Isometric Exercise in NTG

Glaucoma is the second leading cause of blindness worldwide. Literature shows increasing evidence that dysfunction of ocular microcirculation in the optic nerve influences the progression of glaucoma. It has been shown that flicker light-induced vasodilatation of retinal veins is diminished in patients with glaucoma. Also previous studies indicate that the blood flow autoregulation is impaired in patients with glaucoma. Therefor the ocular perfusion pressure can not be maintained stable during changes of the systemic arterial blood pressure. Laser speckle flowgraphy (LSFG) represents a non-invasive method to quantify ocular perfusion also at the ONH. LSFG enables noninvasive quantification of microcirculation of the optic disc in Japanese glaucoma patients. Study Objectives: To assess the changes in LSFG parameters in patients with normal tension glaucoma, compared to healthy subjects during flicker light stimulation and isometric exercises.