National Eye Hospital of Sri Lanka:Common eye conditions

Patient education


 



A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. A cataract can occur in either or both eyes. It cannot spread from one eye to the other.

Cataracts occur when there is a buildup of protein in the lens that makes it cloudy. This prevents light from passing clearly through the lens, causing some loss of vision. Since new lens cells form on the outside of the lens, all the older cells are compacted into the center of the lens resulting in the cataract.

Types of cataracts include:

Age-related: As the name suggests, this type of cataract develops as a result of aging.
Congenital: Babies are sometimes born with cataracts as a result of an infection, injury, or poor development before they were born, or they may develop during childhood.
Secondary: These develop as a result of other medical conditions, like diabetes, or exposure to toxic substances, certain drugs (such as corticosteroids or diuretics), ultraviolet light, or radiation.
Traumatic: These form after injury to the eye.

Other factors that can increase a person's risk of developing cataracts include cigarette smoke, air pollution, and heavy alcohol consumption.

Symptoms:
Adult cataracts develop slowly and painlessly. Vision in the affected eye or eyes slowly gets worse.
Mild clouding of the lens often occurs after age 60, but it may not cause any vision problems.
By age 75, most people have cataracts that affect their vision.
Visual problems may include the following changes:
- Being sensitive to glare
- Cloudy, fuzzy, foggy, or filmy vision
- Difficulty seeing at night or in dim light
- Double vision
- Loss of color intensity
- Problems seeing shapes against a background or the difference between shades of colors
- Seeing halos around lights

Cataracts generally lead to decreased vision, even in daylight. Most people with cataracts have similar changes in both eyes, although one eye may be worse than the other. Many people with this condition have only mild vision changes.

Diagnosis:
A standard eye examination and slit-lamp examination are used to diagnose cataracts.

Treatment:

The following may help people who have an early cataract:
- Better eyeglasses
- Better lighting
- Magnifying lenses
- Sunglasses

As vision gets worse, you may need to make changes around the home to avoid falls and injuries.

The only treatment for a cataract is surgery to remove it. Surgery is done if you cannot perform normal activities, such as driving, reading, or looking at computer or video screens, even with glasses.

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A refractive error is a very common eye disorder. It occurs when the eye cannot clearly focus the images from the outside world. The result of refractive errors is blurred vision, which is sometimes so severe that it causes visual impairment.

The three most common refractive errors are:

1.) myopia (nearsightedness): difficulty in seeing distant objects clearly;
2.) hyperopia (farsightedness): difficulty in seeing close objects clearly;
3.) astigmatism: distorted vision resulting from an irregularly curved cornea, the clear covering of the eyeball.
A fourth condition is presbyopia, which leads to difficulty in reading or seeing at arm's length. It differs from the other disorders in that it is linked to ageing and occurs almost universally.

1.) Myopia (nearsightedness):
Myopia is a condition in which, opposite of hyperopia, an image of a distant object becomes focused in front the retina, either because the eyeball axis is too long, or because the refractive power of the eye is too strong. This condition makes distant objects appear out of focus and may cause headaches and/or eye strain. Eyeglasses or contact lenses may help to correct or improve myopia by adjusting the focusing power to the retina. Corrective surgery may also help by changing the shape of the cornea to a more spherical, round shape instead of an oblong shape.


2.) Hyperopia (farsightedness):
Hyperopia is the most common refractive error in which an image of a distant object becomes focused behind the retina, either because the eyeball axis is too short, or because the refractive power of the eye is too weak. This condition makes close objects appear out of focus and may cause headaches and/or eye strain. Eyeglasses or contact lenses may help to correct or improve hyperopia by adjusting the focusing power to the retina. Corrective surgery may also help by changing the shape of the cornea to a more spherical, round shape instead of an oval shape.


3.) Astigmatism:
Astigmatism is a condition in which an abnormal curvature of the cornea can cause two focal points to fall in two different locations - making objects up close and at a distance appear blurry. Astigmatisms may cause eye strain and may be combined with nearsightedness or farsightedness. Eyeglasses, contact lenses, or corrective surgery may help to correct or improve the condition.


