And according to reports from top clinicians, these new tools are helping. They say they can more accurately diagnose the cause of dry eye in a given patient, and then make changes or recommendations that increase the chances of successful lens wear.
“This is really an exciting time in terms of managing dry eye,” says Milton Hom, O.D., a contact lens researcher and private practitioner in Azusa, Calif. “For years, we didn’t have that many treatments to offer patients, and what
we had to offer was largely palliative. Now, we’re on the cusp of a revolution.”
“Even in patients with significant dry eye, we can keep 90 percent of them in contact lenses,” asserts corneal specialist Henry Perry, M.D., Long Island, N.Y.
These doctors and others say the key is to fully understand what we now know about dry eye syndrome, as well as new products and techniques. Experts say they succeed best with strategies tailored to the individual.
“Dry eye is such a heterogeneous disease. It doesn’t mean one set of signs and symptoms. The patient’s eye can look rotten and feel good, or look good and feel rotten. The doctor has to tailor the treatment regimen,” notes Norfolk, Va. ophthalmologist John Sheppard, M.D.
Following are five steps that clinicians say may help you to counter dry eye more effectively in your contact lens patients.
And Consider the Big Picture.
So much research has been done on dry eye syndrome that it can be overwhelming to sort out. A recent literature search limited to dry eye studies published in 2002 and 2003 produced 335 citations. But doctors urge colleagues to review research to get a handle on the “big picture.”
“Probably the most significant new finding is the role of androgen with the lacrimal gland,” notes Dr. Hom. Androgen maintains the integrity of the lacrimal gland, and also provides normal meibomian production. When androgen is deficient, the lacrimal gland is not protected from inflammatory processes, which will often lead to aqueous tear deficiency.
A new prescription drop, Restasis from Allergan (see “Prescription drugs” below), directly addresses inflammation of the lacrimal gland. “Cyclosporin is the active ingredient. It stops inflammation, takes a burned-out lacrimal gland, rehabilitates it, and allows it to function properly,” says Dr. Hom.
Today’s new products are based on research completed a few years ago. Research being completed now can provide insight into treatments that will become available in the next few years, experts say.
“Thanks to research, we’re beginning to understand more about the true etiology of dry eye,” says Dr. Perry. “Restasis is a new treatment that treats the actual mechanism of dry eye. There will be a whole host of these drugs that will give us better diagnosis and treatment options.” Here’s a quick overview of recent published research:
Measurement of lipid layer thickness is a reliable diagnostic test for dry eye. Forty-four patients had dry eye signs and symptoms. Subjects were assessed with two frequently used dry eye tests, fluorescein break-up time and Schirmer’s test with anesthesia. Some patients showed both aqueous and lipid deficiency.’
Castor oil eye drops are effective and safe in the treatment of meibomian gland dysfunction (MGD), a major cause of lipid-deficiency dry eye. All twenty study subjects had noninflammed MGD. The drops appear to improve tear stability by spreading lipids, easing meibum expression, preventing tear evaporation, and lubricating the eye.’
Dry eye symptoms are common after myopic LASIK surgery. LASIK in 58 consecutive patients (96 eyes) significantly altered the tear break-up time, Schirmer test values, and basal tear secretion. Patients with preexisting tear flow abnormality
(Schirmer test values less than 10 mm) are especially at risk of experiencing dry eye symptoms.’
Blurry vision can be a sign of dry eye syndrome, according to a study from the Indiana University
School of Optometry. When tears are not functioning properly (as demonstrated by tear break-up), patients experience a decline in image quality, expressed as blurry vision complaints.4
A new diagnostic test, fluorescein meniscus time (FMT), is better for testing aqueous tear deficiency than the Schirmer’s test. FMT is a measure of the rate at which a fluorescent tear meniscus is formed using 2% sodium fluorescein, a stopwatch and suitable illumination with a slit lamp. Sixty-two patients with rheumatoid arthritis and dry eye symptoms were tested, along with 51 control patients. A separate control group of 15 patients was tested three times to establish reproducibility.5
Nearly 11 percent of 1,584 optometric patients have dry eye syndrome. Dry eye was found in 18 percent of patients above age 40. Lipid-deficiency dry eye was the most common type of dry eye, followed by aqueous tear deficiency, lid surface/blinking anomalies and allergic/toxic dry eye. Patients over 40 had a higher prevalence of lipid dry eye and allergic/toxic dry eye. Women were more likely to have allergic/toxic dry eye than men.6
One of the most important steps in treating dry eye syndrome is differentiating contact lens related dry eye from allergic dry eye and pathological or “true” dry eye. The correct diagnosis will point you toward management options that are most likely to succeed.
“The first thing you have to do is listen carefully to the patient’s complaint. Do they talk about burning, foreign body sensation, contact lens sensation, or itching?” asks Dr. Perry.
“Most of my differentiation comes from the history,” adds Dr. Hom, “but you cannot rely entirely on that.” For instance, he says, many patients do not know they have allergies. “The hallmark is itching, especially seasonal itching, but this can occur at any time in the year.”
