Glaucoma is leading cause of irreversible blindness in the world and is estimated that there are 60 million cases of glaucoma worldwide. In India, around 12 million people suffer from glaucoma which is 1/5th of the global burden. Glaucoma can affect any age group, including newborn, infants, children and elderly.
What is Glaucoma?
Glaucoma is a group of diseases that damages the optic nerve and can result in vision loss and blindness. It usually happens when fluid builds up in the front part of the eye. The extra fluid increases the pressure, thus damaging the optic nerve. However, early detection and treatment can protect the eyes against vision loss.
To properly understand Glaucoma let us first understand how the eye works.
The eye works like an old style camera. In the camera, the light comes in through the shutter, is focused by the lens and then falls onto the film and then developed. Similarly, in the eye, the light comes in through the cornea and pupil. It is focused by the lens, fall onto the retina and then via the optic nerve to the brain for developing.
What are the Causes of Glaucoma?
Glaucoma is the result of high fluid pressure inside the eye. Normally, the liquid called aqueous humor flows out of the eye through a mesh-like channel and if this channel gets blocked, the liquid builds up. This is what causes Glaucoma. Less common causes include eye injury, severe eye infection, blocked blood vessels inside the eye, and inflammatory conditions.
Who is at risk?
Everyone is at risk for Glaucoma but certain groups are at higher risk than others
- People aged 40 years and above
- Family history of Glaucoma
- People with diabetes/hypertension/thyroid disease
- People who see rainbow coloured rings around the bright light
- People who have Myopia and frequent headaches
- People who take medicines for sleep/anxiety/depression/asthma/parkinsonism
What are the different types of Glaucoma?
There are many different types but the 2 major categories are:
- Open-angle Glaucoma
- Angle-closure Glaucoma (Closed-angle or narrow-angle Glaucoma)
What are the Symptoms?
There are no symptoms early in the disease. However, the symptoms do appear later but they depend on the type and stage
- Patchy blind spots
- Tunnel vision in advanced stages
- Severe headache
- Eye pain
- Nausea and vomiting
- Halos around the lights
- Redness in the eye
How is Glaucoma Diagnosed?
During a routine examination, the ophthalmologist will use drops to dilate the pupils. Then the eyes are examined.
- Tonometry – a device called tonometer is used to measure intraocular pressure.
- Pachymetry – a device called pachymeter is used to measure the thickness of the cornea in the eye.
- Gonioscopy – this test examines the area where the fluid drains out of the eye. It determines whether the angle between the cornea and the iris is open or blocked.
- Ophthalmoscopy – an examination where a special lens and the slit lamp is used to look directly through the pupil into the eye. This test is done to check the damage to the optic nerve.
- Visual Field Testing – maps the visual fields to detect any early sign of damage to the optic nerve.
- Confocal Laser Scanning & Optical Coherence Tomography – non-invasive imaging system that creates a 3-dimensional image of the optic nerve and retina to evaluate the degree of cupping and thickness of the retinal nerve fibre.
Glaucoma tests are painless and take very little time.
What are the Treatment options?
The nerve damage and visual loss cannot be reversed but the condition can be controlled. That is why early detection is important. The treatment process involves the use of Eye Drops, Laser Trabeculoplasty, Conventional Surgery, or a Combination of Any of These.
Glaucoma cannot be cured but can be controlled with regular eye checkups, proper treatment and maintaining a healthy lifestyle.