Vision loss — emergency triage and workup in Australian general practice

Vision loss is one of the most feared symptoms a patient can present with, and the GP’s role is clear: triage urgency correctly, perform the minimum essential examination, and ensure timely ophthalmology access. The distinction between sudden and gradual, painful and painless, monocular and binocular loss determines whether a patient needs emergency care today or routine review next month. Missing the window on a retinal artery occlusion or delaying steroids in giant cell arteritis can cost a patient their sight permanently.

A. Core clinical — the AU general-practice framework

Classification and approach

Vision loss is classified by four parameters: tempo (sudden vs gradual), pain (painful vs painless), laterality (monocular vs binocular/homonymous), and anatomy (ocular media, retina, optic nerve, chiasm, post-chiasmal). These parameters guide the differential before any examination.

Sudden monocular painless loss — central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO), central retinal vein occlusion (CRVO), retinal detachment, vitreous haemorrhage, anterior ischaemic optic neuropathy (AION). All are ophthalmology emergencies.

Sudden monocular painful loss — acute angle-closure glaucoma (severe pain, halos, mid-dilated fixed pupil), anterior uveitis, optic neuritis (pain on eye movement, dyschromatopsia), giant cell arteritis. All require same-day assessment.

Gradual loss — cataract, age-related macular degeneration (AMD), open-angle glaucoma, diabetic retinopathy, refractive error. Routine but important to manage proactively.

Bilateral simultaneous sudden loss — suspect occipital stroke, posterior reversible encephalopathy (hypertensive), pituitary apoplexy (bitemporal hemianopia), or methanol toxicity. Neurological emergency.

Essential examination in general practice

The GP’s minimum required eye examination for any visual complaint includes:

1. Visual acuity — Snellen at 6 m, then with pinhole (improvement with pinhole suggests refractive cause). Record each eye separately.
2. Confrontation visual fields — quadrant by quadrant; detect hemianopia, altitudinal defects, central scotoma.
3. Pupils — direct, consensual, and the swinging-light test for relative afferent pupillary defect (RAPD), which localises pathology to the optic nerve or extensive retinal disease. An RAPD means urgent referral.
4. Red reflex — absent or dull suggests media opacity (cataract, vitreous haemorrhage); white reflex (leukocoria) in a child is retinoblastoma until proved otherwise.
5. Fundoscopy — optic disc (cup, swelling, pallor), macula (drusen, haemorrhage, exudate), vessels (cherry-red spot of CRAO, blood-and-thunder of CRVO), periphery.
6. Blood pressure and pulse — relevant to most vascular causes.
7. Temporal arteries in patients over 50 with headache — tender, thickened, beaded, non-pulsatile: suspect giant cell arteritis.

Key diagnoses — must-not-miss

Central retinal artery occlusion. Sudden painless profound monocular vision loss with RAPD, cherry-red spot (foveal choroidal supply intact against pale infarcted retina), and attenuated arteries. Treat as a stroke equivalent: same-day ophthalmology or emergency department, carotid Doppler, echocardiogram, cardiac monitoring for atrial fibrillation. In patients over 50, always check ESR, CRP, and platelet count for giant cell arteritis.

Giant cell arteritis / arteritic AION. The most important diagnosis not to miss. Age over 50, new temporal headache, jaw claudication, scalp tenderness, raised ESR and CRP. Start prednisolone 1 mg/kg/day (maximum 60 mg) orally immediately — or IV methylprednisolone 1 g/day × 3 days if visual symptoms are present, per eTG. Arrange temporal artery biopsy and rheumatology referral, but steroids first, biopsy later. Delayed treatment risks the fellow eye.

Acute angle-closure glaucoma. Severe eye pain, headache, nausea and vomiting, coloured halos around lights, mid-dilated non-reactive pupil, hazy cornea, rock-hard globe. Urgently lower intraocular pressure with topical pilocarpine 2%, timolol 0.5%, apraclonidine or brimonidine; oral or IV acetazolamide 500 mg per eTG; analgesia and antiemetics. Same-day ophthalmology for laser peripheral iridotomy.

