Glaucoma is the leading cause of irreversible blindness all throughout the world. The disease usually affects the optic nerve and if not detected early enough leads to loss of vision. The optic nerve transmits light-generated impulses from the retina to the brain, which we ultimately recognize as vision. In glaucoma patients, the optic nerve is progressively damaged and often it is as a result of built-up pressure in the eye, known as intraocular pressure.
Glaucoma develops gradually over several years and begins by affecting your peripheral vision. It is however difficult to point out its symptoms, until it is too late and the effects show. This is why so many people do not realize they are suffering from the disease until their sight is affected. Nonetheless, in some few situations there might be a few signs indicating the condition. The signs and symptoms will usually vary depending on the type of glaucoma you have. They include:
Acute (Angle-Closure) Glaucoma;
Secondary glaucoma and normal tension glaucoma usually have no decipherable symptoms.
To prevent sight loss or damage through glaucoma, it is important to have regular and thorough eye exams to allow early detection. Depending on your age and the risk factors you are exposed to, your ophthalmologist may schedule a check up between every 6 months to every four years. Usually, the older you are, the more frequent the examinations.
Glaucoma diagnostic tests are painless and very brief. To make an accurate diagnosis, it takes up to 6 comprehensive tests, although for regular check-up your doctor may not perform them all. Some of these tests include;
This test measures the level of pressure within the eye. The common method for performing this test is applanation. It involves some eye-drops being applied to numb the eye, then a small amount of pressure is applied to the eye using a tiny instrument, to help the doctor measure the pressure inside the eye.
This is a visual field test that allows a doctor make an assessment of your field of vision. From this you will be able to know if any field of vison has been affected by glaucoma, how much of it is lost and also at what rate the disease is progressing. After concluding this test your doctor will be able to come up with a suitable treatment plan to avoid further damage. During the perimetry disease, you will be asked to look straight ahead and then make note when passing light comes across your peripheral vision. The test may be repeated several times, even after diagnosis just to see if there are any changes.
For this test, your pupils will be dilated with eye drops, then a doctor will capture an image of your optic nerve. This may be done using a digital camera or any other suitable technology to help map out your optic nerve. It is usually non-invasive and no radiation is used. From the images the doctor can then track glaucoma progression and advice appropriately.
Your eyes will be dilated and then a magnified 3D image of the optic nerve will be captured to help observe its state. The shape, color, size, depth and vessels of the optic nerve are all taken into consideration. You may also have further examinations of the central and peripheral retina.
After numbing your eyes, a doctor uses a small probe to measure the thickness of your cornea. Cornea thickness sometimes has effect on eye pressure readings and this test helps determine if the pressure test results are reliable or not.
Also known as the angle test, gonioscopy allows the doctor see the point at which the cornea meets the iris. This point where the two meet forms the trabecular meshwork, which is the eye’s drainage system. An angle test will show if the drainage is open or closed.
Glaucoma treatment focuses on reducing intraocular pressure and stop the progression of glaucoma. Depending on the severity and cause, the following treatments may be offered;