Presbyopia in the Farsighted Future
What will management of the disability look like in 10 years?
Blake Williamson |
I’ll start with a bold claim: within 10 years, I believe the majority of ophthalmologists will not be treating presbyopia with spectacles but rather with either topical drops or refractive surgery. Perhaps a wild idea given that our current solutions have limitations – but when you consider the technology that will be available 10 years from now, it doesn’t seem so far-fetched.
Presbyopia is a huge problem – there are 1.8 billion presbyopes worldwide, and the number increases each year. The inability to read at near has always been a disadvantage, but with Johannes Gutenberg’s invention of the printing press in 1439 – which led to the rise of mass communication, global literacy and the transformation of society – the problem became magnified. Centuries later, with the advent of the in-home computer in 1984 and the iPhone in 2007, awareness and complaints about the disability have skyrocketed.
Today, reading glasses and bifocals are the most common treatment – a poor effort, when you think that reading glasses were invented by Italian clergy in the 13th century and bifocals have been around since Benjamin Franklin brought them to market in the 1770s. Innovation is sorely needed in the presbyopia space – and I think ophthalmologists and industry have finally started to answer that call. Five years ago in the US, there were essentially five commonly used surgical options: blended vision LASIK, monovision cataract surgery, multifocal IOLs (two choices), and accommodating IOLs. Just 10 years from now, we are likely to have some 31 different options including: laser vision correction (blended vision LASIK, multifocal LASIK); inlays (synthetic inlays, PEARL, allograft inlays/onlays); IOLs (monvision cataract surgery, multifocals, EDOF, small aperture, trifocals, accommodating); adjustable IOLs (light adjustable lens, refractive indexing IOL; and scleral approaches (scleral implants, lasers).
Several of these future solutions will move the needle for refractive surgery in the presbyopia space, but I believe the most disruptive surgical technologies will be Allotex’s inlay/onlay, RXSight’s Light Adjustable Lens (LAL), and refractive indexing with Perfect Lens. Why? Because several other technologies have been available for years on the EU market (trifocals, EDOFs, and so on) – yet the penetrance of refractive surgery for presbyopia treatment remains low.
The allograft from Allotex is an improvement on the original tissue addition techniques by José Barraquer. Synthetic inlays have remained a niche market because of concerns such as haze, but allografts offer a promising alternative; the pristine biocompatibility of human corneal tissue has been known for decades, and improvements in metrology, tissue banking and laser technologies will solve many of the problems that older tissue addition techniques had. The possibility of onlay procedures without the need for a femtosecond laser cutting a deep flap/pocket are particularly attractive, not to mention the procedure can be easily reversed through removal at the slit lamp.
The LAL will be disruptive because it will be the first lens giving surgeons the ability to adjust the IOL sphere and cylinder after surgery. I believe this will calm many surgeon’s fears about missing their refractive target and not having direct, easy access to an excimer laser in their center. Further, as monovision with cataract surgery is by far the most frequent surgical treatment for presbyopia in the US, the LAL will create a “premium channel” for monovision – and surgeons will be even more confident of hitting their targets.
Lastly, the Perfect Lens will use principles of refractive indexing to give surgeons the opportunity to make monofocal lenses multifocal… And then convert back to monofocal, if the patient doesn’t tolerate multifocality. As no special lens is needed, you can potentially have patients who chose a monofocal IOL years ago opt for retreatment of their lens to provide better near vision. Giving patients the ability to “test drive” multifocality in vivo is an absolute game changer. And, along with the LAL, I believe the era of adjustable IOLs will be as disruptive as the era of foldable IOLs.
“Ultimately, a change in mindset combined with the advanced technologies heading our way will allow us all to better serve our patients.”
Having said all that, refractive surgeons know that we now have excellent surgical treatments for presbyopia, but the market isn’t approaching maturity. And this is where the “Topical Presby-lution” (as I like to call it) comes in. There are four eyedrops currently undergoing trials in the US aiming to be first to market: Novartis EVO6, Presbyopia Therapies PRX100, Orasis CSF1, and Allergan AGN-199201 and AGN-190584. Most of these enhance depth of field via a pinhole effect and EVO6 reduces lens stiffening; some of these medications can be synergistic with each other or combined with refractive surgery to enhance outcomes. In my view, eyedrops will have the biggest impact for plano presbyopes. The vast majority of the global presbyopia population are clustered between -0.50D and +0.50D, and understandably, most surgeons are hesitant to operate on the pristine cornea of a plano presbyope who has 20/20 distance vision. The ability to treat this population medically, and then later surgically with the option for adjustment to provide LASIK-like outcomes, could have a huge impact for this population as well as surgeon confidence.
Lastly, the majority of refractive exams are performed by optometrists who have no surgical options to offer their patients. The financial upside for selling reading glasses in their clinics is less compared with participating in collaborative care with a surgeon to simultaneously improve their patient’s lifestyle. Ultimately, a change in mindset combined with the advanced technologies heading our way will allow us all to better serve our patients. We are now living in the presbyopia revolution, and it’s about time.