Glaucoma – Protect Your Vision From The Silent Vision Snatcher
Glaucoma – Protect Your Vision From The Silent Vision Snatcher
*The views expressed here are solely those of the author in his private capacity and do not in any way represent the views of Centre for Sight.
Title: Glaucoma – Protect your vision from the silent vision snatcher
Source: Stayfit magazine
Date: March 2014 edition
GLAUCOMA: SILENT VISION SNATCHER
PROTECT YOUR VISION
Almost 68% Indians run the risk of developing glaucoma and nearly 1.2 lakh Indians go blind every year due to this disease. Dr. Harsh Kumar, Senior Consultant Glaucoma & Cataract, Centre for Sight group of eye hospitals, explains that while the disease cannot be prevented, it can certainly be controlled.
Kapil Jindal, a 42-year-old executive felt on the top of the world with a steady income, good health prospects and a happy family. One day, however, on accidentally closing one eye, he noticed that his left eye seemed to have some areas of missing vision. He rushed to an ophthalmologist and was diagnosed as having advanced glaucoma in one eye and early glaucomatous changes in the other. Suddenly, the world seemed dark and all his dreams shattered. After a comprehensive ophthalmic examination and an array of tests, a laser procedure was performed and anti-glaucoma drops were initiated. His pressure soon returned to near normal. A dialogue with his doctor made him fully understand the nature of this disease. He felt assured that together with his doctor’s advice, timely checkups and appropriate treatment, this silent vision snatcher could be kept at bay. Jindal is back to where he had left, a man with a new lease of life and new dreams to chase. He says about his experience, “The more I have come to know about glaucoma, the lesser are my fears. Glaucoma is no longer ruling my life.”
WHAT IS GLAUCOMA?
Glaucoma or ‘Kala Motia’ is a condition wherein an increased intraocular pressure damages the optic nerve thereby affecting vision. A fluid known as aqueous nourishes the front part of the eye. In the normal eye, the rate of production of aqueous matches the rate of its drainage, thereby maintaining optimal pressure inside the eye. With age, disease, trauma or other factors, the channels carryingthis fluid may get blocked, increasing the pressure inside the eye. This increased pressure damages the optic nerve, which is the conduit of visual messages to the brain. Working silently, glaucoma damages the outer or peripheral vision first while maintaining the central vision and if not treated on time it may lead to loss of central vision and blindness.
WHY IS IT CALLED THE SILENT THIEF?
Glaucoma is called the silent thief of sight because in the early stages of the disease, there may be no symptoms. This condition threatens vision and is known to gradually steal sight without warning. By the time glaucoma is detected, the patient has already suffered extensive peripheral vision damage which can no longer be restored. The statistics reveal that by the time people realize that something is amiss and consult a doctor, 90% of them have lost half of their vision. It comes so slowly that it goes unnoticed in most of the people. Worldwide, it’s the leading cause of irreversible blindness. In fact, as many as 6 million individuals are blind in both eyes from this disease.
HOW MANY PEOPLE ARE AFFECTED BY GLAUCOMA?
It is the leading cause of blindness in the United States and a study presented at the World Ophthalmological Congress has projected India as the next glaucoma capital. Almost 68% Indians run the risk of developing the disease and nearly 1.2 lakh Indians go blind every year due to this disease.
WHAT ARE THE TYPES OF GLAUCOMA?
Primary Open Angle or Chronic Glaucoma: This is the most common form of glaucoma. Damage to the vision in this type of glaucoma is gradual and generally painless. The affected person might not develop significant symptoms and may be entirely unaware of this disease until the optic nerve has been severely damaged.
Normal Tension Glaucoma: A special type of glaucoma where even at lower intraocular pressure there may be damage to the optic nerve due to factors such as decreased blood flow into the eye. This commonly occurs in people with high blood pressure who are on anti-hypertensive medication. They may get bouts of low BP especially at night which can cause damage to the optic nerve.
Closed Angle or Acute Glaucoma: In this type of glaucoma, the intraocular pressure increases very rapidly due to a sudden and severe block of fluid drainage within the eye. Significant symptoms such as pain, colored halos around light bulbs, headache and decreased vision may develop, indicating the presence of acute glaucoma. This condition has to be treated urgently by an ophthalmologist to prevent permanent visual damage.
Other types of Glaucoma are:
Congenital Glaucoma: If the child at birth or in early childhood has large eyes i.e. cornea is large, child has severe watering when exposed to light and the lids close forcefully or the black portion turns white then this could be a case of childhood glaucoma and doctor must be urgently consulted.
Secondary Glaucoma: In this type of glaucoma, eye has earlier been subjected to trauma, inflammation, surgery or prolonged use of steroids.
POSSIBLE SYMPTOMS OF GLAUCOMA:
Glaucoma in early stages generally does not show noticeable symptoms. It is possible for a person suffering from chronic glaucoma to be completely unaware of the disease. Chronic Glaucoma generally progresses too slowly to get noticed. Some common symptoms of chronic glaucoma could be:
Inability to adjust the eyes to darkened rooms such as theaters
Poor night vision
Frequent changes in eye glass prescription for reading glasses. Generally over 40 years of age, everyone gets reading glasses and these change every 2 to 3 years. If they change very rapidly around every 3 to 6 months, it could be a case of glaucoma
Gradual loss of peripheral vision
In the case of Acute Glaucoma resulting from rapid increase in the intraocular pressure, there could be severe symptoms. Common symptoms suggesting the presence of acute glaucoma could be:
- Seeing rainbow colored halos around lights
- Cloudy vision with halos around light
- evere eye pain, facial pain, nausea and vomiting
- Red eye
IS THERE A CURE FOR GLAUCOMA?
Glaucoma cannot be cured but it can be controlled so that further damage to the optic nerve can be slowed down or halted. This can only be done through disciplined and regular treatment from an ophthalmologist. The treatment of glaucoma is life-long.
Tests for Glaucoma
Perimetry: Must for making diagnosis of all glaucoma patients. This test is essential not only to assess the extent of the existing damage, but also to document and measure the progression of the disease and the response to treatment. This test requires sophisticated machinery with advanced software. This exercise takes time and may have to be repeated at timely intervals or even immediately if patient is not cooperative.
Gonioscopy: A lens is applied on the eye and angle is examined to see if it is open or closed type of glaucoma.
Other sophisticated tests: OCT (Ocular Coherence Tomography), CCT (pachymetry) and Fundus photography. The OCT is a noninvasive test. This means that nothing touches the eye. The patient is simply asked to focus onto a light as the advanced machine and its software assess the status of the optic nerve and the nerve fibre layer. Pachymetry or CCT is measured with the application of an ultrasonic probe onto the cornea.
WHAT DOES THE MANAGEMENT OF GLAUCOMA ENTAIL?
Glaucoma treatment may include medical management, surgical management or management by lasers. Medical management is done with eye drops. There are different formulations of eye drops some of which reduce aqueous inflow while others increase outflow. Please read the pamphlet given with the eye drops and check that you are not having any side effects mentioned in it. Preferably store the eye drops in a cool & dry place.
Management by lasers includes procedures such as trabeculoplasty, in which a laser is used to pull open the trabecular meshwork drainage area; iridotomy, in which a tiny hole is made in the iris, allowing the fluid to flow more freely; and cyclophotocoagulation, in which a laser beam treats areas of the ciliary body, reducing the production of fluid.
Surgical management includes various procedures where an opening is made to create a new drainage pathway for the fluid to leave the eye easily. Even despite surgery, you may have to use anti-glaucoma medication or go for a re-surgery. Also your regular checkups should continue even after surgery.