Limbal vernal keratoconjunctivitis in the tropics

Objective: This study aimed to describe the pathology of vernal keratoconjunctivitis (VKC) in children from Kenya. Design: Case series. Participants: Ten patients with clinically active and untreated limbal VKC and five age-matched control subjects without external eye disease were recruited from a district eye hospital in Kenya. Main Outcome Measures: Paraffin sections of limbal and tarsal conjunctiva were examined by tinctorial and immunocytochemical methods to characterize the inflammatory infiltrate. Results: In comparison with control subjects, patients with VKC were more likely to show squamous metaplasia of the tarsal conjunctiva. The patients with VKC had cellular infiltration of both the stroma and epithelium consistent with chronic inflammation, particularly in the biopsy specimens taken from the limbus. In tarsal conjunctiva, the stromal infiltrate consisted of a diffuse T-lymphocyte reaction with clustering of B- lymphocytes; mast cells, immunoglobulin E (IgE) plasma cells, and eosinophils also were prominent. Mast cells and eosinophils were found within the epithelium in the more severely inflamed biopsy specimens. Conclusions: These features are similar to those in reports of VKC in temperate regions, although the degree of B-lymphocyte clustering is greater in tropical patients with VKC. Although none of the patients had other symptoms of atopy, the authors findings are consistent with those for an allergic basis for this disease.