1. Glaucoma: a brief review
A Brief Report
By: Ankita Rawat
M. Ed. Special Education (VI)
Session: 2022-23
2. Introduction
Glaucoma is a complex condition of the eye. It is an ophthalmic neurodegenerative condition and
is characterized by raised intraocular
pressure. When left untreated, patients may gradually experience visual eld loss, and even lose
their sight completely. It is the second
leading cause of blindness around the globe. The article provides a brief, synoptic overview of this
condition and its pharmacological
treatment options.
Glaucoma is a neurodegenerative condition that affects the eye and is associated with increased
intraocular pressure (IOP). When left untreated, patients may gradually experience visual eld loss, and
even lose their sight completely. It is the second leading cause of blindness around the globe. Glaucoma
may be defined as a condition that causes progressive
neuropathy in the optic eld and is characterized by structural
changes to the optic nerve head or optic disk. This may lead to
functional changes in the patient’s visual eld .
3. Predictions are that glaucoma will affect almost 80 million people by 2020, and 111.8 million people by 2040, affecting more
people
residing in Asia and Africa.
The estimated prevalence of glaucoma is approximately 5-7% in the black population, and 3-5% in the white population of
South Africa.
4. Open-angle glaucoma
Open-angle glaucoma may result from optic nerve damage with any degree of IOP. The rate of progression can be either fast
or slow. Patients may experience increased IOP, and then only present with changes to the optic disk or visual eld at a much
later stage.
5. Close-angle glaucoma
Closed-angle glaucoma may be due to a physical blockage of the trabecular meshwork. This can be more acute in onset than
open-angle glaucoma. When the IOP is > 40 mmHg, optic nerve damage and even permanent nerve damage (> 60 mmHg) can
occur.
6. Medicine-induced glaucoma
Medicine-induced glaucoma may be due to increased IOP brought about by various medicines. Medicines may worsen
pre-existing glaucoma or induce glaucoma based on their mechanism
of action and the patient’s predisposition. Table III provides an overview of medicines that may induce or potentiate increased
IOP.
Glaucoma may be an inherited disorder, either through Mendelian autosomal-dominant or autosomal-recessive traits.
Environmental factors, together with genetics, may cause multifactorial adult- onset glaucoma, as seen in primary open-angle
glaucoma. A more thorough understanding of the genetics underlying the disorder may contribute to the future treatment of
glaucoma.
7. Symptoms of Glaucoma
The symptoms of glaucoma depend on the type and stage of your condition.
Open-angle glaucoma
● No symptoms in early stages
● Gradually, patchy blind spots in your side vision. Side vision also is known as peripheral vision
● In later stages, difficulty seeing things in your central vision
Acute angle-closure glaucoma
● Severe headache
● Severe eye pain
● Nausea or vomiting
● Blurred vision
● Halos or colored rings around lights
● Eye redness
8. Normal-tension glaucoma
● No symptoms in early stages
● Gradually, blurred vision
● In later stages, loss of side vision
Glaucoma in children
● A dull or cloudy eye (infants)
● Increased blinking (infants)
● Tears without crying (infants)
● Blurred vision
● Nearsightedness that gets worse
● Headache
Pigmentary glaucoma
● Halos around lights
● Blurred vision with exercise
● Gradual loss of side vision
9. When to see a doctor
If you experience symptoms that come on suddenly, you may have acute angle-closure glaucoma. Symptoms
include severe headache and severe eye pain. You need treatment as soon as possible. Go to an emergency room
or call an eye doctor's (ophthalmologist's) office immediately
10. Causes
Glaucoma develops when the optic nerve becomes damaged. As this nerve gradually deteriorates, blind
spots develop in your vision. For reasons that doctors don't fully understand, this nerve damage is
usually related to increased pressure in the eye.
Elevated eye pressure happens as the result of a buildup of fluid that flows throughout the inside of the
eye. This fluid also is known as the aqueous humor. It usually drains through a tissue located at the angle
where the iris and cornea meet. This tissue also is called the trabecular meshwork. The cornea is
important to vision because it lets light into the eye. When the eye makes too much fluid or the drainage
system doesn't work properly, eye pressure may increase.
11. Risk factors
Glaucoma can damage vision before you notice any symptoms. So be aware of these risk factors:
● High internal eye pressure, also known as intraocular pressure
● Age over 55
● Black, Asian or Hispanic heritage
● Family history of glaucoma
● Certain medical conditions, such as diabetes, migraines, high blood pressure and sickle cell
anemia
● Corneas that are thin in the center
● Extreme nearsightedness or farsightedness
● Eye injury or certain types of eye surgery
● Taking corticosteroid medicines, especially eye drops, for a long time
Some people have narrow drainage angles, putting them at increased risk of angle-closure glaucoma.
12. Prevention
These steps may help detect and manage glaucoma in its early stages. That may help to prevent vision loss or slow its
progress.
● Get regular eye examinations. Regular comprehensive eye exams can help detect glaucoma in its early
stages, before significant damage occurs. As a general rule, the American Academy of Ophthalmology
recommends a comprehensive eye exam every 5 to 10 years if you're under 40 years old; every 2 to 4 years if
you're 40 to 54 years old; every 1 to 3 years if you're 55 to 64 years old; and every 1 to 2 years if you're older
than 65.
If you're at risk of glaucoma, you'll need more frequent screening. Ask your health care provider to recommend
the right screening schedule for you.
● Know your family's eye health history. Glaucoma tends to run in families. If you're at increased risk, you may
need more frequent screening.
● Wear eye protection. Serious eye injuries can lead to glaucoma. Wear eye protection when using power tools
or playing sports.
● Take prescribed eye drops regularly. Glaucoma eye drops can significantly reduce the risk that high eye
pressure will progress to glaucoma. Use eye drops as prescribed by your healthcare provider even if you have
no symptoms.
13. Treatment
The damage caused by glaucoma can't be reversed. But treatment and regular checkups can help slow or prevent vision
loss, especially if you catch the disease in its early stages.
Glaucoma is treated by lowering intraocular pressure. Treatment options include prescription eye drops, oral medicines,
laser treatment, surgery or a combination of approaches.
(i) Eye-drops: Glaucoma treatment often starts with prescription eye drops. Some may decrease eye pressure by
improving how fluid drains from your eye. Others decrease the amount of fluid your eye makes. Depending on how low your
eye pressure needs to be, you may be prescribed more than one eye drop.
(ii) Surgery and other therapies: Other treatment options include laser therapy and surgery. The following techniques
may help to drain fluid within the eye and lower eye pressure:
● Laser therapy. It is an option if you can't tolerate eye drops. It also may be used if medicine hasn't slowed the
progression of your disease. Your eye doctor also may recommend laser surgery before using eye drops. It's
done in your eye doctor's office. Your eye doctor uses a small laser to improve the drainage of the tissue located
at the angle where the iris and cornea meet. It may take a few weeks before the full effect of this procedure
becomes apparent.
