Differentiation unilateral glaucoma from longstanding or subacute NAION can be challenging. For the best patient outcomes, it important that a comprehensive eye examination including colour vision testing, field testing and OCT be conducted on the initial presentation.

One of the main differentiating clinical features between NAION and glaucoma is that NAION presents with sudden onset of visual loss with a swollen optic nerve while glaucoma presents more insidiously with optic nerve cupping. A swollen nerve is not always found in NAION, as some patients present late when clinical findings relating to an acute insult to the optic nerve have already resolved. The visual field can also look similar with the arcuate scotoma of glaucoma resembling an incomplete altitudinal field loss of NAION. 

With glaucoma on the rise, clinicians are increasingly finding that even with the latest technology, true diagnosis remains stubbornly difficult. Leanne Nguyen from our Specsavers Knox store performed a visual field exam due to a suspicious optic nerve appearance on fundoscopy and corresponding abnormal OCT. She then referred her patient to an ophthalmologist following the detection of a right superior visual field defect. 

It is without saying that Leanne is changing the life of her patient through better sight detection. To find out more with differentiating clinical features between NAION and unilateral glaucoma and to understand the role that OCT-A has in the diagnosis of NAION, read the article that is co-authored by Leannae Nguyen and Dr Lewis Levitz. https://www.insightnews.com.au/unilateral-glaucoma-or-historic-non-arteritic-anterior-ischaemic-optic-neuropathy-naion/