GP LENS UPDATE

GP Annual Report 2012

GP lens use is stable, but the patient population that we are fitting with them is changing.

Dr. Bennett is assistant dean for Student Services and Alumni Relations at the University of Missouri-St. Louis College of Optometry and is executive director of the GP Lens Institute. You can reach him at ebennett@umsl.edu.

By Edward S. Bennett, OD, MSEd, FAAO

The market for GP lenses is still viable and strong as we head toward 2013. There is little talk about their demise today; however, the types of designs and the patients who are being fit into this contact lens category have shifted over the past several years. Whereas in the 1970s and 1980s most astigmatic patients were being fit into rigid lenses, today the ever-improving quality and disposability of soft toric lenses makes them the more popular choice for these patients. Likewise, the introduction of custom soft lenses, such as Novakone (Alden Optical) and KeraSoft IC (Bausch + Lomb [B+L]) for keratoconus, has impacted what was previously a totally GP-dominated market. More GP laboratories are incorporating custom soft lenses into their armamentarium, and the GP Lens Institute (GPLI), which previously focused exclusively on rigid lenses, has now incorporated custom soft lenses into its educational mission.

That said, GP lens use is staying relatively stable with 9 percent (including hybrids) of fits in the United States (Nichols, 2012) and 10 percent internationally (Morgan, et al, 2012). Independent market research obtained by Jeff Johnson, OD, MBA, (vice president, senior research analyst, Robert M. Baird & Co., Inc.) showed that while there was a decrease in global GP revenue in 2011, the first quarter of 2012 indicates sales similar to that experienced in 2008 to 2010 (Table 1).

It is evident that GP lenses still have a prominent role in eyecare practices, as evidenced by comments from leading contact lens practitioners (see “Comments from the Experts,” page 32). Whereas a trend toward spherical lens use for astigmatic individuals is decreasing, specialty lens use for irregular corneas, myopia control, and presbyopia is increasing. Nowhere is this trend more evident than with scleral lens use.

“Our annualized growth rate for large-diameter buttons since 2006 is 50 percent. It is the single largest growth category we have seen in GP lenses,” says David Bland, director of Global GP and Custom Soft Lens Business for B+L. “What really seems to have made this possible is the development of high-performance high-Dk materials. With oxygen delivery no longer an issue, it has led to a substantial amount of design development in this category. Along with this has been the improvement in manufacturing and design software accompanied with excellent training programs offered by the laboratories.”

As I will emphasize in this article, the scleral lens boom should only increase as the potential applications and the ease of fitting both increase. Likewise, based upon recent research, the potential for orthokeratology lens designs for myopia control is outstanding (Charman et al, 2006; Quieros et al, 2010; Kang and Swarbrick, 2011; Smith et al, 2009).

Sclerals, Sclerals, Sclerals

As David Bland emphasized, the increase in scleral contact lens use in the last six years has been remarkable. The overflow crowds for both the fundamentals session and the breakout sessions on scleral lenses at the Global Specialty Lens Symposium (GSLS) in 2012 demonstrated the interest by practitioners who recognize the importance of implementing this lens category into their respective practices.

The initial comfort and vision quality provided by these designs have allowed a significant number of individuals who have moderate to severe keratoconus, corneal surgery, dry eye, and other forms of corneal disease to improve their quality of life immensely. Pecego et al (2012) fit 107 eyes (63 patients) with scleral lenses. The individuals had previously worn another contact lens type including 51 percent conventional GP lenses, 26 percent hybrids, 17 percent soft, and 6 percent piggyback. Of these individuals, 80 percent were either intolerant to contact lens wear or were unhappy with their vision; 63 percent had keratoconus with most of the remaining patients exhibiting high postkeratoplasty astigmatism or corneal scarring. Of the study participants, 77 percent were successful with scleral lens wear and 84 percent indicated that they achieved a high level of comfort with scleral lenses. Most important, the improvement in best-corrected visual acuity versus their previous correction (i.e., spectacles or contact lenses) was 3.5 Snellen lines. It is evident that scleral contact lenses allow many individuals the opportunity to improve their quality of life while also avoiding ocular surgery, which is not uncommon when individuals are intolerant to contact lens wear.

