World data on the association between Helicobacter pylori infection and glaucoma

Data on the prevalence of Helicobacter pylori infection in patients with various types of glaucoma present geographical and ethnic similarities and diversities, possibly reflecting the presence of geographical variability in the prevalence of both H. pylori infection and glaucoma types. Specifically, the relevant Greek data show a high prevalence of H. pylori infection in Greek patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma. H. pylori eradication was shown to have a beneficial effect on glaucoma progression, suggesting a possible causal link between the bacterium and glaucoma. H. pylori-specific IgG antibody concentration was increased in the aqueous humor of patients with POAG, and correlated with the degree of vertical cupping, possibly indicating the severity of glaucomatous damage. These data indicate that H. pylori infection appears to be involved in the pathogenesis of glaucoma. Based on various relevant diagnostic methods for the detection of H. pylori infection, the data from Korean, Chinese, Indian, Iranian and Turkish studies are in accordance with the Greek findings, whereas data from Canadian, Italian and Israeli studies, using serology, failed to document an association between H. pylori infection and glaucoma. It must be pointed out that the serological method has limitations, mainly because it cannot distinguish between current and past infections. This is a review of the relevant data published worldwide, with a critical analysis of the results based on the diagnostic methods employed.