In our hospital we have the specialist doctors with all the machines in the armanterium, like tonometer (both applanation & non contact), field analyzer (Humphrey – Zeiss), GDXVCC, OCT for nerve fibre analysis to come to accurate diagnosis & regular follow up for the glaucoma patients.
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 humour 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?
Most common type of glaucoma.<br />The increase in IOP occurs slowly over time pushing on the optic nerve and the retina at the back of the eye.<br />Painless, Asymptomatic.<br />You are at a high risk if you have a parent or grandparent with open-angle glaucoma.<br /> Children of the parents having glaucoma should be checked regularly after the age of 35 years, as glaucoma usually runs in family.
A Regular eye examinations by the ophthalmologist leads 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.
GDXVCC- Retinal nerve fiber layer analyser.
OCT- for Retinal nerve fiber thickness and optic cup – disc size.
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].
Unfortunately there are no symptoms in early stages. A person with chronic glaucoma is usually unaware of the disease. Like the hands of a clock, chronic glaucoma moves so slowly that it’s progress is not noticed. Thus it is a silent snatcher of vision.On the other hand, acute glaucoma, in which the pressure rises rapidly, causes severe symptoms which force the patient to consult a doctor. Symptoms that suggest the presence of chronic or acute glaucoma include :
- Poor night vision.
- Sensation of a blind area.
- Headaches in the early morning or after dusk.
- Pain in eye, particularly when associated with smoky vision
- Halos around light
People with high pressures have a higher risk of developing optic nerve damage. Other important risk factors include advancing age. Severe myopia (near sighted), a family history of glaucoma or diabetes, past injury to the eye, surgery or a history of severe anaemia or shock.Your ophthalmologist will weigh all these factors before deciding whether you need treatment for glaucoma or not. If your risk of developing glaucoma is higher than normal but there is no optic nerve damage, you will be monitored periodically as a ‘glaucoma suspect’.
Regular eye examination by an ophthalmologist is the best way to detect glaucoma. During a complete work up for glaucoma, your ophthalmologist will measure the intra-ocular pressure (tonometry), inspect the drainage angle of the eye (gonioscopy), evaluate for optic nerve damage (ophthalmoscopy), and test the visual field of each eye (perimetry).Some of these tests may not be necessary for every person. These tests must be repeated on a regular basis to monitor the progress of disease.
Strictly speaking glaucoma cannot be cured but it can be controlled and further optic nerve damage can be slowed and halted.Achieving this goal required a life long commitment to treatment and regular visits to the ophthalmologist. Your eye doctor will decide if, when and how the treatment should start.
Eye drops, pills, laser and surgical operations are available to manage glaucoma.
Medical treatment : The first attempt to control glaucoma is made with eye drops instilled twice/several times a day, sometimes in combination with pills. These medications act to decrease eye pressure either by slowing the production of aqueous fluid within the eye or by improving the flow through the drainage angle. To be affective, these medications must be taken regularly at prescribed intervals.
Some medicine may occasionally result in unwanted side effects. Some drops may sting, redden the eye and cause blurring of vision or headaches. Such side effects usually disappear after a few weeks. Rare side effects may be changes in pulse, heart beat and breathing (Now, specially designed drops for people with cardiac problems and bronchial asthma are available). Medication should never be stopped or changed without consulting your ophthalmologist. Frequent eye examinations and tests are crucial to monitor your glaucoma condition for any changes. Pills sometimes cause tingling sensation in finger tips and toes, drowsiness, loss of appetite, bowel irregularities or kidney stones. Inform your ophthalmologist immediately if you think you are experiencing side effects.
Laser surgery may be effective for some types of glaucoma. In chronic open angle glaucoma, when the drain itself is treated (trabeculoplasty), the laser may help (or replace) the medications to control the pressure. In angle-closure glaucoma, a hole is made in the iris (iridotomy) to restore the flow of aqueous fluid to the drainage angle.
Sometimes, surgery (trabeculectomy) is necessary to control glaucoma. The ophthalmologist uses miniature instruments to create a new drainage channel for fluid to leave the eye, thus lowering the pressure in advanced cases. If surgery fails, special glaucoma valves can be implanted. Fortunately, serious complications of modern glaucoma surgery are rare. Surgery for glaucoma would be recommended only if the medicines fail to prevent damage to the optic nerve.
Whatever may be the approach, the objective of the treatment is to lower the eye pressure to a level at which optic nerve damage does not develop or worsen. Although eye pressure is important, the condition of your optic nerve and peripheral vision are equally or more important. Normal pressure means that all the medicines are adequate and not that glaucoma has been cured.The success of your treatment depends entirely on the team work put in by you and your ophthalmologist. It is therefore important to communicate with your doctor. Finally, remember to keep the follow-up appointments with your ophthalmologist. If you don’t, glaucoma could be stealing your sight without your knowledge.
Suggested Glaucoma screening schedule in High Risk groups
- People with high intra-ocular pressure (IOP) : Regular visit to eye specialist for Tonometry, Fundus and Visual field aa a testing.
- People over the age of forty years with no previous glaucoma : At least once every two years, specially whenever there is a change of reading glasses.
- Family history of glaucoma : Regular screening from younger age for people with parents or close blood relatives a suffering from glaucoma.
- People having minus or plus numbered glasses : Once a year.
- Other high risk factors : Like diabetes, injury to eye, a major eye surgery, prolonged steroid use etc. need more frequent screening as advised by the treating physician.