Biology subjects

Farsiu, S.

Publications and source records attributed to Farsiu, S..

2 recordsLinked to original sources

bioRxiv2023

Aging and intraocular pressure homeostasis in mice

Age and elevated intraocular pressure (IOP) are the two primary risk factors for glaucoma, an optic neuropathy that is the leading cause of irreversible blindness. In most people, IOP is tightly regulated over a lifetime by the conventional outflow tissues. However, the mechanistic contributions of age to conventional outflow dysregulation, elevated IOP and glaucoma are unknown. To address this gap in knowledge, we studied how age affects the morphology, biomechanical properties and function of conventional outflow tissues in C57BL/6 mice, which have an outflow system similar to humans. As reported in humans, we observed that IOP in mice was maintained within a tight range over their lifespan. Remarkably, despite a constellation of age-related changes to the conventional outflow tissues that would be expected to hinder aqueous drainage and impair homeostatic function (decreased cellularity, increased pigment accumulation, increased cellular senescence and increased stiffness), outflow facility, a measure of conventional outflow tissue fluid conductivity, was stable with age. We conclude that the murine conventional outflow system has significant functional reserve in healthy eyes. However, these age-related changes, when combined with other underlying factors, such as genetic susceptibility, are expected to increase risk for ocular hypertension and glaucoma.

physiology↗

bioRxiv2020

Antifibrotic activity of a rho-kinase inhibitor restores outflow function and intraocular pressure homeostasis

Glucocorticoids are widely used as an ophthalmic medication. A common, sight-threatening adverse event of glucocorticoid usage is ocular hypertension, caused by dysfunction of the conventional outflow pathway. We report that netarsudil, a rho-kinase inhibitor, rapidly reversed glucocorticoid-induced ocular hypertension in patients whose intraocular pressures were uncontrolled by standard medications. Mechanistic studies in our established mouse model of glucocorticoid-induced ocular hypertension show that netarsudil both prevented and reversed intraocular pressure elevation. Further, netarsudil reversed characteristic steroid-induced pathologies as assessed by quantification of outflow function and tissue stiffness, and morphological and immunohistochemical indicators of tissue fibrosis. Thus, rho-kinase inhibitors act directly on conventional outflow cells to efficaciously prevent or reverse fibrotic disease processes in glucocorticoid-induced ocular hypertension. These data motivate a novel indication for these agents to prevent or treat ocular hypertension secondary to glucocorticoid administration, and demonstrate the antifibrotic effects of rho-kinase inhibitors in an immune-privileged environment.

physiology↗