Optical Coherence Tomography (OCT) imaging is quick and comfortable, providing vital information for the diagnosis and continued management of almost all retinal patients.
OCT is similar to ultrasound scans in giving a cross-sectional image of the retina, but with much more detail, allowing measurement of the thickness of the macula in conditions like macular oedema as well as showing distortions of the retinal in conditions like epiretinal membrane. Additionally they give information regarding the specific layers of the retina and any abnormalities that may occur in these areas, aiding with the diagnosis of retinal conditions. Newer OCT machines are faster, have higher resolution and contain much more information including 3-dimensional views which allow for better interpretation of the retinal images.
Because of their safety, ease of use and the detailed information they provide, OCTs have become invaluable within ophthalmology practices. They are vital in the diagnosis and monitoring of many retinal conditions, reducing the need for other tests such as fluorescein angiography. They help guide treatment such as surgery, whilst conditions like macular degeneration, diabetic retinopathy, and venous occlusive conditions would not be as effectively managed with intravitreal treatment without OCT imaging.
Unfortunately, despite the importance of OCT imaging within modern ophthalmology, these tests are not covered by Medicare at all.
Cross Sectional (2-dimensional) Oct
This is a cross sectional OCT showing a swollen macula (macular oedema) due to a retinal vein occlusion. The OCT image shows that the macula has increased thickness due to pockets of fluid collecting within and under the retinal layers.
This is a 3-dimensional OCT scan of a macula, with an almost ‘tornado-like’ appearance. It shows an adhesion of tissue to the surface of the macula, and can be analysed from different angles.
3-dimensional OCT scans are actually composites of a large number of 2-dimensional OCTs to allow for a ‘3D’ perspective of the retina.