January is Glaucoma Awareness Month! Glaucoma is the term given to a group of eye diseases that result in progressive damage to the optic nerve. The optic nerve is responsible for collecting visual information from the entire retina and transmitting it to the brain. Optic nerve damage due to glaucoma is irreversible, and can lead to permanent vision loss. Because there are very few symptoms in the early stages of the disease, glaucoma is oftentimes referred to as the “silent eye disease.” This dangerous disease has the potential to cause blindness, but with regular eye examinations and proper care, glaucoma can usually be well controlled and managed before significant vision loss occurs.
The most common type of glaucoma, Primary Open Angle Glaucoma, is caused by an increase in the fluid pressure within the eye. The fluid inside the eye, which is responsible for circulating nutrients, normally leaves the eye through an intricate drainage system. In glaucoma, there is an overproduction of this fluid, or an inadequate amount of fluid drainage, leading to a rise in intraocular pressure. When the pressure in the eye is too high, compressive damage to the optic nerve can occur. In Primary Open Angle Glaucoma, the exact cause of the elevated intraocular pressure is not understood. In other forms of glaucoma, such as Traumatic or Inflammatory Glaucoma, there is a direct cause for dysfunction of the fluid system and the increase in intraocular pressure.
Prolonged increased intraocular pressure permanently damages the optic nerve, resulting in subtle visual changes. In glaucoma, this optic nerve damage can result in visual field loss, meaning small areas of vision can start to go missing. It is difficult for those with glaucoma to notice this irreversible vision loss until significant damage has occurred. Because there are no obvious visual changes from early or mild glaucoma, it is important to receive regular eye examinations so the disease can be detected early. The optometrist can diagnose glaucoma by in-depth clinical evaluation of the optic nerve and additional supplementary testing. Tests like tonometry, which measure the intraocular pressure, a visual field test, which evaluates peripheral vision, or an optical coherence tomography (OCT), which provides detailed structural information about the retina and optic nerve, are important tools the optometrist uses to diagnose and monitor glaucoma.
Glaucoma has the potential to be a blinding disease, which means early detection, proper treatment, and appropriate follow-up care are necessary for a better chance of healthy vision. The first line of treatment for glaucoma is medicated eye drops that work to lower the pressure inside the eye and prevent future optic nerve damage. The number of drops required to adequately treat the disease can depend on the severity of glaucoma at the time of diagnosis and the rate of progression. If therapeutic drops are contraindicated or ineffective, surgical intervention may be necessary to lower eye pressure and prevent glaucomatous damage from occurring.
Treating glaucoma and protecting vision is a long-term commitment. The doctor may require several follow-up visits a year in order to protect vision, and additional testing is frequently required. Luckily, most insurance companies will cover the necessary care for those with glaucoma.