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Expanded parameters, new designs make specialty contact lens fitting easier
Contact Lenses and Eyewear
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An increase in the number of patients who are candidates for specialty contact lenses is closely matched today by an increase in available lens designs. These patients seek contact lenses to address astigmatism, presbyopia, dry eye or keratoconus, as well as to correct regression following refractive surgery or as part of corneal disease treatment.
In this overview of the newest in specialty contact lenses, three clinicians tell Primary Care Optometry News that expanded parameters, improved designs for keratoconus and higher Dk levels have meant more successful soft lens and rigid gas-permeable (RGP) lens fits for patients.
This practice fits many RGPs
Robert M. Grohe, OD, in private practice in Homewood, Ill., outlined what he sees as the top developments in specialty contact lenses. About 40% of his practice is made up of contact lens wearers. While RGPs hover at 10% to 12% of the contact lens market nationally, Dr. Grohe said about 35% of all fits in his practice are RGP lenses.
"In the institutional setting, the lens of choice is almost always a specialty contact lens because of the nature of the patients we see," said Dr. Grohe.
In particular, Dr. Grohe has seen growth in the area of fitting patients following radial keratotomy, photorefractive keratectomy or laser in situ keratomileusis. "These are patients who have some degree of regression following refractive surgery," he said.
Dr. Grohe also named expanded parameters as the top development in specialty lenses in the past year. "Companies have helped practitioners and patients by debuting expanded parameters into existing lines."
According to Dr. Grohe, the approval of Biocompatibles' Proclear Compatibles as the first contact lens indicated for dry eye "indirectly suggests that fitting contact lenses is more than just placing a lens on the eye."
One of the new specialty lenses Dr. Grohe has used with patients, the Boston EO (Polymer Technology), has performed nicely. "It works with any existing RGP patients," he said.
An addition to the daily disposable contact lens market, Focus Dailies from Ciba Vision, works well as an add-on product with some current disposable lens patients, Dr. Grohe said. "We have not quite had the success sometimes suggested in terms of recruiting new patients to wear daily disposables," he said, "but I think, as time goes on and costs are adjusted, we will see that change."
The Rose K lens system (Lens Dynamics), which uses Boston ES material, "is an exciting design because it's a new addition to fitting keratoconus patients," Dr. Grohe said.
Another development that has affected the way Dr. Grohe dispenses lenses is how specialty lenses fit into managed care plans. "There is probably not a practice in the country that hasn't noticed the effect of managed care on the contact lens practice," he said. "Copays can be smaller, and an emerging problem in the contact lens field is prior authorization for specialty contact lenses."
This may be highlighted best, he said, in the area of keratoconus, where patients may go through weeks or months of delays and rejections because this condition is not understood by insurance companies. "The best thing a specialty contact lens fitter can be aware of is that there is a greater level of care that needs to be exercised when writing a contact lens prescription for a specialty lens," Dr. Grohe said.
Bifocal fits on the rise
Stuart Bark, OD, is senior partner in a private group practice in Scottsdale, Ariz. Dr. Bark fits piggyback lenses and prosthetic soft lenses for damaged corneas or damaged irises. He will also fit for modified monovision with a bifocal in one eye and single vision lens in the other. "It's nothing special," he said, "but I have had patients who said they have seen several doctors and no one mentioned these other options. I think sometimes a doctor will try one or two lenses and then tell patients they are not good candidates for contact lenses."
Dr. Bark also manages keratoconus patients, post-refractive surgery patients and those who have undergone penetrating keratoplasties. About 20% of his fits are RGP lenses; the bulk of contact lens wearers he sees want soft lenses. "We prescribe a lot of disposables just because we've seen a significant reduction in contact lens complications such as red eyes or giant papillary conjunctivitis," he said.
Most of Dr. Bark's new fits are in the bifocal design category. "The biggest population opportunity is the baby boomers," he said.
In the RGP category, the SF-P bifocal from Menicon has emerged as Dr. Bark's favorite choice while, in the soft lens category, Soft Sight from Unilens "seems to work the best, although it's not a disposable." The difficulty in fitting RGP lenses, he said, is that the approach works well with simultaneous vision for emerging presbyopes but can become disturbing for the patient when more add is needed because alternating vision lenses (which provide higher adds) move when reading, which becomes bothersome to the patient.
