The Stressed Optic Nerve at High Altitude and Treatment with Chemical Chaperon

High altitude-associated non-arteritic anterior ischemic optic neuropathy (NAION) [1-3] typically occurs in younger patients who have disc-at-risk and few other risk factors [4-9], raising the possibility that hypobaric hypoxia may be the tipping point of vision loss. In this study, we investigated the effects of systemic hypoxia on the retina and optic nerve and assessed the therapeutic potential of pre-treatment with chemical chaperon 4-phenylbutyric acid (4- PBA), which reduces endoplasmic reticulum (ER) stress.