Medication Summary
Medications used to treat red eye depend on the underlying cause of the condition and may include antivirals, nonsteroidal anti-inflammatory drugs (NSAIDs), cholinergic agents, carbonic anhydrase (CA) inhibitors, and osmotic diuretics.
Topical Antiviral Agents
Class Summary
Antiviral agents inhibit viral replication when their phosphorylated form becomes incorporated into viral DNA.
Trifluridine ophthalmic (Viroptic)
Trifluridine is a fluorinated pyrimidine nucleoside. Trifluridine demonstrates in vitro and in vivo activity against herpes simplex virus types 1 and 2, vaccinia virus, and some strains of adenovirus.
Trifluridine Ophthalmic Solution 1% is also effective in the treatment of dendritic epithelial keratitis. Trifluridine interferes with DNA synthesis in cultured mammalian cells. However, its antiviral mechanism of action is not completely known. The solution contains thimerosal 0.001% as a preservative.
Ganciclovir ophthalmic (Zirgan)
Ganciclovir ophthalmic gel (Zirgan) 0.15% contains the active ingredient ganciclovir, which is a guanosine derivative. When phosphorylated, it inhibits DNA replication of HSV. Ganciclovir is transformed by viral and cellular thymidine kinases (TK) to ganciclovir triphosphate, which works as an antiviral agent by inhibiting the synthesis of viral DNA in 2 ways: competitive inhibition of viral DNA-polymerase and direct incorporation into viral primer strand DNA, resulting in DNA chain termination and prevention of replication. Since it does not affect uninfected cells, the toxicity is minimal.
Acyclovir (Zovirax)
Acyclovir is a prodrug activated by phosphorylation by virus-specific thymidine kinase (TK). Herpes virus TK, but not host cell TK, uses acyclovir as a purine nucleoside, converting it into acyclovir monophosphate, a nucleotide analogue. Guanylate kinase then converts the monophosphate form into diphosphate and triphosphate analogues that inhibit viral DNA replication.
Acyclovir has affinity for viral TK and, once phosphorylated, causes DNA chain termination when acted on by DNA polymerase. The result is potent inhibition of viral growth with minimal toxic effects on to uninfected epithelial cells. Acyclovir inhibits the activity of both herpes simplex virus (HSV)-1 and HSV-2.
The topical acyclovir formulation (3% ointment), equal in efficacy but less toxic, is not commercially available in the United States.
Topical Nonsteroidal Anti-inflammatory Drugs (NSAIDs)
Class Summary
NSAIDs inhibit prostaglandin synthesis, and this inhibition results in vasoconstriction, decreased vascular permeability, leukocytosis, and no steroid-induced effect on intraocular pressure (IOP). However, these agents have no significantly favorable effect on IOP. They are potent analgesics and potentiate pupillary mydriasis. They also significantly reduce photophobia in patients with corneal surgery or corneal abrasions.
Diclofenac (Voltaren Ophthalmic)
Diclofenac is one of a series of phenylacetic acids that have demonstrated anti-inflammatory and analgesic properties in pharmacologic studies. It is believed to inhibit the enzyme cyclooxygenase, which is essential in the biosynthesis of prostaglandins. It may facilitate outflow of aqueous humor and decrease vascular permeability. Any equivalent topical NSAID can be used in place of diclofenac.
Ketorolac tromethamine 0.5% (Acular, Acuvail)
This nonsteroidal anti-inflammatory drug inhibits prostaglandin synthesis by decreasing cyclooxygenase activity, decreasing the formation of prostaglandin precursors. It may facilitate outflow of aqueous humor and decrease vascular permeability. This drug has been available for decades and therefore has a substantial track and safety record. The topical preparations tend to sting.
Flurbiprofen (Ocufen)
Flurbiprofen facilitates outflow of aqueous humor by inhibiting prostaglandin synthesis, causing a subsequent decrease in vascular permeability. This is the least potent of the available topical ophthalmic NSAIDs.
Miotics, Direct-Acting
Class Summary
Cholinergic agonists add to the antiglaucoma effects of beta blockers, CA inhibitors, and sympathomimetics as an adjunctive therapy. They produce pupillary constriction and therefore tighten the iris plane, which is extremely useful in patients with angle closure glaucoma. Some patients experience a brow ache, particularly within the initial few days of dosing.
Pilocarpine (Isopto Carpine, Pilopine HS)
Patients may be maintained on pilocarpine as long as the IOP is controlled and no deterioration in the visual fields is present. Pilocarpine may be used either alone or in combination with other miotics, beta blockers, epinephrine, CA inhibitors, or hyperosmotic agents to decrease IOP. The frequency of instillation and concentration are determined by the patient's response. Individuals with heavily pigmented irises may require higher strengths.
Antiglaucoma, Carbonic Anhydrase Inhibitors
Class Summary
CA is an enzyme found in many tissues of the body, including the eye. It catalyzes a reversible reaction whereby carbon dioxide becomes hydrated and carbonic acid dehydrated. By slowing the formation of bicarbonate ions and thus subsequently reducing sodium and fluid transport, CA inhibitors may reduce the action of CA in the ciliary processes of the eye. This effect decreases aqueous humor secretion, reducing IOP.
Acetazolamide (Diamox Sequels)
Acetazolamide, an agent chemically derived from sulfa drugs, reduces the rate of aqueous humor formation by directly inhibiting the action of CA on secretory ciliary epithelium, thereby causing a reduction in IOP by as much as 40-60%. More than 90% of CA must be inhibited before IOP reduction can occur. Effects become apparent in about 1 hour, peak in 4 hours, and reach trough values in about 12 hours.
