Glaucoma

Glaucoma is a disease that damages optic nerve of the eye.

There is fluid inside the eye, known as aqueous humor that maintains shape of the eyeball.When pressure of this fluid increses above the normal limits of around 21 mm of Hg it is kown as glaucoma.. This increased pressure compresses the optic nerve thus damages the nerve which results in irreversible loss of vision gradually.

Glaucoma is a silent thief of sight

Glaucoma has no symptoms in its early stages. In fact, half the people with glaucoma do not know they have it. Having regular eye exams can help your ophthalmologist find this disease before you lose vision. Your ophthalmologist can tell you how often you should be examined.

Who Is At Risk for Glaucoma?

Some people have a higher than normal risk of getting glaucoma. This includes people who:

• Are over age 40
• Have family members with glaucoma
• Are farsighted or nearsighted
• Have had an eye injury
• Use long-term steroid medications
• Have diabetes, high blood pressure

Talk with an ophthalmologist about your risk for getting glaucoma. People with more than one of these risk factors have an even higher risk of glaucoma.

Symptoms :

Symptoms of Open-angle glaucoma :

With open-angle glaucoma, there are no warning signs or obvious symptoms in the early stages. As the disease progresses, blind spots develop in your peripheral (side) vision.

Most people with open-angle glaucoma do not notice any change in their vision until the damage is quite severe. This is why glaucoma is called the “silent thief of sight.” Having regular eye exams can help your ophthalmologist find this disease before you lose vision.

Symptoms of Angle-closure glaucoma :

People at risk for angle-closure glaucoma usually show no symptoms before an attack. Some early symptoms of an attack may include blurred vision, halos, mild headaches or eye pain. An acute attack of angle-closure glaucoma includes the following:

• Severe pain in the eye or forehead
• Redness of the eye
• Decreased vision or blurred vision
• Headache
• Nausea and vomiting

Normal tension glaucoma symptoms

People with "normal tension glaucoma" have eye pressure that is within normal ranges, but show signs of glaucoma, such as blind spots in their field of vision and optic nerve damage.

• Normal Optic Nerve
• Glaucomatous Optic Nerve

Different types of glaucoma :

There are two major types of glaucoma.

Primary open-angle glaucoma

This is the most common type of glaucoma. It happens gradually, where the eye does not drain fluid as well as it should (like a clogged drain). As a result, eye pressure builds and starts to damage the optic nerve. This type of glaucoma is painless and causes no vision changes at first.

Some people can have optic nerves that are sensitive to normal eye pressure. Thus normal eye pressure can damage optic nerve in these people , this is known as Normal Tension Glaucoma. Regular eye exams with eye pressure check ups are important to find early signs of damage to their optic nerve.

Angle-closure glaucoma (also called “closed-angle glaucoma” or “narrow-angle glaucoma”)

This type happens when someone’s iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle. When the drainage angle gets completely blocked, eye pressure rises very quickly. This is called an acute attack. It is a true eye emergency, and you should call your ophthalmologist right away or you might go blind.

Glaucoma Diagnosis

The only sure way to diagnose glaucoma is with a complete eye exam. A glaucoma screening that only checks eye pressure is not enough to find glaucoma.

During a glaucoma exam, your ophthalmologist will:

• Measure your eye pressure
• Inspect your eye's drainage angle
• Examine your optic nerve for damage

In suspicious cases :

• Test your peripheral (side) vision (Visual filed Test )
• Take a picture of retina ( Colour fundus photo)and computer measurement of your optic nerve (OCT RNFL)
• Measure the thickness of your cornea (Pachymetry )

Treatment of Glaucoma :

Medications

Glaucoma is usually controlled with eyedrop medicine. Used every day, these eye drops lower eye pressure. Some do this by reducing the amount of aqueous fluid the eye makes. Others reduce pressure by helping fluid flow better through the drainage angle.

Never change or stop taking your glaucoma medications without talking to your ophthalmologist.

Laser treatment

Laser helps in aqueous drainage from the eye. These procedures are usually done as OPD day care procedure.

• Iridotomy. This is for people who have angle-closure glaucoma. The ophthalmologist uses a laser to create a tiny hole in the iris. This hole helps fluid flow to the drainage angle.
• Trabeculoplasty. This surgery is for people who have open-angle glaucoma and can be used instead of or in addition to medications. The eye surgeon uses a laser to make the drainage angle work better. That way fluid flows out properly and eye pressure is reduced.

Surgical treatment

• Trabeculectomy. This is where your eye surgeon creates a tiny flap in the sclera. This creates a bubble (like a pocket) in the conjunctiva called a filtration bleb. It is usually hidden under the upper eyelid and cannot be seen. Aqueous humor will be able to drained out of the eye through the flap and into the bleb. In the bleb, the fluid is absorbed by tissue around your eye, lowering eye pressure.
• Glaucoma drainage devices. Your ophthalmologist may implant a tiny drainage tube in your eye. The glaucoma drainage implant sends the fluid to a collection area (called a reservoir). Your eye surgeon creates this reservoir beneath the conjunctiva. The fluid is then absorbed into nearby blood vessels.

Your Role in Glaucoma Treatment

• Treating glaucoma successfully is a team effort between you and your doctor. Your ophthalmologist will prescribe your glaucoma treatment. It is your responsibility to follow your doctor’s instructions and use your eye drops.
• Once you are taking medications for glaucoma, your ophthalmologist will want to see you regularly. You can expect to visit your ophthalmologist about every 3–6 months. However, this can vary depending on your treatment needs.
• Glaucoma medications need to be continued lifelong .Do not stop the medicines on your own without consulting your ophthalmologist .