The anterior segment of the lens was found to be clear for both the eye. It was observed that during the swinging flashlight test the RE had a sluggish relative afferent pupillary defect (RAPD) but LE showed a positive response. The intraocular pressure was normal in both the eye and was found to be 18mm Hg. On examination of the patient eyes, it was found that visual acuity was 6/60 in RightEye (RE) and 6/6 in Left Eye (LE), near vision, was N36 in RE and N6 in LE. He is a known case of type II diabetes mellitus and hypertension for the past 12 years. His height is 168 cm body weight is 75 Kg with a body mass index is 26.6 kg/m2. Case ReportĪ 45-year-old male came to the hospital with complaints of sudden onset of painless vision loss in the right eye for 1 month. Mean age reported was 66 years in IONDT (ischemic optic nerve decompression trial), while in most other studies documented age range is 57-65 years. It occurs equally in frequency in both the gender. Inter-ethnic differences in frequency of NAION may be attributed to the different size of optic disc which occurs predominately in small optic nerve head. This occurs most commonly in the white population than black or Hispanic individuals.
Annual prevalence of NAION was reported as 0.30% and incidence was found to be as high as 82 cases per 100,000 in large Medicare database study. NAION is the most common form, constitutes 95% of AION, and is the most common cause of acute optic neuropathy over the age of 50 years. NAION is managed only through antiplatelet and anticoagulant drugs. There is no complete cure to the disease. NAION is diagnosed using fundus fluorescein angiography, ICG angiography, Colour Doppler, and laser Doppler flow. Some of the common causes of NAION are sleep apnea syndrome, optic disc drusen, and medications such as interferon and sildenafil. Among systemic factors, nocturnal hypotension, hypertension, diabetes mellitus, hyperlipidemia, and smoking are associated, whereas among ocular risk factors crowding of optic nerve head is the important one. NAION is mostly of unknown cause, though many systemic and ocular risk factors have been identified. Arteritic Anterior Ischemic Optic Neuropathy (AAION) is secondary to inflammatory small vessel disease, i.e., vasculitis, whereas Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) is secondary to non-inflammatory small vessel disease. AION is the most common cause of acute optic nerve ischemia related vision loss in adults and secondary cause of optic nerve-related permanent vision loss in adults after glaucoma. The characteristic of Anterior Ischemic Optic Neuropathy (AION) is visible disc edema because of ischemic damage to the anterior portion of the optic nerve that is supplied by Posterior Ciliary Arteries (PCA). Ischemic optic neuropathy is an acute ischemic disorder of the optic nerve. Optic Disc Edema articles Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION) articles Visual Field articles Optic Nerve Atrophy articles Article Details Introduction