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