Common eye conditions

What is Conjunctivitis?

Irritation or inflammation of the conjunctiva, typically accompanied by redness, watery discharge, and sensitivity to light. Conjunctivitis is an irritation of the thin, normally transparent lining (called the conjunctiva) that covers the inner surface of the eyelids and the outer surface of the white of the eye (the sclera). The symptoms of conjunctivitis include redness, itchiness, irritation, and sensitivity to light. Conjunctivitis is commonly called "pink eye" because of the pale red appearance of the infected eye. Conjunctivitis is a common and highly contagious infection among young children.

What causes conjunctivitis?

Allergies, an infection by bacteria or viruses, or by exposure to chemicals or other irritants can cause conjunctivitis. In allergic conjunctivitis, the conjunctiva usually appears swollen and red. The eyes are usually very watery, and itchiness can be severe. If conjunctivitis is caused by bacteria, a sticky, yellow discharge may be present. This discharge may accumulate between the eyelids during sleep, causing the lids to stick together. Viral conjunctivitis is usually characterized by redness, itchiness, and a clear, watery discharge.

How common is conjunctivitis?

Conjunctivitis is very common, especially among people with allergies.

How is conjunctivitis treated?

Most types of conjunctivitis are treated with medicated eye drops or ointments. Your optometrist will be able to prescribe the drops required. In some cases, oral medicines may also be used. Most types of conjunctivitis are not damaging to the eye or sight threatening. However, conjunctivitis caused by exposure to chemicals is a medical emergency, requiring immediate action to prevent eye damage. If a chemical has gotten in your eye, flush the eye with a gentle stream of cool water for at least 10 minutes. Then cover the eye and go to a hospital emergency room immediately. Though flushing the eye with water alone may prevent eye damage from some chemical exposures, it is important to have your eye examined as soon as possible by an optometrist or a doctor.

To avoid contracting or spreading conjunctivitis, take the following precautions:

• Wash your hands frequently during the day, especially before and after touching your eyes.
• Avoid rubbing your eyes.
• Do not share washcloths, pillows, towels, and make-up items with others.
• Wash your bedding and towels frequently.
• If you have a case of bacterial or viral conjunctivitis, discard and replace your current make-up, mascara, and eyeliner.
• If you wear contact lenses, clean and disinfect your lenses as directed.
• Wash your hands thoroughly before applying and removing your lenses.
• Replace your contact lenses frequently.
• Don't share your contact lenses with others.
• Wear protective goggles when working with or near chemicals.
• Avoid swimming in non-chlorinated pools or stagnant lakes or ponds.

What is glaucoma?

An eye disease characterised by damage to the optic nerve and loss of visual field. Often cases of glaucoma are related to elevated intraocular pressure (IOP) however it doesn’t have to be elevated for a person to develop glaucoma. The first line of treatment for most types of glaucoma is eye drop medication that lowers the fluid pressure inside the eye. In some cases, eye surgery may be required. Left untreated, glaucoma can lead to permanent loss of sight. Glaucoma is an eye disease in which fluid pressure in the eye damages the optic nerve. This nerve damage first affects peripheral vision, but eventually can cause blindness.

What causes glaucoma?

The space inside the front of the eye between the cornea and the iris is called the anterior chamber. Clear fluid called aqueous flows in and out of the anterior chamber to bathe and nourish the anterior part of the eye. In glaucoma, the aqueous fails to drain from the eye quickly enough, causing the pressure inside the eye to build up. Over time, the increased pressure inside the eye damages the sensitive optic nerve at the back of the eye and causes vision loss.

What are the symptoms of glaucoma?

In the most common form of glaucoma (called chronic open angle glaucoma), there are no early symptoms. The eyes appear normal, vision is normal, and there is no pain or discomfort. As glaucoma progresses, peripheral vision is lost. As this form of glaucoma progresses, the visual field continues to narrow, causing tunnel vision and blindness.
There is a less common form of glaucoma called acute angle closure glaucoma. This form strikes suddenly and usually involves severe eye pain and a much quicker loss of vision.

