Lower Levels of Endogenous Intraocular Interferon Beta in Patients with Primary Glaucoma

Purpose: Glaucoma, a neurodegenerative condition of the optic nerve is driven by increased intraocular pressure (IOP) due to fibrotic changes of the trabecular meshwork (TM). Interferon beta (IFN-β), a pleiotropic cytokine is known for its neuroprotective and antifibrotic potential. Hence, we investigated the intraocular status of IFN-β in patients with primary glaucoma. Methods: Aqueous humor (AqH) from patients with primary glaucoma [107 eyes; primary open-angle glaucoma (POAG), 59 eyes; primary angle-closure glaucoma (PACG), 48 eyes] and controls (70 eyes) were collected during cataract surgery and/or trabeculectomy. TM from patients with POAG (20 eyes) and PACG (18 eyes) was collected during trabeculectomy. IFN-β in AqH was measured using bead-based Enzyme-Linked Immunosorbent Assay (ELISA), and messenger RNA (mRNA) expression of IFN-β in TM was measured by quantitative PCR. Results: AqH-IFN-β levels were significantly (P < 0.05) lower in patients with glaucoma, particularly in patients with POAG compared with controls (area under the receiver operating characteristic curve = 0.723, P < 0.001; odds ratio of 5.1, P < 0.0001). AqH-IFN-β levels correlated positively with visual field index of both patients with POAG (r = 0.307; P = 0.0321) and PACG (r = 0.518; P = 0.0007). Whereas, AqH-IFN-β levels correlated positively with retinal nerve fiber layer thickness in patients with POAG (r = 0.460; P = 0.0042) only. TM-IFN-β mRNA expression was significantly lower in glaucoma patients with poor IOP control compared with those with good IOP control by IOP-lowering medications. Conclusion: Lower IFN-β in AqH and TM of patients with glaucoma and its association with clinical indices suggests its neuroprotective and antifibrotic role in glaucoma. The findings highlight the potential for IFN-β-based prognostication and therapy in the management of glaucoma.