Specialty Contact Lens Update
A review of some highlights from the 2011 Global Specialty Lens Symposium.
By Gretchyn M. Bailey, NCLC, FAAO
The Global Specialty Lens Symposium (GSLS) took place from Jan. 27 to 30, 2011, in Las Vegas. Presented by the Wolters Kluwer Health Care Conference Group and with Contact Lens Spectrum as the exclusive media sponsor, the meeting attracted 400 attendees from more than 30 countries, more than 40 exhibitors, and a new record of 44 posters.
The third annual symposium included lectures, free papers, and industry breakfast seminars and breakout sessions as well as a pre-conference fundamentals track that reviewed key fitting concepts and patient management tips. Topics covered included myopia control, large-diameter lenses, ocular surface disease, irregular cornea management, contact lenses for children and teens, contact lens care and compliance, vision performance, and contact lens complications.
The GSLS Education Planning Committee (Figure 1) included Patrick Caroline, FAAO, FCLSA; Jason Nichols, OD, MPH, PhD, FAAO; Craig W. Norman, FCLSA; Ed Bennett, OD, MSEd, FAAO; and Eef van der Worp, BOptom, PhD, FAAO, FIACLE, FBCLA.
Figure 1. The GSLS Educational Committee from left to right: Ed Bennett, OD, MSED, FAAO; Jason Nichols, OD, MPH, PhD, FAAO, Patrick Caroline, FAAO, FCLSA; Eef van der Worp, BOptom, PhD, FAAO, FIACLE, FBCLA; and Craig Norman, FCLSA.
Following is a summary of some of the information presented at this year's conference. To see the full meeting agenda, visit http://www.healthcareconferencegroup.com /conferences.asp?conf=155.
Contact Lens Industry Update
Dr. Nichols, editor of Contact Lens Spectrum and Contact Lenses Today, reviewed the state of the contact lens industry. Contact lens wearers in the United States continue to grow, albeit slowly—from about 24 million in 1989 to 33 million in 1999 to about 35 million in 2009. Growth in the United States is estimated at 2 percent in 2010 and is anticipated to be 6 percent in 2011. Worldwide contact lens growth is estimated at 4 percent in 2010 and is anticipated to be 5 percent in 2011.
Daily disposable contact lens use continues to dominate worldwide at 29 percent of wearers while the United States holds at 15 percent or less. It remains to be seen whether a silicone hydrogel daily disposable lens will prompt the United States to more fully adopt this modality.
Myopia and Myopia Control
Paul Gifford, PhD, FAAO, FIACLE, FBCLA, discussed applications of orthokeratology for hyperopia, presbyopia, and astigmatism. Greater correction is possible with hyperopic orthokeratology, but it is less predictable. However, researchers have experienced good refractive and topographic predictability when correcting up to +1.50D. The hyperopic corneal shape change is limited in comparison to that of myopic corneas, and this appears to be the limiting factor in refractive outcomes.
Current presbyopic contact lens options are not meeting demand. In 2010, 57 percent of presbyopes wore spectacles, while contact lens corrections were 16 percent for soft multifocals, 3 percent for GP multifocals and 16 percent for monovision. There is opportunity for presbyopic orthokeratology. Dr. Gifford suggests fitting hyperopic designs on early emerging presbyopes and targeting less change than what the add suggests.
Dr. Gifford also presented preliminary data from a study investigating hemi-meridional differences in corneal topography of East Asians and non-East Asians and relating the data to eyelid morphometry. Early data show that there are corneal differences between and within both groups. Additional study will examine whether eyelid morphometry plays a role in orthokeratology lens decentration.
Earl Smith, III, OD, PhD, postulated in his work with monkeys that if it were possible to achieve peripheral retinal focus (or even slight myopic defocus), axial length growth would be significantly reduced. Several possibilities exist for achieving reduced axial length growth, but Dr. Smith says that the most successful potential treatment would be designs similar to those of overnight orthokeratology lenses because they would be the most aggressive. (Note: An award-winning poster describes one such overnight orthokeratology lens design that has potential to create this peripheral focus. See “Winning 2011 GSLS Posters” below.)