In 2012 and beyond, however, there appears to be a much greater emphasis on scleral lens applications for healthy eyes. Although any experienced scleral lens fitter will emphasize that larger lenses (i.e., 15.5+mm) offer the benefit of avoiding limbal complications by landing on the sclera, many of the new designs such as the Onefit P+A from Blanchard (Figure 1) are corneo-scleral or semi-scleral (i.e., 13.5mm to 15.0mm), making patient handling easier and the fit looking similar to that of a soft contact lens.

Figure 1. The Onefit P+A (Blanchard) lens on a normal, healthy eye.

When GPLI Advisory Committee members were surveyed about what they thought was the greatest advancement in GP lenses in 2012, 29 of 33 respondents indicated some form of scleral lens, with an emphasis on the newer smaller designs for healthy eyes. They also indicated that this would be the predominant trend in the next several years (Table 2).

It's important to note that several laboratories have recently introduced scleral multifocal lens designs. This has enormous potential for individuals who are unwilling to adapt to conventional GP multifocals despite the apparent quality of vision benefit. Lens designs that have been introduced recently include DigiForm and Tru-Scleral designs (TruForm Optics), So₂Clear Progressive (Art Optical/Dakota Sciences/Metro Optics), and the Dyna Semi-Scleral (Lens Dynamics) design. A limitation of GP scleral lenses is the absence of translation with downward gaze; therefore, all of the aforementioned designs are center-near. One center-distance design has recently been introduced, the AVT Scleral Multifocal (Advanced Vision Technologies), which consists of a distance-center, back aspheric design.

Several other examples of scleral presbyopic designs just entering the market or entering soon include:

• Lens Dynamics is introducing larger-diameter scleral contact lens designs that range from 16.0mm to 20.0mm. These designs are available in front toric, multifocal, and quadrant-specific lens designs.
• Custom Craft Lens is introducing semi-scleral multifocals for myopia reduction.
• TruForm Optics introduced the DigiForm 18, an 18mm lens with laser etchings indicating peripheral zones that can be tailored to fit, and it has a front-surface add and spherical back surface.
• Valley Contax has introduced the Valley 15 center-near scleral lens bifocal.
• Accu Lens has introduced a center-add multifocal in its Maxim scleral lens and its Comfort SL scleral lens (for healthy eyes).
• Blanchard will soon be introducing a center-near presbyopic design as part of its Onefit P+A series.

These designs are in addition to other scleral designs currently being introduced to the market including:

• Opti-Con is introducing large-diameter scleral lens designs.
• Quality Contact Lens is introducing an 18mm scleral lens design in the Onsi-56 GP material from Lagado Corp.
• TruForm Optics has introduced the TruPMD specifically designed for patients who have pellucid marginal degeneration.

Overnight Orthokeratology and Myopia Control

Whether it is termed overnight orthokeratology, corneal reshaping, corneal refractive therapy, or vision shaping treatment, the potential for controlling a young person's myopia progression appears to be a real and exciting outcome of these designs, and the future looks very promising. In fact, as a result of research initiated by Earl Smith III, OD, PhD, in 2005 with primates and now as a result of recent research with new designs on humans, it is entirely possible that in the near future orthokeratology-like designs will serve as an intermediary step to slow myopia progression in young children who ultimately will not require any correction.

According to Smith, the role of peripheral retinal hyperopic defocus is important regarding the growth in axial length that occurs in myopia. There appears to be an apparent effectiveness of overnight orthokeratology in shifting this hyperopic defocus to a myopic defocus, which could explain the results of studies by Cho et al (LORIC, 2007) and Walline et al (CRAYON, 2009) in which axial length growth in young people wearing orthokeratology lens designs was significantly less than that in either spectacle-wearing or soft lens-wearing young people.

Herzberg (2010) stated that overnight orthokeratology results in a zone of curvature in the midperipheral cornea that is shorter in radius compared to the post-treatment central cornea, allowing light to focus in front of the retina in the midperiphery while central light focuses on the fovea. More recently, Lang and Swarbrick (2011) confirmed previous studies (Charman et al, 2006; and Queiros et al, 2010) indicating that changes in relative peripheral refraction after overnight orthokeratology are similar in children as in adults, and this induced myopic defocus in the retinal periphery may, therefore, provide a potential mechanism for myopia control. Numerous studies are either currently being performed or soon will be performed to not only look at which lens designs are optimum for producing this effect, but also when to introduce this intervention in young people.

