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Rare eye condition

Acute zonal occult outer retinopathy (AZOOR)

AZOOR is a rare retinal condition causing sudden zones of visual loss and persistent shimmering or flickering light, typically in young women, with an initially normal-looking retina.

Key points

The essentials at a glance.

What to look out for, how the diagnosis is confirmed, who looks after it, and the options that exist.

  • 01

    Classic features are a rapidly enlarging blind spot or field defect with photopsia - constant shimmering or flickering - in the affected zone.

  • 02

    The retina can look normal at first; the damage shows on autofluorescence imaging, OCT and electroretinography.

  • 03

    The cause is unknown; an autoimmune process directed at the outer retina is suspected.

  • 04

    Many cases stabilise spontaneously; a minority progress or involve the second eye.

  • 05

    Steroids or immunosuppression are sometimes tried for progressive disease, though evidence is limited - honest counselling matters.

Understanding it

What it is, and what happens next.

In plain English - what is going on, how specialists confirm it, and the routes to treatment in the UK.

AZOOR earns its name: acute onset, affecting a zone of retina, occult because the eye can initially look entirely normal, and confined to the outer retinal layers where photoreceptors live. Patients describe a curtain-edge of missing vision fringed with relentless shimmering, and are sometimes disbelieved until the right imaging and electrodiagnostic tests are done.

The priorities in a specialist clinic are to prove the diagnosis with autofluorescence, OCT and ERG, to exclude mimics including cancer-associated retinopathy and infections, and then to monitor: most zones eventually stop enlarging, and decisions about immunosuppression are reserved for the minority with relentless progression. In many parts of the UK, routine NHS outpatient referrals for problems like this can take several months, whereas an initial appointment with a private consultant is typically available within around two weeks.

A quiet reminder

This guide is for information, not medical advice.

Your GP or specialist knows your history and can tell you which parts apply to you. If in doubt, speak to them.

Published 2026-09-27 · Next review 2027-09-27

Frequently asked

Common questions about Acute zonal occult outer retinopathy (AZOOR).

Quick, plain-English answers to what people ask us most.

  • What is acute zonal occult outer retinopathy (AZOOR)?

    AZOOR is a rare eye condition causing sudden dysfunction of the outer retina, leading to visual field loss and visual disturbances, often affecting one eye more than the other, most commonly in younger adults.

  • What causes AZOOR?

    The exact cause is not fully understood, though it is thought to involve inflammation or an autoimmune process affecting the outer layers of the retina, sometimes triggered by a preceding viral illness.

  • What are the symptoms of AZOOR?

    Symptoms include sudden onset of visual field loss (often described as a blind spot), flickering or shimmering lights (photopsia), and sometimes blurred vision, typically affecting one eye initially.

  • Is AZOOR dangerous?

    It is not life-threatening, but it can cause lasting visual field loss in some cases, and it can occasionally recur or affect the other eye, so ongoing specialist monitoring is important.

  • Can AZOOR be treated?

    There is no proven cure, but some cases improve on their own over time; in more persistent or progressive cases, anti-inflammatory or immune-modulating treatments may be considered by a retina specialist.

  • How is AZOOR diagnosed?

    Diagnosis involves specialised retinal imaging and visual field testing, sometimes combined with electrophysiological tests that measure retinal function, since the retina can look relatively normal on standard examination.

  • How long does AZOOR last and does vision recover?

    The course is variable; some people experience significant improvement in vision over weeks to months, while others are left with some permanent visual field loss, making individual monitoring important.

  • AZOOR vs optic neuritis — what's the difference?

    Optic neuritis involves inflammation of the optic nerve itself, often causing pain with eye movement and more central vision loss, while AZOOR specifically affects the outer retina, typically causing visual field loss without significant pain.

  • Can AZOOR recur or affect both eyes?

    Yes, some people experience recurrence in the same eye or later development in the other eye, which is why ongoing follow-up with an ophthalmologist is generally recommended.

  • When should I see a doctor about possible AZOOR, and how quickly can I be seen privately?

    See a doctor promptly for sudden visual field changes or flickering lights. NHS ophthalmology referral can take several weeks, while private ophthalmology assessment is often available within about one to two weeks.