Retinal detachment. Flashes, new floaters, then a curtain descending across the visual field. Risk factors: high myopia, prior cataract surgery, trauma, family history. Same-day ophthalmology — surgical repair (vitrectomy, scleral buckle, pneumatic retinopexy) is the treatment.

Optic neuritis. Typically subacute monocular vision loss with pain on eye movement and colour desaturation (red looks dull — red desaturation test). RAPD present. Associated with demyelinating disease — 50% develop multiple sclerosis over 15 years. MRI brain and spine with gadolinium; neurology referral.

B. Gradual vision loss — the common causes

Cataract

Cataract is the most common cause of reversible vision loss globally. Patients present with gradually worsening blurred vision, increased glare, difficulty with night driving, and monocular diplopia. Red reflex is reduced or absent. Refer to optometrist for assessment, then to ophthalmologist when quality of life or driving safety is affected. Phacoemulsification with intraocular lens implantation is MBS-rebated and highly effective. AIHW Eye Health 2024 confirms cataract surgery accessibility in Australia is excellent compared with global standards.

Age-related macular degeneration

AMD is the leading cause of legal blindness in Australians over 50 — approximately 1 in 7 people over 50 have early or intermediate AMD, per the Macular Disease Foundation Australia. Dry AMD causes slowly progressive central vision loss from drusen accumulation and retinal pigment epithelium atrophy. Wet AMD causes rapid central vision loss from choroidal neovascularisation — any new metamorphopsia (distorted lines on an Amsler grid) warrants urgent ophthalmology referral. Wet AMD is treated with intravitreal anti-VEGF injections (ranibizumab, aflibercept, faricimab). For intermediate AMD, AREDS2 supplements (vitamin C, E, zinc, copper, lutein, zeaxanthin) slow progression by approximately 25% over 5 years. Smoking is the strongest modifiable risk factor — cessation is paramount.

Open-angle glaucoma

Glaucoma affects approximately 3% of Australians over 50, with half undiagnosed. Elevated intraocular pressure is a major risk factor, but normal-tension glaucoma also exists. The disease is typically asymptomatic until significant peripheral field loss has occurred — hence the importance of opportunistic screening by optometrists during routine eye checks. Treatment involves topical prostaglandin analogues (latanoprost, bimatoprost, travoprost) as first-line, with other agents added as needed. Glaucoma Australia provides excellent consumer resources. Family history (4–9× increased risk) warrants referral for screening even if asymptomatic.

Diabetic retinopathy

Approximately 30% of Australians living with diabetes have some degree of diabetic retinopathy, per NHMRC guidelines. Macular oedema causes most vision loss. Optimising HbA1c, blood pressure, and lipids remains the most powerful prevention. Every diabetic patient should be enrolled in KeepSight — the national diabetic eye check register. Non-mydriatic retinal photography (MBS item 10942) is available through optometry or general practice. Ophthalmology referral for retinopathy beyond mild non-proliferative or for any macular oedema — treatment with anti-VEGF or laser is PBS Authority-listed.

C. Investigations

First-line at GP assessment: visual acuity with pinhole, confrontation fields, swinging-light test (RAPD), red reflex, fundoscopy, blood pressure, BSL, ECG (for atrial fibrillation in embolic CRAO).

Bloods: FBC, ESR, CRP (GCA), fasting lipids, HbA1c (diabetic), U&E, TFT. Vasculitic screen (ANA, ANCA, ACE, RF, CCP) for uveitis with systemic features. Syphilis, HIV, quantiferon for atypical uveitis.

Imaging: CT brain for acute neurological deficit or trauma; MRI brain with orbits and gadolinium for optic neuritis or tumours; carotid Doppler for amaurosis fugax or CRAO; echocardiogram for embolic CRAO.

D. Australian operations

MBS items. Standard GP consultations (items 23, 36, 44). Optometry comprehensive eye examination (item 10918). Diabetic retinal photography (item 10942). Ophthalmologist initial/subsequent consultations (items 104/105). Cataract surgery (item 42702). Intravitreal injection (item 42740). ATSI Health Assessment (item 715) includes visual acuity. 75+ health assessment (item 707) includes vision screen.

