Indira Gandhi Eye Hospital and Research Centre
Indira Gandhi Eye Hospital and Research Centre
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Glaucoma is the result of a gradual increase in the level of pressure of fluid within the eye (hydrostatic pressures) that impacts the sensitive tissues of the eye. The optic nerve is the most susceptible to damage from glaucoma. Such damage is irreparable and visual loss due to glaucoma is irreversible. However, if detected early, glaucoma’s development can be arrested.

Types of glaucoma

Glaucoma can be divided roughly into two main categories: open angle and closed angle glaucoma. Closed angle glaucoma can appear suddenly and is often painful; visual loss can progress quickly but the discomfort often leads patients to seek medical attention before permanent damage occurs. Open angle, chronic glaucoma tends to progress more slowly and patients may not notice that they have lost vision until the disease has progressed significantly.


In most cases, the patient is unaware of the gradual loss of sight until vision deteriorates quite significantly. Unless treated, patients may find the following symptoms:

  • Pain around the eyes when coming out from darkness
  • Coloured halo rings seen around light bulbs especially in the mornings and nights
  • Frequent change of reading glasses, headaches, pain and redness of the eyes
  • Reduced vision in dim light and at night
  • Gradual decrease of side vision
  • Blurring of vision


The anterior chamber in front of the eye is filled with aqueous humour. This fluid bathes and nourishes the tissues of the eye. If the drainage of this fluid is restricted, pressure builds up within the eye causing glaucoma.


Glaucoma is a leading cause of blindness in India. Though it can occur in all age groups, people above 40 years are more susceptible as are those with myopia, diabetes, systemic hypertension and a family history of glaucoma.


A device called the tonometer is used to measure pressure within the eye, but this cannot detect all glaucomas. The ophthalmologist will examine the optic nerve after dilating the pupils and also check the side vision with the aid of a computer-assisted test called Perimetry.


The loss of vision from glaucoma cannot be reversed but regular treatment and follow-up can preserve residual vision. The chances of arresting visual damage are higher if the disease is diagnosed early.


In most glaucoma cases, regular medication controls increased fluid pressure. If drugs prove ineffective after a period of time, the ophthalmologist can either add more drugs or change medication or choose another form of treatment - laser or surgical methods. Periodical eye examinations are therefore essential to ensure that the medication is working.

Laser treatment

This is prescribed only in closed angle glaucoma and serves to reduce the eye pressure by using a strong beam of light to relieve the fluid pressure. Laser treatment is only prescribed if all medication fails but its affect wears off over time.


This form of treatment is the last resort when medication and laser treatment are ineffective. Surgery has its own limitations and risks. Even after surgery, the patient should continue periodical check-ups and may need medication to control eye pressure.