Abstract
Purpose: Retinal ganglion cell (ROC) death is a key feature of glaucoma. Elevated levels of tumor necrosis factor alpha (TNF-alpha), a pro-inflammatory cytokine, can induce RGC apoptosis and play a critical role in glaucomatous neurodegeneration. Based on the possible role of inflammation and oxidative stress in the pathogenesis of primary open-angle glaucoma (POAG), we investigated the association between plasma levels of TNF-alpha and POAG or its clinical indices in comparison to non-glaucomatous controls.
Patients and methods: In a case-control retrospective cohort of 51 POAG cases and 88 controls, plasma TNF-alpha levels were measured using an enzyme-linked immunosorbent assay (ELISA). The assay was performed in duplicates on an automated ELISA analyzer.
Results: Mean TNF-alpha level was significantly elevated in POAG cases (1.88 +/- 2.17 pg/mL) than the controls (0.93 +/- 1.49 pg/mL; p = 0.003). The overall dose-response trend was significant (chi(2) = 6.12, df = 2; p = 0.047). No statistical difference was seen in age, gender and systemic disease distribution. A modest negative and significant correlation was seen between TNF-alpha level and number of antiglaucoma medications, an important clinical index of POAG severity. Moreover, logistic regression analysis showed that the risk of POAG was most significantly affected by TNF-alpha level and not by age and sex.
Conclusion: High systemic level of an inflammatory cytokine, TNF-alpha, is associated with POAG; however, its possible use as a biomarker for early glaucoma diagnosis and/or disease severity needs further investigation.