Background : Chronic inflammation in pterygium occurrence has not been explained. Whether damaged limbal basal epithelial cells are associated with pterygium occurrence in black Africans is not clear. Objective : To explain chronic inflammation in pterygium, and to clarify whether damaged limbal basal epithelial cells were associated with pterygium occurrence in black Africans. Methods : Chronic inflammatory changes and damaged limbal basal epithelial cells were assessed in 59 samples. Results : Chronic inflammatory cells were present in 59 pterygia. Inflammatory cell count in 5 (27.8%) of 18 small pterygia was >200 (high) while in 22 (53.7%) of 41 large growths was <200 (low); p = 0.25. The proportion of pterygia with high counts tended to increase with pterygium extent. Twenty (33.9%) of 59 pterygia recurred after surgery. Ten (50%) of 20 samples had high cell counts and 10 (50%), low counts; p = 0.40. P53 expression was detected in 11 (18.6%) of 59 pterygium samples and 5 (71.4%) of 7 controls; p = 0.007. MMP 1 staining was present in 14 (23.7%) of 59 sections and 5 (71.4%) of 7 controls; p = 0.02. MMP2 in 16 (27.1%) cases and 5 (71.4%) controls; p = 0.03. MMP3 was overexpressed in 16 (27.1%) of 59 cases and 5 (71.4%) controls; p = 0.03. Conclusions : Mild chronic inflammation has a tendency to be more frequent than severe inflammation in pterygia. It is clear that damaged limbal basal epithelial cells are unlikely to be related to pterygium occurrence.

Key words : Pterygium, Inflammatory cells