Glaucoma is a progressive disease characterized by damage to the optic nerve usually caused by increased pressure within the eye.
The optic nerve is like a cable that connects the eye to the brain and functions to transmit visual impulses from the eye to the brain enabling us to see what is directly in front of our eyes or what we are directly looking at (central vision) as well as what is around what we are directly looking at (peripheral vision). The central vision and peripheral vision are what comprise our entire field of vision or the entire area that we see.
This optic nerve, however, is a sensitive part of the eye that functions normally within an optimal range of eye pressure. Beyond this optimal eye pressure range, the optic nerve can get damaged as what happens with glaucoma. When damaged, the optic nerve’s ability to transmit visual impulses becomes impaired, thus causing the visual symptoms. What usually gets affected first is the peripheral vision and it usually occurs gradually. That is why persons with glaucoma may not notice the visual disturbance in the early part of the disease. Without proper control of the disease, the damage to the optic nerve may progress and cause progressive narrowing of the field of vision making the area the eye can see smaller until it is as if you are looking through a peephole. With further damage glaucoma can cause blindness.
Aside from narrowing of the field of vision, glaucoma has other symptoms depending on whether it is the open-angle type or closed-angle type of glaucoma. It will also depend on the severity of the disease.
With the open-angle glaucoma, there is no detectable symptom during the early part of the disease. It is only in the latter part when vision is significantly affected that patients begin to notice they are unable to see certain portions of their vision or that vision is not as clear as before.
Symptoms are usually noticed earlier with closed-angle glaucoma. There may be recurrent headaches or heaviness in the eyes in the late afternoon or when in dark places. This may be accompanied by seeing haloes around lights and blurring of vision or even slight eye redness. When the increase in eye pressure is sudden, all the symptoms of eye pain, headache, blurring of vision, and eye redness are more dramatic and severe. The severe pain usually prompts these patients to seek consultation and treatment.
Symptoms include cloudy vision. Sometimes there is glare, and double vision with one eye. Cataracts are usually caused by age. Our natural lens ages and changes in color, as we get older. There are however other causes of cataracts. These include those who have them at birth (congenital), those who develop them in young adulthood (developmental), those acquired from diseases like diabetes mellitus, and those that result as a complication of the intake of some medications like steroids.
Some forms of glaucoma have a hereditary factor but not everyone born to a parent with glaucoma would get the disease. However, it is advisable that people with a family history of glaucoma get screened and examined regularly, even in the absence of symptoms, because while there may be no symptoms in the early part of the disease, signs of glaucoma may be detected through a thorough eye examination. As with other diseases, the earlier glaucoma is detected and treated the greater the chances of preserving vision. Therefore, periodic eye examinations on people with a family history of glaucoma especially those over the age of 40 is recommended.
Glaucoma can also be a complication of trauma to the eye, overusing or misusing of steroids, or from inflammatory diseases of the eye.
To test for glaucoma, your pressure of the eye will be determined, the optic nerve will be examined in various ways, and your field of vision will be tested. Your glaucoma eye doctor can discuss the different tests needed.
Treatment of glaucoma would depend on how severe the damage has been, or how fast the disease is progressing. This consists of eye medications in the form of drops, laser to help maintain the pressure within the eye, and if medicines and laser do not prevent further damage, surgery may be needed to create a passageway for the fluid when the pressure is too high. When a patient has glaucoma, regular follow ups with the eye doctor is necessary to check if the disease is progressing or not.
The best way to deal with glaucoma is to prevent progression of damage to vision. However, glaucoma despite all efforts to control the disease can significantly damage sometimes vision. When glaucoma significantly damages vision, one’s activities and lifestyle may be affected. Many people with uncontrolled glaucoma are unable to do what they used to do because of they have been incapacitated by damage to their vision. The degree to which activities and lifestyle can be affected depends on which part they cannot see and the size of the non-seeing part of the visual field. For those who have lost their peripheral vision and can see only what is directly in front of them, crossing the street is a real challenge and driving becomes very dangerous. Many people with glaucoma have lost their jobs because they could no longer read. Depression is common among them too. Fortunately, while it is true that damage to vision caused by glaucoma is irreversible, there is hope for them. While it is true that damage to the visual field due to glaucoma is irreversible and that vision that has been lost cannot be regained, something can be done for them. The answer is maximizing what is left of the vision through visual rehabilitation. A Low Vision Specialist can evaluate these people and help find ways to help them cope with their difficulties.