GP ANNUAL REPORT
GP Annual Report 2015
Scleral, multifocal, and other specialty designs continue to trend up in the GP lens market.
By Edward S. Bennett, OD, MSEd, FAAO
While the GP contact lens market experienced a small decline overall in the past year, many new developments that will be discussed in this report give us reason to feel optimistic about the future. According to Nichols (2014, 2015), the percentage of new fits and refits into rigid lenses (including hybrids) decreased from 10% in 2013 to 8% in 2014. In a separate article, Efron et al (2015) reported 9.4% GP lenses fit in the United States in 2014 versus 13% in 2002.
It is encouraging to note, however, that the GP “tool box” available to practitioners now includes options for dry eye patients, a wider range of GP multifocals for almost every astigmatic presbyope, expanded corneal reshaping design capabilities for impacting myopia progression, custom scleral lens designs to fit any eye and improve the quality of life of many individuals for whom surgery would be the only other alternative, very sophisticated topography-based software to accurately design almost any lens, and manufacturing instrumentation that can fabricate toric and quadrant-specific peripheries for special-design GP lenses, to name a few.
This article will also present data from Contact Lens Spectrum’s first annual GP Prescribing Survey, which polled Contact Lens Spectrum readers on their GP lens and lens care prescribing habits, including use of different types of GP lens designs. One hundred and eighty practitioners completed the survey. When asked whether they currently fit GP lenses—including hybrid lenses—it was encouraging to see that 173 respondents (96.11%) do fit them. When asked what percentage of GP lenses they fit in seven different categories, spherical GPs, at 43%, still dominated. It is important to point out that respondents also reported now fitting one in five GP lenses (20%) in scleral designs (Figure 1).
Figure 1. Approximately what percentage of your GP lenses do you fit in each of the following categories (totaling 100%)?
One of the most compelling stories related to GP lenses in 2015 was the recent acquisition of Paragon Vision Sciences by Valeant Pharmaceuticals. No specific details have been released about the acquisition to date.
It is evident that scleral lenses represent the segment of greatest current and potential future growth in the GP category, which was confirmed by respondents of our GP Prescribing Survey (Figure 2). Likewise, the results of this poll indicate that scleral lens use rivals that of small-diameter GP designs as the “go to” lenses for irregular cornea patients. Intralimbal lenses come in at a distant third, followed by hybrids, custom soft, and piggyback lenses (Table 1).
Figure 2. Which one of the following areas do you feel has the most potential for growth in your practice in the next 12 months?
|Small OAD GPs||69 respondents||36 respondents|
|Sclerals||68 respondents||29 respondents|
|Intralimbal||48 respondents||19 respondents|
|Hybrid||25 respondents||6 respondents|
|Soft||13 respondents||4 respondents|
|Piggyback||13 respondents||2 respondents|
Likewise, when practitioners were recently polled online regarding their first contact lens of choice for keratoconus, 50% reported corneal designs, and 44.74% reported sclerals (Contact Lenses Today, 2015). These results are similar to a poll reported last year in which the GP Lens Institute Advisory Board members were asked what percentage of their last 100 irregular cornea patients were fit into any of six different contact lens categories, with responses indicating 43.74% scleral lenses, 33.74% corneal GP lenses (20.8% small-diameter, 12.94% intralimbal), and the remainder divided between hybrid, custom soft, and piggyback lenses (Bennett, 2014).
Recent retrospective reviews have found that scleral lenses have resulted in significantly better visual performance for post-penetrating keratoplasty patients compared to their previous correction, which predominantly consisted of corneal GP lenses (Barnett et al, 2015; Picot et al, 2015). Picot et al (2015) included 83 eyes fitted with scleral lenses (56 keratoconus and 27 post-keratoplasty) and concluded the following:
1) The average scores on the National Eye Institute Visual Function Questionnaire (NEI-VFQ) 25 of patients after at least six months of scleral lens wear were significantly higher compared to those without (80.2/100 versus 48.1/100).
