Non-Arteritic Ischemic Optic Neuropathy: Kajian terhadap Peran Trombosis, Flux Index dan Capillary Perfusion Pembuluh Darah Nervus Optikus dengan Pemeriksaan Optical Coherence Tomography Angiography = Non-Arteritic Ischemic Optic Neuropathy: Study on the Role of Thrombosis, Flux Index, and Capillary Perfusion of the Optic Nerve Blood Flow with Optical Coherence Tomography Angiography