What is glaucoma?

Glaucoma is an eye disorder where the major nerve of the eye, the optic nerve, suffers damage and may cause permanent blindness if untreated or treated inappropriately.

Glaucoma is a silent disease. The patient suffers no symptoms at the initial stages of the disease, and so does not have his eyes checked. However, in the later stages of the disease, he may consult a doctor complaining of blurred vision or eye pain. Glaucoma is the second most common cause of blindness after cataracts, and in Thailand occurs in about 1.7-2.4 per one million people.

Causes of glaucoma

  1. The most important risk factor for glaucoma is increased high pressure of fluid in the eyeball, caused aqueous fluid. Normally the fluid pressure in and around the eyeball is balanced. But in patients with glaucoma, abnormality of the eye itself causes aqueous fluid within the eyeball to accumulate, building up intraocular pressure.
  2. Abnormal vision, such as extreme short-sightedness.
  3. Diabetes mellitus, high blood pressure
  4. Congenital glaucoma (occurring since birth).
  5. May occur secondary to other diseases of the eyes, like eye infections, inappropriately treated cataracts or trauma.

Two types of glaucoma

  1. Open-angle glaucoma is the more common type of glaucoma, affecting both eyes. It occurs after clogging of the drainage system of the eye. The patient will feel no symptoms, but as the parts of the optic nerve are damaged due to high pressure, the patient's visual fields which are represented by those damaged parts are lost.
  2. Angle-closure glaucoma is most common type of glaucoma found in Asia. It occurs due to anatomic closure of the drainage angle of the eye, so that aqueous fluid cannot flow normally. As more and more parts of the drainage system of the eye become closed, the intraocular pressure rises.

Signs and symptoms

  1. Acute angle-closure glaucoma may be associated with severe eye pain, redness of the eye, blurring vision, or seeing halos around lights, nausea and vomiting.
  2. Chronic glaucoma usually presents with gradual visual loss occurring only lately after 5-10 years.

Who are at risk for glaucoma?

  • Aged 40 years and above.
  • Family history of glaucoma.
  • Extreme short- or far-sightedness
  • Diabetes, hypertension, history of trauma to the eye or previous eye surgery.
  • Chronic use of steroid-based eyedrops.


An eye specialist (ophthalmologist) can detect those who he suspects may develop or who may be suffering from glaucoma using different tests.

Treatment of glaucoma

Glaucoma can be controlled by maintaining normal intraocular pressures. Any nerve damage and visual loss which is found at the time of diagnosis cannot be reversed, however prevention of further nerve damage and visual loss is possible. Treatment may involve the use of eye drops, oral medications or surgery.

Use of eyedrops

Eyedrops are a common method of treatment for most types of glaucoma. The eyedrops may have to be applied several times a day. Proper method of application of the eyedrops is very important. These guidelines should be followed:

  • Wash your hands thoroughly with soap and water and dry them with a clean towel.
  • Check the label on the bottle of eyedrops. Shake the bottle then unscrew the cap.
  • Tilt your head back. Place the fingertips of your free hand on the lower eyelid and gently pull to create a small pocket on the base of the eye.
  • Position the tip of the bottle above the pocket, roll your eye upwards and squeeze the bottle of eyedrops. Don't let the tip of the bottle touch anything.
  • Press on the medial part of your eye for 2-3 minutes so that the medicine does not drain into your tear ducts.
  • Wipe away excess drops from the eye with a clean tissue.
  • Wash your hands again.
  • Wait for at least 5 minutes before applying a different eyedrop.

Glaucoma Surgery

Surgery is most appropriate for close-angle glaucoma or those whose disease is not improved by medical treatment. There are two general types of glaucoma surgery: laser surgery and microsurgery.

Laser surgery

After numbing the eye, a laser beam is used to open the drainage channel so allow aqueous fluid (fluid in the eye) to flow out. Laser surgery is only a temporary solution to decrease the intraocular pressure, and is usually followed by conventional surgery. Between laser and conventional surgery, eye drops must be used continually.


Microsurgery to open the drainage channel of the eye is used to treat all types of glaucoma. Local or general anaesthesia is used. It is usually performed on an out-patient basis. After surgery, the patient's eye is covered, and the patient will be instructed not to wet the eye or strain the eye by reading for one week. He or she should not bend his head down or perform any strenuous activities.

Advice for patients with glaucoma

  • The intraocular pressure should be measured on weekly or monthly basis until it returns to normal.
  • Use the eyedrops as instructed even if the intraocular pressure has returned to normal, until your doctor instructs you to stop.
  • Apply eyedrops regularly at a time which is easy to remember, such as before bedtime.
  • Make a schedule for applying your eyedrops and taking your medications and place it in a place.
  • If you forget to apply the eyedrops or take your medicines, apply them at once or take them at once when you remember.
  • Prepare extra doses of your medications if you will be traveling.
  • Write down the name and dose of the medications you are taking.
  • Watch out for any side effects from your medications. If you experience any change in symptoms of your eyes, inform your doctor.
  • Always keep your appointments with your doctors as scheduled.
  • If you have stopped using the eyedrops for any reason, inform your doctor.
  • If you are seeing other doctors, always inform them that you have glaucoma and what medications you are taking.

General care for your health will bring good health to your eyes. Have a well-balanced diet, drink water frequently, exercise regularly, stop smoking, avoid drinking alcoholic beverages, decrease your coffee consumption and control your weight.

Knowing about glaucoma and its effects will help us to prevent it from occurring or progressing, and prevent blindness.

Mission Hospital Ophthalmology Center

Our experienced physicians and staff are ready to provide consultation, diagnosis and treatment of your eye diseases.

Clinic Hours

Sunday 8:00 am - 4:00 pm Thursday 7:30 am - 7:00 pm
Monday 7:30 am - 7:00 pm Friday 8:00 am - 12:00 pm
Tuesday 7:30 am - 7:00 pm Saturday Only IPD & ER
Wednesday 7:30 am - 7:00 pm