The GP market in the United States remains stable compared to 2016, and it may have grown slightly over the past 12 months. The “Contact Lenses 2016” annual report article¹ showed that rigid lenses, in general, comprised 12% of all new fits and refits in 2016 (divided into 10% GPs and 2% hybrids). While this is similar to 2015 (likewise 12% overall, but 9% GPs, 2% hybrids, and 1% PMMA),² it is much above the 6% GPs reported for 2014.³ This is confirmed by independent market research data reviewed by Jeff Johnson, OD, CFA, director and senior research analyst, and his team at Robert W. Baird. Their data show that hard/GP contact lens revenue in the United States increased by 14% for 2016 versus 2015.⁴

Why is the GP market holding steady, if not actually increasing? There are likely several reasons for this stability, among them the increasing use of scleral lenses. However, when asked what percentage of GP lenses that respondents fit in seven different categories, spherical lenses predominated, with scleral lenses only increasing from 23% last year4 to 24% this year (Figure 1). However, it is evident from both a laboratory and a button manufacturer perspective that more scleral lenses were manufactured this past year compared to the previous year.⁵

THE MOST IMPORTANT DEVELOPMENTS IN THE LAST 12 MONTHS

The GP Lens Institute (GPLI) Advisory Board members, consisting of 70 prominent specialty lens fitters, were surveyed as to what they believe was the most important new development in GP lenses in the past 12 months. The sidebar on the next page shows representative quotes from some of the 38 Advisory Board members who responded. It was evident what most of them believe was the most important development in the last year; 25 members indicated that it was the introduction in January 2017 of a 90% water polyethylene glycol (PEG)-based polymer coating, which—after a brief plasma cycle—encapsulates the surface of a GP or a hybrid lens. It is purported to mimic the mucin layer of the tear film, improving wettability and alleviating heavy deposition.^6,7 A recent study comparing coated scleral lenses, uncoated scleral lenses, and the subjects’ habitual lenses reported that 11 of 16 subjects preferred the coated lenses, four had no preference between the three lens types, and one preferred the habitual lenses.⁷

Of course, new developments in scleral lenses continue to evolve, and this is a very dynamic and exciting area of growth as eyecare practitioners (ECPs) increasingly embrace this technology to improve the quality of life of patients who could not tolerate other types of contact lenses, notably those who have irregular corneas and pathological dry eye. Toric peripheries for scleral lenses are increasingly being embraced by ECPs, especially in the larger scleral designs, to better align with the toric sclera while minimizing debris entrapment and midday fogging. In addition, corneo-scleral topographers/profile systems offer the potential both for a more optimal fitting in the lens periphery and for empirical fitting. Finally, an increasing number of scleral lens designs are being introduced for use with normal corneas, notably for presbyopic patients.

A new GP material manufacturer entered the U.S. market in 2017. Acuity Polymers was formed by several leaders in the contact lens industry and introduced several new fluorosilicone/acrylate lens materials in late 2016 and in 2017.

SCLERAL LENSES

Numerous developments in scleral lens designs and methods of evaluation occurred this past year, resulting in their continued growth. When our readership was surveyed about scleral use in their practices in the past 12 months, excluding the 24% who do not prescribe scleral lenses, more than 80% indicated either a mild increase or a great increase (Figure 2).

When choosing among sclerals, small-diameter GPs, hybrids, intralimbals, custom soft, and piggyback lenses for fitting irregular corneas, the overwhelming preference was for scleral lenses: nearly 51% of ECPs prefer scleral lenses for, at minimum, 50% of their irregular cornea patients. This was followed by 29% fitting 50% or more of patients with small-diameter GPs and by 9% fitting 50% or more with hybrid designs (Table 1).

The increasing use of corneo-scleral topographers has been very beneficial in making decisions as to when to use toric haptic designs, which are being recommended for use in the great majority of larger (often ≥ 16mm) scleral lens designs.^6,8 One of these systems can take three images from different gaze directions and “stitch” them together to produce one wide topographic image.⁹ For example, at 15mm, the authors were able to achieve 96% coverage versus 53% with straight-ahead gaze alone; at 16mm, they were able to achieve 93% coverage versus 39% with just straight-ahead gaze.

