Medication Summary
The goals of pharmacotherapy are to reduce morbidity and prevent complications.
Ocular Lubricants
Class Summary
These agents are used for symptomatic relief.
Artificial tears (Altalube, Gen Teal Tears, Bion Tears, Murine Tears, Natures Tears)
Artificial tears act to stabilize and thicken precorneal tear film and prolong tear film breakup time, which occurs with dry eye states.
Antihistamines
Class Summary
These agents are used to treat severe itching.
Azelastine ophthalmic
Azelastine competes with histamine for the H1 receptor and inhibits the release of histamine and other mediators involved in the allergic response.
Ketotifen, ophthalmic (Alaway, Zaditor, Zyrtec Itchy Eye Drops)
Ketotifen is a relatively selective H1 receptor antagonist and inhibitor of histamine release from mast cells. OTC.
Olopatadine ophthalmic (Pataday, Patanol, Pazeo)
Olopatadine is a relatively selective H1 receptor antagonist and inhibitor of histamine release from mast cells.
Corticosteroids
Class Summary
Corticosteroids may be used for pseudomembranes and decreased vision and/or glare due to subepithelial infiltrates. They have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli. Extreme caution should be taken when using corticosteroids, as they may worsen an underlying HSV infection or induce dependency in the context of persistent EKC subepithelial infiltrates.
Prednisolone ophthalmic (AK-Pred, Pred Mild, Omnipred)
This agent decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing increased capillary permeability. Less potent (eg, prednisolone 0.125%, fluorometholone 0.1%) are usually sufficient to treat subepithelial infiltrates. The steroid must be tapered very carefully, often over months. Topical cyclosporine A emulsion (Restasis, Allergan, Irvine CA) may provide a viable steroid-sparing alternative for selected patients.
Fluorometholone (Flarex, FML, FML Forte)
Fluorometholone inhibits edema, fibrin deposition, capillary dilation, phagocytic migration, capillary proliferation, collagen deposition, and scar formation. It decreases inflammation and corneal neovascularization, suppresses migration of PMNs, and reverses capillary permeability. It is believed to act by inducing phospholipase A2 inhibitory proteins.
Loteprednol ophthalmic (Alrex, Lotemax)
Loteprednol etabonate decreases inflammation by suppressing migration of polymorphonuclear leukocytes (PMNs) and reversing increased capillary permeability.
Immunosuppressant Agents
Class Summary
Immunosuppressant agents are used as adjunctive or alternative treatment when steroid use is ineffective or requires minimization.
Cyclosporine ophthalmic (Restasis)
The exact mechanism of the immunosuppressive activity of cyclosporine is unknown, but preferential and reversible inhibition of T lymphocytes in the G0 or G1 phase of the cell cycle has been suggested.
Antivirals
Class Summary
These agents are used for the treatment of HSV infection.
Trifluridine (Viroptic)
Trifluridine is a pyrimidine (thymidine) analogue drug of choice in the United States for topical antiviral therapy for HSV infection. It inhibits viral replication by incorporating into viral deoxyribonucleic acid (DNA) in place of thymidine. It is prescribed initially 9 times per day until resolution of the epithelial keratitis, then QID for another week. If the patient has no response in 7-14 days, consider other treatments. Trifluridine requires refrigeration and contains the toxic preservative thimerosal.
Ganciclovir ophthalmic (Zirgan)
Ganciclovir is a selective antiviral activated only within infected cells by viral thymidine kinase. It is a viral DNA chain terminator and DNA polymerase inhibitor. It is available in gel formulation and is stable at room temperature. It is prescribed 5 times per day until resolution of the epithelial keratitis, then TID for an additional week.
Acyclovir (Zovirax)
This is a prodrug that inhibits viral replication; it is activated by phosphorylation by virus-specific thymidine kinase. The recommended dosage for acute epithelial keratitis or stromal keratitis ranges from 200 mg PO BID to 400 mg PO TID. Some clinicians recommend the highest anti-zoster strength of 800 mg owing to the variability among patients in gastric absorption and the resultant variability and unpredictability of measurable serum concentrations.
Valacyclovir (Valtrex)
Valacyclovir is a prodrug that is rapidly converted to the active drug acyclovir. It produces a greater serum concentration of acyclovir with smaller oral dosing. Valacyclovir is more expensive than acyclovir but can be as effective with a more convenient dosing regimen.
Famciclovir (Famvir)
This agent is a prodrug that, when biotransformed into its active metabolite, penciclovir, may inhibit viral DNA synthesis/replication. It has been used successfully in the suppression of genital herpes. Its efficacy in HSV keratitis currently is under study.
Antibiotics
Class Summary
Therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting. Antibiotics are used to prevent superinfections.
Ofloxacin ophthalmic (Ocuflox)
Ofloxacin is a pyridine carboxylic acid derivative with broad-spectrum bactericidal effect. It inhibits bacterial growth by inhibiting DNA gyrase. It is indicated for superficial ocular infections of conjunctiva or cornea due to susceptible microorganisms.
Trimethoprim/polymyxin B ophthalmic (Polytrim Ophthalmic Solution)
This combination is used for ocular infection of the cornea or conjunctiva caused by susceptible microorganisms.
Ciprofloxacin ophthalmic (Ciloxan)
Ciprofloxacin has activity against Pseudomonas and Streptococcus species, methicillin-resistant Staphylococcus aureus (MRSA), S epidermidis, and most gram-negative organisms; it has no activity against anaerobes.
Sulfacetamide ophthalmic (Bleph 10)
This agent interferes with bacterial growth by inhibiting bacterial folic acid synthesis by competitively antagonizing para-aminobenzoic acid.
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Viral conjunctivitis. Image courtesy of Wikimedia Commons.
