Corneal Confocal Microscopy in Patients with Vernal Keratoconjunctivitis

Abstract

To compare corneal morphologic features using in vivo confocal microscopy in vernal keratoconjunctivitis (VKC) patients compared with normal subjects. Prospective, comparative study. Thirty-two VKC patients (26 males, 6 females; mean age, 17.1 years) and 40 normal subjects (20 males, 20 females; mean age, 19.3 years) were included. All subjects underwent a full ophthalmologic examination. Confoscan CS4 (Nidek, Gamagori, Japan) images of the central cornea were obtained with a ×40 noncontact lens and Z-ring device. The superficial and basal epithelium, subbasal nerve plexus, anterior stroma, stromal nerves, and endothelium of the central cornea were studied. The VKC patients had increased diameter, reflectivity, and presence of nuclear activation of superficial epithelial cells; reduced density of the basal membrane; lower density of keratocytes, increased presence of activated keratocytes, and inflammatory cells in the anterior stroma; and lower density and number of fibers, lower number of beadings, and higher grade of tortuosity of fibers in the subbasal nerve plexus. Increased alterations in thickness, deflections, and tortuosity were observed in stromal corneal nerves. An increased number of inflammatory cells in close proximity to the subbasal and stromal nerve fibers also was observed in VKC subjects. Corneal involvement in VKC is associated with alterations of the epithelium and subbasal and stromal corneal nerves. These changes may relate to the tear dysfunction and nonspecific hyperreactivity typical of these patients. Corneal confocal microscopy is a useful tool for studying in vivo pathologic corneal changes in VKC.