4.) Presbyopia: Another type of farsightedness, presbyopia is caused when the center of the eye lens hardens making it unable to accommodate near vision. This condition generally affects almost everyone over the age of 50 - even those with myopia. Eyeglasses or contact lenses may be prescribed to correct or improve the condition.


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Conjunctivitis is redness and inflammation of the thin layer of tissue that covers the front of the eye (conjunctiva). It is very common. People often refer to conjunctivitis as red eye.

Symptoms:

- Redness in the eyes
- Blurred vision
- Crusts that form on the eyelid overnight
- Eye pain
- Gritty feeling in the eyes
- Increased tearing
- Itching of the eye
- Sensitivity to light

Causes:
The conjunctiva can become inflamed as as result of:

- Infections (infective conjunctivitis): due to Virus (Most common), Bacterial infections.
- Allergic conjunctivitis: an allergic reaction to a substance such as pollen or dust mites.
- irritant conjunctivitis: the eye coming into contact with substances that can irritate the conjunctiva, such as chlorinated water or shampoo, or a loose eyelash rubbing against the eye.

Treatment:
Treatment of conjunctivitis depends on the cause.
See your doctor immediately if you have:
- eye pain
- sensitivity to light (photophobia)
- disturbed vision
- intense redness in one or both of your eyes
- a newborn baby with conjunctivitis

Allergic conjunctivitis may respond to allergy treatment. It may disappear on its own when the allergen that caused it is removed. Cool compresses may help soothe allergic conjunctivitis.

self care:
- Remove your contact lenses. If you wear contact lenses, take them out until all the signs and symptoms of the conjunctivitis have gone.
- Do not rub your eyes, even though your eyes may be itchy. Rubbing them can make your symptoms worse.
- Place a cool compress over your eyes.
- Wetting a flannel with cool water and holding it over your eyes will help ease your symptoms.
- Avoid exposure to the allergen, if possible.

Irritant conjunctivitis will clear up as soon as whatever is causing it is removed.

Infective conjunctivitis:
Antibiotic medication, usually eye drops, is effective for bacterial conjunctivitis. Viral conjunctivitis will disappear on its own. (Need medical opinion in both these conditions).
You can soothe the discomfort of viral or bacterial conjunctivitis by applying warm compresses (clean cloths soaked in warm water) to your closed eyes.

Self-care:
There are several ways that you can treat infective conjunctivitis at home. The following advice should help ease your symptoms:

- Remove your contact lenses. If you wear contact lenses, take them out until all the signs and symptoms of the infection have gone. Avoid using contact lenses until 24 hours after you have finished a course of treatment. Do not re-use the lenses after the infection has passed as the old lens could be a potential source of re-infection.
- Use lubricant eye drops. They may help ease any soreness and stickiness in your eyes. Always follow the medical instructions.
- Gently clean away sticky discharge from your eyelids and lashes using cotton wool soaked in water.
- Wash your hands regularly. This is particularly important after you have touched your infected eyes and will stop the infection spreading to other people.

Antibiotics:
Antibiotics are not usually prescribed for infective conjunctivitis because they make little difference to your recovery and there is a very low risk of complications for untreated conjunctivitis. However, if the infection is particularly severe or it has lasted for more than two weeks, you may be prescribed antibiotics.

The two main types of antibiotics that may be prescribed are: (Should be prescribed by a doctor).
- Chloramphenicol
- Fusidic acid

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Glaucoma refers to a group of eye conditions that lead to damage to the optic nerve. In most cases, damage to the optic nerve is due to increased pressure in the eye, also known as intraocular pressure (IOP).

There are four major types of glaucoma:

- Open-angle (chronic) glaucoma
- Angle-closure (acute) glaucoma
- Congenital glaucoma
- Secondary glaucoma

Causes:
The front part of the eye is filled with a clear fluid called aqueous humor. This fluid is always being made behind the colored part of the eye (the iris). It leaves the eye through channels in the front of the eye in an area called the anterior chamber angle ( This called "Angle").
Anything that slows or blocks the flow of this fluid out of the eye will cause pressure to build up in the eye. This pressure is called intraocular pressure (IOP). In most cases of glaucoma, this pressure is high and causes damage to the optic nerve.

