The Sims

When it comes to multifocal IOLs, there are a number of designs available, each working on a different refractive or diffractive principle, and each representing a different visual experience. Understandably, it can be difficult to explain to patients what their experience of a given IOL will be after implantation.

But thanks to a device developed by the Visual Optics and Biophotonics Lab (VioBioLab) in Madrid, Spain, under PI, Susana Marcos, you might not have to explain at all. Thanks to SimVis, patients could experience improved vision before they are fitted with an intraocular lens.

SimVis – a head-mounted, simultaneous visual simulator – allows patients to trial multiple lens designs and depths of focus. The bonus for clinicians? It’s wirelessly controlled, allowing the operator to adjust lenses and track functional tests from anywhere in the world.

It sounds simple, but the SimVis is far from it. Maria Vinas, a post-doctoral fellow at the VioBioLab, explains how it works. “The SimVis consists of an opto-mechanically tunable lens, operating under temporal multiplexing mode.

The technology allows us to reproduce any multifocal design as the tunable lens scans multiple foci to provide superimposed images on the retina, all of them with the same position and magnification, but corresponding to different planes in focus,” she says.

“The simulated multifocal correction is tuned to match the through-focus optical quality of real existing multifocal lenses. In other words, the device allows a realistic experience of multifocality, which will depend on the simulated multifocal design.”

The technology is a miniaturized version of a laboratory experimental setup, redesigned for a clinical environment. The result of more than 10 years’ work by CSIC scientists, Susana Marcos and Carlos Dorronsoro, the design is protected by four proprietary patents – one of which received the “Best Patent of the Year” award from the Madri+d Foundation.

Vinas says the team is happy with the prototype’s path from lab to clinic – but what’s the reaction been from patients? So far, so good.

“The SimVis has been tested by around 60 patients in different laboratory or clinical environments – both before and after surgery (for crystalline lens replacement) and for multifocal contact lens fitting – and, up to now, they are all extremely satisfied,” says Vinas.

“For them, the process is both clarifying – as they can try different options – and relaxing, as they have an idea of what their vision is going to be like after the surgery.”

With endless visual options offer, the SimVis – and other devices like it – have the potential to radically change not only the patient experience but also that of the surgeon.

“By providing patients with a new, realistic experience of multifocality before the implantation of a new intraocular lens, visual simulators could have a significant impact on the clinician’s ability to reduce uncertainty and to manage patient expectations,” says Vinas.

“Moreover, technologies of simultaneous vision simulation allow for the evaluation of visual quality in designs of multifocal lenses before they are implanted or even manufactured.”