Another area of interest is what the optimum apical clearance should be. Approximately 200 microns is often recommended, and that was the finding of a recent study reporting that when an 18mm diameter scleral lens was fit with 400 microns of clearance, the oxygen tension available to the cornea was reduced by 30% as compared to a similar lens fitted with 200 microns of clearance after 5 minutes of wear.¹⁰

A question that is often asked and that is gradually being answered is: Should scleral lenses be fit on normal, healthy (i.e., astigmatic and presbyopic) eyes? With the increasing number of presbyopic designs being introduced, it is evident that scleral lenses are a viable option for this patient population, notably those who have dry eyes. Likewise, a recent study by Michaud et al reported scleral lenses to be a viable alternative to soft toric lenses for astigmatic subjects.¹¹ Subjects wore each modality for one month, with 75% preferring the vision of the sclerals as compared to the soft toric lenses, and 53% expressed a preference to continue with the scleral modality.

There are now two U.S. Food and Drug Administration (FDA)-approved solutions for filling scleral lenses; a recently approved one is available in 10mL single-use vials, which complements the solution launched last year available in 5mL vials.

KERATOCONUS

The April 2016 FDA approval of a specific corneal collagen cross-linking (CXL) procedure impacts contact lens fitting and will do so more in the years ahead. CXL uses ultraviolet (UV) light at a specific wavelength (365nm to 370nm) with riboflavin (vitamin B2) in the corneal stroma.¹² This procedure strengthens the cornea in an effort to retard progression of the condition. Cost is a factor at present, but going forward it should impact who is fit into contact lenses and what lenses would be optimal for these individuals.

As indicated previously, scleral lenses have vaulted to the forefront as the primary lens modality that prominent specialty lens fitters use for keratoconus patients. Keratoconus may be more prevalent than once believed, as a recent epidemiological study found that its incidence could be as much as 1 in 375 or 265 cases out of a population of 100,000.¹³

Hybrid lens designs continue to evolve with respect to keratoconic (and multifocal) lenses. A recent study evaluated the bond strength at the junction of SynergEyes Duette hybrid contact lenses by measuring the tensile strength. It was found that the lenses could withstand 8.5 times the force applied by a finger during cleaning before breakage occurred.¹⁴ It has also been reported that, when fitting hybrid lenses for irregular corneas, the 250 micron vault is the one used for more than 80% of fits and should be the one to use initially.¹⁵

MYOPIA CONTROL

The most significant news regarding orthokeratology (ortho-k) in the last year is that, contrary to what we reported in last year’s GP Annual Report,⁴ FDA clearance of the modality for myopia control will not occur anytime soon. The same is true for soft multifocal lenses. Andre reported that—like extended wear contact lenses—both overnight ortho-k and soft lenses for myopia control are in the Class III, Significant Risk category.¹⁶

He also discussed the FDA workshop on Sept. 30, 2016, in which experts discussed what it would take for FDA clearance of myopia control lenses. In particular, the workshop covered what questions would need to be answered and what criteria would need to be established in a long-term study to evaluate myopia control. It was decided that such a study would need to be four years in length (three years treatment and one year regression) with children from 7 to 12 years of age. The experimental group would need to have approximately 225 subjects, and the control group would need to consist of 175 subjects. Therefore, whether it is an overnight ortho-k design or a multifocal soft lens, it was predicted that initial FDA approval may be a five- to seven-year process.

Figure 3 shows the readership survey results to the question regarding the use of corneal reshaping/overnight ortho-k lens designs (if applicable) over the past 12 months. With more than 50% of respondents not having incorporated this modality into their practice, of those who have, only 4% indicated that their use of this modality has decreased. Figure 4 supports the fact that peripheral-plus-power soft lenses appear to be becoming more of a common option for myopia control, with more than 10% of respondents indicating that this is the preference in their practice as compared to overnight ortho-k. Interestingly, atropine (in some form) was used by more than 23% of the readership for the purpose of myopia control.

MULTIFOCALS

Our readership survey showed that aspheric GP multifocals are overwhelmingly the preferred GP multifocal option for presbyopic patients, with 63% of the respondents fitting ≥ 50% of their GP multifocal patients into this lens type (Table 2). This was followed, in order, by concentric designs; segmented, translating designs; scleral designs; and hybrids.

It is evident that new surface treatments and coatings to improve wettability can definitely benefit presbyopic wearers. For segmented, translating designs, it has been reported that truncation is less necessary due to better design of the posterior lens surface and better edge performance. Likewise, improvements continue to be made with the intermediate zone for those requiring a trifocal correction.¹⁷ Hybrids remain a niche option but also a viable tool to have in the presbyopic tool box. It has been reported that the medium skirt curve is successful for the great majority of multifocal hybrid wearers.¹⁵

RESOURCES

There are plenty of options if you desire assistance with GP and specialty lens fitting, troubleshooting, or patient education. Table 3 lists some of the more popular websites. The GPLI has a large and diverse number of resources online. In addition to its monthly educational webinar series, the organization has recently introduced—in cooperation with the Scleral Lens Education Society (SLS)—a Scleral Lens Troubleshooting FAQs module. The GPLI has also introduced a comprehensive staff education and training module online.

