This present research project intends to collect five quantitative test series:

• perimetric examination using static stimuli, assessing the entire (80 degree) visual field with a fast thresholding algorithm (GATE) [Schiefer 2008] to know the extent/ magnitude of the visual field defect and its variability within the cohort and over time
• D-BCVA, using FrACT [Bach 2007] and EDTRS chart [Ferris 1982]
• RAPD (using swinging flashlight test).
• IOP (using applanation tonometer)
• RNFT and RNFV using Spectralis OCT (star scan, ring scan 2,8 mm, and volume scan) Optic disk morphology will be documented by fundus photography. This assessment of the above-mentioned data is needed in order to allow for estimation of the spontaneous course / fluctuation of the (quantified) functional and morphometric parameters of the N-AION patients during the follow-up period. This is essential for the estimation of the sample size of the subsequently intended SINN study, that is intended to compare different therapeutic strategies in N-AION patients.

Inclusion Criteria: - physical, intellectual and linguistic abilities, in order to understand the test requirements

• willingness to comply with the protocol (4 visits)
• 41 - 80 years, informed consent
• acute N-AION (< 7 d)
• D-BCVA > 0.1 (2/20)
• RAPD ≥ 0.3 logE steps (neutral density filters) and:
• spherical ametropia max. ± 8 dpt, cylindrical ametropia max. ± 3 dpt
• isocoria, pupil diameter > 3 mm

Exclusion Criteria:

• diabetic retinopathy and any other orbital, intracranial or optic nerve disease
• history of epilepsy or significant psychiatric disease
• medications known to affect visual field sensitivity
• infections (e.g. keratitis, conjunctivitis, uveitis)
• severe dry eyes
• miotic drug
• amblyopia
• strabismus
• any ocular pathology, in either eye, that may interfere with the ability to obtain visual fields, disc imaging or accurate IOP readings
• cataract with relevant impairment of vision
• keratoconus
• intraocular surgery (except for uncomplicated cataract surgery) performed < 3 month prior to screening
• history or signs of any visual pathway affection other than N-AION
• history or presence of macular disease and / or macular edema
• ocular trauma

Patients with acute N-AION (less then 7 days); male and female > 18 years