Treatment Guideline Chart

Conjunctivitis is the inflammation of the conjunctiva.

Allergic conjunctivitis happens when the direct exposure of the ocular mucosal surfaces to the environment causes an immediate hypersensitivity reaction in which triggering antigens couple to reaginic antibodies (IgE) on the cell surface of mast cells and basophils, leading to the release of histamines that causes capillary dilation and increased permeability and thus conjunctival injection and swelling.
Seasonal allergic conjunctivitis is the most common form of allergic conjunctivitis in temperate climates. It usually occurs and recurs at a certain period of the year (eg summer).
Perennial allergic conjunctivitis manifests and recurs throughout the year with no seasonal predilection. It is most common in tropical climates.

Conjunctivitis%20-%20allergic,%20seasonal%20-and-%20perennial Treatment


Antihistamines (Ophthalmic)

  • Eg Alcaftadine, Emedastine, Levocabastine
  • Compete for the histamine receptor sites
    • In human conjunctiva, stimulation of H1 receptor mediates symptoms of pruritus while H2 receptor is involved in vasodilation
  • Reduce itching and vasodilation
    • Emedastine was shown to be more effective than Levocabastine in decreasing chemosis, eyelid swelling, and other signs and symptoms of seasonal allergic conjunctivitis
      • A selective H1 antagonist with no adrenergic, dopaminergic or serotonergic effect
  • Provides immediate ocular relief as compared to oral antihistamines
  • May be used as monotherapy or in combination with decongestants/vasoconstrictors in treating signs and symptoms of allergic conjunctivitis
    • Antihistamine/vasoconstrictor preparations may be used for short-term treatment (≤2 weeks) of acute allergic conjunctivitis 
    • Antihistamine with decongestant/vasoconstrictor should not be used for >2 weeks without medical advice
  • Should not be used for >6 weeks without medical advice
    • Prolonged use of antihistamines that are nonselective may cause ciliary muscle paralysis, mydriasis, and photophobia, especially when used by patients with lighter irides
    • May also cause angle-closure glaucoma particularly in patients who are at risk (ie history of narrow-angle glaucoma, patients with narrow angles)

Antihistamines/Mast Cell Stabilizers (Ophthalmic)

  • Eg Azelastine, Bepotastine, Epinastine, Ketotifen, Olopatadine
  • Have both mast-cell stabilizing and antihistaminic activity
    • Bind to H1 and H2 receptors, stabilizes mast cell, and down-regulates inflammatory markers that affects early and late phases of the conjunctival allergic response
  • May be used for either acute or chronic diseases
    • Relieve acute symptoms (eg ocular itchiness and redness) and prevent recurrence of allergic conjunctivitis
  • Fast-acting, effective and generally well tolerated
  • For patients with SAC, begin treatment at least 2-4 weeks prior to pollen season for optimal effectivity

Antihistamines (Oral)

  • May be used as adjunctive therapy for moderate to severe allergic conjunctivitis
  • Useful in cases accompanied by non-ocular allergies (eg allergic rhinitis)
  • Inferior to ophthalmic antihistamines primarily due to 1- to 2- hours delay from systemic administration to delivery to ocular tissues but has longer duration of action
  • More likely than topical antihistamines to cause side effects
    • May be associated with drying of mucosal membranes and decreased tear production, especially in patients with concomitant dry eye

Nonsteroidal Anti-inflammatory Drugs (Ophthalmic)

  • Eg Diclofenac, Ketorolac
  • Inhibits the activity of cyclooxygenase blocking the production of prostaglandins
  • Helps reduce ocular signs and symptoms like itching or conjunctival hyperemia
  • Do not mask ocular infections, affect wound healing or intraocular pressure (IOP), nor contribute to cataract formation
 Vasoconstrictors (Ophthalmic)
  • Eg Naphazoline, Phenylephrine, Tetrahydrozoline
  • Sympathomimetic agents
  • Decreases vascular congestion and eyelid edema but do not affect allergic response
  • Usually used in combination with ophthalmic antihistamines
    • Have been shown to have synergistic effect
    • Based on studies, Naphazoline plus Antazolin or Pheniramine were comparable in decreasing the signs and symptoms of allergic conjunctivitis
  • Chronic use (>10 days) may cause conjunctivitis medicamentosa

Mast Cell Stabilizers (Ophthalmic)

