Non-arteritic anterior ischemic optic neuropathy (NA-AION) is the most common acute optic neuropathy in the middle-aged and elderly population and can also occur in children and young adults. NA-AION leads to irreversible vision loss, and there is currently no effective treatment. In recent years, acellular calcified deposits in the optic nerve head called optic disc drusen (ODD) have been investigated as an important risk factor for NA-AION in patients under the age of 50.~The purpose of the study is to use new diagnostic methods optical coherence tomography (OCT) and OCT-angiography (OCTA) to shed light on risk factors for the development of NA-AION. We will perform two sub-studies:~Characteristics of the optic nerve head anatomy including the presence of ODD as risk factors for the development of NA-AION.~Vascular comorbidities and in vivo vasculature as a risk factor for developing NA-AION.~The study is an international prospective multicenter study including 20 sites in 9 different countries. The study population is patients diagnosed with NA-AION in a 1.5-year inclusion period. Each included patient gets 1-2 follow up visits during a 3-month follow up time.~Included patients will be examined as per standard clinical care for that site including OCT and OCT-A. Standard clinical care includes at least: obtaining medical history, measurement of visual acuity, slit lamp examination, and automated perimetry.~Characteristics and risk factors in NA-AION patients with ODD (ODD-AION) will be compared with NA-AOIN patients without ODD (nODD-AION).
The purpose of the study is to use new diagnostic methods (OCT and OCT-A) to shed light on risk factors for the development of NA-AION. The risk factors we are focusing on are comorbidities along with anatomical and vascular characteristics of the optic nerve.