The World Glaucoma Association and the World Glaucoma Patient Association, the proponents of World Glaucoma Day, observed a series of activities globally from March 11 to 17 to create and raise awareness among people to have regular eye and optic nerve checks to detect glaucoma earlier and manage same to mitigate blindness.
According to the event organizers, it is estimated that 4.5 million persons globally get blinded due to glaucoma and that this number will rise to 11.2 million by 2022. It is noteworthy that due to the silent progression of the disease – at least in its early stages – up to 50 per cent of affected persons in the developed countries are not even aware of having glaucoma.
“Glaucoma is a group of eye diseases that cause progressive damage of the optic nerve at the point where it leaves the eye to carry visual information to the brain.
Dr Nitin Deshpande, Glaucoma Consultant, says that glaucoma can be diagnosed in two ways.
Since blindness from glaucoma is irreversible, prevention is key; regular eye examinations involving several tests can detect Glaucoma early and with appropriate management, blindness can be averted.
These tests include:
This test measures the internal pressure of the eyes using the instrument called Tonometer. The normal eye pressure range is between 12 and 22mmHg; anyone with eye pressure above 22mmHg is considered to have Glaucoma.
This is a procedure in which the optic nerve at the back of the eye is examined using the instrument called Ophthalmoscope to detect and assess any damage to the nerve. Extensive damage to the nerve causes blindness. Examination of the optic nerve can indicate excessive pressure for that individual if it appears unusual, necessitating more tests.
This test shows whether the eye angle is open or closed; the angle is where the Iris meets the Cornea, both are parts of the eye. The angle is the point in the eye through which fluid is drained from the eye, blockage of this angle leads to Acute Glaucoma. The test confirms the type of glaucoma and helps in determining the type of treatment.
This test measures the thickness of the Cornea using an instrument called Pachymeter. Corneal thickness can influence eye pressure and can also help the doctor decide on the best form of treatment if the pressure is higher than normal.
This test maps your complete field of vision and is subjective to the patient’s response. In this test, you will be given the controls to a machine, and a light is flashed in your peripheral vision. With the help of the buttons on the machine, you will have to respond to the light when it is flashed. This will help your doctor map your entire field of peripheral vision. This test helps determine the functioning of your eye.
The test gives result in a very short period. However, it is not very accurate as it also depends on how well the patient responds to the flashed light.
New software like Swedish Interactive Threshold Algorithm (SITA) is coupled with Perimetry to help doctors determine the loss of vision more accurately. This software is highly sensitive and makes the test more patient friendly giving the results in a very short period.
6. Optical Coherence Tomography
This is a non-invasive diagnostic tool that uses infrared light to map different layers of the retina and helps the doctor in measuring the thickness of these layers. This tool can help your doctor predict your risk of glaucoma seven to eight years in advance.