Pauline Cho, PhD, FAAO, FBCLA, presented initial results of the Retardation of Myopia in Orthokeratology (ROMIO) and Toric Orthokeratology-Slowing Eye Elongation (TO-SEE) studies. Both studies aimed to confirm whether orthokeratology can slow myopia progression in myopic and astigmatic children, and preliminary data show significant reduction in astigmatism for orthokeratology subjects. ROMIO subjects exhibited baseline of −2.28D ±0.79D as compared to 12-month data of −0.39D ±0.42D, and TO-SEE subjects exhibited baseline of 3.43D ±1.39 as compared to 12-month data of −0.64D ±0.55D. In addition, orthokeratology subjects in both studies exhibited a reduction in axial length growth from baseline at 12 months (ROMIO spectacles 0.37 ±0.17 versus ortho-k 0.22 ±0.14; TO-SEE spectacles about 0.36 versus orthokeratology 0.18 ±0.23). The TO-SEE study is especially noteworthy because subjects with a higher amount of corneal astigmatism (1.25D to 3.00D, not typically recommended for orthokeratology treatment) showed significant reduction in myopia as well as cylinder. ROMIO subjects showed a 41-percent decrease in axial length growth after only one year, as compared to Dr. Cho's Longitudinal Orthokeratology Research in Children (LORIC) study, which showed a 46-percent reduction after two years and Jeff Walline, OD, PhD's Corneal Reshaping and Yearly Observation of Nearsightedness (CRAYON) study, which showed a 56 percent decrease after two years. Dr. Cho also reported on early promising results from the Myopic Control for High Myopes Using Orthokeratology (HM-PRO) study examining subjects with ≥6.00D of myopia.
|Winning 2011 GSLS Posters|
|The 2011 GSLS meeting experienced a record number of poster submissions. Out of 44 submissions, three winners were chosen.
FIRST PLACE TIE:● Gina L. Sorbara, OD, MS, FAAO: Use of the Visante OCT Anterior Segment Image to Measure the Sagittal Depth of Keratoconus Cornea Compared to Normals at Their HVID
● Susan L. Gromacki, OD, FAAO: MRSA/MRSE: Colonization in West Point Contact Lens Wearers Seeking Refractive Surgery
THIRD PLACE:● Jaume Pauné Fabré, MSc: Performance of a New Special GP Lens Design for Myopia Control to Produce Peripheral Myopization
Irregular Cornea Management
Patrick Caroline discussed fitting large-diameter lenses. He suggests not rushing the prescribing of these lenses. His clinic schedules patients for several hours for such fittings to give practitioners the opportunity to check the relationship of the peripheral lens design to the sclera. Mr. Caroline recommends fitting with apical clearance and allowing the lenses to settle over a period of several hours; only then are you able to assess the fit. In that time, the lens usually drops about 150 microns. Knowing that your scleral lens is 300 to 350 microns thick, the minimal apical clearance to achieve is 100 microns of tears beneath a full scleral lens (a corneo-scleral lens can perform well with less clearance).
Sophie Taylor-West, BSc, MCOptom, offered helpful fitting information for corneo-scleral and mini-scleral (13mm to 16mm) designs. She suggested to fit from the outside in, aiming for best alignment in the periphery, then looking at the limbus for good tear exchange. Avoid excessive pressure at any point on the cornea. Also, don't be afraid to ask patients how the lenses feel because feedback can be helpful in the fitting process. Consider the sagittal depth required to give the correct fitting relationship with the cornea; the base curve is almost irrelevant once the diameter has gone beyond the limbus. If peripheral standoff or fluorescein pooling at the edge of the lens occurs, steepen the peripheral curve radii; increase overall sag if the lens is simply too shallow. If scleral impingement or vessel blanching is observed, flatten the peripheral curve radii. The push-in method helps assess lens fit: push in at the bottom of the lens to see how much pressure is needed to make the lens flare away from the sclera (Figure 2). The average overall diameter for these lenses is 14.0mm to 14.5mm. If vaulting the cornea, the overall diameter must be, at minimum, 15mm (smaller with small palpebral aperture or pingueculae). A fenestration can significantly affect the fitting relationship by resulting in less apical clearance, but it will also allow for easier removal of the lens from the eye. If bubbles form after the lens has been applied, you can order a new lens without a fenestration. Keratoconus will affect the fitting relationship, depending on cone size and shape. The condition of the epithelium will determine how much touch is acceptable. With post-graft fits, avoid touch on the graft and sutures.
