Review

Wavefront-Guided and Wavefront-Optimised Laser Treatments

10.4274/tjo.42.72792

  • Canan Asli Utine

Received Date: 27.03.2012 Accepted Date: 26.06.2012 Turk J Ophthalmol 2012;42(6):474-478

Optical aberrations of the eye are the errors of the optical system that limit the resolution, contrast and amount of detail in the image formed on the retina. Wavefront technology allows us to measure these optical aberrations, calculate mathematically, and transfer this information into excimer laser system to perform customized treatment on the cornea. Two treatment algorithms developed to create low aberration-corneal profile are wavefront-optimised (WF-O) and wavefront-guided (WF-G) treatments. WF-O treatment, aims not to increase the existing spherical aberration while treatment is based on manifest refractive error as in conventional laser treatments. By increasing the number of laser spots applied peripherally in order to optimize the corneal asphericity, the preoperative central:peripheral keratometry ratio is preserved and optic zone shrinkage is prevented. On the other hand, WF-G treatment is based on aberrometry measurements and aims to correct the existing high-order aberrations in the eye. Thus, retinal image with high spatial details can be achieved. However, presence of postoperative defocus can abolish the successful results obtained with WF-G treatment. Clinical randomized controlled trials showed that in patients with preoperative RMS value of <0.3 µm, higher order aberration outcomes are similar after WF-G and WF-O treatments, but WF-G treatment yields better results when it is ≥0.4 µm. In normal eyes, very limited visual advantage can be achieved with WF-G treatment and preservation of asphericity value with WF-O treatment carries greater importance. On the other hand, in case of high astigmatism or higher order aberrations other than spherical aberration, decreasing aberrations with WF-G treatment becomes more important. In this study, we aimed to make a comparative analysis of characteristics and outcomes of the two treatment algorithms. (Turk J Ophthalmol 2012; 42: 474-8)

Keywords: Wavefront-guided, wavefront-optimised

Full Text (Turkish)