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Glaucoma
 Glaucoma
What are the risk factors for glaucoma?
What is involved in a glaucoma evaluation?
What is the treatment for glaucoma?
Glaucoma is a family of more than 30
diseases that affects pressure within
the eye, damaging the optic nerve. When
pressure inside the eye increases, blind
spots in peripheral areas of vision may
occur. Of all conditions and diseases of
the eye, glaucoma is one of the leading
causes of blindness. Often called the
“sneak thief” of sight, most forms of
glaucoma do not produce symptoms until
vision is already severely damaged. But
if diagnosed early, the disease can be
controlled and permanent vision loss can
be prevented.
What are common types of glaucoma?
- Acute Angle Closure Glaucoma: acute closure of the peripheral drainage angle, characterised by a sudden increase in intraocular pressure.
- Chronic Angle Closure Glaucoma: the iris obstructs the eye’s drainage angle in a slow, progressive fashion.
- Primary Open Angle Glaucoma: the drainage angle is open but does not allow fluid to drain adequate for unknown reasons.
- Pseudoexfoliation Glaucoma: deposits of a fibrillary material obstruct drainage of fluid from the eye.
- Pigmentary Glaucoma: pigment dislodged from the iris obstructs the eye’s drainage structures.
- Angle Recession Glaucoma: scar tissue from previous trauma obstructs the outflow of fluid.
- Neovascular Glaucoma: various disorders cause blood vessels to proliferate on the iris and in the eye’s drainage structures.
- Congenital Glaucoma: the eye’s drainage channels form abnormally during gestation.
What are the risk factors for glaucoma?
Although glaucoma is most common in
adults over the age of 40,
susceptibility is not determined by age
alone. There is a genetic component, and
those with a family history of the
disease, as well as Africans are at
increased risk. Those with hypertension,
diabetes and other systemic diseases are
also at risk. Studies have shown
individuals at greater risk for glaucoma
may fit one or more of the following
criteria:
- are over the age of 60
- have a family history of the disease, elevated intraocular pressure
- are African over the age of 40
- have diabetes or hypertension
- are nearsighted
Since early detection is critical to
avoiding permanent loss of vision,
individuals who possess any of the
non-age-related risk factors should have
regular examinations by an
ophthalmologist every one or two years.
Individuals in the general
population should have a glaucoma
evaluation every two or three years
after the age of 40, and every one or
two years after the age of 60.
Normal eye
What is involved in a glaucoma evaluation?
- Measurement of intraocular eye pressure (IOP). Elevated IOP is considered a major risk factor for the development of glaucoma. Studies have shown that optic nerve damage becomes more likely as the IOP increases.
- Assessment of the optic nerve. A non-invasive slit lamp biomicroscope is used to determine whether or not there are changes in the optic nerve in the diagnosis for glaucoma.
- Evaluation of a patient’s visual field. Glaucomatous damage produces characteristic defects in the visual field
What is the treatment for glaucoma?
Glaucoma treatment seeks to decrease intraocular pressure and prevent damage to the optic nerve. Different types of glaucoma require different therapies to prevent further damage to the eye’s structures. At the beginning of treatment, the doctor will generally recommend medication or a combination of medications for the specific condition.
Therapies may include:
- Eye drops (or combination of eye drops and pills) to reduce intraocular pressure. Several different classes of glaucoma medications are available to provide pressure reduction including beta blockers, prostaglandin analogues, alpha adrenergic agaonists, miotic, epinephrine compounds, and oral and topical carbonic anhydrase inhibitors. These medications work by either reducing the rate at which fluid in the eye is produced or increase the outflow of fluid from the eye.
- Laser treatment to open the drainage angle and reduce intraocular pressure.
- Surgery to create a new passage for fluid drainage. Surgery is usually reserved for cases that cannot be controlled by medication and following appropriate laser treatment.
Frequently Asked Questions About Glaucoma
Is blindness due to glaucoma preventable?
Regular diagnostic examinations by an ophthalmologist are the key to preventing loss of vision due to glaucoma. Ophthalmologists are medical doctors, specialists in eye care and trained to examine and treat eye diseases. Although there is no way to reverse damage, if glaucoma is diagnosed and treated early, blindness almost always is preventable.
What are the symptoms of glaucoma?
In most cases, glaucoma is asymptomatic (has no symptoms). By the time an individual experiences decreased vision, the disease is frequently in its latter stages. Since early warning signs of glaucoma are rare, it is important especially for those at risk to have medical eye examinations at appropriate intervals, as described in this section.
Symptoms depend on the type of glaucoma the individual has.
- Those who have chronic glaucoma may not be aware of any symptoms because the disease develops slowly and patients rarely notice loss of peripheral vision.
- Those who have an acute form of glaucoma may develop severe symptoms because ocular pressure rises quickly and they may experience:
- Blurred vision, especially at night
- Halos or rainbows around lights
- Severe headaches or eye pain
- Nausea
How does glaucoma affect the eye?
The eye has an internal pressure created by production of a clear fluid called aqueous humor. This fluid circulates through the eye and exits through the anterior chamber angle and ultimately drains into the blood stream. In glaucoma, the aqueous humor outflow is obstructed, resulting in increased eye pressure and, eventually, optic nerve damage.
Glaucoma Affected eye
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