PAO SUBSPECIALTY SOCIETY: PHILIPPINE GLAUCOMA SOCIETY
1. What is glaucoma?
Glaucoma is an eye disease in which nerve cells in the retina at the back of the eye slowly die and leads to progressive damage to the optic nerve. The optic nerve is the one responsible for sending visual information from the eye to the brain and damage to the optic nerve prevents some signals from the eye to reach the brain. This results in a reduced field of vision and, if not managed properly, can lead to irreversible blindness. The exact cause of glaucoma is still not known, but build up of pressure inside the eye (intraocular pressure) is a proven major risk factor. If this disease is detected early, there are treatments to stop or delay its progression, and the earlier the detection, the greater the chance of preserving sight.
2. Are all kinds of glaucoma the same?
There are different kinds of glaucoma. Generally, it can be classified into open angle or angle closure glaucoma, depending on the status of the drainage system of the eye. It can also be divided into primary glaucoma, wherein the cause is unknown or secondary glaucoma, wherein the condition is due to other identifiable factors or disease.
3. Who is at risk for glaucoma?
Anyone can develop glaucoma, but some people are at greater risk than others. Some of the risk factors for developing glaucoma are: abnormally high eye pressure, family history of glaucoma, age over 40 years old, high blood pressure, long term use of steroids, high refractive correction for nearsightedness or farsightedness, and previous eye injury.
4. What are the symptoms of glaucoma?
Some people may experience recurring deep eye pain, headaches and blurring of vision due to sudden increase in eye pressure. However, most people with glaucoma do not have any symptoms. They don’t know that they have glaucoma until they have advanced disease and have lost some of their vision, typically described as a gradual narrowing of their peripheral vision. If left untreated, this can lead to total blindness. Unfortunately, loss of vision due to optic nerve damage in glaucoma cannot be reversed. However, eye doctors (Ophthalmologists) can detect glaucoma in its early asymptomatic stages, especially with the aid of specialized diagnostic examinations. They can then give appropriate treatment to prevent its progression. Since early detection is the key in the prevention of blindness in glaucoma, those who have risk factors or have symptoms of this disease should have their eyes examined by an Ophthalmologist at the soonest possible time.
5. How is glaucoma diagnosed?
The Ophthalmologist will evaluate the medical history and perform a thorough eye examination with the use of specialized instruments. Specific procedures for glaucoma evaluation include: eye pressure measurement, drainage pathway examination, optic nerve examination and automated-visual field examination.
Eye pressure measurement: As with blood pressure, pressure in the eye can be measured. High pressure is caused by a build-up of fluid within the eye. If the eye pressure is high, there is a greater risk of developing glaucoma. However, eye pressure measurement alone is not enough to diagnose glaucoma, not all people with high eye pressure will develop glaucoma and some individuals with glaucoma do not have high eye pressure.
Drainage pathway examination: The drainage pathway examination utilizes a special lens and a slit-lamp biomicroscope to examine the status of drainage pathway of the eye and may influence the type of treatment that an individual would receive.
Optic nerve head examination: The optic nerve examination is an important procedure since the optic nerve undergoes recognizable changes in glaucoma and is essential for the diagnosis, staging and monitoring of the disease. The pupils may need to be dilated to get a good stereoscopic view. Optic nerve head photographs may also be obtained.
Automated visual field examination: The visual field examination or automated perimetry checks for defective areas of vision. In glaucoma, peripheral areas of vision are affected first and will be missed by a standard eye chart since the central vision is not affected until the very late stages. This is why some people with glaucoma may still have 20/20 vision in spite of moderate to severe disease.
All of these tests will help the Ophthalmologist determine if glaucoma is present or absent in a particular individual. Furthermore, these examinations can also assess the severity of the disease, if present, or determine the risk of developing glaucoma in the future. Other ancillary examinations may also be requested to aid the physician in the diagnosis and management of this disease.
6. What treatments are available for glaucoma?
The optic nerve damage and loss of vision in glaucoma cannot be reversed. However, the progression of glaucoma may be halted or delayed with treatment, especially when the disease is diagnosed early. The goal of treatment is to preserve the remaining vision throughout the patient’s lifetime. Treatment options include: medical, laser and/or surgical treatment. Each type of treatment has specific uses and the appropriate type of treatment will be determined by the Ophthalmologist, depending on the type and severity of glaucoma, and the presence of other factors. These treatment modalities lower the eye pressure to a certain level where the disease progression would be stopped or slowed down. Medical treatment is the most common form of treatment and there are different types of glaucoma medications available, mostly in eye drop form. Laser treatment may be used as an adjunctive therapy or as a first line treatment in certain types of glaucoma (e.g. angle closure glaucoma). Glaucoma surgery is usually required if the intraocular pressure is uncontrolled with medications and in certain complicated or advanced cases.
7. What is the prognosis on glaucoma?
Glaucoma is chronic disease and needs to be regularly monitored by an Ophthalmologist throughout the patient’s lifetime. The functional status of the patient is largely dependent on the severity of glaucoma and the patient’s response to therapy. If glaucoma is detected early and controlled with treatment, there is a very good chance that vision will be preserved. These individuals will still be able to perform their usual daily activities without any difficulty. If glaucoma is detected in the advanced stage, glaucoma treatment is still needed to slow down and prevent further loss of vision. These individuals may have limitations in their activities and a decrease in their functional status.
8. How can glaucoma be prevented?
Vision loss from glaucoma can be prevented by early detection and treatment. Since most types of glaucoma do not have any symptoms, it is important to have a complete eye examination by an Ophthalmologist to detect or assess the possibility of developing this condition. This becomes more important if an individual has any of the risk factors for this disease: a family history of glaucoma, long term use of steroids, high refractive correction for nearsightedness or farsightedness, and history previous eye injury. Likewise, those who have frequent headaches, recurring eye pain, or blurred vision should also undergo complete eye examination at the soonest possible time. Since glaucoma and other eye diseases are more common in the older age group, it may be prudent to have a regular eye check up once an individual reaches 40-50 years old.