For decades, the traditional IOL design has been a lens with one optic attached to two haptics. In an attempt to improve upon this model, my colleagues and I came up with something entirely new, something that would allow an IOL to be modified throughout a patient’s lifetime depending on his or her refractive needs—a so-called lifecycle lens.
AT A GLANCE
• The base component of the Harmoni IOL System acts
similarly to a capsular tension ring to enhance centration
and allow more predictable effective lens position.
• The uncoupling of the optic and base components of
the Harmoni IOL allows the surgeon to modify the optic
throughout the lifetime of the patient to accommodate
changes in refraction, astigmatism, or eye health.
• The base component of the Harmoni IOL is designed
with multiple square edge barriers to decrease
occurrence of PCO.
THE CONCEPT AND ITS ADVANTAGES
The concept of the Harmoni IOL System (ClarVista Medical; Figure 1) was born out of the device laboratory in the Department of Ophthalmology at the University of Colorado. The base component of the Harmoni lens is implanted into the capsular bag and acts similarly to a capsular tension ring to enhance centration and allow a more predictable effective lens position (ELP). The base component has an annular groove that securely captures the optic component. Once the base is in place, the optic is attached to the base component with a maneuver that takes about 30 to 40 seconds utilizing standard surgical tools such as a Sinskey hook.
What makes the Harmoni IOL unique in comparison with traditional IOLs is that the optic is separate from the base and can be safely and easily exchanged without manipulating the capsular bag. Separating the optic from the capsular bag docking system provides many advantages for enhancing patient outcomes.
Advantage No. 1: More predictable ELP. Poor ability to predict ELP is one major cause of missing the target refraction after cataract surgery. By design, the base component occupies space closer to the capsular bag equator. This results in improved stability of the lens system after implantation, which was confirmed in the first in-human trial recently completed by ClarVista Medical (data on file with the company).
Advantage No. 2: The removable optic. The surgeon has the option to remove and replace the optic postoperatively, if needed, to address a refractive surprise or to exchange an optic that a patient cannot tolerate or is no longer ideal. Multifocal lens intolerance is a major reason for poor adoption by both patients and physicians. The Harmoni IOL System will allow addressing intolerance directly and enhance adoption of novel lens technology.
An additional benefit is that toric IOLs can be rotated if needed without encroaching on the capsular bag. The ability to safely and easily exchange the optic will enable a profound change in patient care. The Harmoni IOL can be modified throughout a patient’s lifetime to accommodate changes in refraction and/or astigmatism, which are constantly evolving over time. Multifocal IOLs may not be the best choice for patients who develop macular degeneration or glaucoma later in life. The Harmoni system will help address these concerns directly. ClarVista Medical is also pursuing a pediatric application for the lens.
Advantage No. 3: More effective barriers to posterior capsular opacification (PCO). By separating the optic and base components, the base can take up a wider footprint inside the capsular bag as opposed to a traditional lens (8.5 vs 6 mm), providing enhanced barriers to PCO. In other words, the Harmoni IOL has design features between the equator and the center of the capsular bag to enhance prevention of PCO. To date, we have completed standard in vivo preclinical testing compared with a standard one-piece IOL and found a dramatic decrease in PCO favoring the Harmoni system (personal data).
Advantages of the Harmoni IOL System
NOTICEABLE VISUAL IMPROVEMENT
The benefits of the Harmoni IOL System have already been demonstrated in a multicenter prospective randomized surgical trial. After implantation in 30 patients, the Harmoni IOL was more stable in the capsular bag and had more predictable ELP compared with two market-leading IOLs. Additionally, patient tolerance was high, and exchange of the optic component was safe and predictable up to 5 months after initial implantation. All patients in whom an optic exchange was performed exhibited improvement in their visual acuity and in their manifest refraction after the exchange.
The company is taking steps toward regulatory approval globally and is about to initiate the next clinical trial sometime in 2015. Additionally, the Harmoni IOL technology is extensible. The separate base component can be leveraged for drug delivery and other nonrefractive purposes without influencing performance of the optic component.
The most exciting thing about the Harmoni IOL System is that it is completely different from any other refractive lens. The novel design will allow surgeons to address refractive correction with confidence and enhance outcomes for patients over their lifetimes. By simply uncoupling the optic from the base component, this modular IOL system has great potential to become the optimal lens implant for all patients.
Malik Y. Kahook, MD
– Slater Family Endowed Chair in Ophthalmology; Vice
Chair, Clinical and Translational Research; and Director,
Glaucoma Service and Glaucoma Fellowship, Department of
Ophthalmology, University of Colorado School of Medicine,
– Financial disclosure: Patent license (ClarVista Medical)