New surface ablation approach shows advantages over PRK

Paris—Advanced surface ablation using the MEL 80 laser (ASA80, Carl Zeiss Meditec) showed significant advantages compared with conventional PRK, especially for the recovery of best-corrected visual acuity (BCVA), pain, and haze formation.

Sven Lee, MD, of Nurnberg, Germany, present clinical results of a cohort study regarding this new approach to excimer-laser-surface ablation for myopia in a free paper presentation at the European Society of Cataract and Refractive Surgeons meeting. Dr. Lee and colleagues evaluated the differences between the modalities, considering uncorrected visual acuity (UCVA), BCVA, stability, predictability, pain, re-epithelialization and haze formation in patients.

The study, conducted between January 2003 and April 2004, looked at 176 eyes of 116 patients treated with the ASA80 laser and 358 eyes of 225 patients treated with PRK. The spot-scanning laser MEL 80 was used in both groups. Follow-up was conducted after 1 and 4 weeks, as well as 6 and 12 months.

The mean preoperative spherical equivalent for the ASA80 group was –5.67 D ± 2.85, with myopia at –1 to –12.75 D and astigmatism at –0.25 to –6.50 D. For the PRK group, spherical equivalent was –5.59 D ± 2.79 D, with myopia at –0.75 to –13.25 D and astigmatism at –0.025 to –6.50 D.

Dr. Lee pointed that after 1 year, predictability, safety, and stability were better in the ASA80 group. Mean postoperative pain, haze formation, and re-epithelialization time in the ASA80 group also were better. There were no differences in the area of efficacy.

After 1 and 4 weeks postoperative, UCVA, BCVA, and recovery of BCVA were significantly better in the ASA80 group. In the 6- and 12-month follow-up, no significant differences between the two groups were found. UCVA in both groups after 6 and 12 months was better than preoperative BCVA.