The Future of Gasc Permeable Contact Lenses
BY EDWARD S. BENNETT, OD, MSED
Various reports circulatingspecifically from Professor Nathan Efronindicate the demise of gas permeable contact lenses. With advancements in design and manufacturing technology resulting in dramatic growth of RGP use in such areas as presbyopia correction and myopia control, this perception can be quite surprising. With this in mind, members of the RGP Lens Institute Advisory Panel were asked for their opinions about the current status and future of gas permeable lenses. Advisory members who participated in this forum included: Keith Ames O.D., Joseph T. Barr O.D., M.S., Robert Grohe O.D., Peter Kastl M.D., Ph.D., James Key M.D., Craig Norman FCLSA and Michael Ward FCLSA.
How important are RGP lenses in your clinical practice?
Keith Ames, OD: "RGP lenses are an indispensable part of my contact lens practice. I fit about 25 percent of my patients with RGPs. They are my lens of first choice for presbyopes desiring a multifocal correction."
Craig Norman, FCLSA: "RGP lenses are very important part of our practice. They have proven to be highly successful for our presbyopes, those with irregular corneas and young children. Approximately 20 to 25 percent of our lens fits are in RGPs."
James Key, MD: "Extremely important because the use of RGP lenses enables us to fit even the most challenging and difficult cornea. At the same time, patients appreciate a choice even with routine fits. RGPs constitute 25-30 percent of all fits."
Michael Ward, FCLSA: "About seven out of 10 new patients are fitted in rigid lenses. The majority of patients seen in our campus facility require tertiary contact lens management (keratoconus, penetrating keratoplasty, refractive surgery, trauma) which often means fitting RGP lenses."
What advances do you see forthcoming in RGP materials?
Mr. Ward: "I expect continued advances in higher gas exchange polymers, which give the fitter greater latitude in design."
Dr. Kastl: "We should observe a continuation of high quality hyper Dk lens materials."
Joseph Barr, OD: "We will see the introduction of 30-day extended wear. Various surface treatments will be helpful. "
Mr. Norman: "RGP material research and resulting technology will continue to focus on higher oxygen transmissibility for overnight wear; surface property modifications to render the lenses more compatible with tears, thus less prone to deposit formation and non-wetting; lighter weight materials to decrease lens mass; and differing indices of refraction for special lens indications."
What impact do you feel RGP use for myopia control will have in the next five years?
Mr. Norman: "Hopefully, a major study will confirm what practitioners have thought for years, i.e., rigid lenses are a positive influence in juvenile myopia control. For adults, the burgeoning field of accelerated overnight orthokeratology shows tremendous promise globally."
Dr. Key: "As studies in this area show the benefit of RGP wear, more parents will ask for RGP lenses for their children."
Robert Grohe, OD: "The impact of myopia control with young people and adults may be mild in that patients will need to be educated as to this option and practitioners will require more well-controlled studies that demonstrate long-term efficacy."
What improvements do you see in RGP multifocal lens designs?
Dr. Grohe: "Multifocal RGPs will experience dramatic growth as aging baby boomers drive the demand and manufacturers refine lens finishing techniques and simplify the fitting process."
Mr. Norman: "The biggest improvement we will see is manufacturers understanding how to generate more add power onto simultaneous vision designs. Work on ballasted alternating vision designs shows promise in decreasing weight and thickness, thus improving stability of vision and patient comfort while still providing excellent positioning."
Dr. Ames: "The advances that will occur will primarily involve improvements in manufacturing technology allowing higher quality, more consistent products."
Dr. Barr: "I see potential for greater predictability in design and fitting, and better quality lenses available at a lower price."
By 2010, where do you see RGPs in the industry?
Dr. Grohe: "By 2010, RGP lenses will remain a small but stable corrective option in today's market due to the continued need for complex bifocal designs and the emerging need for irregular astigmatism designs to correct post-refractive surgery patients."
Dr. Key: "RGPs will continue to be the only choice for certain eyes."
Dr. Ames: "RGP usage will remain stable with significant increases possible if practitioners embrace RGP multifocal fitting."
Mr. Norman: "We will continue to see some decline in RGP lens use due more to improvements in certain soft designs such as torics. On the other hand, we may see an increase in the percentage of RGPs fit in many practices. This will be due to the increasing specialization of lens fits by practitioners who wish to differentiate themselves from others practicing in their community."