Multizone versus tapered transition zone for the correction of moderate myopia with the excimer laser aesculap meditec

PURPOSE: To compare safety, regresion and haze in patients submitted to photorefractive keratectomy that were treated with multizone in one eye and tapered transition zone (TTZ) in the fellow eye. METHODS: PRK was performed in 20 eyes of ten patients with a mean myopia of-8.30 D (range from -7.00 to -11.75 D) and mean age of 28.5 years. Patients with a stable refraction during the last year, and older than 18 years were included. Exclusion criteria were: previous ocular surgery and any ophthalmological. systemic or inmunological disease. In one eye the multizone technique was performed and in the fellow eye a TTZ was used. A complete ophthalmological evaluation was performed in each visit. Patients were examined preoperative, at the first day post op, until healing occurred, and at one, three and six months post op. RESULTS: refractive outcome was similar in both groups with a mean refraction of -2.00 D (±2.00D) at six months post-op. The eyes that were treated with the TTZ showed more haze (mean 1.5+) than the eyes treated with multizone technique (mean 1+), since the first month post op. All the patients gained UCVA, except one in which the UCVA remained unchanged in both eyes (TTZ and Multizone). 37.5% of the eyes sowed no changes in their BCVA, 37.5% lost one line and 25% gained two lines, in the multizone group. 50% of the eyes treated with the TTZ showed no change in their BCVA, 25% lost one line, and 25% lost two lines of BCVA. CONCLUSION: As it produces less haze, and less lost BCVA, multizone is safer method to correct moderate myopia than the TTZ.