What is glaucoma
The LightLas YAG is used to treat Glaucoma, the leading cause of blindness in North America and Europe, and the second leading cause of blindness worldwide. It is estimated that approximately 65 million people are diagnosed with the disease in 2011, with the prevalence set to grow to 80 million by 2020.
Glaucoma is particularly dangerous because in many cases and its variants, it can progress gradually and go unnoticed for years causing irreversible damage.
Glaucoma (rather a group of conditions) is a disease associated with abnormal pressure inside the eye, which eventually causes damage to the optic nerve and permanent loss of vision. In a normal eye, aqueous fluid is constantly produced in the ciliary body and drained from the eye at a balanced rate.
The formation and drainage of aqueous fluid determines the eye’s intraocular pressure, or IOP. Blockage or obstruction of this drainage restricts the balanced flow of aqueous fluid and causes a rise in the IOP. In all cases, the resulting damage is demise of retinal nerve cells leading to irreversible loss of vision.
What Causes Glaucoma?
Although risk factors for glaucoma include heredity, diet, smoking and age, its actual cause remains often unclear even by today’s technology. Clear liquid called aqueous humor circulates inside the front portion of the eye. To maintain a healthy level of pressure within the eye, a small amount of this fluid is produced constantly while an equal amount flows out of the eye through a microscopic drainage system. (This liquid is not part of the tears on the outer surface of the eye.)
Because the eye is a closed structure, if the drainage area for the aqueous humor—called the drainage angle—is blocked, the excess fluid cannot flow out of the eye. Fluid pressure within the eye increases, pushing against the optic nerve and causing damage.
Types of Glaucoma
CLOSED (ACUTE) ANGLE GLAUCOMA
Some people have a naturally narrow anterior chamber angle between the iris and trabecular meshwork. This angle can suddenly close, giving rise to acute angle closure glaucoma. Since the fluid cannot exit the eye, pressure inside the eye builds up very rapidly and causes an acute closed-angle attack.
Symptoms may include:
- Blurred vision.
- Severe eye pain.
- Excessive headache.
- Rainbow-coloured halos when looking at bright objects.
- Nausea and vomiting.
- This is a true eye emergency as irreversible vision loss may occur fast.
- Two-thirds of those with closed-angle glaucoma develop it slowly and without any symptoms prior to an attack.
Closed Angle Glaucoma affects particularly the Asian population, and an immediate Laser treatment is necessary to save the Optic Nerve. This treatment is called Laser Iridotomy.
PRIMARY (Chronic) OPEN-ANGLE GLAUCOMA (POAG)
Is the most common form of Glaucoma affecting approximately 75% of sufferers? The risk of developing chronic open-angle glaucoma increases with age. The drainage angle of the eye becomes less efficient over time, and pressure within the eye gradually increases, which can damage the optic nerve. In some patients, the optic nerve becomes sensitive even to normal eye pressure and is at risk for damage. Treatment is necessary to prevent further vision loss.
Typically, open-angle glaucoma has no symptoms in its early stages, and vision remains normal. As the optic nerve becomes more damaged, blank spots begin to appear in your field of vision. You typically will not notice these blank spots in your day-to-day activities until the optic nerve is significantly damaged and these spots become large. Once the optic nerve fibres die, blindness occurs. Its strains can be further defined as:
- “Normal Tension”, which exists in eyes that do not tolerate seemingly normal pressure.
- “Ocular Hypertension”, a condition in which the IOP is high without loss of visual field.
- Primary (Chronic) Open-angle Glaucoma (POAG) can be effectively treated with Selective Laser Trabeculoplasty (SLT).