Diagnostic Procedures

Fundus photography uses a special camera to take images of the back of the eye. The camera consists of a microscope attached to a camera.

This procedure is invaluable at documenting and monitoring conditions such as diabetes, glaucoma and many macula conditions.

Taking a fundus photo is quick and painless, with just a few bright flashes of light experienced as the photos are taken. Your eyes will usually be dilated (with dilating drops) for this procedure. While the camera flashes are bright, they will not harm your eye. Vision is usually blurry for a few minutes from the flash and will remain blurry for a few hours from the dilating drops.

A fluorescein angiogram involves having a small amount of a special dye injected through a small vein in the arm, which is followed by a rapid sequence of photographs as it passes through the retinal blood vessels. This test allows us to visualise and document the blood circulation of the retina/choroid, particularly for conditions such as vein or artery occlusions, macular degeneration and diabetic retinopathy. It allows for the diagnosis of certain conditions, and can guide the treatment of others.

Your pupils will be dilated prior to this test, which is generally well tolerated. Some patients may feel a little nauseous or light-headed as the dye circulates (about 20 seconds), and some report a feeling of warmth in their arm as the dye is injected. The dye is excreted through your kidneys, so it is normal to see bright orange/yellow urine for the next 24 hours or so. Very rarely a transient itchy rash lasting an hour may be reported and this generally responds to an antihistamine. With the very small dose of dye that is used these days severe reactions (such as asthma and anaphylaxis) are very rare. In the few hours after the angiogram heavy use of the injected arm should be avoided. About 20 to 30 photographs are taken in the 2 minutes after the dye is injected, with a further few photographs about 5 minutes later.

Similarly to fundus photography, your vision will be blurred from the flashes for a few minutes and the blur from the dilating drops will last for several hours.

Optical Coherence Tomography is a non-invasive imaging test that uses light waves to take cross-sectional images of your retina. It allows the layers of the retina to be visualised, and their thickness measured. This technology has become invaluable in the diagnosis and monitoring of glaucoma, macular degeneration, diabetic macula oedema, macula hole, epiretinal membrane and other macula conditions. It has become the gold standard in monitoring response to treatment with intravitreal anti-VEGF injections for wet age-related macular degeneration and determining ongoing treatment intervals.

Your pupils will be dilated, and so vision will remain a little blurred for several hours. OCT is non-invasive and painless, so is always well tolerated by patients. Unfortunately Medicare does not offer a rebate for corneal topography.

Automated assessment of your peripheral and also your central field can be performed with a Humphrey Visual Field Analyser. For this test the patient sits in front of an illuminated dome. Lights of varying intensity are projected into the dome, and the patient is required to press a button whenever a light is seen in any part of the side vision. The test requires a lot of concentration but does provide very useful information on visual field for conditions such as glaucoma and ocular hypertension, retinal degenerative diseases (eg retinitis pigmentosa), monitoring of drug side effects (eg plaquenil), and neurological problems (eg stroke).