glossary

A disease entity that most commonly affects young men in their teens and early twenties and causes significantly decreased central vision in both eyes. The genes that cause LHON are carried on small circular mitochondrial DNA molecules that are inherited from an individuals mother. This condition is extremely rare (affecting fewer than 1 per million people per year) and does not affect everyone who harbors the genetic defect. The visual field defects in LHON are typically cecocentral scotomas. There are three other eye diseases named after Theodore Leber: 1) Leber congenital amaurosis (blindness at birth) inherited in an autosomal recessive fashion, 2) Leber’s stellate neuroretinopathy (a non-heritable condition associated with cat scratch disease) and 3) Leber’s military aneurysms (a non-heritable vascular malformation of the retina similar to Coat’s disease).

A condition, usually characterised by raised pressure in the eye which causes damage to the optic nerve resulting in defects in the field of vision. It is treated by reducing the pressure in the eye. Increase in intra-ocular pressure resulting, if left untreated, in an irreversible deterioration of the optical nerve and of the retina, as well as an alteration of the visual field, i.e. a reduction in visual performance, often accompanied by headaches and aching eyes. A disease of the eye characterized by increased intraocular pressure. A common cause of preventable vision loss. May be treated by prescription drugs or surgery.

Glaucoma in which the intraocular pressure is normal but there is progressive optic nerve damage and visual field loss. Also known as Low Tension Glaucoma.