PBS items. Ranibizumab (Lucentis), aflibercept (Eylea), and faricimab (Vabysmo) are Authority Required for wet AMD and diabetic macular oedema — ophthalmologist-initiated. Latanoprost, bimatoprost, travoprost, timolol are General Schedule for glaucoma. Prednisolone oral is General Schedule (GCA, optic neuritis, uveitis). Acetazolamide is General Schedule (acute angle closure). AREDS2 supplements are not PBS-listed — OTC.

Driving. The Austroads standards require best corrected visual acuity of at least 6/12 binocularly and horizontal visual field of at least 120° for an unconditional private licence, per Austroads Assessing Fitness to Drive. GPs have a duty to report visual impairment that does not meet driving standards to the relevant driver licensing authority.

Closing the Gap / ATSI pathways. Aboriginal and Torres Strait Islander Australians have approximately three times the rate of vision loss and blindness. The Indigenous Eye Health Roadmap sets national targets. The SAFE strategy (Surgery, Antibiotics, Facial cleanliness, Environmental improvement) addresses trachoma, which persists in remote communities. KeepSight enrolment for Indigenous patients with diabetes is a key GP role.

E. Special populations

Older adults. GCA must be considered in every patient over 50 presenting with new headache and visual symptoms. Cataract surgery reduces falls risk and may slow cognitive decline — refer when QoL is affected, not only when acuity reaches an arbitrary threshold.

People with diabetes. Annual KeepSight-linked retinal screening is the standard, confirmed at every diabetes review consultation. If a diabetic patient reports any sudden vision change, treat as urgent — do not wait for the scheduled annual check.

Children. White reflex (leukocoria) in any child must be urgently assessed to exclude retinoblastoma. Vision screening at Healthy Kids Checks, school entry, and school screening should identify amblyopia and significant refractive errors early. Asymmetric red reflex or eye turn warrants prompt paediatric ophthalmology referral.

Immunocompromised patients. CMV retinitis in HIV with low CD4 count, toxoplasma retinochoroiditis, and other opportunistic infections cause vision loss and require specialist management. Any vision change in an immunocompromised patient warrants urgent ophthalmology input.

When to escalate

Refer or escalate urgently when:

• Any sudden loss of vision in one or both eyes — same-day ophthalmology or emergency department
• Suspected giant cell arteritis — start prednisolone immediately and arrange same-day assessment
• Flashes, floaters, or curtain across vision — suspected retinal detachment, same-day
• RAPD detected on examination — urgent ophthalmology regardless of cause
• Acute angle-closure glaucoma — emergency
• Optic neuritis — urgent ophthalmology and neurology
• Wet AMD (new metamorphopsia) — urgent ophthalmology within days
• Visual impairment from any cause in a patient who drives — formal driving assessment

What this article is and is not

This is general health information drawn from current Australian guidelines — RACGP, Therapeutic Guidelines (eTG), RANZCO, NHMRC, Macular Disease Foundation Australia, and KeepSight. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about specific investigations, specialist referral, and treatment are made with your own GP, optometrist, and ophthalmologist.

For consumer information: HealthDirect — Sudden vision loss, Better Health Channel, Macular Disease Foundation Australia, Glaucoma Australia, Vision Australia.

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Sources cited

1. RACGP — Acute vision loss in general practice
2. Therapeutic Guidelines (eTG) — Eye conditions
3. RANZCO — Referral pathways
4. NHMRC — Diabetic retinopathy and AMD guidelines
5. Macular Disease Foundation Australia
6. KeepSight — Diabetic eye check register
7. AIHW Eye Health 2024
8. NPS MedicineWise
9. Australian Medicines Handbook — Ophthalmic preparations
10. Glaucoma Australia
11. HealthDirect — Sudden vision loss
12. Better Health Channel
13. Austroads — Assessing Fitness to Drive
14. Indigenous Eye Health Unit — University of Melbourne