Medical Device Daily Contributing Writer
WASHINGTON – The past two decades have featured remarkable progress in cataract surgery technology, as the combination of minimally invasive phaco-emulsification surgery and the availability of foldable intraocular lens (IOL) materials have made cataract surgery and IOL implantation highly predictable, efficacious and very safe.
The next frontier for the industry and its highly adoptive physicians is to correct for presbyopia, which represents an enormous opportunity, as an estimated 90 million Americans, or roughly 30% of the population, are expected to be presbyopic within the next decade.
Presbyopia is characterized as a progressive, age-related loss of accommodative amplitude. Progression of presbyopia typically begins in early adulthood, culminating in the complete loss of accommodation, usually no later than age 50. It is the most prevalent of all ocular afflictions, ultimately affecting 100% of the population during the normal human life span.
The exact causes and mechanisms of presbyopia remain highly controversial in the ophthalmic community, and this was well demonstrated at this year’s American Society of Cataract and Refractive Surgery (ASCRS; Reston, Virginia) annual Symposium on Cataract, IOL and Refractive Surgery, which concluded at the Washington Convention Center earlier this week. A common refrain from this meeting was that there is still much to learn about accommodation. As one ophthalmologist told Medical Device Daily, “we are still a long way from understanding all there is to know about accommodation.”
The lack of consensus on what causes presbyopia, plus the highly entrepreneurial and innovative nature of the ophthalmic community, has given rise to a plethora of early stage companies, that appear to be making impressive strides.
Venture capital-backed Visiogen (Irvine, California) has a developed a novel dual optic system with a plus-powered lens anteriorly and a minus-powered lens posteriorly, joined by a spring. Accommodation is achieved when the two lenses move back and forth with the contractions of the ciliary body in the eye.
Ivan Ossma, MD of Bucaramanga, Colombia, reported excellent results for the latest iteration of this silicone lens, trade-named Synchrony, indicating that it can provide about three diopters of accommodation. He told the audience that this is a “very promising device; it appears safe, effective and should provide ample accommodation for the vast majority of patients.”
Visiogen received an investigational device exemption (IDE) from the FDA in late 2004 and is expected to begin its U.S. clinical trials shortly. David Chang, MD, of Altos Eye Physicians (Los Altos, California) will be the medical monitor for this study.
Another exciting, early stage company, presenting for the first time at an ophthalmic meeting, was Acufocus (Irvine, California). Its technology features an ultra-thin, opaque, biocompatible corneal inlay device inserted under a flap in the corneal bed. Daniel Durrie, MD, of Durrie Vision (Overland Park, Kansas), who presented the Acufocus story, described its device in layman’s terms as a “doughnut in the eye.” Durrie will be the company’s medical monitor for its upcoming U.S. clinical trial.
The design is based on a small-aperture optics principle that is not expected to interfere with the normal function of the lens so the patient’s distance vision will remain unaffected. This process allows the presbyopic patient to focus on objects that are within an arm’s length.
One of the attractive features of the device is the potential that it could be implanted in a patient who previously had laser in situ keratomileusis (LASIK) and now desires a presbyopic correction.
Like many other refractive implants, this device has gone through numerous design changes and materials since it was first conceived several years ago. It has now been implanted in 150 eyes in Mexico, Brazil and Turkey, although Durrie only presented data on the latest design, which was implanted in 57 patients.
Clinical results to date, albeit on relatively few eyes and with less than a year follow-up, are clearly exciting, with patients enjoying both excellent near and far vision. During his talk, Durrie quoted one of the luminaries in the ophthalmic surgery field, Jack Holladay, MD, of Holladay LASIK Institute (Bellaire, Texas), who, after carefully examining this technology, said that “this is the most exciting concept I’ve yet seen for the treatment of presbyopia.”
Acufocus will file for an IDE this summer and hopes to begin a multi-center clinical trial in the U.S. later this year.
The company recently completed its third round of venture capital financing, led by Pequot Ventures (Westport, Connecticut).
Another fascinating technology in this space is being developed by privately owned and venture capital-backed PowerVision (San Carlos, California). The company is developing a proprietary, microfluidic-controlled accommodating IOL, which uses natural muscular accommodating forces in the eye to transport fluids in the lens. In the eye, the lens goes from thin (unaccommodated) to thick (accommodated) as fluids move from the periphery of the lens through internal fluid channels to a piston-like structure in the center of the lens, pushing it outward. This results in a shape change of the lens, similar to what occurs in the natural lens (changing from thin to thick and back).
The company believes that this approach will enable its IOL to afford an accommodative range of up to 10 diopters, equivalent to the vision of a 25-year-old. This potential accommodation would sharply exceed the products currently commercial available or in clinical development.
In a talk in mid-2004 in the UK, Emanuel Rosen, MD, a well-known ophthalmologist from Manchester, England, said that “truly accommodating IOLs will be those with actual accommodation achieved by change of the curvature of the lens.” He went on to say that current generation of multifocal and “pseudoaccommodating” IOLs for presbyopia are only an interim solution. “Pseudoaccommodating” refers to the fact that accommodation occurs by changing the location of a fixed-power lens.
The PowerVision technology was presented at ASCRS by Louis Nichamin, MD, of the Laurel Eye Clinic (Brookville, Pennsylvania). Nichamin, who is on the PowerVision scientific advisory board, told MDD that “there is no question in my mind that the future of accommodative IOLs is in shape change.”
He went on to explain that “we need to emulate Mother Nature and it appears that this lens, in theory, will accomplish that.” Finally, he said, “if this lens can do what the company hopes, we will have accomplished the Holy Grail in accommodation.”
The industry’s leading ophthalmic surgery companies, Advanced Medical Optics (AMO; Santa Ana, California), Alcon (Fort Worth, Texas) and Bausch & Lomb (B&L; Rochester, New York), are diligently pursuing this major opportunity. AMO recently received FDA approval for its second-generation multifocal lens called Re-Zoom, which will likely supplant its older, less-efficacious, first-generation silicone Array lens. Several papers at ASCRS extolled this product, which is a different material (acrylic) and features some design changes that substantially reduces bothersome nighttime glare and halos.
In addition, in May 2004, AMO acquired an option to purchase privately owned Quest Vision Technologies (Tiburon, California), which features an accommodative IOL designed to closely resemble the natural lens in design and function. Acquisition of Quest is a distinct possibility in the near future.
As discussed in a report earlier this week on the ASCRS meeting (MDD; April 20, 2005), the industry’s largest player, Alcon, will soon launch its new ReSTOR multifocal IOL, following a very successful ASCRS meeting where more than 20 papers were presented. Alcon CEO Cary Rayment told MDD that his company has several projects to further improve its technology in the refractive market.
B&L also is intending to be a participant in this market, having licensed accommodative technology in mid-2003 from Faezeh Mona Sarfarazi, MD, inventor of a single-piece, molded silicone lens with a dual-optic design. The licensing agreement means B&L will pay research and development costs for the lens, with several milestone-based license fee payments. The company also will pay royalties on product sales upon successful commercialization of the lens.
Sarfarazi is considered to be one of the world’s experts on accommodation, although her hypothesis is in conflict with other, more widely accepted theories.