What is Glaucoma?
Glaucoma is a condition that causes damage to your eye’s optic nerve and gets worse over time. It’s often associated with a buildup of pressure inside the eye. Glaucoma tends to be inherited and may not show up until later in life.
The increased pressure, called intraocular pressure, can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma will cause permanent loss of vision. Without treatment, glaucoma can cause total permanent blindness within a few years.
Because most people with glaucoma have no early symptoms or pain from this increased pressure, it is important to see your eye doctor regularly so that glaucoma can be diagnosed and treated before long-term visual loss occurs.
If you are over the age of 40 and if you have a family history of glaucoma, you should have a complete eye exam with an eye doctor every one to two years. If you have health problems such as diabetes or a family history of glaucoma or are at risk for other eye diseases, you may need to visit your eye doctor more frequently.
Why Does Pressure Rise in the Eye to Cause Glaucoma?
Glaucoma usually occurs when pressure in your eye increases. This can happen when eye fluid isn’t circulating normally in the front part of the eye.
Normally, this fluid, called aqueous humor, flows out of the eye through a mesh-like channel. If this channel becomes blocked, fluid builds up, causing glaucoma. The direct cause of this blockage is unknown, but doctors do know that it can be inherited, meaning it is passed from parents to children.
Less common causes of glaucoma include a blunt or chemical injury to the eye, severe eye infection, blockage of blood vessels in the eye, inflammatory conditions of the eye, and occasionally eye surgery to correct another condition. Glaucoma usually occurs in both eyes, but it may involve each eye to a different extent.
What Are the Types of Glaucoma?
There are two main types of glaucoma:
Open-angle glaucoma : Also called wide-angle glaucoma, this is the most common type of glaucoma. The structures of the eye appear normal, but fluid in the eye does not flow properly through the drain of the eye, called the trabecular meshwork.
Angle-closure glaucoma : As the name suggests, its onset is quiet sudden. In certain individuals, the angle from where the fluid drains from the eye is genetically narrow. It can be blocked suddenly due to many reasons resulting in sudden increase in eye pressure.
Following are the symptoms of acute/ Closed Angle Glaucoma
- Severe pain in the eye with headache.
- Cloudy vision with coloured haloes seen around the lights
- Red eyes
Congenital Glaucoma: Occurs in children born with defective drainage channels
Following are the symptoms:-
- Excessive watering
- Abnormal sensitivity to normal light
- Cornea appears cloudy and is abnormally large in size
Secondary Glaucoma : The intraocular pressure in the eye can increase secondary due to –
- Any other eye disease.
- Injury for e.g. blunt fist injury.
- Overuse of certain drugs like ‘Steroids’
- Any systemic disease e.g. ‘Diabetes’
Who Gets Glaucoma?
Glaucoma most often occurs in adults over age 40, but it can also occur in young adults, children, and even infants.
- You are at an increased risk of glaucoma if you:
- Are over age 40.
- Have a family history of glaucoma.
- Have poor vision.
- Have diabetes.
- Take certain steroid medications, such as prednisone.
Most of the people discover they have glaucoma during a routine eye check up when intraocular pressure is spotted. To definitely say that a person has glaucoma several tests need to be done and even repeated over time before confirming the diagnosis.
Intraocular Pressure (IOP):
This is pressure within the eyeball which us usually between 10-21mmhg. Sometimes a single recording cannot confirm or rule out diagnosis of glaucoma. In such case it needs to be repeated. If elevated pressure is confirmed, further tests need to be done to establish the diagnosis of glaucoma.
This is the test by which the drainage area from where the aqueous fluid is drained is examined by a special lens this area is known as the angle. In case some abnormality is found in the angle, steps can be taken to correct the defect and restore normal fluid circulation in the globe.
This is to evaluate the central corneal thickness. This may influence the recording of pressure within the eyeball.
Perimetry/ Visual Field
This test is done to evaluate the field of vision. It is conducted on a computerized machine which is able to pick up defects. Repeat tests periodically are also necessary to pick up any deterioration so that timely treatment may be given.
Done to view the optic nerve head changes that are characteristic of glaucoma.
HRT (Heidelberg Retinal Tomography)
One of the latest tools used to diagnose and follow the progression of glaucoma.
Often people tend to think that once their IOP is controlled they have been cured of glaucoma. What most of them do not realize is that glaucoma is only being effectively controlled by keeping IOP at normal levels. Hence, a periodic eye examination is vital in controlling glaucoma.
TREATMENT MODALITIES AVAILABLE:
MEDICAL: This consist of eye drops which have to be put into the eyes on daily basis. Glaucoma medications are required for long periods; usually life long.
Laser iridotomy : Done for acute or narrow angle glaucoma with hole. A hole or opening is made in the iris to relieve the blockage of drainage channels.
Laser trabeculoplasty : useful in open angle glaucoma cases. Here the laser is used to open the blocked passages in the eye
SURGERY/TRABECULECTOMY : It is the operation where an additional channel is created surgically to drain the excess fluids by passing abnormally blocked channel. It is useful for most types of glaucoma.
Best defense against glaucoma is REGULAR eye check up specially after the age ‘40’
Risk Factor for glaucoma are:
1.Strong family history of glaucoma
- Far sightedness/Plus number
Never use any medication without an eye doctor’s approval. Continuous use of drops like STEROIDS can cause glaucoma.
Once diagnosed glaucoma, patient needs PERIODIC CHECK UP.