Analysis of Enhancement Rate According to Age after Refractive Surgery with Schwind Amaris

ABSTRACT

PURPOSE: To evaluate the clinical effects of an automatic energy-lowering system in patients over the age of 28 years with Schwind Amaris laser platform by analyzing the enhancement operation rate according to age. METHODS: A total of 20448 eyes from 10224 patients who received a bilateral LASIK or LASEK operation with the Schwind Amaris laser platform between August 2007 and April 2011 in our clinic were included in the present study. The rate of enhance operation due to undercorrection was analyzed to determine whether the age affects the enhancement operation rate. RESULTS: There were a total of 17 enhancement operations. Fifteen out of 17 eyes who received the enhanced operation were above the age of 28 years (p=0.005). In multivariate analysis, patient age over 28 years (OR=6.75, CI 1.54-29.60, p=0.011), preoperative higher spherical equivalent (OR=0.56, CI 0.41-0.77, p=0.0004) and preoperative higher mean keratometric value (OR=1.38, CI 1.01-1.88, p=0.043) were significantly associated with a higher enhancement operation rate. CONCLUSIONS: Surgeons should be aware that the amount of laser energy from Schwind Amaris laser platform is automatically reduced in patients above the age of 28 years. Therefore, the nomogram should be adjusted to reduce the enhancement operation rate for a specific age group, especially in patients with higher preoperative myopic errors and steeper cornea.