Abstract
Purpose: :
Abilities to improve the image quality in corneas with high aberrations of higher orders using an excimerlaser system of the newest generation.
Methods: :
In 37 eyes after perforating keratoplasty, lamellar keratoplasty, after corneal injuries and corneal inflammations with a spherical equivalent from 0 to -9.0 diopters and a corneal astigmatism up to 10.0 diopters a superficial excimerlaser treatment with mitomycin application was performed. Corneal aberrations of higher order were determined preoperatively (root-mean-square (RMS) error 2.36 µm ± 1,05; PV- value 15.98 µm ± 7.32; diameter 6mm). Ablationprofile was calculated using the corneal wavefront and the subjective refraction. All treatments were done with the Amaris-Excimerlaser (Schwind) at the Department of Ophthalmology and Optometry, Medical University Vienna.
Results: :
The follow-up time was 12 month. In all patients the corneal haze was below stage 1. The RMS- error improved to 1.48 µm ± 0.79 (minus 37.7%); the PV - value to 10.34 µm ± 7.22). Furthermore coma, trefoil and the spherical aberration could be reduced significantly.
Conclusions: :
Superficial excimerlaser treatment is a valid option for improving image quality in case of corneas with high irregularities. Small spot diameters and modern eyetracking systems enable corrections of aberrations up to the fourth order.
Keywords: laser • refractive surgery: optical quality