How common is glaucoma?
Approximately 1 in 10 have glaucoma, but half are unaware of it.

Risk factors include:
Anyone over the age of 40
A family history of glaucoma
Diabetes

What is the treatment for glaucoma?
There is no cure for glaucoma, but it can be controlled with prompt treatment. Depending on the type and severity of the condition, glaucoma is treated in one or several of the following ways:
Medicine - Glaucoma medicines may be in the form of eye drops, pills, or both. Some medicines reduce pressure by improving aqueous drainage from the eye; others work by slowing aqueous production.
Laser surgery - Laser surgery may be used to create wider openings in the aqueous drainage structures within the eye so the aqueous can exit the eye more easily.
Other microsurgery - Other microsurgical techniques may be used to increase aqueous outflow if drugs and/or laser surgery are contraindicated or cannot sufficiently reduce eye pressure.
None of the treatment options for glaucoma can restore vision that has already been lost because of the disease. Treatment is performed to prevent further vision loss.

Can glaucoma be prevented?
Routine eye exams are the only way to ensure glaucoma is diagnosed before extensive damage occurs. During your exam, your optometrist will perform a test called tonometry to measure the pressure inside your eyes. They will also examine the appearance of the optic nerve at the back of the eye. If glaucoma is suspected, a visual field test may be performed to evaluate your peripheral and central vision. Early structural changes of the retina will also be investigated using a Scanning Laser Ophthalmoscope.

Zeiss GDx Scanning Laser Ophthalmoscope is the latest technology available to allow earlier detection of glaucoma. It scans the retinal nerve fibre layer, using a laser, looking for defects indicative of glaucoma. Often, before there is functional vision loss from glaucoma, there are structural changes to the nerve fibre layer. The Zeiss GDx Scanning Laser Ophthalmoscope can pick up these changes.

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Remember that the most common form of glaucoma has no symptoms. By the time you notice a change in your vision from glaucoma, it's too late. See your Optometrist as directed for routine glaucoma testing to protect your eyes from this serious sight-threatening disease.

What is a cataract?

A cataract is a clouding of the crystalline lens inside the eye. The crystalline lens (often called simply the lens) is located directly behind the pupil and iris. The lens helps the cornea focus light on the retina to begin the process of sight. A cataract decreases the clarity of the lens and causes blurred vision.

The word cataract comes from an ancient Greek term meaning "waterfall." People with cataracts often feel as though they are trying to see the world through an opaque watery film or waterfall.

What causes cataracts?

The specific cause of cataracts is unknown, but the most common type of cataract develops in response to aging.The crystalline lens consists mainly of water and protein. The protein is arranged in a specific way to keep the lens clear and to allow light to pass through it. As we age, the arrangement of the lens protein may become disrupted, causing the lens to become cloudy. As cataracts worsen, vision becomes blurred and distorted.

Risk factors for cataracts (in addition to advancing age) include:

• Gender - Cataracts appear to be more common in women than men
• A family history of cataracts
• Long-term exposure to UV rays from sunlight
• Smoking
• Long-term use of steroid medications
• Diabetes

Types of cataracts

Though age-related cataracts are by far the most common, there are other types of cataracts as well, based on time of onset and cause:
Congenital cataracts - These cataracts are present at birth or shortly thereafter. May be related to premature birth or low birth weight.
Secondary cataracts - These cataracts develop because of diabetes or other health problems. Secondary cataracts are also sometimes linked to steroid use or radiation therapy.
Traumatic cataracts - These cataracts develop after a serious eye injury - soon afterward or years later.

How common are cataracts?

Because most cataracts are age-related, everyone is potentially at risk.
About 50 percent of the population ages 65 to 74 have some clouding of the crystalline lens. This increases to 70 percent for person’s aged 75 or older.

What are the symptoms of cataracts?

Symptoms of cataracts include:

• Blurred or hazy vision of gradual onset
• Increased glare, especially at night
• Sensitivity to light
• Colours appearing faded
• Frequent spectacle prescription changes
• Double vision (or "ghost images") in one eye

What is the treatment for cataracts?

