Glaucoma

GLAUCOMA also known as "Kala Motia or "Neela Motia", is one of the leading causes of blindness all over the world.In India one out of every 80 patients who have lost their sight, are glaucoma patients. The most disturbing fact is that this blindness is needless and preventable. A proper awareness, careful examination and meticulous adherence to the prescribed treatment can certainly prevent bllindness due to glaucoma.

WHAT IS GLAUCOMA ?
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glaucoma_cutout2To retain the shape and configuration of the eye, a fluid called the aqueous humor is formed inside the eye. This fluid is being continuously formed and is simultaneously being drained out of the eye. Nature has provided a very delicate balance of inflow and outflow of this fluid and as long as this balance is retained, eye functions in a healthy way. Sometimes this balance is disturbed. Either the production of the aqueous is increased, or the exit channels of the drainage start malfunctioning. This results in an increase of aqueous pressure inside the eye ball.

This increase in pressure presses on the blood vessels which bring blood supply to the vital optic nerve at the back of the eye

Optic nerve is like an electrical cable. It contains millions of wires each carrying messages from, the eye to the brain. These wires work together to provide central sharp vision as well as "Side Vision” or Peripheral vision.

Glaucoma causes gradual damage to these wires or nerves causing blind spots in the areas of vision. Patients rarely notice these blind areas in the vision until significant optic nerve damage has taken place. If the entire nerve is destroyed total loss of vision takes place and this loss of sight is permanent and irrecoverable. Fortunately this rarely occurs if glaucoma is diagnosed and treated before major damage occurs.

Proper and periodic examination of the eyes by a competent eye specialist is of utmost importance for all adults over 40 years of age.

CAUSES AND SYMPTOMS:

Sometimes patients suffering from glaucoma may present with symptoms but generally glaucoma patients have no complaints and are diagnosed on routing eye examination it is for this reason that glaucoma is often labelled as the Silent Killer of vision.

Depending upon the manner in which the exit channels get closed or obstructed glaucoma manifests itself in 4 ways:

1. OPEN ANGLE GLAUCOMA : This is the most common form of glaucoma The rise in the pressure of the eye ball is gradual. This is aiso known as "Chronic open angle glaucoma" and can steal vision so quietly that the patient is unaware of visual loss until the optic nerve is very badly damaged Because no symptoms occur, the only way to diagnose this type of glaucoma is by periodic eye checkup. Usually patients of this type of glaucoma manifest with complaint of frequent change of glasses.

2. ANGLE CLOSURE GLAUCOMA :This is found more often in elderly females. This usually causes blurred vision, severe pain, rainbow, haloes around lights, nausea and vomiting. Unless this condition is relieved promptly, blindness can result.

3. CONGENITAL GLAUCOMA : The "Exit Channels" may be poorly formed since birth. Because infant tissue is more elastic, the baby's eyes increase in size due to high pressure. The baby's eyes appear cloudy and abnormally large. The baby may shy away from light and keep its eyes closed to escape light.

4. SECONDARY GLAUCOMA : Any injury, drugs like steroids, tumor, haemorrhages, inflammation etc., can increase the aqueous pressure and result in Secondary Glaucoma.

 

DETECTION & DIAGNOSIS :

Early detection of Glaucoma is of utmost importance. The most common form of glaucoma is "Chronic open angle glaucoma" which is painless and generally occurs is adults above the age of 40 years.

Hence once a year check up by an ophthalmologist is essential for this age group. Glaucoma detection needs the help of the few specialized investigations.

TONOMETRY : It is used to measure the pressure in the eyes. Applanation Tonometry is the most sensitive technique to detect the level of intraocular pressure which is an indicator of Glaucoma.

OPHTHALMOSCOPY: It is used to assess the optic nerve at the back of the eye.

glucomaPERIMETRY: Perimetry is a special and a very sensitive test for detection of glaucoma. It produces a map of the patient's complete field of vision. Glaucoma damage first appears as slight changes in the field of vision. Perimetry is also a sensitive indicator of the progress of Glaucoma.

GONIOSCOPY: It is used to see the exit areas of the anterior chamber of the eye and the extent to which they are blocked.

OCT: It is used to measure the thickness of the retinal nerve fibre layer. In patients of Glaucoma the thickness of the retina is less than normal. It is one of the earliest indicators of the disease.

 

More frequent checkups are needed if there is:-

  1. A possible history of glaucoma in the family.
  2. Dull pain around the eyes specially after sitting in dark or watching movies and T.V.
  3. Unexplained Headaches.
  4. Intermittent Blurring of Vision.
  5. Loss of field of vision
  6. Difficulty in seeing at night.
  7. Frequent change of glasses.
  8. Visualizing coloured haloes around
  9. Patients with general health problems such as diabetes, hardening of arteries, and anaemia.
  10. Use of cortisone for some other disease. People who consume mustard oil should be careful. Mustard oil adulterated with argemone oil can cause glaucoma (along with Epidemic Dropsy).

 

TREATMENT :

Treatment depends upon the type & severity of glaucoma. Glaucoma can be treated either by drugs, laser or by operative surgery. In case drugs are prescribed for instilling in the eye, continuous and regular use is a must. The regularity and the usage of the medicine with proper periodicity is extremely important.

In case drugs fail to achieve the objective, glaucoma can be treated with laser or Incision surgery. Fortunately complications of modern glaucoma surgery are rare.

Once the glaucoma has been controlled by drugs, laser or surgery, the patient can live a normal life and may continue with his/her regular occupation.

GLAUCOMA AND CATARACT :

Though Glaucoma and Cataract occur in the same age group, they are quite different. Cataract is due to opacities in the lens and Glaucoma is due to a rise of pressure in the eye. Loss of vision is recoverable in cataract by a simple operation but the visual loss is irreparable in case of glaucoma. The key is to consult your eye specialist periodically for glaucoma if you are more than 40 years of age. Your doctor is the only person who can guide you to preserve your own vision.