Figure 2. The “push-in” method for assessing the fit of a corneo-scleral or mini-scleral lens.
Greg DeNaeyer, OD, FAAO, discussed lens care for scleral (18mm to 24mm) lens designs. According to a survey conducted by Dr. van der Worp's I-Site e-mail newsletter (http://www.i-sitenewsletter.com), 22 percent of respondents use GP care solutions to fill their lenses prior to application. The anterior surface has much exposure to these solutions, Dr. DeNaeyer said, and he suggested that patients use nonpreserved, bottled saline for this purpose. Alternatives are nonpreserved artificial tears in single-dose ampoules or prescribed, thicker, nonpreserved artificial tears. Some patients are more sensitive to non-native ingredients in solutions, including those in nonpreserved artificial tears. For these patients, he suggested using sodium chloride inhalation solution 0.9% off label. Some practitioners use balanced salt solution (BSS), which is isotonic and pH buffered as well as extremely expensive.
Hans Bleshoy, PhD, shared the European perspective on soft lens management of irregular corneas. He showed the importance of Dk and Dk/t when using soft lenses for specialized indications. This is an area that may change in the next several years with renewed and better-performing lenses.
Mark André, FAAO, FCLSA, reminded attendees that soft contact lenses remain a back-up plan when nothing else is successful. Although custom soft lenses are more than 30 years old, the past few years have brought more options for fitting irregular cornea patients. Contamac's Definitive joins Ciba Vision's (Ciba) O2 Optix Custom as a latheable silicone hydrogel material. “Off the rack” soft lenses can also be successful for irregular cornea (including keratoconus) patients by eliminating a tremendous amount of distortion. Mr. André suggests thinking of a soft scleral lens as a thick GP scleral lens. It's possible to reduce 4+ distortion to only a trace, thereby turning irregular astigmatism into regular astigmatism. In addition, hypoxia and neovascularization are not customarily observed with these lenses because they allow a large amount of tear exchange. Remember that lens movement is not a factor in comfort; most of these patients have been wearing smaller GP lenses. Knowing the center thickness of diagnostic sets is important. Mr. André performs keratometry over the diagnostic lens to observe how much of the distortion has been eliminated. Then he estimates how much thicker the lens needs to be. It's a trial-and-error process, but he has learned, for example, that another 0.1mm thickness is needed for reducing 2+ distortion.
Robert L. Davis, OD, FAAO, shared information about the options that hybrid lenses provide. The ideal fit vaults the lens over the cornea and rests on a bed of tears; the soft skirt provides alignment of the fit. Dr. Davis recommends not using fluorescein and cautions that patience should be exhibited during the fitting process. Once the central curve is known, you should fit steeper than the flat curve. Dr. Davis fits 0.50D steeper than mid-K. Hybrid lenses are nothing more than a customary GP design with an 8.5mm/5.7mm design. Dry eye is the nemesis of hybrid lenses; you can diagnose via osmolarity testing and treat any dry eye prior to fitting.
Duette, a recent launch from SynergEyes, incorporates a reverse geometry design to bring improved stability for patients who have >2.00D of corneal astigmatism, Dr. Davis said. Duette's junction area is twice as wide as that of SynergEyes A, which is designed for patients who have <2.00D of cylinder. Using SynergEyes A for patients who have greater cylinder results in more force on the landing area when compared to Duette. Duette utilizes the entire posterior optical zone to distribute and support the weight of the lens, and its flexural resistance improves hybrid lens fitting characteristics, according to Dr. Davis.
