Close-Up Look at Progress in Surgical Presbyopia Correction
Presbyopia, the age-related loss of accommodation and near/reading vision, typically begins at about age 40 and affects nearly everyone over age 50. This huge opportunity is inviting several companies to pursue disruptive approaches.
Stephen Lane, MD, from the University of Minnesota, opened the Breakfast Breakout session at OIS@AAO with an overview of current presbyopia treatment options in clinical practice. Because currently available technologies have allowed surgeons to successfully provide cataract and refractive surgery patients with good distance vision, attention has turned to the more challenging objective of simultaneously addressing near and intermediate vision. All forms of surgical presbyopia correction available today involve some level of compromise, so the aim of new technologies is to provide near vision without sacrificing high-quality distance vision.
The most common form of surgical presbyopia correction today is monovision using intraocular lenses (IOLs) or LASIK, which corrects one eye for near vision and one eye for distance. IOL-based options that have become available over the past decade include multifocal IOLs (MF-IOLs) and first-generation accommodating IOLs (AIOLs). Although MF-IOLs, which include trifocal IOLs outside the US, provide good near and distance acuity, visual disturbances such as halos are common. While AIOLs have the potential to deliver a full range of near-to-distance vision without compromise or visual disturbances, currently available AIOLs, most notably Crystalens from Bausch & Lomb, provide high-quality vision but do not provide a full range of vision.
According to Dr. Lane, the “chair time” involved in explaining the various presbyopia-correcting options to cataract patients, along with the potential compromises, has been a key barrier to adoption of premium IOLs for many surgeons. His clinical approach is to simplify this process by offering the option that he thinks will work best for each individual patient.
Douglas D. Koch, MD, from the Baylor College of Medicine, noted that some of the new MF-IOLs are delivering better quality of vision, and the new extended depth-of-focus (EDOF) IOLs, which are available outside the US and will be available in the US in the future, are promising because they deliver a greater range of vision with less compromise. The Symfony EDOF-IOL from Abbott Medical Optics is already gaining traction in Europe, and the IC-8 small aperture IOL from AcuFocus has shown promising results.
Koch noted that there are also several promising AIOL options in the pipeline, including the FluidVision lens from PowerVision, which translates movement of the ciliary body into a shape change of the lens optic. This lens has shown good early data, and PowerVision announced during the OIS Company Showcase the introduction of a “leapfrog” second-generation lens that is expected in the clinic in the first half of 2016. There are also disruptive electronically actuated lens concepts, from Elenza and from the Alcon-Google collaboration, that do not rely on force transfer within the eye. Dr. Lane said that it will be a “long and difficult road” to FDA approval for AIOLs, although he is “absolutely convinced that we will get there. As a class, this is the Holy Grail.”
Corneal inlays are intracorneal implants designed to improve near and intermediate vision, typically in a patient’s nondominant eye, with minimal compromise of distance acuity. The KAMRA inlay from AcuFocus, which received FDA approval in April, works on the principle of small aperture (pinhole) optics. The Raindrop Near Vision Inlay from ReVision Optics creates a change to corneal curvature that increases depth of focus; the company announced in November that the FDA has accepted its PMA submission for Raindrop, and the firm is hoping for approval in 2016. A third inlay, the Flexivue Microlens from Presbia, works on the principle of multifocal optics; the company announced in September the completion of enrollment in its FDA pivotal study.
According to Dr. Lane, “The greatest excitement right now is with the various corneal inlays. KAMRA is the one that’s approved in the US, was recently launched, and is gaining momentum on a daily basis.” It was announced at OIS that there have been over 1,000 KAMRA implants since the May 2015 US commercial launch. Dr. Lane said that corneal inlays could be more universally adopted than MF-IOLs because there are fewer options and visual complications that have to be explained to patients. Corneal health and nutrition is always an issue when implants are placed in this tissue, and both KAMRA and Raindrop have overcome this hurdle. “Fortunately, both are reversible; you can take them out,” Lane noted. “There’s no eraser at the end of an excimer laser, but there is an eraser at the end of a corneal inlay. That’s one of the great benefits of inlays as a class.”
Dr. Koch explained that the intracorneal inlays represent an improvement over monovision because they largely preserve distance vision in the eye that is corrected for near vision, thereby preserving stereopsis, or binocular depth perception. Koch said that the “sweet spot” for inlays will be “the huge population of emmetropes” (who are neither nearsighted nor farsighted) who have presbyopia, which will be the initial FDA-approved indication for all of the inlays. Koch said that inlays could also be implanted preemptively in 40-year-old LASIK patients who are not yet aware of presbyopia, and as a second procedure in prior LASIK patients aged 45+ who are beginning to experience presbyopia, although inlays will not be FDA approved for some time in these LASIK patients. Koch said that he would be biased toward lens-based surgery in presbyopes over age 55.
ReVision Optics has initiated an IDE clinical trial for Raindrop in pseudophakic patients, addressing the large population of patients who have had prior cataract surgery. According to Dr. Lane, “The pseudophakic patient who has a good distance result is probably a great candidate for inlay technology.” Both Koch and Lane said that inlays would be less likely to be used concurrently with cataract surgery, where it makes more sense to address presbyopia with IOLs.
Wende Hutton said that Canaan Partners, which is an investor in ReVision Optics, typically looks for market opportunities of $500 million or more. Within the vision correction field, the firm focuses on biocompatibility and clinical data that validate a product’s mechanism of action. Hutton commented that “there’s something viral about patients getting rid of their reading glasses and becoming spectacle-free.” With multiple major players developing the corneal inlay category with products that have distinct mechanisms of action, Hutton believes that inlays could represent a $500 million to $1 billion opportunity over the next several years.