The SLS has continued to provide scleral lens education—with an emphasis on hands-on workshops—throughout the United States. The SLS also offers a fellowship program for active fitters.

The American Academy of Orthokeratology and Myopia Control (AAOMC) has a number of online resources as well as a fellowship program available. In addition, for ECPs interested in either incorporating overnight ortho-k into their practice or expanding their use of this modality, the Vision by Design symposium is beneficial; the next program will be held April 11 to 15, 2018 in Orlando.

For great keratoconus resources and assistance, visit the International Keratoconus Academy and the National Keratoconus Foundation.

The premier symposium on specialty contact lenses, the Global Specialty Lens Symposium, will take place Jan. 25 to 28, 2018 in Las Vegas. Finally, your most important resource for GP lens design, fitting, and problem-solving assistance is always your laboratory consultants.

WHAT TO EXPECT IN THE NEXT 12 MONTHS

The next 12 months should result in several new and important developments. The sidebar on p. 24 includes representative responses from GPLI Advisory Board members. New lens materials are expected to be introduced, in part because some of the popular, currently used materials are going off patent. This should help reduce lens costs to ECPs.

Scleral lens designs will continue to be more customized, notably the back-surface peripheral optics, during the next year and beyond. Improved toric and quadrant-specific haptic designs will allow for an even better-aligned lens-to-sclera relationship. The increasing popularity of corneo-scleral topographers will allow more practitioners tto provide well-fit lenses with little risk of complications.

It is hoped that the next year or so will bring more diversity in overnight ortho-k lens designs and manufacturers. Certainly, the technology continues to improve with the increasing interest in myopia control. Most of this interest is pointed toward peripheral-plus soft lens designs, so time will tell whether overnight ortho-k will benefit from, or be negatively impacted by, the increased promotion of slowing myopia progression with soft lenses.

In the care system arena, we may see the availability of new scleral filling solutions that can provide nutrients to the cornea, optimizing long-term wear success. We could also see a solution specific to surface-coated lenses, which could serve the purpose of refreshing the lens surface.

Over the long-term, GP lenses should be an integral part of some fascinating contact lens developments, as summarized by renowned specialty lens fitter Bruce Williams, OD: “The future of contact lens fitting is a panacea of unimaginable dimension. Instrumentation will continue to advance the ability to more accurately reproduce the physical surface, hence providing a more meticulous platform to design our therapeutic devices. Integration of micro-electronics and liquid crystal will provide adjustable focal lengths and telescopic potential. Micro-laser light emitting diodes may be able to show detail at the nano level. We already use technology to monitor glucose, intraocular pressure, insulin, and hypertension. It should be an incredibly interesting decade.” CLS

Acknowledgements: Roxanne Achong-Coan, OD; Tom Arnold, OD; Melissa Barnett, OD; Daniel Bell (Acuity Polymers); Doug Benoit, OD; David Bland (Bausch + Lomb); Mile Brujic, OD; Steve Byrnes, OD; Karen Carrasquillo, OD, PhD; Gloria Chiu, OD; Robert Davis, OD; Tim Edrington, OD; Barry Eiden, OD; Melanie Frogozo, OD; Susan Gromacki, OD, MS; Jason Jedlicka, OD; Lynette Johns, OD; Jeff Johnson, OD; Mike Johnson (Art Optical); Matt Kauffman, OD; Beth Kinoshita, OD; Jim Kirchner, OD (SynergEyes); John Laurent, OD, PhD; Martyn Lewis (Contamac); Michael Lipson, OD; Derek Louie, OD; Ken Maller, OD; Marsha Malooley, OD; Bob Maynard, OD; Langis Michaud, OD; Clarke Newman, OD; Roxanna Potter, OD; Tom Quinn, OD, MS; Susan Resnick, OD; Buddy Russell, COMT; Pam Satjawatcharaphong, OD; Donald Sanders, MD, PhD (Visionary Optics); Jack Schaeffer, OD; Muriel Schornack, OD; Brian Silverman, OD; Jeff Sonsino, OD; Jeff Walline, OD, PhD; Ron Watanabe, OD; Bruce Williams, OD; and Stephanie Woo, OD.

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