Fusion recently introduced its Recess Pillow Lens System, a soft lens base with a GP lens design fitted into the cutout insert. Designed by Leonard Seidner, OD, Dr. Davis and S. Barry Eiden, OD, FAAO, proved the concept. The soft base controls the lens fit, and the GP lens acts as an optical refractive surface. Both lenses move as single unit. The lenses center very well, and movement is controlled by the steepness or flatness of the soft lens base curve. Drs. Davis and Eiden feel that the greatest asset of this design will be to improve the success of GP bifocal lens designs.
Silke Lohrengel, Dipl, Ing, retrospectively analyzed penetrating keratoplasty patients who were unhappy with their visual outcomes. Of the 131 patients, 56 percent had keratoconus, 17 percent had Fuchs' dystrophy, 7 percent had trauma, and the remainder had other indications. Patients were managed with back-surface lenses: 70 percent toric and 30 percent spherical. She devised a fitting method decision tree, which indicated that patients who had one to two sutures were fit with mini-scleral lenses, and patients without sutures were fit with reverse geometry lenses (steeper or flatter graft).
Jessica Mathew, OD, PhD, speculated whether corneal thinning in keratoconus can be explained in terms of lamellar loss. Her research showed that keratoconic corneas contain more lamellae (average 319) compared to normals (average 242). Lamellae in normal corneas are wide and uniform while keratoconic corneal lamellae are thin, numerous, and fragmented (Figure 3). Dr. Mathew suggested that lamellae in normal corneas are similar to a rope, tightly bound and strong. Keratoconic lamellae are unraveling rope, becoming frayed and weak and therefore causing weakness and loss of rigidity in the cornea. In fitting such corneas, it is important to vault over this area to avoid putting pressure onto already compromised tissue.
Figure 3. Corneal lamellae in a normal cornea (left) and in a keratoconic cornea (right). Both images are at the same magnification.
Jan Bergmanson, OD, PhD, suggested looking beyond Fleischer's ring with keratoconus patients, fearing that the rest of the cornea has been ignored in favor of the cone. Measuring further peripherally in the cornea, keratoconic corneas are thinner compared to normals across the entire web of the cornea, which is clinical evidence that the periphery is involved in the disease. Consider its presence when fitting keratoconus patients with scleral lenses by vaulting the cornea and clearing the cone and periphery.
Lens Care and Compliance
Philip Morgan, BSc, PhD, MCOptom, FAAO, shared that despite the surge in the use of multipurpose solutions (MPSs), the rate of microbial infection has remained steady. In a United Kingdom (UK) study, the relative risk of Acanthamoeba keratitis across solution types is 3.4 percent for one-step hydrogen peroxide, 1 percent for two-step hydrogen peroxide, and 0.5 percent for MPSs. He also reported that the United States uses more hydrogen peroxide solutions compared to most of Europe, and the past few years showed a decrease in MPS usage. Recently launched Bausch + Lomb's (B+L) BioTrue is exhibiting good antimicrobial characteristics; Abbott Medical Optics has launched its European Complete RevitaLens in the United States as RevitaLens OcuTec, and Alcon has been working on a product to improve wettability with silicone hydrogel lenses.
Dr. Morgan reaches out to his research subjects via SMS text messaging. He texts patients five times a day for a week asking about comfort. Most patients respond within five minutes, and he has learned that comfort is reduced as the day goes on. Looking forward, he suggests the industry needs to increase its focus on the lens surface by conducting laboratory testing on friction characteristics to improve comfort. More research is needed on antimicrobial lenses, and new materials need to go beyond silicone hydrogel because contact lens wearers worldwide have not increased since the launch of these lenses.