2) Scleral lenses showed a significant improvement in quality of life for patients who had failed in or were intolerant to corneal GP lenses.
The results of these studies truly beg the question: “Has the recent emergence of scleral lenses as a more comfortable first-choice option for irregular cornea patients reduced the need for corneal transplants?” According to a recent survey of prominent contact lens specialists, more than 75% reported that scleral lenses had reduced the number of referrals in their respective offices, although further study is necessary to confirm this conclusion (Bennett, 2015). Likewise, scleral lenses might represent the only potentially successful contact lens option in patients manifesting any form of ocular surface disease.
Some of the recent challenges related to scleral lenses include lens decentration, cloudy vision from post-lens tear debris, and the potential for corneal hypoxia resulting from a combination of tear film and lens thickness. As the conjunctiva and sclera typically are more elevated nasally compared to temporally, it is not uncommon for the lens to shift slightly temporally or inferior-temporally as reported initially by Patrick Caroline, FAAO, at the 2013 Global Specialty Lens Symposium (Bennett, 2013). The use of toric peripheries in scleral designs can help with this problem. Likewise, toric peripheries, reduced limbal clearance, and smaller designs (i.e., corneo-scleral) can be beneficial in reducing problems associated with post-lens tear debris (Nichols et al, 2015). To minimize corneal hypoxia, Jaynes et al (2015) concluded that clinicians should prescribe scleral GP lenses manufactured in the highest-Dk materials available and to fit without excessive corneal clearance.
Several of the more recent scleral contact lens designs to enter the market were designed or co-designed by some of the foremost scleral lens experts in the world. It is evident that with the difference in elevation present in different regions of the sclera, peripheral toricity is an important and increasingly popular feature of newer scleral lens designs.
Technology that provides a three-dimensional view of the ocular surface can be an outstanding aide to fitting scleral lenses because it allows for virtual fitting. This fall, Visionary Optics is introducing such technology with its sMap3D corneo-scleral topography system, manufactured by Precision Ocular Metrology. The company says that this instrument uses a structured light approach for three-dimensional mapping to obtain micro precision measurements of the cornea and sclera with a 22mm maximum field of view. It is able to stitch together multiple images, which the company says produces a complete three-dimensional model of a patient’s eye. It can also provide sagittal depth data at any specified chord, and scleral toricity can be calculated from any specified radius from center.
According to Greg DeNaeyer, OD, FAAO, who helped design this topography system with Visionary Optics, virtually fitting custom scleral lenses will decrease chair time, reduce remakes, and improve patient satisfaction.
Another continuing trend is that scleral lenses are not just for diseased eyes in 2015. An increasing number of scleral designs for astigmatic and presbyopic patients have recently been introduced. Most recently, Visionary Optics introduced the Elara Scleral lens, which is a prolate design for healthy eyes and for dry eye patients.
The future indeed looks bright for scleral lenses. In the sidebar on p. 29, several prominent contact lens fitters provide their predictions for future innovations with these designs.
Whereas corneal reshaping (overnight orthokeratology) has not yet exploded onto the market, the research continues to demonstrate that it has a definite myopia control effect in young people. Sun et al (2015) reviewed all of the literature pertaining to the effects of overnight orthokeratology on school-aged children. They reported on seven studies that met their criteria as well-designed, controlled studies. They found that over a two-year period of overnight orthokeratology, myopia progression was slowed by an average of 45%. This is close to the goal stated by Professor Brien Holden (Nichols et al, 2015) of 50% to potentially result in a significant reduction in myopia-induced ocular disease. In addition, these studies reported a significant reduction in the progression of both axial length and vitreous chamber depth as well as an absence of serious adverse events. In another recent review of the literature, González-Méijome et al (2015) concluded that contact lenses were reported to be well accepted, consistent, and safe methods to address myopia regulation in children. They stated that corneal reshaping is at present the modality with the largest volume of accumulated evidence relating to the efficacy to regulate myopia progression in children.
