Optical coherence tomography

OCT stands for optical coherence tomography, which is the latest generation in imaging the internal structures of the eye.  The OCT is a special scanner that creates a sort of optical ultrasound three dimensional image of the inside of the eye. The unique way the image is formed means that for the first time we can actually see below the surface of the retina and view the microscopic layers beneath. This is of profound importance in determining the precise diagnosis of visual problems and in helping us guide patients on the treatment options possible. Having tested various OCT instruments we have acquired a Heidelberg Engineering Spectralis, an instrument typically found in ophthalmology departments rather than optometric practices!

It is a simple and quick test to perform. The patient sits in front of a special type of camera and pictures are taken of the structures inside the eye.

 

 

 

 
The remarkable detail allows optometrists to detect abnormalities that are not apparent during a standard eye examination. The OCT machine can create a contour map of the optic nerve, optic cup and measure the retinal nerve fibre layer thickness, which are all extremely helpful in the early diagnosis of glaucoma and progression of the disease. Use of the OCT is vital in accurately detecting certain diseases of the macula, making it key in determining the level of urgency of referral.

Typical conditions benefitting from OCT scans:

• Macular degeneration or drusen
• Macular hole or epiretinal membrane
• Early glaucoma
• Diabetic retinopathy
• Optic nerve disease
• Retinal tears or detachments