What are alternative treatment options for a patient with allergic conjunctivitis who has not responded to ketotifen (antihistamine/mast cell stabilizer) eye drops?

Alternative Treatment Options for Allergic Conjunctivitis After Ketotifen Failure

For patients who have not responded to ketotifen eye drops, switching to another dual-action agent such as olopatadine, epinastine, or azelastine is recommended as the next step in treatment. 1

First-Line Alternatives

• Try another dual-action agent (antihistamine + mast cell stabilizer) such as olopatadine, epinastine, or azelastine, which have an onset within 30 minutes and are suitable for both acute and longer-term treatment 1, 2
• Add refrigerated preservative-free artificial tears to dilute allergens and inflammatory mediators on the ocular surface 3, 1
• Apply cold compresses to provide symptomatic relief 3

Second-Line Options

• Consider a topical NSAID such as ketorolac, which is specifically indicated for the temporary relief of ocular itching caused by seasonal allergic conjunctivitis 4
• Ketorolac works by inhibiting prostaglandin biosynthesis, which plays a role in ocular inflammation 4
• Recommended dosage: one drop four times a day 4
• Pure mast cell stabilizers (cromolyn, lodoxamide, nedocromil, pemirolast) may be effective but require several days of treatment before optimal symptom relief is achieved 3, 1

Third-Line Options

• For severe or persistent symptoms, a brief course (1-2 weeks) of topical corticosteroids with a low side effect profile, such as loteprednol etabonate, can be added to the regimen 3
• Important caution: Topical corticosteroids should be used with careful monitoring due to risks of increased intraocular pressure, cataract formation, and secondary infections 3, 1
• For severe cases, topical cyclosporine or tacrolimus can be considered 3

Environmental and Supportive Measures

• Wear sunglasses as a barrier to airborne allergens 3
• Use hypoallergenic bedding and eyelid cleansers to remove allergens 3
• Frequent clothes washing and bathing/showering before bedtime can help reduce allergen exposure 3
• Avoid eye rubbing, which can worsen symptoms and potentially lead to keratoconus in predisposed individuals 3

Important Considerations

• Avoid prolonged use of vasoconstrictor agents as they can lead to rebound hyperemia (conjunctivitis medicamentosa) 3, 1
• Oral antihistamines may worsen dry eye syndrome and impair the tear film's protective barrier 3, 1
• Punctal plugs should be avoided in allergic conjunctivitis as they prevent flushing of allergens from the ocular surface 3
• If symptoms remain uncontrolled despite appropriate therapy, consider referral to an allergist or ophthalmologist for further evaluation 1

Monitoring

• If corticosteroids are used, baseline and periodic measurement of intraocular pressure and pupillary dilation should be performed to evaluate for glaucoma and cataract 3
• Schedule follow-up visits based on the severity of symptoms and the treatment regimen chosen 3