The average normal Intraocular pressure is 10 to 21 mHg. A pressure above 21 mHg can slowly damage the retinal nerve fibres and optic nerve at the back of an eye, which forms the main optic nerve carrying visual impulse to the brain.
The high pressure of the eyes slowly damages the retinal nerve fibres and Optic nerve, thereby decrease the vision. If not detected well in time, it can lead to an irreversible vision loss.
How will you know that you have Glaucoma?
It is a silent disease and most of the time will have no symptoms. Several times this condition is detected upon routine eye examination. Sometimes patients perceive this problem only when the central vision gets affected. Therefore, it is required that all patients are screened for the same. If the pressure inside the eyes becomes too high (normal pressure is 10 to 21mmHg, you can witness the following symptoms:
- Heaviness in the eyes
- Severe Headaches
- Colored Halos around a light bulb
- Sudden redness with a blurred vision
- Frequent changes in spectacles power
Why do the eye pressures Increase?
To understand this, compare your eye to a balloon filled with water. If the water is more, balloon will become tense. Similarly, if the pressure in the eyes becomes high, it affects the optic nerves at the back of the eye. Therefore, it is important that a delicate balance is maintained between the area that forms fluid in eye and area draining out the same. Due to miscrostructual changes in these areas, the fluid is either produced or drained less, resulting in high pressures.
Can I have Glaucoma with normal pressure?
Yes, some people have a susceptibility to damage even with normal pressure (Low Tension or Normal Tension Glaucoma). There are various theories for this kind of Glaucoma, mainly a change in vascularity-blood supply of optic nerve.
What tests are done to diagnose Glaucoma?
Routine eye examination includes-
Applanation Tonometry- To measure intraocular pressure
Fundus- documents the changes of Optic Nerve head(disc) while looking at your fundus through pupil
Gonioscopy- The type of Glaucoma is detected by assessing the angle of an interior chamber of Eye by gonioscopy.
Additionally, depending on the level of suspicion, we ask for following confirmatory tests:
Perimetry - Computerized visual field test to detect areas of fading vision.
Central corneal thickness- To refine the results of our eye pressure measurements
Optical Coherence Tomography (OCT) - Anatomical documentation of the optic nerve head and nerve fibre layer
How is Glaucoma treated?
It could be in the form of medicines, laser or eye surgery. Treatment often begins with Eye drops for lowering intraocular pressure, which will prevent further damage. Newer medications are now available which are effective and have few side effects. Medicines used for each individual has to be chosen with great care according to his eye condition, systemic illness and lifestyle pattern.
What is the Role of Laser?
A certain type of Glaucoma eg. Pigmentary Glaucoma is treated by Argon Laser Trabeculoplasty (ALT). Peripheral Iredectomy (P.I.) has a role in narrow angle Glaucoma.
Is there Surgery for Glaucoma?
With the newer medications, surgical intervention is less required. However, in patients who have failed laser treatment, or presence of advanced progressive Glaucoma, filtering surgery trabeculectomy is done. An alternative microtrack is created for the fluid to flow out, thus controlling the eye pressure. The success rate of this surgery varies according to the type and stage of Glaucoma. Various modifications can be done to ensure that filtering passage works throughout life.
What are the complications of Glaucoma surgery?
Glaucoma Surgeries require precision of an eye surgeon and patience. The microtrack created by surgery can overfiltrate or underfiltrate. Like any other surgery there might be few complications like bleeding, infection, low or high pressures etc. Some trabeculectomies may fail to function after months or years.
I have been diagnosed with Glaucoma, what should I do to ensure that my vision remains normal?
Do not worry, you will enjoy healthy sight if you put the antiGlaucoma eye drops regularly and keep your eye pressures under control. It is very crucial that you visit your eye specialist and report for follow-ups as advised. Normally, the patient is asked to visit every 4 months for to check for eye pressure and repeat the visual field examination every year.
Are there any lifestyle do’s and don’ts for a Glaucoma patient?
Not really. There is nothing external influencing the course of Glaucoma. There is no diet restriction. Carry on with our routine lifestyle and just be regular with your medicines. If you have hypertension, diabetes or thyroid disease, it needs to be well controlled. Avoid having excess of tea and coffee as caffeine has been shown to increase eye pressures in some individuals.