Abstract
Purpose: :
We will present our preliminary experience using a different approach on excimer ablation, based in the manipulation of the final spherical aberration value (polynomium Z(40))
Methods: :
We evaluated the results of the treatment in 17 eyes of 13 patients, with mean age of 45 years. Asphericity changes were measured with a Hartmann–Shack aberrometer (WASCA, Zeiss Meditec) and amplitude of accommodation were measured objectively with the double–pass based instrument ( OQAS (Optical Quality Analysis System, Visiometrics). A standart myopic or hyperopic treatment was combined with aberrometric correction of a fourth–order aberrometric correction of a fourth–order aberration to obtain the desired increase in spherical aberration
Results: :
Subgroup analysis showed that near vision with distance correction improved in the myopic eyes, was stable in the hyperopic eyes and had a marked increase in the pseudophakic eyes, both myopic and hyperopic. Measurements with the WASCA aberrometer showed that, as we expected, spherical aberration increased in all groups, especially in the hyperopic group.. Clinically non–significant but important data came from the OQAS analysis. Amplitude of accommodation increased between 1.25D and 2.25D and was again particularly notable in the pseudophakic eyes.
Conclusions: :
The treatment proved to be safe, with no loss of high or low contrast visual acuity in any of the patients. The efficacy on near vision was remarkable in most cases, without any loss of distance vision quantity and quality
Keywords: presbyopia • optical properties