Corneal surface disease topology.

The specific morphology and distribution of corneal surface lesions may point toward a specific diagnosis and pathogenesis in individual cases (see Fig 1). Staining lesions may be fine (e.g., staphylococcal) or punctate (e.g., keratitis sicca). The size and appearance of staining and nonstaining lesions of the epithelium and subepithelial cornea may be characteristic for a particular disease process (e.g., HSV, EKC). Finally, the location of lesions is important. Inferior staining (staphylococcal disease, lagophthalmos) will be incited by a different cause as compared to superior (molluscum, trachoma, vernal keratoconjunctivitis) and peripheral (contact lens-induced, collagen vascular disease) staining patterns. Central lesions are more likely to indicate tear deficiency, superficial corneal dystrophies, viral infections, or metabolic conditions. Knowledge of these patterns of disease can allow accurate diagnosis and more expedient and successful treatment of corneal surface disease.