Impression cytology findings in bullous keratopathy

To evaluate, by impression cytology (IC), the cytological features of the central area of corneal epithelial surface of patients with symptomatic bullous keratopathy (BK). Design Cross-sectional observational case series.

IC of the central cornea was performed in 72 eyes of 72 patients with symptomatic BK between June 2005 and December 2006. Patients were divided into two groups according to the presence (group GC) or not of goblet cells (group NGC). The diagnosis of limbal stem cell deficiency (LSCD) was defined by the presence of one or more intact goblet cells on the corneal surface. Squamous metaplasia was classified according to Murube and Rivas.

Epithelial squamous metaplasia was found in 72 (100%) eyes, along with conjunctival goblet cells in 25 (34.72%) eyes. Squamous metaplasia was grade 1 in group GC and more advanced grades in group NGC. Corneal neovascularisation was present in 62 (82.11%) eyes. Vessel measure was more than 4 mm in 11 eyes (23.4%) in group NGC and 10 eyes (40%) in group GC (p=0.559), and they were mostly subepithelial in 23 eyes (48.9%) in group NGC and 12 (48%) eyes in group GC (p=0.822).

Squamous metaplasia was the most frequent finding associated with advanced BK. The presence of goblet cells on the surface of corneas with squamous metaplasia grade 1, in a significant number of patients, suggests that limbal stem cell deficiency is a common condition associated with advanced cases of BK.