Article Date: 6/1/2004

dry eye
Getting Serious About  Dry Eye
BY DEEPAK GUPTA, O.D., Stamford, Conn.

Symptoms stemming from dry eye are more than a nuisance. The condition is a legitimate medical condition and is one of the more common reasons why patients visit us. As research in this area evolves, our management strategies will shift away from lubricating drops and ointments to treatments geared toward getting at root of the problem.

If you deal with dry eye patients, then one of the first things you want to do is to identify pertinent risk factors for developing the condition.

Know who's affected

Middle-aged women are particularly at risk for developing dry eye, as this population generally tends to have a higher incidence and prevalence of dry eyes. With all patients, look for dry work and home environments (e.g., those that heavily rely on heating and air conditioning units) and time spent working on computers.

Also find out if a patient is taking any systemic medications, such as antihistamines, antidepressants, anti-psychotics, hormone replacement therapy and oral contraceptives, which all can contribute to ocular dryness. Ask about a history of refractive surgery (LASIK procedures sever corneal nerves and contribute to corneal surface dryness). Don't forget to also ask patients about contact lens wear, which has been shown to decrease corneal sensation and disrupt the mucin layer of the tear film, thereby contributing to dry eyes.

Confirming your suspicions

Many tests are available to us for assessing tear function. The most commonly used tests in the clinical setting include the Schirmer test, phenol red thread test, fluorescein and rose bengal staining, tear break-up time (TBUT), tear meniscus height measures and corneal staining with sodium fluorescein. The major problem with most of these tests is that they lack repeatability. In addition, studies generally show a lack of association between test signs and patient-reported symptoms.

Other tests are more laboratory-based and are more precise measures of dryness. These include tests such as freezing point depression osmometry, lactoferrin microassay and fluorophotmetry. However, in the vast majority of cases, you can use the tests that are more easily available clinically, such as the Schirmer and fluorescein.

Regardless of which diagnostic technique(s) you use, once you've made your definitive diagnosis of dry eye syndrome, you need to initiate a treatment plan. This plan will vary depending on the severity, as described below.

Forging ahead with dry eye treatment

Even if you prescribe over-the-counter (OTC) medications, which you will for many patients, always underscore the fact that dry eye can develop into a serious medical condition and that each patient should always return for proper follow up.

When figuring out how to address your dry eye patients' needs, you have several treatment options from which to choose.

Restoring moisture in mild cases. Lubricating eye drops and artificial tears are appropriate for patients who have mild dryness complaints. They help to restore the compromised ocular surface to its naturally moist state. The number of OTC products that are available is staggering. Many of these products are functionally the same and quite a few dry eye patients will instill these artificial tears several times each day. And keep in mind that many patients run into problems with preservative sensitivity and keratotoxicity.

For these patients, you can try lubricant formulations that contain "disappearing" preservatives such as Refresh Tears (Allergan) and GenTeal (Novartis). Systane (Alcon) is a welcome addition to this category because it has demonstrated excellent efficacy with minimal effect on visual acuity. As an added bonus, samples have been easy to obtain through the manufacturer. Even though these products are OTC, giving samples to patients is good patient management and gives the patient first-hand knowledge about the products you recommend for him.

Adding nighttime moisture for more difficult dry eye cases. In more difficult cases of dry eye, you can keep a patient on his lubricating drops during the day and add a gel or ointment at bedtime. These supplements last longer, but may periodically blur patients' vision, which is why q.h.s. dosing is usually the best option. The one thing to watch out for here is that if your dry eye patient has accompanying meibomian gland dysfunction, then the use of thick gels and ointments may exacerbate an already oily tear layer and lid margin.

Introducing anti-inflammatories for severe or nonresponsive conditions. For patients who fall into this category, you'll want to use one of two options or a combination of both.

1. A short course of mild steroids (such as loteprednol etabonate 0.2% [Alrex] and loteprednol etabonate 0.5% [Lotemax]) to help manage the inflammatory nature of severe forms of chronic dry eyes. Both formulations of loteprednol do an excellent job of decreasing inflammation, but are far less likely to cause IOP increases. Once you've gotten the inflammatory process under control, taper steroid use and initiate a long-term management program.

