Objectives: To report a new clinical finding, decreased corneal sensitivity, in epidemic keratoconjunctivitis and to evaluate this sign with corneal confocal microscopy.
Methods: Forty-one eyes of 28 patients who developed corneal infiltrates after an outbreak of epidemic keratoconjunctivitis were included in the study. Clinical and confocal microscopic findings are described.
Results: In this outbreak of 72 patients, 28 (38.9%) developed corneal infiltrates. The corneal involvement was unilateral in 15 patients (53.6%) and bilateral in 13 patients (46.4%). Corneal sensitivities were measured in 35 eyes of 24 patients and found to be decreased in 26 eyes (74.3%). Decreased corneal sensation was a feature of mainly stage 2 (7 eyes) and stage 3 (11 eyes) keratitis. Corneal sensitivity returned to normal levels in all eyes in a mean of 8.5 days. The main confocal microscopic features during the period of decreased corneal sensitivity were morphologic changes in the infected epithelial cells, extracellular bright microdeposits, infiltration with round inflammatory cells and dendritic cells, increased brightness in the extracellular matrix and the stroma surrounding the corneal nerves, and increased keratocyte activity. The intensity of the inflammatory reaction in the extracellular space and corneal stroma and the reflectivity of the corneal nerves had subsided by the second confocal measurements.
Conclusion: There may be a transient decrease in the corneal sensitivity during the course of epidemic keratoconjunctivitis. Confocal microscopy can help to evaluate the changes in the cornea during this period. Future studies are needed to understand the nature of this clinical finding.