Article Date: 1/1/2006

contacts
Contact Lenses for Your Over-40 Patients
How the latest advances in lenses can help patients who have presbyopia.
BY BARBARA ANAN KOGAN, O.D., Washington, D.C.

Eye care practitioners around the country claim that the prospects for presbyopic contact lens wearers have never been better. "Maintaining binocular vision well into presbyopia can be achieved by the now 80% successful fitting rate with bifocal contact lenses," says Ed Bennett, O.D., M.S., Executive Director of the Contact Lens Manufacturers Association's (CLMA) educational division, the GP Lens Institute.

Whether the choice was bifocal lenses or monovision, keeping presbyopes in contacts hasn't always been so easy. Contact lens wearers complained of discomfort and decreased quality of vision. It was also a challenge to fit new contact lens wearers with comfortable lenses that provided clear vision.

Facing up to the challenges

According to Rex Ghormley, O.D., of St. Louis, prior to the advent of silicone hydrogel contact lenses, "Patients would complain about reduced wearing time every day, and chronic redness and dryness, especially the over-40 patient suffering from topical and systemic medication-induced disruptive corneas."

Dry eye-related contact lens discomfort and reduced tear film quality/quantity often are caused by therapeutics such as hormone replacement therapy, anti-depressants, allergy and cardiovascular medications.

Earlier contact lens manufacturing technology was not always able to provide both clear distance, intermediate and especially near visual acuity in a multifocal contact lens. "Tweaking" the contact lens design or prescription was challenging, as was selecting pre-manufactured base curves, diameters and prescriptions in soft materials. While GP materials were primarily custom-designed, there were fewer but similar challenges in providing visual clarity at all distances. The problems often resulted in refunds, contact lens dropouts and lost patients.

Challenges overcome

Lens materials have improved greatly over the past few years, allowing us to keep our patients in contact lenses longer.

One of the most significant developments has been silicone hydrogels. "Silicone hydrogels were a breakthrough in new technology after 20 years of not much change in the soft lens market, to now providing five to six times more oxygen to the eye, and allowing for healthier, whiter eyes," Dr. Ghormley says.

Higher oxygen transmission reduces corneal edema even to the endothelial layers. This results in a much more comfortable contact lens that can be worn for many more hours. Presbyopes are more prone to dry eyes and allergies. Silicone hydrogels' high-Dk enables it to maintain oxygen transmission during closed-eye conditions.

The number of normal blinking tears a patient produces decreases with age, which creates a less wettable tear film for presbyopes. Silicone hydrogels' high-Dk and material chemistry provide a more wettable eye and keep the contact lenses lubricated. This allows for contact lens movement with blinking. It also helps avoid: contact lenses stuck on the eye, pockets of dry areas as seen under the biomicroscope, reduced comfort, reduced visual clarity, the need to use rewetting drops frequently, and the use of saline.

This is important for presbyopes who often take medications for allergies, hormone replacement therapy (HRT) and other conditions that make them more prone to dry eye.

GP materials have advanced as well. Dr. Bennett, a clinical researcher who's also studied GP comfort, says: "GP materials have modified the amount of silicone acrylate and additional wetting and comfort properties, such as now providing hydrogel capabilities combined with GP materials. Using hybrid materials ... provides additional wetting and comfort properties." He adds, "Lathing technology techniques can provide graded power options and better contrast sensitivity in multifocal designs."

Dan Bell, president of both CLMA and of Corneal Design laboratory, finds that "A combination of more manufacturing methods and greater oxygen permeability has significantly increased both GP comfort and vision, while the surface treatments are more hydrophilic and [wettable]. Additionally, laboratories have eliminated many of the non-wettable ingredients, such as waxes."

Hyper-Dk is the fastest growing GP material for continuous wear and existing refits of current GP wearers. Hyper-Dk GP material minimizes corneal epithelial changes, as seen in confocal microscope studies.

Additional presbyopic toric designs. While traditional GP materials cover low to moderate amounts of astigmatism, many CLMA-member labs provide consulting for custom GP front- and back-surface, as well as bi-toric presbyopic designs in many parameters and materials.

National sales manager of Blanchard Contact Lens Inc., Lee M. Buffalo says of current toric custom designs, "Differing focal lengths create gradual radius changes that provide multiple radii. This provides the necessary powers throughout the contact lens's asphericity. These radii keep presbyopes in bifocal contact lenses into their mid 60s."

