Investigation of the association between glaucoma and Helicobacter pylori infection

Glaucoma is a neurodegenerative disease characterized by retinal ganglion cell degeneration. Although glaucoma is prevalent worldwide, its etiopathogenesis remains incompletely understood. Increased intraocular pressure (IOP) is the most frequently implied cause for retinal ganglion cell degeneration. Recent studies show that cytokines, impaired ocular blood flow, and structural changes in blood vessels are also involved in the pathogenesis of glaucomatous optic neuropathy. Helicobacter pylori is a helical, Gram-negative bacterium known to be involved in the pathogenesis of gastritis, gastric ulcer, gastric carcinoma, and Alzheimer’s disease. Some studies have also suggested that H. pylori infection may be involved in nongastrointestinal disorders because of the release of reactive oxygen species. Thus, it is thought that H. pylori facilitates glaucoma pathogenesis by causing the release of Nitric Oxide, endothelin-1, and reactive oxygen species. Several recent studies have investigated the association between H. pylori infection and glaucoma. In most such studies, serum IgG levels have been used to establish the presence of H. pylori infection. Recently, noninvasive and invasive methods have been used to evaluate the presence of H. pylori. Invasive methods include histopathological examination gastric mucosal samples, polymerase chain reaction, culture methods, and the rapid urease test. Noninvasive methods include serological tests, C-urea breath test (14C-UBT), and H. pylori antigen level measurements in stools. Accurate diagnostic rates of 80%-84% have been reported for noninvasive tests by the serological method; however, tests can be positive for 6-12 months after H. pylori eradication; thus, positivity does not necessarily confirm active infection. Because samples need to be stored at -20°C, the use of the H. pylori stool antigen method is restricted. The other noninvasive test is the 14C-UBT, which is the most common test reported in the literature. Many studies have reported a sensitivity of 95%-100% and a specificity of 97%-100% for 14C-UBT. Thus, in recent years, it has become the preferred method for detecting H. pylori infections. To the best of our knowledge, this is the first study to investigate the relationship between H. pylori and glaucoma using 14C-UBT.