A NEW upgrade to the Zyoptix wavefront- guided refractive surgery system (Bausch&Lomb) greatly simplifies pre- operative examination and calculation of the ablation profile by removing the need for pupil dilatation during aberrometry

A NEW upgrade to the Zyoptix wavefrontguided refractive surgery system (Bausch&Lomb) greatly simplifies preoperative examination and calculation of the ablation profile by removing the need for pupil dilatation during aberrometry and automatically incorporating wavefront data in the treatment algorithm, said Erik Mertens MD,Antwerp Eye Center,Antwerp, Belgium. The upgrades include a better computer for measurements with the Orbscan topographer and the Zywave aberrometer and new software.A wireless link allows direct data transfer of diagnostic measurements to the new updated laser treatment calculator, without the need for floppy discs. In addition, the system's software eliminates the need for pupil dilation by extrapolating wavefront measurements from eyes with undilated pupils, he noted. “When we do higher-order corrections we need to dilate the pupil in a lot of cases because otherwise we won't have enough information. But the problem with dilation is you can get dry eye and de-centred pupils and it gets much more difficult to do a good job. Now with the new software from Bausch&Lomb you can have a 10 per cent larger treatment zone than the pupil diameter during wavefront measurement,” Dr Mertens told the 11th ESCRS Winter Refractive Meeting. As a result, the new software makes it possible to perform wavefront-guided treatments with optical zones up to 7.1mm when the pupil size at the time of examination was only 6.5mm, he added. In addition, the system eliminates the need for pharmacological pupil dilation and removes the extreme pupil shift issues and other sources of variation caused by dilation process. It also creates the possibility for one-day procedures. Moreover, it enables speedier examinations, which provides increased comfort to the patient and improved patient throughput for the surgeon, Dr Mertens said. The system's new personalised nomogram automatically incorporates the influence of pre-operative factors, including lowerand higher-order aberrations into the laser ablation algorithm, he noted. “The problem is that when you are going to treat higher-order aberrations and the patient has a lot of positive spherical aberration and you do not take that into account in your refraction you will get an overcorrection.This program does that for you, you just do a very good subjective refraction and your higher-order aberration measurements with Zywave, click the advanced nomogram button, and it will give you the treatment algorithm and you don't have to do anything to correct it yourself,” he added.