Disposable materials and wearing options. Disposable daily- and extended-wear lenses allow practitioners to offer binocular, bifocal contact lenses, especially for the more active and younger presbyope, says Derrick L. Artis, O.D., M.B.A., Director of Professional Affairs for Vistakon.

Fitting tips

Presbyopes are at increased risk for dry eye. For medication considerations, check your PDR frequently, as well as the local pharmacy for dry eye side-effects prior to selecting lens material and solution. Also, schedule follow-up office visits, and advise the patient to contact your office if dry eye symptoms occur.

When it comes to fitting, Jon Walker, O.D., M.S., of Jacksonville, advises "not grabbing too high an add too early in presbyopia years." His rule-of-thumb for a bifocal disposable soft contact lens is this: +1.00D for patients 46 to 47-years old, even up to 48; +1.50D to age 54 and +2.00D for patients over 54.

"Keep the add power on the non-dominant eye for distance versus changing the add power at near." To avoid failures, Dr. Walker uses his "real world" test: Have the patient look far, then near, then go outside for 40-45 minutes to experience what the vision is like. Then have the patient return to your exam room chair for a subjective opinion, as well as objective distance, intermediate and near visual acuity evaluation, and a slit lamp evaluation.

Diane Robbins-Luce, O.D., associate professor of practice management at Pacific University College of Optometry and private practitioner, recommends asking the patient more specific questions about eye health, visual demands, work space lighting, computer screen distance and viewing time, hobbies or sports. She recommends presenting GP multifocal/bifocal lenses in a positive manner with benefits tied into lifestyle.

With more challenging fits, discuss prescription, topography, or size of cornea to help patients understand the customization, lens exchanges and time needed to complete the fitting process. Better informed patients, Dr. Robbins-Luce says, understand limitations of lens designs and are more likely to accept vision that's not absolutely the clearest at all distances. They also see the value in higher professional fees.

Have fitting sets and modification tools at hand: This helps decrease follow-up visits. These tools also become the tangible measure of your expertise for patients, helping you center a lens better and increase visual acuity by one or two lines.

Patient education pearls

Sonja Biddle, O.D., of Dover, Del., says her first rule is listening to patient expectations, wants and needs. She recommends addressing price as well. Early on, tell the patient an approximate price range for: custom-designed bifocal GP lenses versus a set parameter soft lens fit; follow-up visits; material cost; approximate visits to complete the fit.

Doug Becherer, O.D., of Belleville, Ill., advises beginning the education process before presbyopia strikes. "Prepare patients for presbyopia by educating them about it in their late 30s so they become 'current' with multifocal options, how near vision changes and visual acuity is preserved." Explain that presbyopia did not happen overnight, but took years to develop. A more knowledgeable patient will more likely understand that it takes longer to adapt to the new prescription, just as it does with bifocal eyeglasses.

Mary Jo Stiegemeier, O.D., of Beachwood, Ohio, concurs with the "educate early" approach. She claims that patients approaching presbyopia are worried about the end of contact lens wear. It's often easy to introduce to multifocal lenses' advanced technologies.

Last but not least

Finally, don't forget to educate patients about the importance of solutions in their contact lens-wearing experience. Ocular irritation, redness, itching, or burning are among the adverse events from preservatives in some contact lens solutions for both GP and soft contact lens materials. Reactions from care products can cause contact lens dropouts. You can help patients avoid these problems through education and re-education at each office visit to follow your recommendations for their contact lens solutions. Warn the patient that using different solutions can induce discomfort, dryness and reduced visual acuity from dry spots on the contact lens.

A GP care system is recommended for use with several GP materials. It is extremely important to warn patients about the chance of acquiring an ocular infection from topping off the storage solutions in an unclean contact lens case. Even for long-time contact lens wearers, you must re-emphasize the use of an oil and perfume-free hand-washing soap and a lint-free hand drying cloth. Both long-time wearers and first-timers should receive these instructions at contact lens dispensing and at every office visit.

Dr. Anan Kogan has published over 125 contact lens articles. This presbyope's referral-only practitioner's focus was binocular vision with contact lenses and/or vision therapy. She served on the AOA Contact Lens Section's public information committee from 1985-1988.



Optometric Management, Issue: January 2006