iDesign Lasik (laser eye surgery) - is it the best?

For patients considering laser eye surgery, the internet can be a confusing place. Most clinics claim to offer the best technology and unbeatable results, but is this really true?

A frequently advertised technology is the iDesign customised treatment for Lasik that treats your prescription more accurately than glasses.

So what exactly is iDesign?

iDesign is a wavefront aberration scanner used to evaluate the properties of the eye as an optical system. Whilst glasses correct simple short sightedness or long sight as well as astigmatism, the actual optics of the eye can be assessed with a much higher degree of sophistication and resolution.

In this way, the optical power of multiple different points of the eye can be assessed individually and this data can be used to guide the laser correction with a much higher degree of accuracy. Thus rather than say a simple -2.0 uniform correction to the whole eye, a wavefront-guided treatment will typically target multiple points slightly differently (-2.01, -2.02, -2.04, -2.1, -1.99 etc) to deliver a highly resolved and customised vision correction.

Wavefront scanners such as the iDesign work through a system called a Hartman-Shack sensor. Very simply the scanner projects points of light into the eye. Each ray of light enters the eye and returns back out again after being reflected from the retina. The deviation of the light ray on the HS sensor array from the path of a perfect optical system is used to calculate what is known as the wavefront measurement of the eye. These are imperfections in the optics of the individual eye. The iDesign scanner measures 1257 individual data points on the eye. This can be thought of as its degree of resolution.

iDesign works exclusively with the Visx S4 IR laser systems which were approved in 2007.

Advances on iDesign

Wavefront scanning technology has been used since the late 1990s and the iDesign was first registered for use in 2015. Limitations of iDesign relate to its resolution (number of captured data points) and technical issues relating to measurement accuracy in more complex eyes.

All technologies keep advancing and the newest generation wavefront scanning technology is incorporated into the Peramis high-resolution wavefront analyser from Schwind. The Peramis aberrometer has a significantly higher resolution than other commonly used systems. This exceptional performance is based on a high-resolution pyramidal wavefront sensor that measures ocular wavefront aberrations with an unequalled 45,000 measuring points.

This highly resolved data is utilised in perhaps the best currently available excimer laser – the Schwind Amaris 1050RS with Smart Surface. The Schwind Amaris is equipped with a 3-dimensional eye tracker for absolute precise delivery of the wavefront derived optical correction which delivers exceptional results with all corrections including astigmatism and long sight.

In addition, the sophistication of the measurements taken from the Peramis and laser delivery from the Amaris allows advanced treatments such as Presbymax for correction of presbyopic age-related reading vision difficulties.

iDesign VS Peramis