Open-angle (chronic) glaucoma is the most common type of glaucoma.

- cause is unknown. An increase in eye pressure occurs slowly over time. The pressure pushes on the optic nerve.
- tends to run in families. Your risk is higher if you have a parent or grandparent with open-angle glaucoma. People of African descent are at particularly high risk for this disease.

Angle-closure (acute) glaucoma occurs when the exit of the aqueous humor fluid is suddenly blocked. This causes a quick, severe, and painful rise in the pressure in the eye.

- Angle-closure glaucoma is an emergency. This is very different from open-angle glaucoma, which painlessly and slowly damages vision.
- If you have had acute glaucoma in one eye, you are at risk for an attack in the second eye, and your doctor is likely to recommend preventive treatment.
- Dilating eye drops and certain medications may trigger an acute glaucoma attack.

Congenital glaucoma is seen in babies. It often runs in families.

- It is present at birth.
- It is caused by abnormal eye development.

Secondary glaucoma is caused by:

- Drugs such as corticosteroids
- Eye diseases such as uveitis
- Systemic diseases
- Trauma

Symptoms:

1.) OPEN-ANGLE GLAUCOMA

- Most people have no symptoms
- Once vision loss occurs, the damage is already severe
- There is a slow loss of side vision (called tunnel vision)
- Advanced glaucoma can lead to blindness

2.) ANGLE-CLOSURE GLAUCOMA

- Symptoms may come and go at first, or steadily become worse
- Sudden, severe pain in one eye
- Decreased or cloudy vision, often called "steamy" vision
- Nausea and vomiting
- Rainbow-like halos around lights
- Red eye
- Eye feels swollen

3.) CONGENITAL GLAUCOMA

- Symptoms are usually noticed when the child is a few months old
- Cloudiness of the front of the eye
- Enlargement of one eye or both eyes
- Red eye
- Sensitivity to light
- Tearing

Signs and tests:

A complete eye exam is needed to diagnose glaucoma. You may be given eye drop to widen (dilate) your pupil. The eye doctor can look at the inside of the eye when the pupil is dilated.
A test called (tonometry) is done to check eye pressure. However, eye pressure always changes. Eye pressure can be normal in some people with glaucoma. This is called normal-tension glaucoma. Your doctor will need to run other tests to confirm glaucoma.

Some of the tests your doctor may do can include:

- Using a special lens to look at the eye (gonioscopy)
- Photographs or laser scanning images of the inside of the eye (optic nerve imaging)
- Examination of the retina in the back of the eye
- Slit lamp examination
- Visual acuity
- Visual field measurement

Treatment:

The goal of treatment is to reduce eye pressure. Treatment depends on the type of glaucoma that you have.
If you have open-angle glaucoma, you will probably be given eye drops. You may need more than one type. Most people can be treated successfully with eye drops. Most of the eye drops used today have fewer side effects than those used in the past. You may also be given pills to lower pressure in the eye.

Other treatments may involve:

- Laser therapy called an iridotomy
- Eye surgery if other treatments do not work

Acute angle-closure attack is a medical emergency. Blindness will occur in a few days if it is not treated. If you have angle-closure glaucoma, you will receive:

- Eye drops
- Medicines to lower eye pressure, given by mouth and through a vein (by IV)

Some people also need an emergency operation, called an iridotomy. This procedure uses a laser to open a new pathway in the colored part of the eye. This relieves pressure and prevents another attack.

Congenital glaucoma is almost always treated with surgery. This is done using general anesthesia. This means the patient is asleep and feels no pain.

If you have secondary glaucoma, treatment of the underlying disease may help your symptoms go away. Other treatments may be needed.

Prognosis:

Open-angle glaucoma cannot be cured. However, you can manage your symptoms by closely following your doctor's instructions. Regular check-ups are needed to prevent blindness.
Angle-closure glaucoma is a medical emergency. You need treatment right away to save your vision.
Babies with congenital glaucoma usually do well when surgery is done early.
How well a person with secondary glaucoma does depends on the disease causing the condition.

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