Considering these findings, it is still surprising that this modality has not gained more traction in the United States. New designs, aided by advancements in software programs, may help accelerate corneal reshaping use. For example, EyeSpace is a program that recently became available in the United States via Custom Craft Lens Service. It imports data from corneal topographers and uses this information to design rigid lenses. It has notable applications in designing specialty lenses, including the Forge Orthokeratology lens (Custom Craft Lens Service).
Table 2 shows our GP Prescribing Survey respondents’ prescribing habits with corneal reshaping. Almost 44% of the respondents indicated that they do perform corneal reshaping in their practice. It does appear that among these individuals, the overall trend with corneal reshaping is slightly increasing.
|The use of corneal reshaping/overnight orthokeratology lens designs (if applicable) in your practice in the last 12 months has:|
|Stayed the same:||16.11%|
Interestingly, when asked what is included in their myopia control program, almost as many respondents chose soft multifocals (37.78%) as corneal reshaping (40.0%) (Figure 3). With the current research at the Brien Holden Vision Institute with peripheral plus power soft lenses (Nichols et al, 2015), it will be interesting to see whether these designs will ultimately challenge corneal reshaping as devices to help slow myopia progression in young people.
Figure 3. Your myopia control program includes:
It is evident that improvements in GP, hybrid, and soft multifocal lens designs are ongoing. In fact, recent surveys have concluded that multifocals have surpassed monovision as the presbyopic lens of choice (Nichols, 2015; Efron et al, 2015).
Overwhelmingly, the most popular GP multifocal is some form of aspheric design (i.e., front aspheric, back aspheric, bi-aspheric, or aspheric-concentric combination). Table 3 shows responses from our GP Prescribing Survey respondents when asked what percentage of several different GP multifocal designs they used in the last year. The great majority responded that they do fit multifocal GP lenses, with 83% fitting aspherics. Fifty of 164 respondents fit ≥70% of their GP multifocal lens wearers into aspherics, and 96 of 164 respondents fit at least 30% into these designs. Fifty-six percent of the respondents indicated that they fit segmented, translating designs, although only 19 of 150 respondents fit them to more than 30% of their GP multifocal lens wearers. This was followed (in order) by concentric, hybrid, and scleral lens designs.
|Aspheric (N = 164)||40||96||50||28|
|Segmented, translating (N = 150)||65||19||0||66|
|Concentric (N = 140)||40||33||0||67|
|Hybrid (N = 127)||39||17||0||71|
|Scleral (N = 130)||33||8||0||89|
The reason why aspheric designs are predominant today is because newer front-surface aspheric multifocal or aspheric-concentric combination designs allow the incorporation of high add powers combined with the ease of empirical fitting.
However, several segmented, translating designs have recently been introduced that not only provide uninterrupted vision at distance and near, but also correction at all distances. The SpectraVue By Tangent Streak design (Firestone Optics) has the distance correction in the upper section of the lens, which joins seamlessly with a crescent-shaped middle segment that provides a progressive intermediate power change, similar to a spectacle progressive addition lens, but without a limiting channel. In addition, ABB Optical Group has introduced the TriVA segmented translating design, which has optics that are designed to provide presbyopes with vision correction at all distances. These new designs complement many other multifocal segmented translating designs introduced in recent years.
GP Lens Experts Predict Future Scleral Lens Innovations
Experts were asked: “In the next few years, what innovations in design do you see forthcoming with scleral lens designs?” Following are some of their responses.
“I think that there will be more use of toric haptics in scleral lenses, improved imaging of the sclera, and perhaps more attention to the conjunctiva.”
–Gloria Chui, OD
“We will see synergies in technologies in which new instrumentation that can scan the anterior segment will allow for highly accurate digital modeling of anterior surface shape that will allow creation of lenses that contour the most irregular surfaces.”