2. In lieu of steroids, or in addition to steroid therapy, you can write the patient a prescription for Restasis (cyclosporine ophthalmic emulsion 0.05%, Allergan), which has demonstrated statistically and clinically significant relevant increases in Schirmer wetting at six months. The trials also showed a dramatic improvement in conjunctival Rose Bengal staining and corneal superficial punctate keratitis (SPK).

From a clinical standpoint, Restasis has also shown improvement in patients' subjective measurements of dry eyes. The drug is indicated in patients who have dry eye caused by ocular inflammation. It works by reducing the cell-mediated inflammatory responses of ocular surface disease, specifically activation of T lymphocytes. Thus, the drug downregulates the inflammatory response and allows those cells to recover their normal activity.

The most common side effects in the trials were ocular burning (roughly 17% of patients) and conjunctival hyperemia, discharge, epiphora, eye pain, foreign body sensation, pruritus, stinging and blurring of vision (1% to 5%). The only drawback to using this drug is that it can take a patient two to six months to realize its full therapeutic effects.

However, because you'll most likely prescribe Restasis for patients for whom other therapy has failed, your patients will be more receptive to taking a medication that may take one to three months to work. Plus, as an added bonus, by giving the patient an agent that needs a prescription, you underscore the legitimacy of dry eye syndrome as a potentially serious medical condition.

In many cases, you can start a patient on both the steroid and on Restasis and then slowly taper the steroid after several weeks once the Restasis begins to take effect.

And then there's the surgical option, which is really only recommended for patients who have severe dry eye.

Occluding the puncta. The first and most common surgical option you'll consider for dry eye patients are punctal plugs. In most cases, you'll start by inserting temporary collagen plugs in the lower punctum of both eyes. Once you've inserted the plugs, schedule the patient for a follow-up visit in 10 to 14 days. Many patients won't need lubricating drops at all after the procedure, and some will notice a decreased dependency on them.

Either way, have the patient keep track of his symptoms because the collagen plugs self-dissolve in three to seven days. If the plugs improved the patient's symptoms, then insert silicone plugs for long-term management. Remember that most insurance policies have a 10-day post-op period with punctal occlusion, so you should wait until that before you insert the silicone plugs.

In some instances, permanent plugs may recurrently dislodge, even with a proper fit. If this happens, then your patient might benefit from the second most common surgical procedure for dry eye: punctual cautery, in which you cauterize the puncta. Experts have developed many cauterization methods, but the most common methods are thermal and laser.

When all else fails. In severe and refractory cases of dry eyes, you may recommend tarsorrhaphy (suturing the peripheral aspects of the eyelids together to reduce the interpalpebral aperture). You'll typically want to save this for extreme cases and as a short-term measure to protect a compromised ocular surface.

A bit of homeopathy. One homeopathic treatment that's gaining recognition for managing dry eye is flaxseed oil. One tablespoon in the patient's juice of choice in the morning may provide some relief for dry eyes associated with a rapid TBUT. This mixture appears to reduce T cell lymphocyte proliferation. One problem that might limit the widespread clinical use of flaxseed oil is the side effect of transient facial acne.

Testosterone for your eye. Based on the large body of evidence of the positive influence of androgens on the lacrimal gland-ocular surface unit, Allergan is investigating the use of topical testosterone eyedrops for managing dry eye. These studies are now in Phase II FDA trials.

Inspire's upcoming dry eye drug. Lastly, clinical trials are underway for Inspire Pharmaceutical's INS365 Ophthalmic for the treatment of dry eye. INS365 is a small-molecule drug that stimulates the P2Y2 receptor, a key mediator of mucosal-surface hydration and lubrication. This new product enhances the eye's natural cleansing and protective systems by stimulating the release of salt, water, mucus and other natural tear components. Doing this should increase hydration and lubrication of the ocular surface and decrease patient complaints. A recent study also showed that INS365 may promote corneal integrity by inducing the production of a mucin-like glucoprotein in the dry eye rabbit model.

Get it under control

Treatment choices abound for dry eye. There's no reason for your patients to suffer. Make sure you ask about dry eye symptoms in the patient history and that you convey the importance of treatment to your patients. Taking this condition seriously and finding a treatment that works for each individual will speak volumes about you to your patients and to everyone they talk to.

References available on request.

Dr. Gupta practices full-scope optometry and is clinical director of the Optometric Glaucoma Referral Center. Contact him at deegup4919@hotmail.com.

 

 



Optometric Management, Issue: June 2004