Topical antibiotics are indicated for the treatment of bacterial conjunctivitis, blepharitis, nasolacrimal duct obstruction with purulent discharge, bacterial keratitis, and endophthalmitis, and as prophylaxis for ophthalmia neonatorum. Combination antibiotic-corticosteroid preparations may be used after surgery or in cases where risk of infection is high. Most cases of bacterial conjunctivitis in children are caused by gram-positive organisms, particularly staphylococcus and streptococcus species. Keratitis is rare in childhood, and it is associated most commonly with trauma, surgery, or contact lens wear. The most common pathogens are Pseudomonas , staphylococci, and alpha-hemolytic streptococci, as well as herpes simplex virus (HSV). Endophthalmitis can be bacterial or fungal, instigated either by direct microbial penetration of the eye or by hematogenous spread.
Antimicrobial medications for conjunctivitis are typically given as one drop (or one-half inch of ointment) four times daily for 5-7 days. Ointments have the advantage of increased dwell time in the eye, but often patients and parents of children prefer drops, and no therapeutic advantage of one over the other has been demonstrated. Microbial keratitis is usually treated as it is for adults with more frequent dosing of broad-spectrum antimicrobial agents.
Trimethoprim-polymixin b (Polytrim®, Allergan, Irvine, CA), sodium sulfacetamide (Bleph®-10, Allergan, Irvine, CA), and gentamicin sulfate (Genoptic®, Allergan, Irvine, CA) are all relatively inexpensive with benign side-effect profiles. These medications had similar rates of efficacy treating Haemophilus influenzae or S. pneumoniae conjunctivitis in a study of 158 children. A significant percentage of staphylococcal isolates are completely resistant to sulfa drugs; moreover, instillation of sodium sulfacetamide is accompanied by significant stinging.
Aminoglycosides are broad-spectrum agents, but they can be toxic to the corneal epithelium with long-term use. Neomycin has been reported to cause contact allergy with prolonged application. In one study of 27 patients treated for prolonged or chronic conjunctivitis, keratoconjunctivitis, or blepharoconjunctivitis, 18.5% of patients suffered allergic reactions to neomycin. Streptococcus and Chlamydia spp are resistant to aminoglycosides. Newer aminoglycoside semisynthetic derivatives, such as amikacin (Amikin®, Bristol-Myers Squibb, New York, NY), are less toxic and more effective against strains resistant to gentamicin and tobramicin, although bacterial resistance to amikacin is increasing slowly. In a retrospective non-comparative case series, 22 of 141 (15.6%) culture-proven cases of pseudomonas keratitis were ciprofloxacin-resistant; 14 of 22 (63%) were resistant to gentamycin also, but 19 of 22 (90.9%) were susceptible to amikacin.
Erythromycin 0.5% ointment is useful for mild bacterial conjunctivitis. It is effective against gram-positive organisms and some atypical microbes, including Mycoplasma, Legionella, Chlamydia , and certain Mycobacterium . The Centers for Disease Control recommend 1% silver nitrate solution, 0.5% erythromycin, or 1% tetracycline as equivalent and acceptable regimens of prophylaxis of gonococcal ophthalmia neonatorum. Povidone-iodine 2.5% (Betadine® Ophthalmic, Alcon, Ft. Worth, TX) in a single dose has been advocated for prophylaxis as well. Its advantages include coverage for viruses, such as HSV and the human immunodeficiency virus (HIV).[92,93]
Fluoroquinolones, such as ciprofloxacin and ofloxacin, are broad-spectrum agents, albeit more expensive than other topical agents. They may be preferable as adjuncts to less expensive agents in some cases because they are effective against Pseudomonas as well as Haemophilus . In one study designed to test safety of ciprofloxacin in children, ciprofloxacin and tobramicin were found to produce clinical cures of conjunctivitis with similar rates (90.1% and 84.3%) after 7 days of treatment. Fourth-generation fluoroquinolones have an enhanced activity against quinolone-resistant strains, notably S. aureus , as well as against penicillin- and macrolide-resistant isolates. Moxifloxacin 0.5% (Vigamox®, Alcon, Ft. Worth, TX), newly approved for topical use in children, may be dosed three times daily and is effective against Chlamydia and Haemophilus in trials. Formulated without benzalkonium chloride, it is approved for use in children as young as 1 year of age, although data regarding its use are limited (FDA/Center for Drug Evaluation and Research, NDA 21-598 Page 3, 4/15/03).
Compr Ophthalmol Update. 2005;6(2):85-101. © 2005 Comprehensive Ophthalmology Update, LLC
Cite this: Ophthalmic Medications in Pediatric Patients - Medscape - Mar 01, 2005.