Dr. Cho reported that the contact lens case is a major source of contamination. Biofilms appear more frequently and densely on the case than on lenses. She suggests brushing the lens case with a clean, soft-bristle toothbrush (avoid scratching the surface) and a liquid cleaner or MPS because mature biofilm cannot be easily removed without scrubbing, and then drying the case. Drying is an important step in reducing the bacterial load; contamination rates remain high if the case is not adequately dried. She also recommends weekly care: soak the case in a mug of boiling water for 10 minutes. Avoid microwaving the case, even in the mug of water, because high-wattage microwave ovens can distort the case. Also avoid putting the case in the dishwasher because the case may get scratched or caustic detergent may leave behind a film. Seventy-nine percent of patients said they would replace the case if a new one is provided with a new bottle of MPS.
Michael A. Ward, MMSc, FAAO, explained that microbial keratitis (MK) is the most feared complication of contact lens wear; bacterial keratitis is the most destructive, and Pseudomonas aeruginosa is the most common. Risk factors for MK include sleeping in lenses, wearing lenses during water activities, wearers who are <25 years of age, ordering lenses online (almost five times greater risk), poor hygiene, smoking, and high ametropia. There is little evidence that the risk of infection is lower with daily disposables than with two-week disposables. For peroxide users, he suggests turning the case upside down once or twice during disinfection to disinfect the lid of the case.
Ocular Surface Disease
Dr. Nichols discussed that contact lens-related dry eye is a true form of dry eye disease, and practitioners need to begin treating it as such. One-third of contact lens wearers have blepharitis, and 16 percent of lens wearers discontinue wear due to this problem.
Kathy A. Mastrota, MS, OD, FAAO, shared that the tear film is loaded with substances that can't be mimicked in an artificial tear. She also discussed that up to 30 percent of buildings contribute to Sick Building Syndrome as classified by the Environmental Protection Agency, in which people have unidentified illnesses with top symptoms of eye and nose irritations. Inadequate ventilation is a major cause, along with poor lighting and ergonomics. She suggested encouraging patients to alter their environments to help with dry eye, such as repositioning computer screens, adding humidifiers, or putting a plant on their desks. Smoking is a big risk factor for dry eye, and coconut water is an excellent source of rehydration.
Bill Townsend, OD, FAAO, reminded attendees that seborrheic blepharitis is common in children, and 62 percent of sufferers are boys. Linked to blepharitis as well as to rosacea is the mite demodex. Conventional therapies remain for blepharitis (lid hygiene, topical antibiotics, and steroids), but Dr. Townsend recommends tea tree oil lid scrubs for treating demodex. The mite is resistant to 75% alcohol and 10% povidone-iodine. Tea tree oil cleanses cylindrical dandruff from the lash root and stimulates embedded mites to migrate out to the skin.
Giancarlo Montani, FIACLE, showed that differing lens materials after one day of wear can affect tear osmolarity. Tear osmolarity was measured before and after 50 subjects wore omafilcon A (OD) and methafilcon A (OS) lenses for seven hours. In the right eyes, average tear film osmolarity before lens wear was 323 mOsm/L (SD ±4.3) and after lens wear it was 325 mOsm/L (SD ±13.3). This was not a significant difference. However, average tear film osmolarity in the left eye before lens wear was 323 mOsm/L (SD±4) and after lens wear was 340 mOsm/L (SD±15.64), which was significant.
Contact Lenses for Infants and Teens
Dr. Cho discussed the challenge of noncompliance with young contact lens wearers. Avoid fitting a reluctant child, such as if a parent insists on contact lenses for myopia control. For these patients, monitoring corneal integrity is difficult, the fitting can be traumatic for the child, and the child is not likely to be compliant. Parental monitoring of lens care is crucial, especially during handwashing. Children's idea of handwashing is a quick rinse under tap water. Educate children—and their parents—about proper handwashing techniques, including that hands must be dried thoroughly before handling lenses. Teens need monitoring as well because they frequently don't return for follow-up visits, and they tend to share lenses and solutions with friends. Remind teens that if lenses are worn in the water to: wear watertight goggles, remove lenses after leaving the pool and before showering, discard disposable lenses, disinfect lenses immediately after removal, and rinse eyes with a unit dose of artificial tears.