–Barry Eiden, OD
“Sclerals will continue to become more customized, both on the back and front surface. Scleral topography will allow practitioners to fit customized lenses from measurement rather than through using diagnostic lenses. Wavefront-corrected lenses will improve visual performance for some keratoconus patients.”
–Greg DeNaeyer, OD
“As our knowledge of scleral lenses expands, I foresee additional oblate lens design options, additional designs for pellucid marginal degeneration, and expansion of multifocal scleral lens designs.”
–Melissa Barnett, OD
“In the next few years, I think that advanced lathing—that is tied to topography maps and anterior segment optical coherence tomography (AS-OCT)—will enhance our ability to provide a better and safer fit. This coupled with corneal collagen cross-linking gaining U.S. Food and Drug Administration approval should allow us to greatly reduce the number of transplants needed.”
–Doug Benoit, OD
“Development of custom scleral lens designs will allow for greater precision and greater success. As of today, our only limitation is our inability to interface the scleral topography with the manufacturing lathe.”
–Michael Lipson, OD
“Front-surface aberration control will equal better visual acuity for irregular corneas, and there will be more customizable haptics (toric, quadrant-specific, asymmetric).”
–Jason Jedlicka, OD
“We will use improved lens solutions that will have some of the healing properties found in amniotic membranes and will act as a reservoir for enhanced healing. We will also see scleral lenses commonly used for corneal reshaping due to their ability to remain static and centered. Our ortho-k effects will take less time to accomplish—perhaps 30 to 60 minutes—with the use of softening gels that can soften the cornea and allow the new shape to remain fixed for a month or two.”
–Ray Brill, OD
“I see a trend toward minimum scleral chamber depths (which helps to control debris accumulation) and overall looser-fitting scleral lens designs (particularly in the periphery/haptic) to promote healthier long-term wearability.”
–Michael Ward, MMSc, FCLSA
“New designs have made scleral fitting much easier, and the use of OCT has made it more precise. In our office, this combination has essentially reinvented the way in which we manage challenging patients.”
–Art Epstein, OD
GP Materials and Designs
The trend in recent years has been to order plasma-treated GP lenses to assist in initial surface wettability and possibly comfort. According to our survey, among respondents who are aware of whether their lenses are plasma treated or not, only 17% do not have any of their GP lenses plasma treated (Figure 4). Of course, unanswered questions remain regarding how long plasma treatment lasts and how it is impacted by certain cleaners, solutions, and modification procedures.
Figure 4. What percentage of your GP lenses (if applicable) do you order plasma treated?
In hybrid contact lens technology, the newly introduced UltraHealth FC (Flat Curve) (SynergEyes) is designed for oblate corneas, such as post-refractive surgery patients, as well as for pellucid marginal degeneration. The vaults range from 55 to 505 microns in 50-micron steps and three skirt radii: 8.4mm, 8.1mm, and 7.9mm. The powers range from +10.00D to –20.00D.
Regarding diagnostic versus empirical fitting of GP lenses for healthy eyes, the results of our GP Prescribing Survey were interesting. Despite improved lens designs that make empirical fitting more successful—not to mention that empirical fitting is easier and often allows patients to experience good vision with the initial lens application—there was parity between empirical and diagnostic fitting, with 46 respondents fitting 100% of their GPs empirically and 48 fitting exclusively with diagnostic lenses. Of those respondents fitting empirically, approximately 40% preferred to order based on corneal topography findings, whereas 60% preferred to order from keratometry and refraction and/or a nomogram.