The only treatment for cataracts is surgery. In cataract surgery, the cloudy crystalline lens is removed and replaced with a clear plastic lens. Cataract surgery is very successful at restoring vision. Most people who have the procedure regain 6/6 vision. Cataract surgery is one of the safest and most common surgical procedures performed in the United States. Over 1.5 million cataract surgeries are done each year.

Can cataracts return after surgery?

Cataracts cannot return. However, when the cloudy lens is removed in cataract surgery, the clear posterior capsule of the lens is usually left intact to keep the vitreous (the clear gel that fills the posterior cavity of the eye behind the lens) from leaking from the eye during surgery.

Months or years later, this thin capsule may become cloudy and cause blurred vision. This is sometimes called an after-cataract.
An after-cataract can be treated with a short and painless laser procedure called a posterior capsulotomy. In this procedure, a YAG laser removes the central cloudy portion of the lens capsule to restore clear vision. Because the artificial lens remains firmly intact and is unaffected by the laser, there is little risk of vitreous leakage after a posterior capsulotomy.

Can cataracts be prevented?

There is some evidence that antioxidants and other nutritional supplements may slow or prevent the development of cataracts in some people. However, additional study is needed to confirm this. In the meantime, taking daily supplements that include riboflavin, vitamins C and E, Carotenoids, zinc, and copper may be beneficial.
Because certain cataracts appear to be associated with exposure to ultraviolet (UV) radiation, it's wise to wear sunglasses outdoors that provide 100 percent UV protection. A wide-brimmed hat also helps limit the amount of UV radiation reaching your eyes.

What is diabetic retinopathy?

Diabetic retinopathy is damage to the retina (the light-sensitive inner lining of the back of the eye) associated with the systemic disease diabetes mellitus. Diabetic retinopathy is the leading cause of blindness among adults in Australia.

What causes diabetic retinopathy?

Diabetes mellitus (also simply called diabetes) is characterised by an altered metabolism of carbohydrates and lipids, resulting in a chronic elevation in blood sugar (hyperglycemia). Hyperglycemia can lead to long-term changes in the circulatory and nervous systems in the body. The hyperglycemia experienced by diabetics is related to an inability to produce sufficient insulin, a resistance to the effects of insulin, or both.

The diagnosis of diabetes is made based on a person's fasting plasma glucose (FPG) levels, (commonly referred to as the fasting blood sugar). An FPG level of 7.0mmol/l or higher indicates the presence of diabetes mellitus.

Diabetic retinopathy is a complication of diabetes in which the tiny blood vessels in the retina are damaged by the disease. Damage to the retinal blood vessels can cause a number of problems. In some cases, the damaged blood vessels leak fluid and lipids under the macula, the most sensitive part of the retina that allows us to see details. The fluid causes the macula to swell, blurring vision. In other cases, the retinal blood vessels can become blocked, causing portions of the retina to cease functioning because of lack of oxygen and nutrients.
In its advanced stage, diabetic retinopathy is characterised by the growth of fragile blood vessels along the retina and into the clear, gel-like vitreous that fills the inside of the eye. These tiny blood vessels can break open and bleed, causing vision to be obscured and permanent damage to the retina.

How common is diabetic retinopathy?

Approximately 1.5 million Australians have diabetes, 50% are unaware of their condition. All people with diabetes - those with Type 1 diabetes (previously called juvenile onset diabetes) and those with Type 2 diabetes (previously called adult onset diabetes) are at risk of developing diabetic retinopathy.

According to the National Eye Institute, nearly half of all people with diabetes will develop some degree of diabetic retinopathy in their lifetime. The longer a person has diabetes, the more likely they are to have diabetic retinopathy. After having diabetes for 15 years, about 80% of Type 1 diabetics will have some degree of retinopathy.

Risk factors for diabetes (and therefore diabetic retinopathy) include:

• Obesity (more than 20% heavier than your ideal body weight)
• A family history of diabetes
• Hypertension (blood pressure of 130/90 or higher)
• Having a high density lipoprotein (HDL or "good cholesterol") reading of 1.0 mmol/l or lower
• Elevated triglyceride levels (2.5 mmol/l or higher)
• Having been diagnosed with gestational diabetes during a pregnancy or having given birth to a baby weighing 9 pounds or more
• Being a member of a high risk ethnic group

What are the symptoms of diabetic retinopathy?

