NA-AION Risk Factors: New Perspectives

Study Overview
=================
Brief Summary
-----------------
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.

Detailed Description
-----------------
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).

Official Title
-----------------
Non-Arteritic Anterior Ischemic Optic Neuropathy Risk Factors: New Perspectives

Conditions
-----------------
Non-arteritic Ischemic Optic Neuropathy, Optic Disk Drusen

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Diagnosis of first episode of NA-AION in study eye with symptom onset within 14 days prior Subject age: Age >10 NA-AION diagnosis requires: disc edema seen and documented by site PI visual field defect in the study eye consistent with NA-AION and mean deviation worse than 3.0 dB using the study visual field examination protocol relative afferent pupillary defect (unless the fellow eye had previous NA-AION or other optic nerve or retinal disease that is not exclusionary) Exclusion Criteria: Previous episode of NA-AION in the study eye only Intraocular pressure of >21 mm Hg in the study eye Clinical or pathological evidence of giant cell arteritis Diseases that may affect the optic nerve: glaucoma, multiple sclerosis, Alzheimer disease, and Parkinson disease. Evidence of optic disc drusen and optic nerve hypoplasia are not exclusion criteria given they are important parts of the study. We will not exclude significant retinal diseases, since they may be related to underlying etiologies giving rise to ODD, such as macular degeneration, retinal dystrophies, but eyes with significant retinal diseases will be analyzed separately.

Ages Eligible for Study
-----------------
Minimum Age: 11 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ODD-AION<br>NA-AION patients with ODD aka. Optic disc drusen associated non-arteritic anterior ischemic optic neuropathy. | |
| nODD-AION<br>NA-AION patients without ODD aka Non-optic disc drusen associated non-arteritic anterior ischemic optic neuropathy. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anatomical characteristics on OCT | Presence of ODD. Diameter of the scleral canal, disc area and rim on each quadrant of the optic disc, thickness of the peripapillary choroid, presence of peripapillary hyperreflective ovoid mass-like structures, and prelaminar hyperreflective lines. | At enrollment | 
| Anatomical characteristics on OCT | Presence of ODD. Diameter of the scleral canal, disc area and rim on each quadrant of the optic disc, thickness of the peripapillary choroid, presence of peripapillary hyperreflective ovoid mass-like structures, and prelaminar hyperreflective lines. | 3-months follow-up visit | 
| Vascular characteristics on OCT-A | Transient versus persistent findings of ischemia, segmental location and extent of reduced vessel density. If ODD is present the vessel density will be compared to ODD location and volume. | 3-months follow-up visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ODD characteristics | If ODD is present the volume and location of the ODD (superficial vs. deep) is measured using 3D-segmentation | At 3-months follow-up visit | 
| Best corrected visual acuity | Assessed on Snellen or ETDRS chart | At enrollment | 
| Best corrected visual acuity | Assessed on Snellen or ETDRS chart | 3-months follow-up visit | 
| Visual field test | Autoperimetry: SITA fast or standard 24-2 | At enrollment | 
| Visual field test | Autoperimetry: SITA fast or standard 24-2 | 3-months follow-up visit | 
| Questionnaire score: NEI-VFQ-25 including 10-item NO supplement score | Score on questionnaire: National Eye Institute Visual Function Questionnaire 25 and 10-item Neuro-Ophthalmic Supplement A vision-targeted composite score of the NEI-VFQ-25 together with the 10-item NO supplement score is calculated. The scale is 0-100 where a high score represents better functioning. | At enrollment | 
| Questionnaire score: NEI-VFQ-25 including 10-item NO supplement score | Score on questionnaire: National Eye Institute Visual Function Questionnaire 25 and 10-item Neuro-Ophthalmic Supplement. A vision-targeted composite score of the NEI-VFQ-25 together with the 10-item NO supplement score is calculated. The scale is 0-100 where a high score represents better functioning. | 3-months follow-up visit | 
| Prevalence of comorbidities | ischemic heart disease, stroke (ischemic or hemorrhagic), arterial hypertension, diabetes mellitus, end stage renal disease, smoking (now or previous), dyslipidemia, obstructive sleep apnea/continuous positive airway pressure (CPAP) use, phosphodiesterase-5 inhibitor use or ocular surgery. | At enrollment | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Optical Coherence Tomography, Optical Coherence Tomography Angiography