Optimized Zernike Term Selection in Customized Treatments for Laser Corneal Refractive Surgery: Case Report

To report a case in which a tissue saving program in an aberrated eye was used.

A new algorithm for the selection of an optimized set of Zernike terms in customized treatments for laser corneal refractive surgery was developed and clinically tested. Ablation was performed using the SCHWIND ESIRIS excimer laser. Pre- and postoperative corneal wave aberrations were analyzed using the Keratron Scout videokeratoscope (Optikon 2000).

Required ablation was reduced by approximately 15% compared to full customized correction. Refraction was corrected to subclinical levels, uncorrected distance visual acuity improved to 20/20, corrected distance visual acuity gained 2 lines, aberrations were reduced by approximately 40% compared to preoperative baseline levels, and the functional optical zone of the cornea was enlarged by approximately 40% compared to preoperative baseline levels. Trefoil, coma, spherical aberration, and the root-mean-square value of the higher order aberrations were reduced.

Eliminating all higher order aberrations may not optimize visual function in highly aberrated eyes. The new algorithm minimized tissue removal in refractive surgery but further clinical evaluations are required to confi rm preliminary results.