Glaucoma

Early detection of glaucoma including Retinal Nerve Fibre Layer Analysis (GDX) and computerized automated visual field testing. Various treatment modalities for glaucoma including laser (YAG laser iridotomy, Selective Laser Trabeculoplasty) & microsurgery (Trabeculectomy & Drainage Valve surgery)

What is Glaucoma?

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Glaucoma, otherwise known as “Kala Motia” is an eye disease in which there is an increase in pressure inside the eye. Just as some people have high blood pressure, in the same way a glaucoma patient has high eye pressure.

If the eye pressure remains high for a long time it damages the optic nerve which carries the light sense from the eye to the brain. This damage to the nerve is irreversible and leads to permanent and incurable blindness. That is why glaucoma is a dangerous disease of the eye and has been labeled as “lurking thief of vision”. Glaucoma is the second leading cause of blindness in the world with 70 to 105 million people affected worldwide (WHO).

 

Why is it important to know about glaucoma?  

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Damage due to glaucoma is preventable, not curable. It is therefore necessary that the disease should be detected and treated at its earliest stage to prevent blindness.

 

 

 

 

 

How does a person come to know that he/she is suffering from glaucoma?  

Glaucoma is usually asymptomatic or is associated with very mild symptoms which the patient often tends to ignore. Some of the early symptoms include:

  • Frequent change of reading glasses.
  • Mild eye ache or headache towards the evening after a day’s work.
  • Seeing rainbow colored haloes of light around a bulb associated with slight decrease in vision.
  • Inability to adjust one’s vision on entering a dark room. ” Difficulty in focusing on close work.
  • In advanced cases, there is a loss of side vision, while the central vision remains good. The patient becomes more prone to accidents as he/she is unable to see vehicles coming from the sides.
  • It is to be remembered, that cataract (“Safed Motia”) also starts developing at the same age as glaucoma. Many people may think that they are losing vision due to cataract whereas it may actually be due to glaucoma, which is a much more dangerous disease.
  • It is therefore advisable to undergo a routine examination around the age of 40 years to screen for glaucoma

Which age does glaucoma affect?

lAthough glaucoma is most common above the age of 40 years, it may affect any age group. A special type of glaucoma called Congenital Glaucoma may affect even a newborn or a child. Any eye that appears bigger than normal in a child should be shown to an eye specialist.

Who all are at high risk of developing glaucoma?

Presence of glaucoma in other family members

  • Increasing age – above 40 years
  • Thyroid disease o Patients who are on long term steroid therapy for other diseases such as asthma, arthritis etc.
  • Previous eye injury or surgery o Hypermetropia (farsightedness)

Damage due to glaucoma may be more severe in those patients who have associated diabetes, widely fluctuating blood pressure and myopia.

What are the types of glaucoma in adults?

There are three main varieties of glaucoma in adults which concern us:-

  • Chronic Glaucoma or Open-angle Glaucoma
  • Acute Glaucoma or Closed-angle Glaucoma
  • Secondary glaucoma, which develops due to systemic diseases like prolonged diabetes, complicated high blood pressure, thyroid disease, bleeding disorders etc. It may also occur as a complication of associated eye disorders such as vascular blocks, bleeding inside the eye, uveitis, swollen lens, blunt injury to the eye etc.

Since glaucoma more often affects the side vision, the central vision may be retained till a very advanced stage. It is important to remember that a good central (straight ahead)vision test may mislead a glaucoma patient about the severity of glaucoma and the extent of damage to the optic nerve.

Measurement of eye pressure

This is done by tonometry (non-contact/applanation). This helps your doctor to determine how high your pressure is and how well the medicine is controlling it.

Evaluation of optic nerve damage

By ophthalmoscopy and optic nerve photography.

Evaluation of drainage channels

A special magnifying contact lens is used on your eye to help your doctor determine why the fluid is not draining properly. This examination is called gonioscopy.

Visual field examination

This test detects defects in your central and peripheral field of vision.

GDxVCC Retinal Nerve Fiber Layer Analyzer / HRT / OCT

These special tests measure the thickness of the nerve fibre layer and helps your doctor detect glaucoma at a very early stage.

 

How is glaucoma detected or diagnosed?

  • After the age of 40 years, one should get an eye check up for glaucoma every 3 to 4 years even if there are no symptoms.
  • If a family member has glaucoma, if you have diabetes, if you are on long term systemic steroids for some other disease, or if you have suffered a blunt eye injury in the past, you must get your eyes checked every 1 to 2 years.

 

How often should one get an eye check up?  

  • After the age of 40 years, one should get an eye check up for glaucoma every 3 to 4 years even if there are no symptoms.
  • If a family member has glaucoma, if you have diabetes, if you are on long term systemic steroids for some other disease, or if you have suffered a blunt eye injury in the past, you must get your eyes checked every 1 to 2 years.

 

How is glaucoma treated?

As damage to nerve caused by glaucoma cannot be reversed, the aim of the treatment is to prevent or reduce further damage to the optic nerve. The first step to do that is to lower the eye pressure.

The three modalities of treatment are:-

Medical (Eye drops and tablets) Laser treatment Surgery

Medical treatment: –

Your doctor will prescribe you certain medication (Eye drops and tablets) so as to lower your eye pressure. ” You must use the medicines regularly as directed by your ophthalmologist.

You should not stop medicines even if you do not have symptoms.

A regular follow up, as advised by your doctor, is mandatory.

Laser treatment:

If glaucoma is not controlled with the help of medicines, if the side effects of the medicines are not well tolerated and the patient is non compliant, or cannot afford the cost of the medicines, the second option is LASER TREATMENT. There are various types of lasers that are used in the treatment of glaucoma.

They are: –

YAG Laser Peripheral Iridotomy

A small opening is made in the iris so that the stagnant fluid finds a way to the anterior chamber, the front portion of the eye, and subsequently drained off. This is an OPD procedure, done under local anesthetic drops and takes only a few minutes to be completed. After the laser, you can wash your eye with water and can lead a normal life.

Selective Laser Trabeculoplasty (SLT)

Argon Laser Trabeculoplasty

Diode Laser Cycloablation

Operative procedures (Glaucoma Filtering Microsurgery or “By-pass” surgery of eye)

 

Some commonly asked questions by glaucoma patients

Q My vision is good, then why do you say I have glaucoma?

A In glaucoma the central vision is not lost till the very late stages. It starts with damage to your peripheral vision and gradually comes to the center. When the central vision is affected it is too late and nothing can be done to restore vision. In a way, a good vision is misleading as far as severity of glaucoma and extent of damage is concerned.

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Q How serious is my glaucoma problem?

A It depends upon the amount of optic nerve damage that has already been caused. The damage can be measured by visual field analysis (VFA) and GDx (which measures the thickness of nerve). As the damage is permanent, appropriate measures are taken to prevent or slow down further damage.

Q Can I get back my side vision after treatment?

A Unfortunately the vision loss caused by glaucoma is permanent and cannot be regained.

Q What precaution must one take?

One must remember that glaucoma treatment is life long, and one should use the medicines regularly and should come for follow-up as and when advised.

Persons who are at the risk of developing glaucoma (as listed previously) should undergo regular eye examinations.

Diabetics should ensure good control of blood sugar levels

Avoid smoking