The term glaucoma refers to a group of eye diseases that lead to the damage of the optic nerve and loss of vision. There are several types of glaucoma – the most common type is known as open-angle glaucoma; the less common types are closed angle glaucoma and normal tension glaucoma. Open angle glaucoma develops gradually, and patients are unaware of the condition as there is no pain.
Vision loss that occurs due to glaucoma is permanent. The risk factors for glaucoma includes a positive family history for the disease, increased pressure in the eye, and high blood pressure. Eye pressures that are greater than 21 mmHg have a higher risk of glaucoma. However, there are also patients who have high eye pressure for many years without developing glaucoma. There is also normal tension glaucoma, where damage to the optic nerve occurs despite normal pressure.
The diagnosis of glaucoma is achieved via a dilated eye examination where the optic nerve shows a significant amount of cupping. Early treatment can slow or stop the progression of disease; however, the treatment of closed-angle glaucoma is considered to be a medical emergency. Most glaucoma can also be managed with medication, surgery, or laser treatment. Laser treatments can be effective in both open and closed angle glaucoma.
Globally, approximately 67 million individuals suffer from glaucoma; approximately 2 million of those individuals are in the United States. It is more commonly seen among older people; closed angle glaucoma is more likely to occur among women. Glaucoma has been called “the silent thief of sight” as the loss of vision occurs gradually over a prolonged duration without the patient being aware. It is also the second leading cause of blindness after cataracts.
Symptom #1: Decrease of Peripheral Vision
Peripheral vision is the part of vision that occurs out the sides of the eyes. Peripheral vision is important in recognizing well-known structures without needing to focus, identification of similar forms and movements, and delivery of sensations that form the background of detailed visual perception.
In glaucoma, the peripheral vision starts to decrease, and this is followed by a loss of central vision, which eventually results in blindness if left untreated. Peripheral vision is divided into far peripheral vision, mid peripheral vision, and near peripheral vision. When one loses peripheral vision and retains central vision, it results in tunnel vision.