Article

CONTACT LENS DESIGN & MATERIALS

DRY EYE OR ALLERGIES?

Contact lens wearers can present with many symptoms, of which “dryness” is a common contributing factor in creating contact lens dropouts, so practitioners are continually trying to figure out how to reduce lens-related dryness and make patients more comfortable.

Another common problem that creates comfort issues for patients is ocular allergy. Allergies can come from many sources, including dust, chemicals, pet dander, mold, and pollen. Even though allergy symptoms are a little different from those of dryness, it can be unclear what the underlying cause of a patient’s problem is. Before making any recommendations, we should differentiate between dry eye and ocular allergies.

Dry Eye

Dry eye is a complex disease, often exacerbated by contact lens wear. Evaporative dry eye is worsened by contact lens wear because the lens disrupts the normal tear film structure. This, in turn, decreases tear film stability and causes the tears to evaporate at a faster rate. Aqueous-deficient eyes often don’t have enough tear volume to maintain surface hydration of the contact lens, resulting in a dry lens surface that becomes increasingly uncomfortable throughout the day.

Dry eye testing should include vital dyes (e.g., fluorescein, lissamine green), tear breakup time, tear volume estimation, and meibomian gland expression. Tear osmolarity may also be helpful in making the proper diagnosis. On examination, the eye may have bulbar conjunctival hyperemia, punctate staining (typically inferior-centrally on the cornea and conjunctiva), and lid wiper staining of the upper lid.

Treatment depends on the type of dry eye that patients have. For evaporative dry eye, lid hygiene, meibomian gland therapy, and supplements such as lipid-containing artificial tears and omega-3 capsules can be very helpful. In extreme cases, oral doxycycline, topical steroids, azithromycin, or treatment with devices that can heat and mechanically express the meibomian glands may be of benefit. For aqueous-deficient dry eye, tear supplements, punctal plugs, and medications to help stimulate tear production can help. Some patients may have both forms of dry eye, so combination treatment may be needed.

Ocular Allergies

Spring and fall are often the most difficult times for allergy sufferers, though some may suffer year-round. Contact lenses may increase the intensity and duration of the allergic response because allergens can be trapped under the lens or stick to the lens surface, increasing contact time with the eyes. There may be times during the year when patients are so uncomfortable that they can’t wear their lenses.

Eye exams may show bulbar conjunctival hyperemia and chemosis, hyperemia and papillae on the palpebral conjunctiva, and tearing and stringy mucous discharge. Generally, there is no punctate staining of the ocular surface. Patients also may complain of itching and feel that their lenses are uncomfortable.

Mild ocular allergies can be treated with ocular antihistamines/mast cell stabilizers, while more severe cases may require corticosteroids. Discontinuing lens wear or refitting to daily disposable lenses will also help reduce symptoms. In extreme cases, a referral to an allergist for treatment may be warranted.

In Conclusion

At times, it may be difficult to differentiate between dryness and allergy, and some patients may present with both conditions concurrently. Using your clinical acumen to properly diagnose your patients’ condition is the key to effectively reduce their symptoms. CLS