Certain complaints will indicate a general direction, clinicians say:
Itching often indicates allergy.
Dryness only when wearing contact lenses points to contact lens-related problems.
Awareness of the eyes indicates pathological dry eye. GPC indicates contact lens intolerance.
Your differential diagnosis should include tear film break-up time, as measured by the time it takes for flourescein pattern to disperse (5 to 10 seconds is normal).
“If you see punctate keratitis, it’s a significant condition and will require much more planning,” warns Dr. Perry.
Along with tear film break-up, Dr. Perry says clinicians should perform a Schirmer strip test, measuring tear flow over a five-minute period. In more difficult cases, clinicians may perform a Schirmer with anesthesia test, which eliminates reflex tearing, or even a Schirmer 2 test, in which a nasal plegette is inserted to determine if the patient has reflex tearing.
If your diagnosis is not entirely clear, experts urge you to make an educated guess and see what happens.
“You don’t have to reinvent the wheel,” says William Potter, O.D., of Freehold, N.J. “If you change modalities of lens or care products, and still have similar symptoms, you probably have `true’ dry eye. Of those with `true’ dry eye, you only have a 50-50 chance of success with contact lenses. You have a much higher chance for success with contact lens-related dry eye problems.”
Consider Switching Lenses or Solutions. Many dry eye patients will benefit from a change in lens material, frequency of lens replacement, and/or lens care products.
“My first choice is to switch to the Proclear lens by Cooper. 1 would say 80 percent of dry eye patients prefer it to their previous soft lenses in comfort. It seems to provide more wearing time, too,” Dr. Potter says.
Proclear Compatibles are made of omafilcon A, the only material that is labeled by the FDA as follows: “may pro
vide improved comfort for contact lens wearers who experience mild discomfort or symptoms related to dryness during lens wear.” Studies sponsored by CooperVision indicate that the material retains 96 percent of its water content after 12 hours of wear, and that patients wearing Proclear lenses showed the least change in the lipid layer of tear film.
“Proclear’s material and technology was originally developed for cardiovascular stents. It had to be extremely biocotmpatible. The biocompatibility of
Proclear keeps the lens extremely clean.
The lens also stays wet, which helps to keep the lens clean and comfortable,” explains Nikki Iravani, O.D., Director of Professional Relations for CooperVision.
A care product that claims to benefit dry eye patients is Alcon’s Opti-Free No Rub contact lens solution. Studies sponsored by Alonn indicate that more patients who used Opti-Free No Rub described their lenses as comfortable at the end of the day than patients who used another brand of care product.
“Opti-Free has a unique, tetronic chemistry that shields the lens against deposits. With reduced deposits, the lens stays wetter, and patients feel more comfortable,” Dr. Potter says.
In some cases, the patient may benefit from taking a temporary break from contact lens wear, particularly if they have signs of GPC.
“When anything is placed in the body, it forms a biofilm,” says Dr. Perry. This biofilm rests on the surface of the contact lens. People can become allergic to biofilm or intolerant of it, and develop GPC. Dr. Perry’s recommendation is to stop lens wear for three months because the lymphocytes (cells that “remember” this allergy) only live for 110 days. “When the patient resumes contact lens wear, there will be fresh lymphocytes,” he says.
At the time the patient resumes lens wear, Dr. Perry will consider switching to a lens made of a different polymer, and may also prescribe Restasis, which is antilymphocytic.
Contemplate the Power of Artificial Tears. This product category is booming, and it’s no wonder. Worldwide, some 60 million people use artificial tears, according to Allergan, Inc. Clinicians say these products are helping to keep patients
in contact lenses.
Systane is the newest offering from Alcon. Its unique component is HP Guar, a naturally-occurring substance that alters the pH of the tear film, and “thickens” the tears.
“This gives the tears `staying power,’ without blurring vision,” says Dr. Potter, who is conducting a study of Systane for Alcon. “It promotes wetness, and was originally used in another Alcon care product, Unique pH, for RGP lenses.”
A colleague who participated in the FDA clinical trial for Systane says his dry eye patients benefited from it. “None of the patients in my practice had severe dry eye, but the moderate dry eye patients loved Systane. Many of them had been self-medicating, and never found anything that helped them,” says John Rinehart O.D., of Peoria, Ariz.
Both the FDA study and Dr. Potter’s current study are with dry eye patients who do not wear contact lenses (Systane is not labeled for use with contact lenses). Dr. Potter says he has used Systane as a preconditioner to contact lens wear, and at nighttime, when contact lenses have been removed. In a few cases, he’s recommended offlabel use during contact lens wear.
“We’re tried it with RGP lenses and soft lenses. We’ve had the best effect with RGP lenses. The patient feels more comfortable when wearing lenses, but does not achieve additional wearing time,” he notes.
Although Dr. Potter praises Systane as a treatment for dry eye syndrome, he says it’s too early to predict if the product will help to keep dry eye patients in contact lenses.