Also in the soft lens category, Ultra Vue bifocal from Acuity One has shown potential, he said. "It's a different design, a reverse geometry lens with a central and peripheral zone. On the dominant eye, you use the central distance and peripheral near, but on the nondominant eye, you use the central near and peripheral distance," Dr. Bark said.
Already a fan of Dk levels in the 50s and 60s, Dr. Bark said Dk levels that reach into the 80s and beyond have not found a niche in his practice. "I am getting good results with a Dk of 50 or 60, and as I get into the higher levels there's a trade-off between permeability and wettability," he said. "If you go back to basic hard lens fitting philosophy and if you get the tear flow and tear pumping, DK is important but not as important as everyone would like us to believe."
Meanwhile, developments in disposable lenses, especially daily disposables, have opened the door to many new potential wearers as well as to contact lens drop-outs who want to try them again.
In the future, Dr. Bark said he would like to see a better soft bifocal lens developed. "The science is there, but I'm not sure that's a possibility because I am not sure that soft lenses are really conducive to bifocal wear," he said. "The gas permeables are conducive because they move, but that creates another problem for some patients."
Expanded parameters with the Soft Perm lens (Wesley Jessen) for keratoconus fits would also be a welcome addition, Dr. Bark said. "It's not a lens many people use, but I have really good success in keratoconic patients with it," he said. "Sometimes the hard optic zone fits well, but the soft peripheral skirt does not. "
Reverse geometry succeeds
Patrick J. Caroline, COT, assistant professor of optometry at Pacific University in Forest Grove, Ore., works in a referral contact lens practice and said the bulk of specialty design work being done today is through Flexlens, a subsidiary of Paragon.
"We predominantly do specialty contact lens work and have used virtually every design by Flexlens on our patients," Mr. Caroline said. "The soft lens materials today are all quite similar, but the key differences can be found in the design and application of the materials."
Mr. Caroline agrees that the Rose K lens system for keratoconus is one of the top developments in specialty lenses recently. "It's gaining momentum, and we have more than 150 patients in the Rose K design," he said. "The Rose K and the OK lens from Contex are both primary lenses of choice for keratoconus."
Mr. Caroline also manages post-refractive surgery patients and does this successfully using reverse geometry de signs. "These designs have a relatively long history of being used in orthokeratology, but we use them frequently in our post-surgical patients who have had decentered corneal ablations," he said.
Looking ahead, Mr. Caroline said he expects the United States to one day take a page from other countries when it comes to lens manufacturing. "There are lenses being manufactured in Europe that allow you to vary the eccentricity of the lens in various zones," he said. "That will have an impact on specialty RGP lens design because if the cornea steepens down below, you could make the bottom portion of the lens steeper. If the cornea flattens above, you could make that area of the lens flatter."
For Your Information:
- Stuart Bark, OD, may be contacted at 868 East Becker Lane, Ste. 103, Scottsdale, AZ 85354; (602) 991-2157. Dr. Bark has no direct financial interest in any products mentioned in this article, nor is he a paid consultant for any company mentioned.
- Patrick J. Caroline, COT, may be contacted at Oregon Health Sciences University, Casey Eye Institute, 3375 S.W. Terwilliger Blvd., Portland, OR 97201; (503) 494-4519.
- Robert M. Grohe, OD, may be contacted at 18019 Dixie Hwy., Homewood, IL 60430; (708) 799-2020.
- Neither Mr. Caroline or Dr. Grohe disclosed whether they have a financial interest in any products mentioned in the article or if they are paid consultants for any companies mentioned.
- Boston EO and Boston ES are available from Polymer Technology, a Division of Wilmington Partners L.P., Rochester, NY 14692-0450.
- Flexlens products are available through Paragon Vision Sciences, (800) 528-8279.
- Menicon may be contacted at (800) 636-4266.
- The OK lens is available from Contex Inc., (800) 626-6839.
- Proclear Compatibles Eyecare is available from Biocompatibles Eyecare Inc.; (978) 640-4999.
- The Rose Keratoconus lens system is available through Lens Dynamics Inc., (800) 228-2691.
- SoftPerm is available from Wesley Jessen Corp., 333 East Howard Ave., Des Plaines, IL 60018-5903.
- SoftSight is available from Unilens Corp. USA, (800) 446-2020.
- UltraVue lens is available from Acuity One LLC, 7642 E. Gray Rd., Scottsdale, AZ 85260; (877) 228-4891.