Microbial Keratitis

DEFINITION: It is the microbial infection of the cornea located in the front surface of the eye.

SYMPTOMS AND FINDINGS: It causes pain in the eye, sensitivity to light, redness, decreased vision, watering of the eye, and blurring.

Figure 1. The hallmark of HSV keratitis; presence of multiple small branching epithelial dendrites on the surface of the cornea.  The bed of the ulcer stains with fluorescein

CAUSES AND RISK FACTORS: Chronic eyelash-base inflammations which can cause defense mechanisms of the eye surface (eye closing reflex, tear fluid, fast healing capacity of epithelium cells in the eye surface) to deteriorate, lacrimal duct obstructions, xerophthalmia, contact lens use, traumas damaging the eye surface, and use of medications that weaken immunity are among the risk factors.

AUXILIARY INVESTIGATIONS AND DIAGNOSIS: Diagnosis is made through biomicroscopic examination. In cases non-responsive to treatment, samples taken from the corneal surface to determine the microbial factor are colored or cultures made and thus the factor and the effective medication (antibiogram) can be found.

TREATMENT: Topical treatments are applied with antimicrobial agents of a suitable spectrum.

Figure 2. Slit-lamp photograph of mild (left) and severe (right) bacterial keratitits.