Acetazolamide is used adjunctively for treatment of chronic simple (open-angle) glaucoma and secondary glaucoma and preoperatively for acute angle-closure glaucoma when delay of surgery is required. It is available as a 500-mg sustained-release capsule, as well as a 250-mg generic tablet. If one form of the drug is not well tolerated, another form or a lower dose of the same form may be better tolerated.
Diuretics, Osmotic Agents
Class Summary
Osmotic diuretics increase the osmolarity of the glomerular filtrate and induce diuresis. This in turn hinders the tubular reabsorption of water, causing sodium and chloride excretion to increase as well. The diuretic effect of these agents can subsequently reduce IOP.
Mannitol (Osmitrol)
Mannitol reduces elevated IOP when the pressure cannot be lowered by other means. Caution should be exercised in patients with renal failure. Initially assess for adequate renal function by administering a test dose of 200 mg/kg IV over 3-5 minutes. In adults, this should produce urine flow of at least 30-50 ml/hr over 2-3 hours; in children, it should produce urine flow of at least 1 mL/kg over 1-3 hours.
Ophthalmic Lubricants
Class Summary
Lubricants act as humectants in the eye. The ideal artificial lubricant should be preservative-free; contain potassium, bicarbonate, and other electrolytes; and have a polymeric system to increase its retention time. Lubricating drops are used to reduce ocular surface disease morbidity and to prevent complications. Lubricating ointments prevent complications from dry eyes. Ocular inserts such as carboxymethylcellulose (Lacrisert) reduce symptoms resulting from moderate-to-severe dry eye syndromes.
Artificial tears (Advanced Eye Relief, Bion Tears, Hypo Tears, Murine Tears, Tears Naturale II)
Artificial tears are used to increase lubrication of the eye.
Hydroxypropyl methylcellulose (GenTeal, Isopto Tears, Natural Balance Tears, Nature's Tears, Systane Overnight Therapy, Gonak, ImproVue)
These substances serve as lubricants and emollients.
Antihistamines, Ophthalmic
Class Summary
These agents are used to treat symptoms of itching and to prevent future symptoms by controlling the degranulation of mast cells. Mast cell–stabilizing medications/antihistamine combination drops are most likely to achieve the therapeutic effect with minimal complications.
Olopatadine (Patanol, Pataday, Pazeo)
This is a relatively selective H1 receptor antagonist and inhibitor of histamine release from mast cells.
Ketotifen (Zaditor, Alaway, Claritin Eye, Zyrtec Itchy Eye)
Ketotifen is a relatively selective H1 receptor antagonist and inhibitor of histamine release from mast cells. It is available over the counter.
Topical Antibiotics, Ophthalmic
Class Summary
Therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Ofloxacin ophthalmic (Ocuflox)
Ofloxacin is a pyridine carboxylic acid derivative fluoroquinolone with broad-spectrum bactericidal effect. It inhibits bacterial growth by inhibiting DNA gyrase. It is indicated for superficial ocular infections of the 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. It is available as a solution (polymyxin/trimethoprim) and as an ointment (polymyxin/bacitracin). Polymyxin shows potency against gram-negative organisms. Both trimethoprim and bacitracin show potency against a wide variety of gram-positive and gram-negative organisms.
Ciprofloxacin (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.
Moxifloxacin (Vigamox, Moxeza)
Moxifloxacin has activity against susceptible gram-negative and gram-positive bacteria. Antibiotics in this class inhibit bacterial DNA synthesis and thus growth by inhibiting DNA gyrase. Vigamox is self-preserved and used topically for ocular surface infections, perioperative prophylaxis, and intracamerally to reduce the risk of postoperative endophthalmitis.
Erythromycin ophthalmic (Ilotycin)
Erythromycin is indicated for infections caused by susceptible strains of microorganisms and for prevention of corneal and conjunctival infections.
Sulfacetamide ophthalmic (Bleph 10)
This agent interferes with bacterial growth by inhibiting bacterial folic acid synthesis by competitively antagonizing para-aminobenzoic acid. It is available in solution, ointment, and lotion form. Use of this class of antimicrobial has decreased owing to the presumed risk of Stevens-Johnson syndrome and similar severe allergic reactions.
Tobramycin ophthalmic (Tobrex)
Tobramycin is an aminoglycoside that interferes with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits, causing a defective bacterial cell membrane. It is available in solution, ointment, and lotion form. The aminoglycosides show excellent activity against methicillin-resistant Staphylococcus epidermidis and Staphylococcus aureus.
Gentamicin (Gentak, Garamycin)
Gentamicin is an aminoglycoside antibiotic that covers gram-positive and gram-negative bacteria.
Polymyxin B/bacitracin ophthalmic (Ak-Poly-Bac, Polycin Ophthalmic)
Bacitracin prevents transfer of mucopeptides into the growing cell wall, which causes inhibition of bacterial cell wall synthesis. Polymyxin B damages bacterial cytoplasmic membrane and alters permeability, causing intracellular constituents to leak. Used to treat open excoriations and erosions.
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Follicular conjunctivitis and subconjunctival hemorrhage.
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Symblepharon secondary to epidemic keratoconjunctivitis.
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Blepharitis. Courtesy of Wikipedia Commons.
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Scleritis. Courtesy of Wikipedia Commons.
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Acute dacryocystitis.
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Canaliculitis of the left lower lid. Courtesy of Peter Rubin, MD, Director, Eye Plastics Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School.
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Corneal abrasion.
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This photograph depicts a child with a bilateral eye condition known as interstitial keratitis (IK), a stigma related to congenital syphilis.
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Conjunctivitis. Courtesy of Wikipedia Commons.
