Optic nerve drusen are small deposits of protein matter that build up in the optic disc. Also known as optic disc drusen or optic nerve head drusen, these protein pockets calcify and can cause potential vision problems. The condition affects a very small number of people — about one percent of the population — and symptoms are exceedingly rare, even in individuals who have a major buildup of drusen. In a few highly unusual instances, drusen has led to vision loss.
Experts are not entirely certain how and why drusen develop. One commonly held theory is that mucopolysaccharides — a type of carbohydrate structure — and mucoproteins accumulate as a side-effect of cell metabolism. Many patients with optic nerve drusen have inherited the condition from a family member, though a genetic basis is not a prerequisite for the development of drusen. They develop in both eyes more often than in just one eye.
In the majority of cases, optic nerve drusen present no noticeable problems and are detected only during a regular eye examination. Many eye doctors find that a patient with drusen buildup possess a slight aberration in side vision to such a minor extent that the patient does not notice it. The severity of any side vision problems can be deduced by a more thorough examination, in which a patient's side vision is tested with special "visual field" machines. If an eye doctor is unsure whether optic nerve drusen is present, he or she may order a CT scan, an optic ultrasound, or a fundoscopy to gather a more definitive diagnosis.
By its very nature, damage to the optic nerve is progressive. While most patients with optic nerve drusen do not go blind, other conditions may develop over time. Some of the most frequently reported vision issues are enhanced blind spots, general weakness in the main line of vision, and other abnormalities in the visual field.
There is no definitive treatment for optic nerve drusen nor are there any preventative measures that can be undertaken to ensure they don't develop. An individual with drusen is commonly examined regularly by a doctor to gauge the extent of the buildup or any additional growth that may have occurred. Some doctors may prescribe eye drops that alleviate intraocular strain and allay pressure on the fibers of the optic disc. Certain cases of optic nerve drusen may necessitate laser therapy, though this type of treatment is rare.