There is ample evidence that the topical agents used to treat glaucoma are associated with an increased prevalence of ocular surface disease (OSD) and the associated typical signs and symptoms of dry eye disease.1-6 In addition, because glaucoma and dry eye disease are both associated with increasing age, it is highly likely that patients with glaucoma coincidentally also have dry eye disease. This discussion reviews the basics of diagnosing and managing OSD.
DIAGNOSIS
To diagnose and manage OSD in your glaucoma patients,
start by being suspicious. Inquire about symptoms. Ask
patients if they have any ocular irritation or consider using a
dry eye questionnaire such as the Ocular Surface Disease
Index that they can complete in the waiting room before
their eye examination.
During the slit-lamp examination, look for signs of OSD. One approach is corneal staining with fluorescein. It is important to use more than the typical amount for application measurements. Wet the strip and then apply it to the sclera. A second, readily available diagnostic test is to perform lissamine green staining of the conjunctiva. You can also assess the quantity of the tear film along the lower lid margin and measure tear breakup time.
Do not forget to evaluate the patient's eyelids! Meibomian gland dysfunction can cause the tear film to break up due to changes in the lipid layer. Check for neovascularization of the eyelids and abnormal meibum. Applying gentle pressure on the lid with your finger or a cotton swab will reveal whether the gland expression is clear, thick and opaque, or absent. Also consider lid function—the blink and possible lagophthalmos.
TREATMENT
Treatment starts with acknowledging patients' symptoms.
Let them know that you understand that their
chronic irritation or pain and fluctuating vision are real
problems and that you can treat the OSD to help decrease
these difficulties.
Consider which eye drops the patient is using. Can you eliminate or decrease his or her exposure to benzalkonium chloride? Can you decrease the number of drops he or she needs? Be sure to ask the patient about over-the-counter drops he or she may be using, since they can contribute to OSD, especially if they are preserved with benzalkonium chloride .
You may want to prescribe artificial tears for regular use. If so, select brands that have “soft“ preservatives or unit dose preparations without preservatives. Suggest the patient use artificial tears every day to keep the ocular surface healthy rather than wait for the symptoms of OSD to occur. Bear in mind that not all artificial tears are alike; in addition to the preservative used, they differ in their composition, viscosity, and mechanism of action.
If the patient has significant lid disease, warm soaks and lid scrubs can help. You may also wish to consider artificial tears. If you think there is an element of exposure, instruct the patient to apply before sleep a lubricating gel or ointment or to use Lacrisert (Aton Pharma, Inc.). The last is a tear pellet that melts once placed in the inferior cul de sac of the lower eye lid. Another option is Restasis (cyclosporin ophthalmic emulsion) 0.05% (Allergan, Inc.), which may improve tear production, but inform the patient that several months may elapse before he or she will notice an improvement. Most ophthalmologists try several modalities to treat OSD; for the more severe findings, doctors reported trying five different treatments per year on average.7
CONCLUSION
Treating OSD is challenging, so plan to try a few
approaches to see what works best for each patient.7 He or
she will appreciate your concern for the “whole” patient versus
a focus solely on the IOP reading or visual field results.
Moreover, when the patient begins to feel better, it may be
more likely that he or she will take his or her glaucoma
medications as prescribed.