It is apparent that overnight orthokeratology is relatively safe if patients are fitted properly, comply with follow-up care, and exhibit proper compliance to the recommended care instructions. Santodomingo-Rubido et al (2012) assessed the relative clinical success of orthokeratology and distance single vision spectacles in children in terms of adverse events and discontinuations over a two-year period. Interestingly and significantly, more discontinuations occurred with the spectacle-wearing group. Although several adverse events were reported with the orthokeratology group, none were considered serious.

There are also several new developments in overnight orthokeratology lens designs. B+L continues to increase the number of lens designs approved for use with its Boston lens materials under the Vision Shaping Treatment umbrella (Table 3). At press time, Paragon Vision Sciences was set to launch NormalEyes on Oct. 1. This consists of a large-diameter design (15.5mm) with the same fitting terminology as the conventional CRT lenses. According to Pam Scoggins, director of Sales & Marketing Development for Paragon Vision Sciences, NormalEyes will feature the Paragon CRT Dual Axis Technology, Proximity Control Technology to adjust sag without adjusting base curve radius, and an anterior surface that mirrors the posterior surface, the result being less lens mass. It will be plasma-treated and available in the Paragon HDS 100 Clear (Paragon) material.

Other Lens Designs and Care Systems

Multifocals Laboratories still see GP multifocal designs in conventional diameters as an ongoing area of growth, both with front-surface aspheric designs for normal eyes and with reverse geometry designs for post-refractive surgery individuals. Firestone Optics is introducing its Tangent Streak AAA, an anterior aspheric add simultaneous multifocal. It has a pupilsize-specific central distance zone with add powers up to +4.50D. It is also available in back-surface and bitoric designs. Art Optical will be releasing a new GP option for post-LASIK presbyopic patients using a reverse geometry design with a center-near multifocal add power. This design will utilize a largerthan-normal inside-the-limbus diameter to stabilize centration and provide a simultaneous vision effect.

Irregular Cornea Recent studies by Charman et al (2012) and Shi et al (2011) have confirmed the benefit of GP contact lenses in reducing higher-order aberrations and increasing optical quality in keratoconic eyes. It is also important to note that even though Snellen visual acuity may be quite good in a GP-corrected moderate-to-severe keratoconus patient, the overall visual performance is still poorer than normal.

For correcting irregular cornea patients, it is evident that the trend is toward large-diameter lenses. In a poll of 100 attendees of the August 2012 GPLI webinar pertaining to managing irregular cornea patients with corneal, scleral, and custom soft lenses, 51 percent indicated that they use intracorneal (i.e., small-diameter and intralimbal) designs less in irregular cornea patients than they did three years ago, 28 percent used them more often, and 23 percent used them about the same. Of those polled, 65 percent indicated that they will use scleral lenses as their first choice for irregular cornea patients.

Hybrids SynergEyes Inc. is expecting to bring its next-generation product to market in the fourth quarter of 2012. This new lens will feature a 130-Dk rigid center bonded to a silicone hydrogel soft skirt. According to Christina Kirby, director, Duette HD Marketing, the company has found that previous ClearKone wearers are able to wear this lens longer and more comfortably than they could wear their former lens while enjoying good acuity.

Lens Care Menicon continues to expand access to its WebStore by improving the site and adding new ways to make it easier for practitioners and patients to sign up. The WebStore is the online source for Menicon's new line of GP lens care solutions including Unique pH and Progent. Menicon will also be introducing a lens case for use with Progent and scleral and semi-scleral lenses. Several companies are looking at the potential of developing and marketing a nonpreserved saline to be used with scleral lenses.

Miscellaneous DAC introduced laser marking of lenses for use in trial fitting sets and production lenses. Many laboratories have embraced this new technology with their lathes to mark lens parameters, zones, axes, and other identification marks to assist practitioners' ability to both identify a custom lens and help troubleshoot.

Q-Case, Inc., introduced the EZi Scleral Lens Applicator (http://ezibyqcase.com), a ring-like device designed for easier scleral lens application.

Resources

As always, the most important resources are the laboratory consultants, experts who handle specialty contact lens fits every day and are well qualified to help in the design and troubleshooting of GP lens patients. If corneal topography and/or fluorescein pattern photographs are available, consultants would welcome these aids for optimizing the successful fit of any given wearer. Laboratories also often have fitting resources, calculators, and webinars available to practitioners interested in learning how to successfully implement a given design into their practice. There are several organizations and manufacturers who also have resources (Table 4).

