Leber optic atrophy is named after the German ophthalmologist, Theodor Leber, who, among others, first described its features in the late 19th century. The optic nerve connects the eye to the brain and carries the visual signals that enable us to see. This nerve is subject to damage from a number of sources including gene mutations of which there are many.
Most patients are asymptomatic until about age 30 years when they suddenly experience an acute, painless loss of vision on one eye (sometimes both eyes). This is often followed about 2 months later by the same symptoms in the other eye. In a few patients the loss of vision takes place over several months to a year, but in most cases vision loss to the counting fingers level is much more rapid. Some recovery of vision may occur but this is uncommon. Males are affected 4 times more often than females for unknown reasons.
Other symptoms such as unsteadiness, loss of sensation, and some muscle weakness are less common and severe. A few patients have heart rhythm abnormalities. Some females have a multiple sclerosis-like illness.
This is an inherited disorder but the gene mutations lie in the DNA of mitochondria instead of the nucleus of the cell where most of our DNA is located. Mitochondria are sometimes called the energy factories of our cells for they generate the power our bodies need to grow and use the nutrients we provide. The mitochondria each have only 37 genes (all of us have about 23,000 genes) but there can be thousands in each cell and they are vital to our wellbeing.
Mitochondria are passed to the next generation only by the ova (sperm do no transmit mitochondria) so Leber optic atrophy is always inherited from the mother. She will pass the mutation to all of her children, both male and female. However, for unknown reasons, not all adult children will necessarily show symptoms of the optic atrophy even though they are at risk.
The diagnosis is made by an ophthalmologist after examination of the eye. Once the disease has damaged the optic nerve, there is seldom any recovery. Longevity is not impacted. No treatment is available at this time but low vision aids can be helpful for some individuals.