Vigamox: How good is its self-preservation?

Abstract

and is not dependent on the calculation method. In clinical practice, the transition zone is known to cause visual disturbances at low-illumination conditions, especially when localized light sources are present. The severity of these symptoms is dependent on the actual pupil diameter and its relation to the functional optical zone of the cornea and on the amount of dioptric difference between the central (treated) and peripheral (untreated) cornea. However, these visual effects result from aberrations originating from the actual corneal geometry, which cannot be adequately approximated by low-order (eg, up to the 4th order) Zernike polynomials. We strongly believe that in postoperative eyes, especially after correction of high refractive errors, the optical system should be divided into 2 parts: the central part, including the uniform part of the cornea, that can be measured using commercial instruments and approximated with Zernike polynomials and the peripheral part, involving the transition zone and the untreated cornea, which is not suitable for sharp image formation. Conventional optical analysis of postoperative eyes should be restricted to pupil diameters including the central part only. It is therefore suggested that the transition zone should not interfere with the sampled pupil if a limited set of Zernike polynomials are used to approximate the wavefront. Furthermore, the statistical evaluation of isolated Zernike coefficients (eg, C4 ) may lead to erroneous conclusions because they exhibit high intrasubject variability and because their true impact may be balanced by other higher-order coefficients, possibly neglected at wavefront reconstruction.