The GPLI has a wealth of clinical resources and recently introduced narrated Microsoft PowerPoint presentations pertaining to fitting young people with GPs, scleral lens fitting and troubleshooting (both from Christine Sindt, OD), and orthokeratology (from Craig Norman, FCLSA). The Scleral Lens Education Society continues to sponsor hands-on workshops and has several useful resources on the web, including videos on how to handle large-diameter lenses. This is complemented by an excellent clinical handbook of scleral lenses authored by Eef van der Worp, BOptom, PhD, FAAO, FIACLE, FBCLA, via a grant from B+L.

The GSLS in Las Vegas was again attended by more than 400 eyecare specialists in 2012 with a program that included numerous tracks of clinical courses with an emphasis on specialty lenses, notably GP lenses. The next GSLS is scheduled for Jan. 24 to 27, 2013.

The Orthokeratology Academy of America sponsored exceptional clinical symposia on this lens type in both the United States and internationally in 2012. For any practitioners interested in learning how to implement orthokeratology into their practice, the “Boot Camp” how-to fundamentals sessions at the annual meeting in April is almost essential.

For consumers, allaboutvision.com and contactlenses.org are excellent resources for consumer information pertaining to the benefits and applications of GP lenses. In addition, a recent collaborative effort between the Contact Lens and Cornea Section of the American Optometric Association and the Cornea, Contact Lenses and Refractive Technologies Section of the American Academy of Optometry has resulted in the introduction of contactlenssafety.org. This website provides answers with sources for 50 common consumer questions about contact lens safety including care and compliance issues pertaining to GP lenses.

Summary

Although there has been a gradual decline in the fitting of conventional GP lens designs on healthy eyes, it is apparent that GP lenses are holding their own, both nationally and internationally. This is largely the result of the rapidly increasing use of scleral lens designs, which, without doubt, are dramatically increasing the quality of life—and are often life-changing—for numerous individuals who were unsuccessful in other contact lens types, often as a result of discomfort. That said, it is apparent that much of the excitement in 2012 and the next several years pertains to the ongoing introduction of scleral lenses for healthy eyes, notably corneo-scleral and semi-scleral lenses for astigmatic and presbyopic individuals. This will be accompanied by the introduction of scleral lens designs for myopia reduction, another future area of large growth with GP lenses. Recent studies pertaining to the effect of orthokeratology-like designs on controlling eye growth via reducing relative peripheral hyperopia is very exciting and may provide a solution that could ultimately result in young potential myopes never having to wear a correction—until presbyopia—after early intervention with this type of GP lens design (Charman et al 2006; Quieros et al 2010; Kang & Swarbrick, 2011). As a result of these developments, when combined with new and innovative lens designs for correcting presbyopia and irregular corneas, GPs will play an important role in vision correction for many years to come. CLS

For references, please visit www.clspectrum.com/references.asp and click on document #203.

Acknowledgements: Practitioners: Bruce Anderson, OD; Mark André, FCLSA; Doug Benoit, OD; Richard Brannen, OD; Steve Byrnes, OD; Karen Carrasquillo, OD, PhD; Walter Choate, OD; Robert Davis, OD; Greg DeNaeyer, OD; Barry Eiden, OD; Robert Grohe, OD; Jack Hartstein, MD; Jason Jedlicka, OD; Lynette Johns, OD; Pat Keech, OD; John Laurent, OD; Ken Lebow, OD, PhD; Mike Lipson, OD; Bob Maynard, OD; Bruce Morgan, OD; Clarke Newman, OD; Roxanna Potter, OD; Tom Quinn, OD, MS; Phyllis Rakow, FCLSA;, Renee Reeder, OD; Susan Resnick, OD; John Rinehart, OD; Jack Schaeffer, OD; Jeff Walline, OD, PhD; Michael Ward, FCLSA; Ron Watanabe, OD; Frank Weinstock, MD; Joe Yager, OD.

Laboratories/Manufacturers: Josh Adams (Valley Contax), David Bland (B+L), Lee Buffalo (Blanchard Contact Lens), Don Dixon (TruForm Optics), Richard Dorer (Blanchard), Greg Goodrich (Tru-Form), Mike Johnson (Art Optical), Christina Kirby (SynergEyes), Bill Masler (Accu Lens), David Moriera (Menicon), Daren Nygren (Custom Craft Lens), David Panichello (Opti-Con), Chr? Pantle (DAC), Keith Parker (Advanced Vision Technologies), Dave Rusch (Firestone), Pam Scoggins (Paragon V?ion Sciences), Al Vaske (Lens Dynamics).