how-does-glaucoma-affect-the-optic-nerve

Glaucoma, The Silent Thief Of Sight

Glaucoma is the name for a group of diseases that damages the optic nerve. In many cases, glaucoma appears without symptoms and is only noticed when vision starts to erode. Over 3 million Americans deal with glaucoma, and only half are actually aware. If left untreated, the ailment can cause total blindness in the affected eye.

Don’t get on my nerves

The optic nerve makes up more than 1 million nerve fibers connecting the eye to the brain. Light entering the eye gets focused on the retina, where the optic nerve begins. From there, the optic nerve converts light into electrical signals and takes the information to the brain. The brain then processes those signals into an image of what the eye is seeing.

Glaucoma versus the optic nerve

A fluid called aqueous humor transports nutrients to the front of the eye while keeping everything in a pressurized state. After delivering nutrients, the liquid normally leaves the eye through a series of drainage channels. When these channels become completely or partially blocked, excess aqueous humor remains trapped inside. The eye becomes too full of fluid and begins exerting pressure in an outward motion.

That pressure begins to crush the very optic nerve fibers that send information to the brain. These fibers become damaged and eventually die, destroying the connection entirely. The process typically begins on the outside of vision, leaving blind spots as nerves stop functioning. Over time, blindness moves inward until all sight is consumed. Once a nerve fiber dies, there is no way to repair the damage.

Don’t mess with my vision

The rate glaucoma consumes vision depends on the type of disease found in the eye. Open-angle glaucoma, by far the most common form, is typically asymptomatic and leads to very slow progression. Patients with this condition can go several years before noticing an issue. Angle-closure glaucoma, on the other hand, usually comes with extreme pain because damage occurs much more rapidly.

Locating the invisible disease

Since glaucoma is rarely detectable to a patient with the condition, routine eye exams are important to look for signs. The eye doctor will perform a series of tests to look for signs of the disease.

Tonometry: Checks pressure levels inside the eye

Gonioscopy: Checks drainage channels to ensure fluid leaves the eye as intended

Ophthalmoscopy: Looks at the shape and color of the optic nerve in the back of the eye

Perimetry: Checks the field of vision for any blind spots

Pachymetry: Checks the thickness of the cornea to look for pressure damage

Battle back against glaucoma

If glaucoma is detected in the eye, the physician will likely prescribe eye drops to address the disease. These drops work to lower pressure in the eye and prevent damage to the optic nerve. In more severe cases, an ophthalmologist can perform surgery to reopen drainage channels or create new passageways.

At this time, there is no cure for glaucoma. If caught early enough, damage to the optic nerve can be avoided and keep vision from fading.