Influence of patient age on photorefractive keratectomy for myopia.

BACKGROUND: To determine whether the outcomes of photorefractive keratectomy (PRK) for myopia are age-dependent. METHODS: The influence of age on PRK outcomes was analyzed for one eye of each of 72 patients divided into two groups: 39 patients (18 to 26 years) and 33 patients (35 to 54 years). The influence of the amount of preoperative myopia (low myopia less than -4.00 diopters (D); moderate to high myopia -4.00 or more D) was also evaluated. All patients were followed for at least 1 year, and all underwent cycloplegic refractions. RESULTS: One year after PRK, the average refraction was -0.15 D in the younger group and +0.38 D in the older group. The achieved refraction was higher than the attempted by +1.00 D or more only in eyes with moderate to high myopia (-4.00 to -10.00 D); 11.54% (3 eyes) of the younger group and in 34.78% (8 eyes) of the older group. CONCLUSIONS: After PRK for myopia, patients between the ages of 35 and 54, with moderate to high myopia, obtained more refractive change with the same intended dioptric correction compared to younger patients with moderate to high myopia. Attempted correction should be adjusted according to age and amount of myopia.

The effect of spherical photorefractive keratectomy on myopic astigmatism.

The aim of this report is to present the effects of spherical photorefractive keratectomy (PRK) by excimer laser on myopic astigmatism. Spherical PRK was performed in 96 eyes with myopia associated with astigmatism of between 0.75 and 2.00 diopters (D) using the Summit excimer laser. The reduction both in sphere and in cylinder was found to be highly statistically significant (P < 0.0001 for both). The mean reduction of cylinder was 46%. Astigmatic error of less than 2.00 D can be corrected significantly by spherical PRK.

Symmetry of outcome after photorefractive keratectomy for myopia.

The aim of this study was to find out whether the outcome of excimer laser photorefractive keratectomy (PRK) in the second eye can be predicted from the results of the first, and to determine whether we should modify our therapeutic approach to the second eye according to the results of the first. Bilateral PRK was performed in 73 patients using the Summit Technology excimer laser. All patients included in this study had a follow-up of at least 12 months in both eyes. The change of refraction and the haze of the two eyes were compared. Sixty percent of patients had a difference in refraction between the two eyes smaller than 0.50 diopters (D), and 75% had a difference smaller than 1.00 D. The degree of symmetry in response to treatment was greater in patients with a preoperative spherical equivalent refraction of less than -6.00 D. Most patients had a similar degree of haze in both eyes. The results of our study demonstrate that a considerable degree of symmetry in the outcome of surgery exists between the two eyes of the same patient undergoing PRK, especially in low to moderate myopia.