Optical and Ultrasound Biometry

Our newest addition to our growing collection of specialised equipment, the ocular biometer measures the size and shape of the eye by looking at axial lengths, anterior chamber depth and keratometry. Each of these measurements aids in the management of diseases like cataract, and the monitoring of progressive myopia. Both our Adelaide and Woodville branches are equipped with either optical or ultrasound biometers.


The main function of an optical biometer is to calculate the power of the intraocular lens (IOL) for patients who are undergoing cataract surgery. Patients with cataracts develop opacities within the lens inside their eye, which causes blurry and cloudy vision. The lens is replaced during surgery with an artificial IOL, the optical power of which is decided beforehand for clear vision at a chosen distance. There are a multitude of intraocular lenses available, including aspheric, toric, multifocal and monovision lenses. The optical biometer helps us to measure the power of the lens in the eye, and have more informed discussions with our cataract patients about their IOL options.

Myopia control

Our optical biometers are crucial for our myopia patients. Axial myopia, or short-sightedness, is a condition that causes the eyeball to elongate and as a result light is focused in front of the retina causing blurred distance vision. As it progresses, the eye gets longer which increases the risk for retinal detachment due to the stretching of retinal tissue. The optical biometer measures axial length to monitor (link: /what-we-do/myopia-control text: myopia progression) and better manage myopic patients to reduce the risk of complications. It’s also useful for assessing the impact of orthokeratology on slowing myopia progression.

Anterior chamber depth

The health of our patients’ eyes is of the utmost importance to us. While we have a range of equipment that tests for a multitude of eye conditions, the optical biometer is particularly critical for patients who have been diagnosed with or are suspects for glaucoma, who often need their anterior chamber depth measured. Closed-angle glaucoma occurs when the angle of the anterior chamber becomes too narrow, increasing the pressure inside the eye which can potentially damage the retina. With the optical biometer at our disposal, we can better identify the signs of glaucoma and manage cases.


Astigmatism is a refractive condition that causes blurred vision at all distances due to variations in the optical power of the eye as a result of abnormal corneal curvature. The degree of astigmatism is measured using an optical biometer, a measurement known as keratometry (K). This is particularly crucial for our patients who are spectacle or contact lens wearers who need accurate readings to ensure their prescriptions are as precise as possible.