Glaucoma a leading cause of blindness in the world, especially for older people. However visual loss is preventable or stabilized with early diagnosis and treatment.
Glaucoma is a condition of the eye where the optic nerve is damaged. The optic nerve carries images to the brain, which are then perceived as vision. Minute nerve fibres from various parts of the retina join to form the optic nerve. Glaucoma results when the pressure within the eye is high enough to be detrimental to the normal functioning of these nerve fibres, some of which stop functioning. Non-functional nerve fibres result in a loss of retinal function in the area from where they originate, leading to defects in the field of vision…
The disease is called the `sneak thief of sight´ because it is painless, without symptoms and irreversible. Therefore, the person with glaucoma is usually unaware of it until much loss of vision has occurred. In fact, half of those suffering damage from glaucoma do not know it. Currently, damage from glaucoma cannot be reversed and if the entire nerve is damaged, blindness results. Early detection and regular treatment are the keys to preventing optic nerve damage and blindness from glaucoma.
What causes Glaucoma ?
The aqueous humor is the clear fluid circulating within and nourishing some parts of the eye which have no blood supply. ‘Normal’ individuals have an equal production and drainage of this fluid resulting in a constant pressure within the eye. If the drainage is compromised due to any reason, there is a pressure build-up in the eye, which can damage the optic nerve.
What are the different types of Glaucoma ?
Chronic open-angle glaucoma
Most common type of glaucoma; damages vision gradually and painlessly. The pressure is rarely high enough to be symptomatic.
An acute attack of glaucoma caused by sudden blockage of the drainage channels leading to a sharp rise in pressure within the eye.
» Blurred vision
» Severe eye pain, nausea and vomiting
» Rainbow haloes around lights
» Pain around your eyes after watching TV or after leaving a dark theatre
» Red eyes
An acute attack requires the immediate attention of an eye doctor.
How is Glaucoma detected ?
Regular eye examinations by the ophthalmologist lead to detection.
The complete and painless examination includes among other tests:
» Tonometry – Measurement of the intraocular pressure ( tension )
» Gonioscopy – Inspection of the drainage angle of the eye
» Ophthalmoscopy – Evaluation of optic nerve damage
» Perimetry – Testing the visual field of each eye
Who is at risk for Glaucoma ?
Everyone should be concerned about glaucoma and its effects. It is important for each of us, from infants to senior citizens, to have our eyes checked regularly, because early detection and treatment of glaucoma are the only ways to prevent vision impairment and blindness. There are a few conditions related to this disease that tend to put some people at greater risk.
This may apply to you if:
Someone in your family has a history of glaucoma
Age: If you are over 45 and have not had your eyes examined regularly
Near – sightedness ( myopia )
Any injury to your eyes
Secondary to other ocular conditions ( cataract, inflammation, tumours etc. )
Long – term medication ( cortisone )
How is Glaucoma Treated ?
The main treatment for chronic glaucoma aims at reducing the pressure in your eye. Damage already caused by glaucoma cannot be reversed. Eye drops, tablets, laser and surgical operations are used to prevent or slow further damage from occurring. With any type of glaucoma periodic examinations are very important to prevent loss of vision. Because, glaucoma can irreversibly worsen without your being aware of it, your treatment may need to be changed from time to time during the periodic examination.
When taken regularly and continuously as prescribed, they control the eye pressure either by slowing the formation of aqueous fluid within the eye or by increasing the flow at the drainage area. The proper technique of using your medication is a key to successful treatment. Our glaucoma clinic doctor or assistant will teach you the technique.
These are sometimes combined with the eye drops to decrease higher levels of eye pressure. They are occasionally known to cause tingling of fingers and toes, bowel irregularities, and in the very long term, kidney stones.
Why a drug causes side effects in some persons and not others is not fully understood.
By visiting the clinic regularly will help keep a check on what treatment suits you and its results.
Lasers are usually used in one of three ways:
- In open-angle glaucoma the draining angle itself is enlarged to control eye pressure.
- In angle-closure glaucoma the laser creates a hole in the iris to open up and improve the flow of aqueous fluid to the drain.
- In painful late-stage glaucoma medication or surgery do not control the pressure. The laser closes some aqueous fluid-producing areas in the eye and lowers the eye pressure.
A new drainage channel is created for the aqueous fluid to leave the eye. Sometimes a tube drains the fluid in very resistant cases.
Surgery is recommended when your doctor feels that it is safer to operate than to allow optic nerve damage to continue.
The best treatment for you should be decided after a thorough examination and discussion with us.
Our centres run Glaucoma Clinics for the special purpose of preserving sight in sight-threatening conditions such as glaucoma.
- The patient receives specialized care provided by our glaucoma specialists.
- Glaucoma needs regular follow-up since the condition can cause asymptomatic and irreversible loss of vision if poorly treated or neglected.
- The effect of your treatment on the eye pressure may not always be constant and needs to be regularly measured by our glaucoma specialist.
- At the clinic we record images and maintain records of your eye condition for comparison on following visits.
What is your part in the treatment ?
Treatment requires a team effort ( you and the doctor ): The prescription must never be altered or stopped without consulting your doctor. Frequent eye examinations and tests are critical to monitor your eyes for any changes.
How do i minimize the risk of getting Glaucoma ?
You need an eye examination –
» Every 18 – 24 months if you are age 39 years or over.
» Every 12 months if a family member has glaucoma, if you have had a serious eye injury in the past, or if you are taking steroid medication
( tablets or eye drops ).
» The Glaucoma Clinic has an early diagnosis centre keeping in mind the higher risk for glaucoma among family members.