Glaucoma is one of the leading causes of irreversible blindness in Australia, and one of the most treatable — provided it is detected and managed before significant optic nerve damage has occurred. The challenge is that most forms of glaucoma cause no pain and no obvious visual symptoms until the disease is well advanced. By the time a patient notices peripheral vision loss, up to 40 per cent of their optic nerve fibres may already be gone.
This is why routine eye examinations by an optometrist are so important, and why knowing when to refer to a glaucoma specialist matters for both patients and their referring practitioners.
What is glaucoma?
Glaucoma is a group of conditions characterised by progressive damage to the optic nerve, typically — but not always — associated with elevated intraocular pressure (IOP). The most common form in Australia is primary open-angle glaucoma, which develops gradually and silently over years. Less common forms include normal-tension glaucoma (optic nerve damage despite normal IOP), angle-closure glaucoma (which can present acutely with pain, redness, and blurred vision), and secondary glaucomas caused by other eye conditions.
Which signs should prompt referral to a glaucoma specialist?
From an optometrist's perspective, several findings should trigger an urgent or routine glaucoma referral.
Elevated intraocular pressure is a significant risk factor, particularly when IOP is consistently above 24 mmHg or when there is asymmetry between the two eyes. However, IOP alone is not diagnostic — many patients with high IOP never develop glaucoma, and many with glaucoma have normal IOP.
Optic disc changes are among the most important findings. A cup-to-disc ratio greater than 0.7, asymmetric cupping between the two eyes (a difference of more than 0.2), disc haemorrhages, or notching of the neuroretinal rim are all findings that warrant specialist assessment.
Visual field defects that are consistent with glaucomatous loss — particularly arcuate scotomas, nasal steps, or paracentral defects correlating with optic disc findings — require urgent review.
Corneal thickness below 520 microns is an independent risk factor for glaucoma progression and affects the interpretation of IOP measurements. Thin corneas cause IOP to be underestimated on standard tonometry.
From a patient's perspective, symptoms that warrant prompt ophthalmic review include sudden eye pain, redness, and blurred vision with haloes around lights (suggestive of acute angle closure), or any sudden loss of peripheral vision.
What happens at a glaucoma specialist consultation?
At Northern Eye Consultants, glaucoma assessments are conducted by FRANZCO-certified specialist ophthalmologists with subspecialty training in glaucoma. A comprehensive initial assessment includes gonioscopy (examination of the drainage angle), optic disc photography, optical coherence tomography (OCT) of the optic nerve head and retinal nerve fibre layer, and automated visual field testing. These investigations allow precise staging of any existing damage and establish a baseline for monitoring progression.
Where treatment is required, options include topical IOP-lowering medications, selective laser trabeculoplasty (SLT), and surgical procedures including trabeculectomy and minimally invasive glaucoma surgery (MIGS). The choice of treatment depends on the type and severity of glaucoma, the patient's systemic health, and their life expectancy.
How to refer a patient to Northern Eye Consultants for glaucoma assessment
GPs and optometrists can refer patients via our HealthLink EDI (nthneyec) or by faxing a referral to (03) 9466 8833. Our Clinical Referral Hub at northerneyeconsultants.com.au/for-referrers provides urgency guidance and downloadable referral templates. Patients with suspected acute angle closure should be sent to the nearest emergency ophthalmology service immediately.
Routine glaucoma referrals are typically seen within four to eight weeks. Semi-urgent referrals — including those with significant disc changes or field loss — are seen within one to two weeks.