[Results of photorefractive keratectomy in myopia with flying spot excimer laser with high speed and small beam diameter].

PURPOSE

To examine the result of photorefractive keratectomy (PRK) with the next generation of flying spot excimer laser for the treatment of myopic refractive errors.

PATIENTS AND METHODS

During the study 164 eyes of 98 patients were assessed. The average age was 29.4 +/- 4.62 years. The myopic eyes were divided into 3 groups: in Group 1. (n = 115 eyes) the eyes between -1.0 D and -6.0 D were evaluated, in this group the preoperative average refraction was -3.43 +/- 1.2 D (SE = spherical equivalent); in Group 2. (n = 31 eyes) the eyes between -6.1 D and -9.0 D were evaluated; the preoperative average refraction was -7.26 +/- 2.4 D (SE). In Group 3. (n = 18 eyes) eyes above -9.0 D were examined; in Group 3. the average preoperative refraction was -10.22 +/- 3.4 D (SE) Follow-up is 6 months. PRK treatments were carried out with the Zeiss Meditec MEL 80 G-Scan flying spot excimer laser, which was operated with a 0.7 mm beam diameter and 250 Hz frequency.

RESULTS

In Group 1. The preoperative correction decreased to -0.14 D (SE); in 71% of the treated eyes uncorrected visual acuity (UCVA) was 1.0; in 24% of the eyes UCVA improved to 1.2. Best corrected visual acuity (BCVA) was unchanged in 65% of the eyes; while in 34 improved (in 24% it improved by more than 2) Snellen lines. In Group 2. the preoperative correction decreased to -0.13 +/- 0.01 D (SE); 67% had 1.0 and 8% had a 1.2 UCVA. BCVA was unchanged in 92% in Group 2.; in 8% BCVA increased by 1 or 2 Snellen lines. In Group 3., the preoperative correction decreased to -0.44 +/- 0.2 D (SE); 96% of the eyes had a 0.8 UCVA; BCVA did not change in 75% of the eyes, 25% of the eyes gained 1 Snellen line.

CONCLUSIONS

Myopic PRK treatments with the 3rd generation of excimer laser were effective and safe. Regarding BCVA, best results were obtained in the low and medium myopia groups.