASIK patients had a visual acuity of 1.0 or better compared with 19 of the 20 LASIK patients. At 3 months, all patients who underwent epi-LASIK had vision of 1.0 or better compared with 19 of the 20 patients who underwent LASIK.

Initially, at 1 month after the procedure, the patients who underwent epi-LASIK also had worse higher-order aberrations compared with those who underwent LASIK. After 3 months, again as with the visual acuity levels, the reverse was true for the higher-order aberrations, Dr. El-Massry said.

After 1 month, patients in the LASIK group had lower levels of coma compared with those in the epi-LASIK group. At 3 months, patients in the epi-LASIK group had lower levels of coma. Trefoil behaved similarly.

Haze resolves at 3 months

Dr. El-Massry demonstrated the progressive healing process postoperatively. On the seventh postoperative day and 8 weeks after surgery, patients who had undergone epi-LASIK had minimal epithelial haze. By 3 months, the haze had resolved.

"Epi-LASIK is safe for treating patients with low to moderate levels of myopia. The postoperative haze is minimal but may take up to 3 months to resolve. The learning curve is steep, and a longer follow-up period is needed for these patients," he said. "The surface separator solved the problem of thin corneas in patients with low to moderate myopia with or without astigmatism. Higher-order aberrations are worse 1 month after epi-LASIK than with LASIK but better than with LASIK 3 months after the procedure."

The data are preliminary, Dr. El-Massry emphasized, and long-term studies are needed to evaluate the ablations after epi-LASIK and LASIK.