  • Eg Cromoglicic acid, Lodoxamide, Nedocromil, Pemirolast
  • Inhibit degranulation of mast cells which limits the release of inflammatory mediators and platelet-activating factor
  • Used for prevention of symptoms and for conditions that are recurrent or persistent
  • Have slower onset of action as compared to antihistamines
    • Effects of Cromoglicic acid are evident 2-5 days after the initiation of the therapy with maximum improvement of ocular symptoms after 15 days
  • Requires multiple applications everyday to show effects
  • Most useful in the seasonal management of chronic allergic diseases of the eye
  • More effective when used prophylactically with loading period and administered before triggering of allergic reaction
  • Usually given to patients with moderate symptoms, after an ophthalmic decongestant have been administered to provide immediate relief
  • Studies have shown that Lodoxamide is more effective than Cromoglicic acid in reducing eosinophil activation, and clinical signs and symptoms
  • Pemirolast was shown to specifically inhibit mast cell degranulation, thus preventing the release of chemical mediators like histamine
  • May also help in improving symptoms of allergic rhinitis
  • Generally well tolerated and may be used as long as needed

Lubricants (Ophthalmic)

  • Consist of saline solution combined with wetting and viscosity agents, which is used 2-6x/day as needed
    • Non-preserved formulations are recommended if will be used frequently to prevent allergic reactions secondary to preservatives
  • Assist in the removal and dilution of allergens that come in contact with the eye surface
    • Do not alter the pathophysiology of the disease but treat co-existing tear deficiency
    • Washing the eyes frequently with water decreases the integrity of the layer of tears, hence, artificial tears may be used instead
  • Numerous lubricants that differ by class, osmolarity and electrolyte composition are available
  • Many ophthalmic lubricants are available. Please see the latest MIMS for specific formulations.

Corticosteroids (Ophthalmic)

  • Should be given and supervised by an ophthalmologist
  • Reduces inflammatory cytokine production, mast cell proliferation and cell mediated immune response
  • May be considered for use in the treatment of severe and chronic ocular allergy
    • Block inflammatory pathways that perpetuate the persistent and chronic forms of ocular allergy
  • May be used when patient’s symptoms have not responded to other agents
    • 1-2 weeks course can be added to antihistamine/mast cell stabilizers if symptoms were not controlled
    • Lowest potency and frequency that relieves the patient’s symptoms should be given
  • Should only be used for a short period of time (≤2 weeks)
    • Chronic use of topical steroids is associated with glaucoma, cataract formation, and infections of the cornea and conjunctiva
  • Inappropriate use in herpes simplex, fungal, and other viral or bacterial keratitis may cause complications that may threaten vision (eg corneal melting, perforation, and scarring)


  • Used in patients with atopic disorders like SAC, PAC, allergic rhinitis, or asthma
  • Desensitizes a patient against a specific allergen
    • However, ocular symptoms takes longer than nasal symptoms
  • Topical Cyclosporine or Tacrolimus may be used in severe conditions
    • Cyclosporine A limits type IV allergic response thereby reducing infiltration of eosinophils
    • Tacrolimus reduces action of T cells
      • Giant papillae and corneal lesions as well as total sign and symptom scores are reduced in refractory disease
  • Needs careful monitoring by a specialist
  • Its use is limited by cost, long-term patient commitment and the possibility of anaphylaxis

Non-Pharmacological Therapy

General Eye Care Measures

  • Avoid excessive eye rubbing
    • May cause worsening of symptoms and degranulation due to mechanical disruption of mast cells
  • Apply cold compress to reduce symptoms such as eyelid and periorbital edema
    • Causes vasoconstriction which can improve patient comfort by reducing itching
  • Reduce or avoid use of contact lens during seasonal flare-ups

Identification of Trigger Factors

  • Trial of avoidance may identify antigens
  • Skin testing or allergen challenge may be useful for identifying specific problematic antigens but are rarely needed

Avoidance of Trigger Factors

  • Eg closing windows, filtering air, removing pets and stuffed toys, vacuuming and dusting regularly, etc
  • Mainstay of managing allergic conjunctivitis
  • Use of goggle-type glasses are recommended during pollen-flying period
  • Sensitive patients should attempt to limit exposure to outdoors during times of high pollen count or other allergen counts
  • House mites are a common allergen and can be reduced by using dust mite-proof encasings on pillows and mattresses, and washing sheets in hot water
    • Washing clothes frequently and bathing before bedtime may be helpful

Surgical Intervention

  • Tarsal Conjunctival Resection (including the papillae)
    • Performed when symptoms are not alleviated by pharmacological therapy and progressive conjunctival papillary hyperplasia worsens the corneal epithelium disorder
    • Therapeutic effect is observed immediately though symptom recurrence may occur
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