Diabetic retinopathy often has no early warning signs. There is no pain, and vision may remain unaffected until the disease becomes severe.
If leaking blood vessels cause swelling of the macula (called macular oedema) central vision will become blurred, making it hard to see clearly when driving or reading. Vision may get better or worse during the day, depending on the degree of oedema.

If leaking blood vessels cause bleeding in the eye, symptoms will vary based on how much blood is involved. With relatively limited bleeding, the visual disturbance may appear as spots floating in your visual field. These spots may go away after a few hours.

If bleeding is more severe, vision may suddenly become severely clouded. This can occur overnight during sleep. It may take months for the blood to clear from the eye, or it may not clear at all.

What is the treatment for diabetic retinopathy?

There are two treatments for diabetic retinopathy - laser surgery and vitrectomy. These surgical treatments are typically used only when diabetic retinopathy is in an advanced stage.

Laser surgery can be used to seal leaking blood vessels in the retina or to shrink fragile new blood vessels. Laser surgery is typically performed on an outpatient visit or in the doctor's office. You will be able to go home the same day.

Laser surgery usually cannot restore vision that has already been lost. Therefore, early detection of diabetic retinopathy is the best way to prevent serious vision loss from the disease.

If a significant amount of blood has leaked into the vitreous, a vitrectomy may be required to restore vision. In this procedure, the surgeon makes a tiny incision in the sclera and gently suctions out the bloody vitreous, replacing it with a sterile clear fluid. After the surgery, you may be able to go home the same day or you may be asked to stay in the hospital overnight.

Can diabetic retinopathy be prevented?

It's estimated that 50% of people with Type 2 diabetes are unaware of their condition. In some cases, detection of their diabetes takes place during a routine eye exam.

During a routine eye exam, your optometrist will examine your retina and look for early signs of diabetes. These signs include:

• Small haemorrhages from leaking blood vessels
• Macular oedema
• Areas of pale retina (called cotton wool spots) where blood supply has been obstructed
• Yellowish, waxy-appearing deposits in the retina caused by localised retinal oedema

If your optometrist detects signs of early diabetic retinopathy, they may refer you to an ophthalmologist who is a retinal specialist for additional testing and/or treatment.

Most cases of Type 2 diabetes can be managed through proper diet and exercise. Daily exercise and a high fibre diet with restricted amounts of carbohydrates, cholesterol, and saturated fat can improve overall health and help lower blood glucose levels. In cases where diet and exercise cannot sufficiently reduce blood glucose levels, oral medicines or injections of insulin may be added to the treatment plan.

If you have been diagnosed with diabetes, you should have an annual dilated eye exam to monitor the health of your retina. (Depending on your individual needs, your optometrist may recommend more frequent exams.) Annual eye exams are also recommended if you are not a diabetic but have one or more of the risk factors for diabetes listed above.

Different people need glasses for different tasks. Some people require them to read a paper and thread a needle. Others require glasses for driving or watching television and some people require glasses for everything they want to see and do.

Hyperopia

Hyperopia, or long-sightedness, is a condition where close objects are blurry. In a relaxed hyperopic eye, the image is focused behind the retina, the back of the eye. To focus the image on the retina, a plus spectacle lens is required to be placed in front of the eye. This will allow the spectacle wearer to see all distances clearly. Hyperopia may be hereditary and often the size of the eyeball itself is slightly smaller than average.

Myopia

Myopia, or short-sightedness, is a condition where faraway objects are blurry. In a myopic eye, the image is focused in front of the retina. To focus the image on to the retina, a minus spectacle lens is required to be placed in front of the eye. This will allow the spectacle wearer to see all distances clearly. Myopia may be hereditary and often the size of the eyeball itself is slightly longer than average.

