OCT Measurement of TM/SC Stiffness in Living Mice

The most important factor in preventing blindness in glaucoma patients is early diagnosis and effective treatment of the disease. We have developed a way, without touching the eye, to visualize the mouse outflow pathway, ie, the tissues draining fluid from the eye that control intraocular pressure (IOP), as that pathway may be affected by different pressure readings and various glaucoma drug treatments. This project is vital in three ways: 1) we can make glaucoma eyes in mice that mimic the disease in humans in order to test how the outflow tissue of diseased eyes differs from normal eyes; 2) we can treat the glaucoma eyes with newly developed drugs to see whether they are safe and effective for glaucoma; 3) we can apply the information collected from these animals to clinical purposes for glaucoma early diagnosis and effective treatment.

Lowering intraocular pressure (IOP) is neuroprotective, delaying/preventing vision loss in primary open-angle glaucoma patients. Much of the functional morphologic knowledge about the conventional outflow pathway has been limited to fixed samples, often from patients on long-term medical treatment, and thus is subject to artifact and represents only a “snapshot” in time. In actuality, IOP is dynamic and integrated, and IOP oscillations are dampened by the pressure-dependent conventional outflow tract. The aim of this study is to understand the vibrant response of conventional outflow tissues to changes in IOP and to a conventional outflow drug, in real-time. Specifically, we aim to develop non-invasive methodologies to determine the stiffness of the trabecular meshwork (TM)/Schlemm’s canal (SC) inner wall in young, aged, and corticosteroid-induced glaucoma mouse eyes (plus/minus treatment with a rho kinase inhibitor) using spectral domain OCT. Our study has potential impact for three important clinical unmet needs: (i) early glaucoma diagnosis, (ii) monitoring treatment response and (iii) following disease progression.