Could colour LED topograpy open up more widespread use of advanced contact lenses?
I-Optics has issued the bold claim its Cassini colour LED topographer could replace the use of Placido topography and assist the 150 million people worldwide that wear contact lens, including 75 million people suffering from dry eyes and five million Keratoconus patients.
Whilst Premium lenses can correct astigmatism and other irregularities that standard lenses can not, such as multifocal, toric, aspheric and ortho-k conditions, potential users can be excluded because fitting these advanced lenses tends to be a lengthy process. With submicron accuracy and ability to map and measure all eyes, including dry eyes and irregular corneas, the Cassini system claims to outperform the classic ring-based âPlacidoâ topography and offers the potential to allow patients to choose more effective contact lenses.
The Cassin system is designed to diagnose irregularities in the shape of the cornea far more precisely than the current ring topographers. As a result, it claims to be in a position to support the latest vision improvement techniques. In some cases, I-Optics believes that specialty lenses such as ortho-k and toric lenses, representing more than 10 per cent of the contact lens wear market, require the accuracy that can only provided using Cassini colour LED topography. It also claims superior indices for early detection and progression monitoring of corneal pathologies such as Keratoconus, as well as for measuring dry eyes or irregular corneas resulting from corneal surgery.
Cassini is a multi-coloured point-to-point reflection method developed in close cooperation with the VU University Medical Centre in Amsterdam, Netherlands. It involves the use of hundreds of colour-coded LEDs set in a unique pattern. Using its smart measurement system, Cassini achieves submicron accuracy and precision of corneal height and can measure the periphery of the cornea. According to recent preliminary data from a study comparing Cassini to the Nidek OPD-Scan ll (Pladico ring) and the Oculus Pentacam (Scheimpflug) in co-operation with the VU University Medical Centre showed that colour LED topography was most precise and consistently accurate. Out of 14 penetrating keratoplasty patients, Cassini could measure the cornea reliably, where the Oculus Pentacam failed on five and the Nidek OPD-Scan II on six patients.