Histopathological study of delayed Mustard Gas Keratopathy

Abstract

Aims: Ocular injury by mustard gas (HD) leads to severe eye damage. Long term characterization of mustard gas ocular toxicity has not been described in detail yet. Present study was performed in order to explore chronic histological and immunopathologic effects of HD ocular exposure and try to find etiology for these effects. Methods: This descriptive case study was performed on corneal and conjunctival samples of 22 chemical injured victims with late-onset keratophathy who needed surgical treatment between 1997 to 2007 in Baqiyatallah hospital. Samples were selected by simple sampling method. Both eyes underwent surgery in 7 cases therefore 29 samples were delivered to pathology section. 29 limbus specimens were studied by light, direct immunofluorescence and electron microscopy. Results: Histological findings revealed signs of chronic inflammation. Conjunctivalization, epithelial thinning and goblet cell depletion in light microscopy as well as corneal edema, basement membrane destruction and cytoplasmic vacuolization in electronic microscopy were dominant findings. Fluorescent microscopy demonstrated nonspecific changes. Conclusion: There are no diagnostic histopathologic or microscopic findings in late-onset HD ocular injuries. According to our observations, neither humoral nor cell mediated immunity could explain all histological damages. It seems that primary alkalizing injury is the keystone of HD late-onset pathogenesis.