BENEFIT OF SIMULATORS

A new binocular adaptive optics simulator, AOneye (Voptica), may allow for a more customised approach to the surgical treatment of presbyopia, providing patients with a preview of their postoperative vision in terms of both visual acuity and visual quality, said Pablo Artal PhD, University of Murcia, Spain, who is co-founder and chairman of the Voptica company.

“In my opinion, customisation is the key in the binocular correction of presbyopia. If you provide patients with the optical values they require, they will be happy. And we can do this with adaptive optics customisation,” Dr Artal told the XXXIII Congress of the ESCRS in Barcelona, Spain.

He noted that the new instrument which he and his associates have developed consists of a wavefront sensor and a liquid crystal device that projects any proposed optical profile into the patient’s eye. It can therefore provide patients with a preview of what their postoperative vision will be following any proposed treatment.

Furthermore, using the system binocularly allows presbyopic patients to sample the various presbyopic treatments that are based on binocular retinal disparity. Those treatments include conventional monovision, where one eye is targeted for emmetropia and the other for up to -1.5D of myopia, and more sophisticated techniques, such as those employing asphericity.

When tested with conventional defocus curves, all of the treatments appear to provide similar results. However, patients are sometimes unhappy despite achieving a large range of good visual acuity. Sometimes, two patients receiving the same treatment and achieving the same results in terms of through-focus visual acuity will express markedly different levels of satisfaction, Dr Artal said. “Depth-of-focus visual acuity is not enough. We also need to consider contrast sensitivity, binocular summation, stereoacuity, and neuroadaptation,” he added.

BEST VISUAL ACUITY

Dr Artal noted that studies they have conducted with adaptive optics simulations of conventional monovision closely mirrors clinical experience, showing that binocular summation will be maintained so long as the focal disparity between the two eyes is less than 1.5D. Beyond that, there is inhibition, with the result that binocular acuity is worse than monocular acuity.

Pablo Artal:

pablo@um.es