Monochromatic aberrations and pseudophakia
Jurkutat S., Schultze B., Strobel J.
Augenklinik der FSU-Jena
Purpose: The optical system of the human eye has beside spherical, astigmatic and chromatic image distortions monochromatic aberrations of a higher order, which contrast the ideal image reproduction. These aberrations can be measured through wave front analysis and depicted as Zernike coefficients. Because of the balancing of the image distortions of the lens and the cornea, we expect changes in the entire system.
Method: Wave front analysis was carried out with the help of the WASCA workstation (Carl Zeiss Meditec AG) on 19 eyes with a foldable silicone lens (type 911A, Pharmacia GmbH), on 18 eyes with a one-piece PMMA lens (type 808C, Pharmacia GmbH) and 24 unaffected eyes (all age-related).
Results: Both types of intraocular lenses show an induction of astigmatism represented by the Zernike coefficients Z2/2. Except for a significant increase in spherical aberration (Z4/0), the foldable silicone IOL offers only unsystematic low changes of aberrations. The PMMA lens shows an increase in the coefficients Z3/3 and Z3/-3 and the spherical aberration to.
Conclusions: The cataract operation with small incision technique increases the spherical aberration. These findings point to an aspherical form of the natural lens. The higher numerical value of the coefficients Z3/3 and Z3/-3 after the implantation of the PMMA lens can be put down to the larger incision with seal by stitch. Because of the increase of the spherical aberration in a strictly neg
Zurück | Back