Christine W. Sindt, OD, FAAO, said that cost is the most important reason to fit infants with GP contact lenses. Her clinic pays for many of the lenses fit on babies. GP contact lenses are also easier to handle and they mask cylinder. She rarely performs exams under anesthesia but recommends having a kit ready if needed. It should include a retinoscope, trial lenses or skiascopy bar, diagnostic contact lens set, saline, sodium fluorescein, and handheld slit lamp. She recommends getting children behind the slit lamp as early as possible, even as early as four months of age (Figure 4). She performs most of her exams at the slit lamp under a blue light (a Burton lamp is not bright enough) and uses an LED flashlight for better viewing. (Try www.flashlightsunlimited.com for a low-cost supply.) When the child has grown and the eye is bigger, lenses will tend to pop out if they are too steep. Esotropia, increased intraocular pressure, center thickness >0.7mm, or excessive toricity with edge lift will cause lenses to pop out as well. If the lens is too flat, it will slide off. You should expect base curve radius changes at about 6 to 8 weeks of age, 4 to 6 months, and then 9 to 12 months. Be warned that at about 9 months, children will have learned how to remove the lenses themselves.
Figure 4. Get children behind the slit lamp as early as possible.
Pete Kollbaum, OD, PhD, found that wavefront measurement of keratoconic eyes as compared to normals has shown that levels of aberrations are two to five times higher in keratoconic eyes. This leaves room for much improvement with contact lens corrections, such as CooperVision's XC, which aims to induce no spherical aberrations on the eye. B+L and Ciba are also taking advantage of current technologies to fine-tune corrections for patients.
Carla Mack, OD, MBA, FAAO, shared that among a vision-corrected population, vision needs are of highest importance, according to results of the Needs, Symptoms, Incidence, Global eye Health Trends (NSIGHT) study. The survey of 3,800 patients, aged 15 to 65, spanned seven countries and asked patients to rank 40 different features from most to least compelling. Feature categories included personal appearance, convenience, environment, comfort, and vision, among others. Vision was the only category ranked as “most important” for each of three geographic regions and for both spectacle and contact lens wearers. Next was health and environment, with personal appearance ranking last. Of the top seven features rated, six were related to vision. The study shows that vision is highly important to patients around the world.
Contact Lens Complications
Buddy Russell, FCLSA, COMT, LDO, and Dr. Townsend joined forces to discuss contact lens complications. Competent contact lens prescribers should know when there's a problem, understand its nature, know what to do about it, know what to do if the first plan fails, and know what to do when the problem worsens.
Following are tips given by the duo:
● Solutions are guilty until proven otherwise.
● It may not always be a contact lens problem.
● Don't get so caught up in the eye that you forget to look at the lens.
● If patients are using two compatible products, ask whether they are putting something else into their eye. Patients don't know that this is important until you ask.
● Rechallenge with care solutions.
● Experience has shown that contact lens complications can be resolved 65 percent of the time by lens design changes, 20 percent of the time with care system changes, and 15 percent of the time through material changes.
See You Next Year
Contact lens practitioners are discovering that GSLS is one of the leading meetings for specialty lens research and information. Join us next year for the fourth annual Global Specialty Lens Symposium from Jan. 26 to 29, 2012, in Las Vegas. CLS
|Ten Billing and Coding Tips for Specialty Contact Lens Practice|
|John Rumpakis, OD, MBA, provided insight to a standing-room-only audience during one of the breakout sessions at the 2011 GSLS meeting:
1 Always tell the patient record why you're ordering or prescribing something.
|Ms. Bailey is a longtime editor and writer for ophthalmic publications. She has more than 20 years of ophthalmic experience and is based outside of Philadelphia. You can reach her at firstname.lastname@example.org.|