Aqueous Humor Growth Factor Levels and Trabeculectomy Outcomes in Primary Open-Angle Glaucoma Patients: A 2-Year Prospective Study

Abstract

Purpose Maintenance of a filtering bleb is essential for long-term intraocular pressure control after trabeculectomy. Surgical site fibrosis and excessive extracellular matrix production are common causes of trabeculectomy failure, mediated by several growth factors. We aimed to evaluate the levels of five growth factors and their correlation with trabeculectomy outcomes in patients with primary open-angle glaucoma (POAG). Methods We collected aqueous humor samples intraoperatively from patients with POAG who underwent trabeculectomy and measured the concentrations of transforming growth factor-β (TGF-β), acidic fibroblast growth factor (aFGF), insulin-like growth factor-1, vascular endothelial growth factor, and platelet-derived growth factor using multiplexed immunoassay kits. Intraocular pressure was measured with Goldmann applanation tonometry at 1 week and at 1, 3, 6, 12, 18, and 24 months after trabeculectomy. We allocated the eyes based on surgical outcome into a success or failure group. Results Significantly high levels of aFGF and TGF-β were observed in the failure group (both P < 0.0001) and were significant risk factors for trabeculectomy outcomes. Higher success rates were observed over the 24-month follow-up period in eyes with low aFGF and TGF-β levels compared to eyes with high levels ( P = 0.0031 and P = 0.0007, respectively). The levels of TGF-β were significantly positively correlated with aFGF. Conclusions In POAG patients, high aFGF and TGF-β levels were significant risk factors for trabeculectomy failure. Translational Relevance Modulation of aFGF and TGF-β expression may have potential clinical applications after filtration surgery.

Aqueous Humor TGF-β2 and Its Association With Intraocular Pressure in a Naturally Occurring Large Animal Model of Glaucoma

“…Thus, even secondary increases in TGF-β2 concentrations can modulate ECM composition, AH outflow, and IOP, most consistently reported in POAG and can also negatively impact outcomes of glaucoma surgery, such as trabeculectomy. 38 , 70 , 71 Although a robust, positive association between AH TGF-β2 levels and IOP was identified in cats with glaucoma, the present study was not designed to establish the cause-and-effect relationship between these factors. Accumulating evidence from in vivo and ex vivo studies support that TGF-β2 contributes to IOP regulation and dysregulation.…”