“I only have a dozen or two reports to go on. We’ve used Clerz Plus as our lubricating drop for contact lens wearer. Clerz has cleaning action, which Systane doesn’t have or show at this time,” he says.
Clinicians say Refresh, a whole line of artificial tears from Allergan, have benefits for contact lens wearers. Refresh comes with or without preservatives, and in several viscosities. The most viscous, Refresh Endura, is an emulsion that Allergan claims will help patients with moderate to severe dry eye.
Says Dr. Sheppard: “Variety is the key to success with dry eye patients, and Refresh offers this, from very thin, less viscous solution to thick and quite viscous emulsion.” The thin product gives moderately long duration for mild dry eye. For severe dry eye, Dr. Sheppard recommends Endura, an emulsion that contains all three of major components of tears: water, mucin and oil. “Patients will use this a couple of times during the day, or at night,” he says.
Refresh contains carboxymethylcellulose (CMC), which has been shown to bind to PHMB, a preservative found in some lens care products. Dr. Sheppard points out that studies sponsored by Allergan indicate that the use of Refresh “on a lens or in the eye prior to lens insertion may protect the eye from disinfectant-related ocular insult.”
“All contact lens wearers need more tears, and if they have dryness symptoms, any irritation bothers them more. CMC neutralizes trace amounts of preservative, which over time, causes irritation in the eye,” says Dr. Sheppard.
Other new products that may help are TheraTears Nutritional for Dry Eye, which contains flaxseed oil, and TheraTears LiquiGel for Bedtime, which provides electrolyte balance while the patient sleeps.
Clinicians also praise products that have been on the market for a while, such as Blink-N-Clean and Clerz Plus. “If a patient has dryness problems, these are useful tools,” says Dr. Hom. He uses both with contact lenses and says that the in-the-eye cleaners do not cause red eye or adverse reactions. “The manufacturers have fine-tuned cleaners to make them safe and gentle. These products maintain cleanliness, and there’s a direct correlation between dirty lenses and dryness symptoms.”
Prescribe the Appropriate Drugs and Employ Other Techniques as Needed. Restasis is the biggest news in prescription drugs. Although it is not approved for use while wearing contact lenses, doctors say it reduces dry eye symptoms, enabling some patients to continue contact lens wear.
“In a contact lens patient with true dry eye, I use Medennium SmartPlug, a punctum plug that is totally inside the puncta, and nonpreserved artificial tears,” says Dr. Perry. He also uses Restasis following lens removal.
Allergan makes these additional points about Restasis: It treats inflammation, an underlying cause of dry eye syndrome.
It is thought to act as a partial immunomodulator, although its exact mechanism of action is unknown.
Formulated as an eye drop, the recommended dosage is one drop in each eye twice a day approximately 12 hours apart.
It can be used concomitantly with artificial tears (allowing a 15-minute interval between products), and may decrease the need for artificial tears.
Dr. Rinehart says there’s another way to restore meibomian function that has worked well for his patients. He recommends warm compresses and lid massage to express meibomian glands. During the time it takes to restore meibomian function, the patients supplement with artificial tears.
Another prescription drug, Alocril from Allergan, benefits patients whose dryness is related to ocular allergies. This second-generation mast-cell stabilizer prevents the release of mediators (histamine and chemotaxin) responsible for the allergic response. A study sponsored by Allergan shows that allergy patients who used Alocril every 12 hours were able to wear their lenses longer than patients who used artificial tears.
Allergan makes these additional points about Alocril: It provides fast relief of itchy eyes.
It provides continuous symptom relief during the 12hour dosing period.
It can be used by all patients, including children under the age of three.
In general, experts say, today’s tools are much more effective in managing dry eye and keeping these patients in contact lenses. They look forward to new products in just the next few years.
“Comparing past products with products now is like comparing a pogo stick with a jaguar,” asserts Dr. Sheppard. “We just had water with electrolytes before. Now we have much more sophisticated products, the biochemistry is far more sophisticated, and we have more variety.”
1. Isreb MA, et al. Correlation of lipid layer thickness measurements with fluorescein tear film break-up time and Schirmer’s test, Eye, 2003, Jan.17(1), 79-83.
2. Goto E, et al. Low-concentration homogenized castor oil eye drops for non-inflamed obstructive meibomian gland dysfunction. Ophthalmology, 2002 Nov; 109(11):2030-5.
3. Yu EY, et al. Effect of laser in situ keratomileusis on tear stability, Ophthalmology, 2000, Dec; 107(12):2131-5.
4. Tutt R, et al. Optical and visual impact of tear break-up in human eyes. Invest Ophthalmol Vis Sci 2000 Dec;41(13):4117-23.
5. Kallarackal GU, et al. A comparative study to assess the clinical use of Fluorescein Meniscus Time (FMT) with Tear Break up Time (TBUT) and Schirmer’s tests (ST) in the diagnosis of dry eyes. Eye 2002 Sep;16(5):594-600.
6. Albietz JM. Prevalence of dry eye subtypes in clinical optometry practice. Optom Vis Sci 2000 Jul;77(7):357-63.
Contributor: Judith Lee