Renewed hope for extended wear with silicone hydrogels

Issue: June 2005

ByJennifer Byrne

In 1997, as refractive surgery was becoming a popular vision correction option, Primary Care Optometry News held a roundtable discussion to address the future of the contact lens industry.

PCON June 1997 [cover]
June 1997: This issue, which spotlighted contact lenses and solutions, also discussed how the lack of a DEA number was preventing many optometrists from being credited for the prescriptions they write.

The ensuing conversation, which was moderated by PCON Editor Michael D. DePaolis, OD, FAAO, held out hope for the extended-wear modality, but also cautioned against its risks.

“I think the FDA is going to require some lengthy studies before they approve something beyond 7 days,” said roundtable participant James D. Atwood, MD, in a June 1997 article. “I think surface biocompatibility is an issue, as well as metabolic waste products getting trapped behind the lens at night. I also sense tremendous negative reactions for a 30-day extended-wear lens coming from the ophthalmology academic centers.”

Less than a decade after this article was published, silicone hydrogel lenses have proven themselves as a safe material for extended wear – and possibly the lens material choice of the future.

“I now feel like I have a tool to offer patients that rivals refractive surgery or even surpasses refractive surgery,” David B. Seibel, OD, FAAO, chair of the American Optometric Association Contact Lens and Cornea Section, told Primary Care Optometry News. “Now, we can offer health and convenience, rather than convenience and ulcers.”

Changed perceptions

Walter L. Choate Jr., OD, FAAO, a Primary Care Optometry News Editorial Board member who participated in the roundtable discussion, said while he supported overnight wear from the beginning, there was a period where practitioner enthusiasm began to wane for this modality. “The interest in overnight wear was diminished with early reported complications,” he said in an interview.

Dr. Seibel said a 1988 report by Tom Brokaw on NBC exposed the risk of corneal ulcers associated with extended-wear, disposable contact lenses. “This scared patients and doctors alike, nationwide,” he said. “It took more than a decade for practitioners to come around to the idea of silicone hydrogels in a continuous wear modality.”

Dr. Choate said his concerns about extended wear were assuaged by the new lens materials in silicone hydrogels. “Both of the early entries into the silicone hydrogel market, the PureVision (Bausch & Lomb, Rochester, N.Y.) and Focus Night & Day (CIBA Vision, Duluth, Ga.) have changed all of that for me,” Dr. Choate said. “If the patient is properly screened, properly fit and properly followed, not only does this new material work well for my patients on a continuous-wear basis, it solves most of the previous problems we encountered with first-generation materials.”

Significant breakthrough

Dr. Seibel said silicone hydrogel technology has revolutionized both continuous wear and contact lens wear in general. “It raised the bar and the standard of health for the cornea and anterior segment. It is one of the most significant breakthroughs in contact lenses in the past 30 years,” he said. “We will see that unfold more as more baby boomers move into more specialty needs of fitting. We are going to see that these materials in specialty lens designs will take over the market even more aggressively than they have already.”

Dr. Choate said the increased oxygen transmissibility of silicone hydrogels makes them an easy choice for suitable candidates. “The superior oxygen transmission of silicone hydrogel lenses, coupled with all-day comfort, has certainly raised the bar on lens performance for my practice,” he said. “I fit many materials in my practice, but I certainly focus on those most able to supply the oxygen necessary to keep my patients’ eyes healthy.”

Dr. Seibel said while most practitioners have learned to embrace silicone hydrogels, the reluctance of some doctors continues to slow the progress of this technology. “Although silicone hydrogels are being adopted, if you talk to manufacturers, they will complain that this is not happening fast enough, because practitioners’ attitudes have not changed fast enough,” he said. “And I think there is some truth to that. We need to revisit that for the health of our patients.”

LASIK alternative?

Dr. Seibel said, in the past, the contact lens industry had no suitable product to offer as an alternative to LASIK. “LASIK and refractive technologies have been a very attractive choice and are continuing to expand and improve,” he said. “At one point, contact lenses were the fatted calf waiting to be sacrificed, because there were no new innovations. There was no answer to the need for convenience, especially for the baby boomers.”

Baby boomers, many of them emmetropic presbyopes turning to their first pair of reading glasses, may have previously turned to LASIK because contact lenses could not offer them the same convenience, Dr. Seibel continued. “We needed to find something to provide as a really convenient, safe alternative to LASIK,” he said. “Silicone hydrogels have presented that arena to the contact lens practitioner. That is one of the most exciting and important developments for optometrists.”

Dr. Seibel said that because silicone hydrogels have alleviated many of the early fears of extended wear, patients now tend to ask different kinds of questions about the lenses. “It’s funny, but since the safety concerns are not reported in the public media, patients now tend to ask if they really work,” he said. “They now want to know about the convenience and the performance rather than eye health risks.”

In terms of safety, Dr. Seibel pointed out that today’s extended-wear lenses most likely pose fewer health risks than LASIK. “We may not know about all the long-term physiological effects of continuous wear,” he said. “But we do know the short-term effects of LASIK, and that is having a blade going across your cornea. And is that a healthier cornea? This kind of thinking is driving some practitioners to introduce continuous wear technology to their patients.”

Lens platform of choice?

Dr. Seibel said while silicone hydrogels are a very promising technology, he would hesitate to classify them as the lens of choice for all patients. “I don’t know that this is the lens material of choice for everybody, but I certainly think for the majority of people, this could become the lens of choice,” he said. “But I think that will only happen as it becomes more available by more manufacturers in different designs and materials at a higher profit margin for the practitioner and at a lower price point for the patient.”

He said most silicone hydrogels are currently a premium product at a premium cost. “Patients who don’t want the continuous-wear modality and are very healthy in the daily wear modality with conventional materials are not going to aggressively pursue this more expensive lens option,” Dr. Seibel said. “You are still going to have the mainstream lens product for the mainstream lens wearing modality. Not everybody buys a Cadillac.”

Dr. Choate agreed that silicone hydrogels are not necessarily for every patient, citing fitting challenges. “Because the materials have other characteristics that sometimes challenge the fitter, they will not be the choice for everyone,” he said. “I believe that the silicone hydrogel for the future will be a much-improved polymer with better optics, better wetting characteristics and better solution capability.”

H. Dwight Cavanagh, MD, PhD, FAAO, of the University of Texas Southwestern Medical Center, said he definitely sees broader applications for silicone hydrogels. “They should replace conventional soft lenses for all patients,” he said.

For Your Information:

David B. Seibel, OD, FAAO, chair of the AOA Contact Lens and Cornea Section, can be reached at 12121 Tesson Ferry Professional Center, St. Louis, MO 63128-1224; (314) 843-5700; fax: (314) 843-1353.

Walter L. Choate Jr., OD, FAAO, is a Primary Care Optometry News Editorial Board member who practices in Madison, Tenn. He can be reached at 607 Due West Ave., Ste. 111, Madison, TN 37115; (615) 868-4262; fax: (615) 860-2016; e-mail: walterchoate@aol.com.

H. Dwight Cavanagh, MD, PhD, FAAO, is based at the University of Texas Southwestern Medical Center. He can be reached at 5323 Harry Hines Blvd., Dallas, TX 75390-9057; (214) 648-8074; e-mail: dwight.cavanagh@utsouthwestern.edu.