Presbyopia

Presbyopia is a common condition where the eye loses its ability to see close objects clearly. In a presbyopic eye, the lens, which would normally alter shape to adjust focus for close objects, slowly loses its flexability. This usually starts happening between the ages of 40 and 45 and can continue up to the age of 65. To focus a close image on the retina, a plus spectacle lens is required to be placed infront of the eye. This will allow the spectacle wearer to see close objects clearly, but it will make distant objects blurry. Presbyopia is experienced by everyone as it is part of the aging process and it cannot be prevented.

Astigmatism

Astigmatism is a condition where there is asymmetric blur of an object. In an astigmatic eye, one direction of the image may be focused on the retina and part in front or behind the retina. Astigmatism is usually due to the shape of the front of the eye, the cornea, not being completely spherical. This results in light which would normally be focused as a point on the retina, being focused as a line. To focus the image on the retina, a cylindrical spectacle lens is required to be placed in front of the eye. This will make objects at any distance clear.

What is dry eye syndrome?

Dry eye syndrome (or dry eyes) is a chronic reduction in the normal amount or quality of tears, causing insufficient lubrication of the eye. It can cause mild to severe discomfort and damage to the tissues of the surface of the eye - the cornea and conjunctiva.

What are the symptoms of dry eye syndrome?

Symptoms of dry eye syndrome include:

• Eye irritation and redness
• A gritty or burning sensation to the eyes
• A foreign body sensation - the feeling that something is in your eye
• Blurred vision (that may clear with repeated blinking)
• Sensitivity to light
• Contact lens discomfort or intolerance

What causes dry eye syndrome?

The normal tear film of the eye has three components:

Water
Most of our tear film is composed of a watery substance, secreted by the lacrimal glands, located above and behind our upper eyelids. This watery (or aqueous) component of our tears nourishes and cleans the cornea and other tissues on the front of the eye.

Oils
Oils secreted from Meibomian glands (located at the margins of our eyelids) help keep our tears from evaporating too quickly.

Mucin
Mucin is a mucous-like substance that is produced by cells in the conjunctiva and outer surface of the eye. It helps tears spread more easily across the cornea.

A deficiency in the quantity or quality of any of these three components of the tear film can cause dry eye syndrome.

The most common cause of dry eye is a deficiency in the watery component of tears - also called aqueous tear deficiency (ATD). Keratoconjunctivitis sicca (KCS) is the medical term used to describe dry eye syndrome resulting from ATD.

Who is at risk of dry eye syndrome?

Risk factors for dry eye syndrome include:

• Age. Our tear glands produce fewer tears as we get older. Many people begin to notice dry eye symptoms after age 40.
• Gender. Women are more likely to have dry eyes than men due to hormonal changes that accompany menstruation, pregnancy, and menopause.
• Contact lens wear. Soft contact lenses in particular can cause tears to evaporate more quickly.
• Computer use. We blink our eyes less frequently when using a computer. This increases tear evaporation.
• Dehydration. Failure to drink enough fluids can lead to general dehydration and dry eye symptoms.
• Alcohol and caffeine consumption. Both can lead to dehydration and dry eyes.
• Environmental conditions. Exposure to smoke, wind, air pollution, air conditioning, and dry climates can cause eye irritation and dryness. The partially-recirculated air in airplane cabins is especially dry and irritating.
• Medications. Many medications, including antihistamines, decongestants, oral contraceptives, blood pressure and ulcer medications, and antidepressants can cause dry eye symptoms.
• Health conditions. Health problems that affect the body's ability to produce tears include arthritis, diabetes, thyroid disease, asthma, and lupus.
• Sleeping with eyes partially open. Some people sleep with their eyes partially open, causing the eyes to be chronically dry.

How common is dry eye syndrome?

Dry eye is a very common disorder that affects a significant percentage of the population - especially people over age 40. Studies vary in their estimations of this percentage, but at least one survey suggests that approximately 20 percent of people suffer from dry eye syndrome. Some researchers believe 75 percent of the population over age 65 experiences dry eye symptoms.

How is dry eye syndrome diagnosed?

