In Vivo Confocal Microscopic Evaluation Of Corneas With Active Herpetic Keratitis

Abstract

Purpose: : To evaluate the corneal findings of patients with herpetic keratitis using in vivo confocal microscopy

Methods: : Twenty-one eyes of 20 patients (9 females, 11 males) whose corneal findings were compatible with active herpetic keratitis were included in the study. Confoscan 3.0 (Nidek, Italy) was used to image the corneas of all patients. For all corneas, the epithelial characteristics, basal epithelium density, subepithelial nerve plexus, anterior and posterior stromal keratocyte densities, stromal structural alterations, endothelial density, keratic precipitate morphology and inflammatory findings were evaluated.

Results: : Unilateral corneal involvement was present in 95% of cases. Three (14.3%) eyes had epithelial keratitis, six (28.6%) had stromal keratitis, five (23.8%) had endotheliitis and seven (33.3%) had keratouveitis at presentation. Loss of the regular basal epithelial structure was observed in 65% of corneas. Epithelial dendritiform inflammatory cells were observed in 8 (38.1%) corneas. Attenuation or total absence of the subepithelial nerve plexus was observed in 17 (81%) of corneas. Focal areas of subepithelial inflammatory infiltrates were observed in all cases with epithelial keratitis and in 85.7% of all cases. Inflammatory foci within the corneal stroma were observed in 20 (95.2%) of all eyes, in 12 (57.1%) corneas, the entire stroma demonstrated inflammatory infiltration. Small, dendritiform or globular keratic precipitates were observed in 76.2% of cases. Basal epithelial, anterior stromal keratocyte, posterior stromal keratocyte and endothelial densities were measured as 6269±1221 cells/mm², 945±249 cells/mm², 698±125 cells/mm² and 2351±648 cells/mm², respectively. Compared to the cell densities of 130 healthy subjects, the endothelial cell densities of corneas with herpetic keratitis were found to be significantly lower (p<0.001).

Conclusions: : Herpetic keratitis appears to be associated with substantial degeneration of the subepithelial nerve plexus, loss of endothelial cells and an extensive inflammatory response involving all corneal layers.

Keywords: cornea: clinical science • herpes simplex virus • keratitis