THERAPEUTICS

ALLEVIATE OCULAR ALLERGY

THE FOLLOWING TREATMENT OPTIONS CAN HELP YOU TAILOR TREATMENTS TO MEET SPECIFIC PATIENT NEEDS

Patricia Fulmer, O.D., F.A.A.O., Huntsville, Ala.

WITH AS much as 40% of the population suffering from allergic conjunctivitis, it is one of the most common conditions O.D.s face daily. Many think of allergy season as a spring event, however, numerous patients suffer from fall allergies (ragweed, etc.) This means doctors must be prepared to treat allergic conjunctivitis with as much diligence in the fall months as they do in the spring.

The clinical presentation of allergic conjunctivitis can differ among patients. Some may present with symptoms only (e.g. itching, burning, watery eyes), while others report symptoms and mild, moderate or severe signs, such as conjunctival injection, chemosis and papillae. Due to this variability, it is important to understand the treatment options, so that management may be tailored to each specific case.

A caveat: During acute phases of allergic conjunctivitis, it is important to remember that the body has already initiated the allergic cascade, which allows for mast cells to release histamines. H1 histamine receptors are then activated, leading to an inflammatory response and the signs of an allergic reaction. This inflammation must be treated and the histamines reduced to provide the most immediate improvement for patients. Once acute signs have been addressed and symptoms are subsiding, the practitioner should then look to stabilize mast cells to prevent future cascade activation.

Currently, steroids, antihistamines, mast cell stabilizers and combination mast cell stabilizers/antihistamines are effective against allergy. Below, these groups are reviewed.

STEROIDS

A topical steroid is the fastest way to relieve eye inflammation, represented most commonly in allergic conjunctivitis by conjunctival injection and chemosis. Steroids halt this response by inhibiting inflammatory cytokines and producing glucocorticoid and mineralocorticoid effects.

Loteprednol etabonate (Alrex, Bausch + Lomb) is the only steroid FDA approved specifically for allergic conjunctivitis, though others have been utilized off-label when deemed clinically necessary. Dosed q.i.d. for adults, adverse effects include IOP elevation, glaucoma, secondary ocular infection, cataracts and corneal perforation.

ANTIHISTAMINES

This drug class is useful for the acute phase of allergic conjunctivitis. Antihistamines selectively antagonize the H1 receptors, blocking histamine uptake and, therefore, stopping the allergic cascade. Antihistamines are not ideal for chronic therapy because of their inability to stabilize mast cells.

Emadastine (Emadine, Alcon) is the only stand-alone antihistamine. Dosed q.i.d. for patients ages 3 and older, possible adverse effects include keratitis, corneal infiltrates, headache, abnormal dreams, asthenia, bitter taste, blurred vision, burning, dryness, foreign body sensation (FBS), hyperemia, pruritus and excessive tearing.

MAST CELL STABILIZERS

These drugs are for the acute presentations of allergic conjunctivitis, as their mechanism of action is to stabilize mast cells, thereby preventing the future release of histamines. As such, they are ideal for chronic control after signs and symptoms resolve.

Three drugs comprise this category:

• Cromolyn (Crolom, Bausch + Lomb). Dosed q.i.d. in patients ages 4 and older, possible adverse effects include burning/stinging, itching, watering and ocular redness.

• Lodoxamide tromethamine (Alomide, Alcon). Dosed q.i.d. in patients age 2 and older, possible adverse effects include burning/stinging, itching, blur, redness, FBS, dryness, tearing and, rarely, corneal ulcers, ocular edema and corneal abrasions.

• Nedocromil (Alocril, Allergan). Dosed b.i.d. in patients ages 3 and older, possible adverse effects include headache (most common), burning/stinging, irritation, nasal congestion, asthma, conjunctivitis, redness, photophobia and rhinitis.

COMBINATION DRUGS

Combination mast cell stabilizers/antihistamines prevent the activation of mast cells and provide short-term relief through selectively inhibiting H1 histamine receptors, making them ideal for chronic care. Patients who present with symptoms and mild or no signs also benefit. Additionally, combination drugs can be added for patients who have moderate to severe signs once a steroid or NSAID has calmed the initial presentation.

Nine drugs make up this category:

• Alcaftadine (Lastacaft, Allergan). Dosed q.d. for patients ages two and older, possible adverse effects include irritation, burning/stinging, redness and pruritus.

• Azelastine (Optivar, Meda). Dosed b.i.d. in patients ages 3 and older, possible adverse effects include burning/stinging, headache, bitter taste, asthma, dyspnea, ocular pain, fatigue, influenza-like symptoms, pharyngitis, pruritus, rhinitis and transient blur.

• Bepotastine (Bepreve, Bausch + Lomb). Dosed b.i.d. in patients ages 2 and older, possible adverse effects include tasting the product, ocular irritation, headache and nasopharyngitis.

Remember that ocular allergy can strike in the fall as well as in the other seasons.

• Epinastine (Elestat, Allergan). Dosed b.i.d. in patients ages 2 and older, possible adverse effects include burning, pruritus, hyperemia, folliculosis, cold symptoms, rhinitis, upper respiratory infection, sinusitis, cough, pharyngitis and headache.

• Ketotifen fumarate (Alaway, Bausch + Lomb and Zaditor, Alcon). Dosing is b.i.d. in patients ages 3 and older. Possible adverse effects include conjunctival injection, headache, rhinitis, burning/stinging, conjunctivitis, dryness, keratitis, pain and itching.

• Olopatadine 0.1%, 0.2%/0.7% (Patanol, Alcon, Pataday, Alcon and Pazeo, Alcon). The latter two are dosed q.d. in patients ages 2 and older. The former drug is dosed b.i.d. in patients ages 3 and older. Possible adverse effects for all include blur, dryness, keratitis, FBS, abnormal taste (most common), URI symptoms, headache, burning/stinging, hyperemia, lid edema and nausea.

TOOLS OF RELIEF

When faced with ocular allergies, remember that for patients who present with marked symptoms and signs, steroids and NSAIDs should be considered. An antihistamine is useful for acute symptoms, and mast cell stabilizers are great for chronic care. Finally, combination drugs can combat acute presentations and provide long-term control. OM

DR. FULMER is the center director at VisionAmerica and a member of the AAO. Her interests include disease management, particularly glaucoma and uveitis, neurology-related cases and educating students and colleagues through lecturing and writing. Email her at patricia.fulmer@eyehealthpartners.com, or send comments to tinyurl.com/OMcomment.