By combining the individual layers we are able to build up a 3D picture of the inside of the eye. Using this technology, we can now see autofluorescence in the RPE cell layer and can depict the photoreceptor mosaic in the adjacent layer. We can also produce pictures of neural cell layers and follow the nerve fibres as they travel over the surface of the retina. This is the only place in the world where it is possible to see the nerve fibres leave the eye at the lamina cribrosa or head of the optic nerve on their way to the brain. In a normal eye, aqueous fluid is continually produced through a series of holes called the trabecular meshwork and is drained away.
Glaucoma occurs when the drainage canals become blocked.
A certain amount of pressure is necessary to maintain the shape and function of the eye but too much pressure can injure the optic nerve. The nerve fibres from the retina converge on a focal point in the back of the eye known as the optic disk and lead to the optic nerve. Elevated pressure causes the centre of the optic nerve head to bulge outwards, a process known as optic nerve cupping. It is this that results in loss of peripheral vision, contrast sensitivity and ultimately blindness. Types of Glaucoma Glaucoma is in fact a group of diseases characterised by raised intraocular pressure, optic nerve damage and gradual visual field loss.