|Sterile Corneal Infiltrates
SIGNS AND SYMPTOMS
Patients with Staphylococcal hypersensitivity reactions may present without symptoms. Here, scattered multiple areas of sub-epithelial and anterior stromal infiltrates, with or without epithelial defects, line the limbal area (mostly inferiorly). The entity is usually bilateral. One distinct characteristic is the notable clear zone that lies between the areas of infiltrate and the limbus.
Frequently the patient will provide an ocular history of having a dry eye and a systemic history of rheumatoid arthritis or other collagen vascular diseases. Other known associations are vernal keratitis, vitamin A-deficiency and contact lens solution reaction. The principle differential diagnoses include infectious corneal ulcer, marginal sub-epithelial infiltrates secondary to contact lens wear and Mooren's marginal corneal ulcer.
Staph. aureus is recognized as one of the common opportunistic ocular pathogens. The organism is a gram-positive non-encapsulated coccus capable of producing a variety of exotoxins and enzymes. In addition to its ability to infect the central cornea, it is a leading cause of sterile marginal keratitis.
Powerful exotoxins released by bacteria colonizing the eyelid margin induce peripheral corneal destruction through antigen-antibody reactions. Polymorphonuclear leukocytes and fibroblasts, which migrate to the area to help fight exotoxins, produce collagenase and proteoglycanase enzymes that often produce additional damage.
To fully eradicate dense colonies of lid margin bacteria, prescribe a topical aminoglycoside (gentamicin, tobramycin) or fluoroquinolone (ciprofloxacin, norfloxacin, ofloxacin) QID. The antibiotics kill the bacteria and also mechanically wash organisms and their toxins away from the eyelid margin. If the patient complains of discomfort, prescribe a cycloplegic. Rx a topical steroid based on the severity of the condition.
Other reports in this section
Eyelids & Eyelashes | Conjunctiva & Sclera | Cornea
Uvea | Vitreous & Retina | Optic Nerve & Brain | Oculosystemic Disease
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