Persistent corneal subepithelial infiltrates (SEIs) that arise from epidemic keratoconjunctivitis may cause greater corneal density and diminish corneal optical quality, a study in Clinical and Experimental Optometry suggests.

Turkish investigators enrolled 46 eyes of 23 patients who had persistent SEIs in one eye for at least three months in this prospective cross-sectional study. The patients’ fellow eyes were clinically normal. Researchers measured corneal densitometry with a corneal topographer and analyzed the total corneal higher-order aberrations, including coma, spherical aberration, higher-order root mean square and total root mean square in the Zernike analysis.

Researchers found the mean corneal densitometry values were significantly higher in all annular concentric areas (0-2mm, 2-6mm, 6-10mm and 10-12mm) of the anterior and central corneal layers in the eyes with SEIs compared with the unaffected fellow eyes. Additionally, the study reported statistically significant differences between the eyes with SEIs and the fellow eyes in coma, trefoil, higher-order root mean square and total root mean square in the Zernike analysis.

“This study quantitatively demonstrated that persistent corneal subepithelial infiltrates associated with epidemic keratoconjunctivitis decrease corneal transparency and corneal optical quality in affected eyes,” the researchers wrote in their paper.