Corneal Wavefront-Guided LASIK Treatment for Vision Correction

Wavefront laser eye surgery is the most advanced form of excimer laser technology. Just like a fingerprint, each person’s vision is unique to them, which warrants a customized treatment. But besides this there is another feature of the optical system of the eye which needs consideration before treatment and can make a whole lot of difference to the quality of vision.

Theory behind Wavefront Technology – ‘Higher – Order Aberration’:

Nature has designed the eye like an Optical System, similar to something like a telescope. When you see some object, light rays from that object pass through different layers of the eye and then create an image of that object. These light rays are subject to being distorted by the imperfections found in the cornea and the lens.

The distortions that are created are referred to as ‘aberrations’. The vast majority- 80% or more–of these aberrations create common refractive errors, such as near-sightedness, farsightedness and astigmatism, which can be treated glasses and contact lenses, or by Standard Laser Correction. The remaining 20% of optical aberrations are known as “higher order aberrations”. These are not corrected by Conventional or Standard Lasik treatment. Higher-order aberrations, cause the visual glare and halos that cause night vision problems, and affect quality of vision. It is seen in everyday life as glare experienced during night driving, surrounding car headlights, streetlights etc.

Types of Higher Order Aberrations:

1. Corneal Higher Order Aberration: These are the imperfections present in the cornea which contribute to Higher Order Aberration.
2. Ocular Higher Order Aberration: These are the imperfections present in our optical system as a whole which are contributing to Higher Order Aberration.

The Treatment:

The decision whether to go for Corneal or Ocular Wavefront guided treatment will depend upon how much is the contribution of corneal component towards causing higher order aberration. Also, depending upon a patient’s nature of complaint (too many haloes or glare at night) the doctor may decide in favour of one or the other procedure.

 To achieve a customized Wavefront-Guided corneal shaping, the higher order aberrations are measured using a Wavefront analysis system with advanced topography features called Sirius Topographer .This system takes thousands of measurements at unique points in the patient’s vision in order to create a “map,” which is then used to measure imperfections that corrective lenses can’t correct. This helps the surgeon see refractive aberrations in clear and accurate, rotating 3-D images and also understand how your entire optical system processes light. All this information cannot be seen by regular or standard testing. This information is then transferred to the laser system, thus achieving Customized Wavefront-Guided Treatment designed to suit your eye. Once it is ascertained that the major or significant component of Higher Order Aberration is being caused by corneal imperfections, these are treated by Corneal Wavefront Guided Lasik Module.

The advantages of Wavefront over conventional laser treatments are thought to include greater accuracy and improvements in visual quality. Wavefront treatments also include additional elements such as iris registration, or even iris recognition, and pupil size measurement in order to be more precise. The latest excimer lasers in use at AELC for example can offer ‘dynamic rotational tracking’ of eye movements in order to achieve greater accuracy. It is important to realize that not all eyes will have higher order aberrations warranting their correction. Some such aberrations may be present at such a point in the optical system so as to have very minimal influence on the overall quality of vision and thus need not be treated.

TO LEARN MORE, GO TO ‘Understanding Laser Vision Correction Page’

TO GET THIS TREATMENT, GO TO ‘Getting Refractive Services at Angel Eyes Page’