Ocular Perfusion in Patients With Idiopathic Intracranial Hypertension

This study is measuring blood flow to the eye in people who have idiopathic intracranial hypertension (IIH) — a condition where pressure around the brain is too high for no clear reason, often causing headaches and vision problems — to better understand how this condition affects the eyes. **You may be eligible if...** - You are 18 or older and have been newly diagnosed with IIH, or are experiencing a relapse - You are a non-smoker - Healthy volunteers who are age- and sex-matched may also be eligible as a comparison group **You may NOT be eligible if...** - You have donated blood in the 3 weeks before the study - You are a smoker - You are pregnant or have recently given birth - You have other significant eye or medical conditions that could affect results Talk to your doctor to see if this trial is right for you.