:: main links ::.
  about us
  eye disorders
  eye care
  contact us

Glaucoma is a "silent killer" like Diabetic Retinopathy. It is commonly called as Kala Motia in vernacular. In most cases it begins un-noticeably and damages the eyes without any sign or symptom till it is very late. This is the reason that awareness about glaucoma and its treatment is important to prevent this blinding disease.

What is Glaucoma?
Glaucoma has been rightly called the “The silent stealer of eyesight”. Glaucoma is a group of disorders in which [I.O.P] intra-ocular pressure (I.O.P maintains the shape of the eye ) is raised above the normal value (11 - 21 mm Hg) in the affected eye , resulting in a damage to the optic nerve head & irreversible visual field defects. The loss of vision is so gradual from along the periphery of the eye that the patient is largely unaware of the loss. What is most tragic is that vision loss due to glaucoma is irreversible. Medication and surgery can at the best preserve the remaining eyesight of the patient.

Glaucoma is a result of build up of fluid within the eye and the resultant increase in pressure. This pressure falls on the sensitive optic nerve resulting in irreversible damage.

What are the risk factors for Glaucoma?

Following are the risk factors for Glaucoma:

1. Family history of glaucoma especially in parents and siblings (risk of 10% in siblings).
2. Diabetes mellitus
3. Thyroid Diseases: Thyroiditis
4. Refractive error :mostly seen in high Myopes
5. Cigarette smoking
6. Injudicious use of steroids (eye drops)
7. Age: Mostly glaucoma affect people in the fifth & seventh decade of their life but it can occur at any age.

Can glaucoma can occur in children? Glaucoma can occur even in young children and infants (Developmental/Congenital Glaucoma). Occurring before the age of 3 years it is called Congenital Glaucoma. Between the age of 3 and 30-35 years it is called Juvenile Glaucoma.

Types of Glaucoma-  There are two main types of glaucoma:

Open Angle Glaucoma & Angle Closure Glaucoma 

Normally, the fluid of the eye (aqueous) circulates through anterior chamber and passes through the angle exits from the eye into the Canal of Schlemn but in open angle glaucoma the passage to the canal of Schlemn offer resistance to the flow of aqueous.

Chronic Open Angle glaucoma
As there are hardly any symptoms, the patient is largely unaware that there is a progressive loss of vision. The only way of diagnosis is through periodic eye examinations.

Congenital Glaucoma
This is visible literally from birth. Since the eye of an infant is more elastic than that of an adult, the increase of pressure leads to the eye bulging out.

Acute Angle Closure Glaucoma
This is a sudden onset. Blurred vision, severe pain, rainbow haloes around light, nausea and vomiting are the immediate symptoms. Unless medical attention is provided immediately, blindness can result in a day or two.

Anybody over the age of 40 years is susceptible to Glaucoma. That’s why it is advised that people above 40 should go in for an ophthalmologic examination every 6 months.

In angle closure glaucoma the angle of the chamber is narrow or gets closed preventing the drainage of aqueous from the eye. Both types lead to increase in intra-ocular pressure.

What are the signs & symptoms? Primary open angle glaucoma usually insidious & asymptomatic (does not give rise to any symptoms) in early stages.  In late stages patients may feel pain in eyes (eye-ache).

Some individuals may notice field defects (inability to see certain areas of the field of vision). Usually this type of glaucoma is diagnosed on examination by an eye specialist. Patient with very high I.O.P may complain of occasional colored rings (haloes) around lights due to transient corneal epithelial oedema.

Patient can develop delayed dark adaptation. Reading & close work often present increasing difficulties owing to accommodative failure due to constant pressure on the ciliary muscle & it is nerve supply. Therefore patient usually complain of frequent changes in presbyopic glasses.

How glaucoma can lead to blindness?

Increase in pressure in the eye leads to resistance to flow of blood into the eye leading to damage to the optic nerve head which carries the images to the brain. First it leads to some area of loss of visual field (the extent of surrounding visible to any one eye). This field loss progresses gradually till the eye is completely blind. Early field loss can be detected by an eye specialist with a test called Visual Field Charting.

How to diagnose  Glaucoma ?

Glaucoma can be diagnosed by following tests:

Intra-ocular Pressure [I.O.P] or Eye Pressure: Measured by an instrument called Applanation Tonometer (Normal I.O.P ranges between 11 and 21 mm Hg). It may be mildly raised in open angle glaucoma and markedly raised in angle closure glaucoma. In between the attacks of angle closure glaucoma it may be normal. It may vary at different times of the day and this variation can be measured by noting pressures round the clock at specified interval (Phasing / Diurnal Variation). In low tension or normal tension glaucoma the pressure may never be higher than normal range.

Gonioscopy: It’s method by which one can assess the angle of anterior chamber of the eye. It helps in diagnosing the type of glaucoma or even the vulnerability of the person to have attacks of angle closure glaucoma.

Fundus examination: The retina and optic nerve of the eye can be seen by an instrument called ophthalmoscope. The optic disc undergoes characteristic changes in glaucoma which are noted by measuring cup : disc ratio or the C : D Ratio [ normal range is 0.3 to 0.4]. It is increased in open angle glaucoma and later stages of angle closure glaucoma & is proportionate to the extent of damage done [In some normal individuals the C : D ratio may be increased].

Visual Fields: It measures the "area of vision"&, the sensitivity of each point in this area of a single eye. In this test patient is shown light targets of various sizes and brightness and note is made of the area where the patient can see this. The data thus collected , analyzed & compared with data of normal population. Glaucoma gives rise to characteristic field defects &  progress in a peculiar manner. This is the definitive test to detect glaucoma and assess the severity and extent of damage in the eye.

Remedies: Glaucoma is usually controlled with eye drops or oral medication given in various combinations. These medications act to decrease the eye pressure either by assisting flow of fluid outside the eye or by decreasing the amount of fluid entering the eye. If medication is poorly tolerated or not effective in controlling the intra-ocular pressure, surgery is done to create an artificial drainage channel for the fluid to drain out.

Can Glaucoma be treated? Glaucoma can be treated but the damage done by it cannot be reversed. But further damage to the eye by glaucoma can be stopped.

 The treatment for glaucoma includes:

Drugs :Initial therapy of Primary open angle glaucoma is still medical.

Surgeries: Goniotomy,Trabeculotomy,Trabeculectomy.see Diagram below.

Laser Operation  [ Argon or diode laser trabculopasty ] see laser .

With early treatment, serious loss of vision and blindness can be prevented.

To view an informative poster on Glaucoma click here.....


Home | Site Map | Diseases | Feedback | Contact

Copyright © 2005 PannuEye Inc. All rights reserved.
site designed and maintained by Cyberbrainz™ Web Solutions