Our survey also asked practitioners how often they recommend that their patients replace their GP lenses. There was close to parity between 1) as needed (35%), 2) every two years (28.33%), and 3) annually (26.67%), with 10% responding that it depends on lens material (Table 4).
|What do you recommend for GP lens replacement?|
|Every two years:||28.33%|
|Dependent upon the lens material:||0%|
GP Care Trends
When practitioners were asked about their preferred care system for corneal GP lens wearers, the use of a GP multipurpose solution, in combination with an additional cleaner, was the most preferred choice (20.56%) (Table 5). Interestingly, when asked what is their preferred wetting/filling solution, 10% of the respondents—or 13% of those who are fitting scleral lenses —indicated that they used a (preserved) GP multipurpose solution (Table 6), which is contraindicated for scleral lenses. Companies are currently working on solutions specifically for wetting/filling scleral lenses.
|What is your preferred care system for corneal GP lens wearers?|
|GP multipurpose solution (no separate cleaner):||16.67%|
|GP multipurpose solution (with additional cleaner):||20.56%|
|GP two bottle (wetting and cleaning/disinfection):||17.22%|
|Which one of the following is your preferred wetting/filling solution for scleral lenses?|
|Unpreserved contact lens lubricant/rewetting/saline: 37.78%|
|Sodium chloride inhalation solution: 23.89%|
|Combined unpreserved contact lens solution/sodium chloride inhalation solution: 5.56%|
|GP multipurpose solution 10%|
|Not applicable: 22.78%|
A number of resources continue to be introduced to assist practitioners with GP lens fitting and care. Bausch + Lomb offers a number of scleral and irregular cornea resources at www.fit-boston.com/en-us/eye-care-professional/scleral-gp-lenses. This includes a five-volume video series on central clearance, compression and impingement, limbal clearance, anatomy and nomenclature, and initial lens selection. Also available on this site are the publications “Guide to Scleral Lens Fitting” and “Guide to Correction of Keratoconus” as well as the excellent downloadable resource “Scleral Lens Fitting Scale” developed at the Michigan College of Optometry.
Care and handling videos are available at the Scleral Lens Education Society (www.sclerallens.org), and numerous webinars are available from the GP Lens Institute (www.gpli.info). In addition, many scleral lens manufacturing laboratories offer online resources and webinars pertaining to their respective lens designs.
Corneal reshaping resources are available from organizations such as The American Academy of Optometry and Myopia Control (www.orthokacademy.com) and the International Academy of Orthokeratology (http://internationalorthok.com). The Vision Research Institute (VRI) at the Ferris State University Michigan College of Optometry has recently launched a new website at www.myopiacontrol.org, which is intended to be a central portal where global eyecare practitioners can obtain information on myopia and myopia prevention.
Many additional resources are available at www.gpli.info and www.fit-boston.com. However, the best resource is still the laboratory consultants who, if provided with information such as photos, videos, and corneal topography maps, can greatly help in the ultimate success of GP lens wearers. Our survey showed that lab consultants remain an underutilized resource; when asked how often someone in their practice contacts a laboratory consultant regarding a GP wearer, the most popular response was less than one time a month (32.78%), followed by between once a week and once per month (29.44%), at least once per week (26.67%), and never (11.11%).
It is apparent that GP lenses continue to represent a viable option for young myopic, irregular cornea, high astigmatic, and presbyopic patients. Although spherical GP lens use continues to decrease, the advancements in lens design technology and manufacturing, notably with scleral lens designs, ensures that GP lenses will continue to play an important role in increasing the quality of life of lens wearers well into the future. CLS
Peg Achenbach, OD (SynergEyes); Josh Adams (Valley Contax); Greg DeNaeyer, OD; Richard Dorer (Blanchard Contact Lens); Cassandra Gordon (Visionary Optics); Mike Johnson (Art Optical); Mary Ann Kail (Essilor); Daren Nygren (Custom Craft Lens Service); Keith Parker (Advanced Vision Technologies); John Patterson (Orion Vision Group); Gary Richardson (Essilor); David Rusch (Firestone Optics/Diversified Ophthalmics); Ann Shackelford (ABB Optical Group); Bill Shelly (Alden Optical); and Jan Svochak (TruForm Optics).
For references, please visit www.clspectrum.com/references and click on document #239.
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 firstname.lastname@example.org.