Looking Forward
The future is now for gas permeable contact lenses. Here, a look at the potential for this option in your dispensary
By Barbara Anan Kogan, OD

The predictions for the future needs of GP contact lens wearers reveal a full market that is ripe for exploration. With the rise in myopia and an aging population, the field is ready to grow.

The GP market has been expanding and improving since Kevin Tuohy pioneered contact lenses in 1948 and received a patent for the PMMA material in 1950. In 2002, the Contact Lens Manufacturers Association (CLMA) changed the name rigid gas permeable to GP lenses, reflecting a more user-friendly image.

With this revamp in the GP image, the optical industry has the opportunity to focus on growing the market by keeping long-time wearers whose modality has changed, attracting new users, and taking advantage of the latest technology.

Many successful patients have a rigid contact lens history since the 1960s when they began wearing PMMAs and upgraded to GPs to improve oxygen permeability in the 1980s. As these patients age, their needs are changing and some wearers want to continue using GPs, but in formats offering optical clarity and comfort in distance, intermediate, and near ranges to which they are accustomed. Included in these 30-to-40-year wearers are presbyopic, long-time GP contact lens wearers who need bifocal upgrades and first-time bifocal wearers.

The current GP multifocal design concepts run the gamut from segmented bifocal and trifocals to no-line multifocals with and without truncation.

When it comes to designing successful GP bifocals, "The whole goal of a GP bifocal contact lens is to design a lens that is not limited by distance power or amount of the add," says Bob Mandell, OD, PhD, a contact lens bifocal design pioneer who is a long-time University of California Berkeley College of Optometry instructor and author of the textbook Contact Lens Practice.

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Contact Lens Manufacturers Association (CLMA) member laboratories can design GPs to provide comfort, good centering, and visual acuity in the near-, mid-, and long-distance ranges for spherical to bitoric designs and adds up to 4.0 diopters. Laboratory consultants can guide practitioners through the bifocal GP contact lens process from design to fit.

Utilizing new designs requires patient training, even for long-time GP wearers. "First-time bifocal GP wearers should be treated the same as first-time spectacle lens bifocal wearers," Mandell says. To help, the GP Lens Institute (GPLI), the educational division of the CLMA, has a bifocal fitting video, a clinical management guide, and a bifocal fitting and application laminated pocket card.

Another burgeoning GP area is the myopic market, which is on the rise worldwide. With unreleased but "in press" results of the thee-year Contact Lenses and Myopia Progression (CLAMP) study, it is anticipated that ECPs will be able to provide evidence to parents and myopic children that GPs can slow and control this progression.

Also, the Children's Overnight Orthokeratology Investigation (COOKI) pilot study was conducted to determine the safety and efficacy of overnight ortho-k in children ages eight to 11 years old with a maximum of 5.0 diopters of myopia and 1.5 diopters of astigmatism. It found an average uncorrected visual acuity better than 20/25 with stable vision after two weeks.

	A monthly symposium is in its eighth year at rgpli.org

Several CLMA-member laboratories are currently working with practitioners to design GPs which can non-surgically reduce up to six diopters of myopia and astigmatism. "We can enable their patients to experience visual acuity during their waking hours in as short as overnight to a few weeks," says CLMA president Lee Dickerson. "This is the most exciting and profitable segment of the contact lens industry."

Increased interest is shown in many ways. For example, a 2004 BCI-Global Ortho-k Symposium is anticipating brisk attendance due to increasing interest in myopia management with GPs and learning how to reduce/eliminate this condition.

TECHNOLOGY UPDATE

The sophistication of lens software and precision of CNC lathe technology for manufacturing GP lenses are on the rise. "GP manufacturers are able to design and lathe precise optical surfaces, resulting in improved acuity, comfort, fitting success, and superior reproducibility," says Kevin L. Hing, JD, former CLMA secretary/treasurer, and Sarasota, Fla., lab owner. With this new technology, ECPs are experiencing an increased level of confidence in prescribing GPs.

The CLMA's Seal of Manufacturing Excellence award also has helped improve GP lens quality. This seal is awarded bi-annually by the CLMA to GP lens manufacturers who pass a stringent examination of lenses.

Technology has opened the door to new GP wearers. It also offers ECPs an opportunity to build their practices with expanding choices.