If you suspect you have dry eyes, you should make an appointment to see your optometrist. He or she will ask you a number of questions about your symptoms and health history and perform one or more diagnostic tests to determine if you have dry eye syndrome.

One common diagnostic test is called the Schirmer test. It is performed by placing a thin strip of filter paper under your lower eyelid. An anesthetic eye drop may or may not be used prior to positioning the paper strip. You will then be asked to keep your eyes closed for five minutes. The amount of wetting of the paper strip is then measured to determine how well your lacrimal glands can produce the aqueous component of your tears.

Another common diagnostic test for dry eye is called the Tear Break-Up Test (TBUT). It is performed by placing a small amount of a fluorescent dye in your tear film. Your optometrist will then examine your eyes with a blue light. The dye mixes with your tears and causes the tear film on your eyes to glow under the examination light. You will be asked to blink several times and then keep your eyes open as long as you can without blinking. Your optometrist will measure how long it takes for dark spots to appear on your cornea, indicating that the tear film has broken up and the surface of your eye has become dry at those spots. A tear break-up time of less than 10 seconds suggests an unstable tear film and dry eyes.

Your optometrist may perform other tests in place of (or in addition to) the Schirmer test and/or Tear Break-Up Time test to determine whether or not you have dry eye syndrome.

How is dry eye syndrome treated?

There are a number of ways to treat dry eyes. The treatment your optometrist chooses for you will depend on the type and severity of your condition.

Artificial Tears

Mild cases of dry eye syndrome can be treated with non-prescription artificial tears. There are many brands and formulations to choose from, including preservative-free products in single-dose packaging for people with sensitive eyes. Your optometrist will recommend one or more brands for you to try.

Lubricating Ointments

In some cases, your optometrist will recommend that you supplement daytime use of artificial tears with bedtime use of a lubricating ointment. If so, you will be instructed to put about a half-inch application of the ointment inside your lower lid. Your body heat will melt the ointment and your lids will spread it across your eye when you blink. Ointments stay on your eyes much longer than artificial tears, but they will blur your vision. For this reason, ointments should be used only at bedtime.

Punctal Occlusion

For more significant dry eye problems, your optometrist may recommend a procedure called punctal occlusion. This procedure keeps more tears on your eyes by blocking the ducts in your lids that drain tears away from your eyes. Punctal occlusion involves inserting small plugs in the openings (puncta) of the tear drainage ducts that are located on the inner surface of each eyelid, near the nose. The plugs may be temporary (made of collagen that dissolves in a week or two) or permanent (made of silicone). If necessary the permanent plugs can be removed later. The procedure is painless and takes only a few minutes. Punctal occlusion may eliminate or significantly reduce your need for artificial tears. Ask your optometrist for details.

Nutritional Therapy

There is growing evidence that supplements of omega-3 fatty acids may be effective in treating some cases of dry eyes. Omega-3s are essential fatty acids - meaning that because our body cannot produce them, they are a required part of a healthy diet.
Most people don't consume enough omega-3's. Some research shows that the risk for dry eye decreases with increased dietary intake of omega-3s. Other research shows that omega-3 supplements may have a positive effect on the Meibomian glands in your lids that secrete the oils that reduce tear evaporation.
Because of these and other studies, some optometrists recommend that their patients with symptoms of dry eye increase their daily intake of omega-3 fatty acids. The two best natural sources of omega-3s are dark, oily cold-water fish (e.g. salmon) and flaxseed. Omega-3s are also available in supplement form. Ask your optometrist for details.

How can I reduce my risk of dry eye syndrome?

To reduce your risk of dry eyes, take the following precautions:

• Keep your body well hydrated. Drink at least eight large glasses of water every day.
• Avoid alcohol and caffeine. They have a dehydrating effect.
• Run a humidifier in your home for during winter or if you live in a dry climate.
• Moisten your contact lenses routinely with rewetting drops.
• Clean your contact lenses daily and replace them as directed.
• Wear close-fitting sunglasses when outdoors (particularly on windy days).
• Eat salmon once a week or consider taking a daily supplement of omega-3 fatty acids.