Marsden Eye Specialists

Your gateway to better vision begins here at Marsden Eye Specialists.



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	Practice Hours:

	Monday - Friday 8am to 4:30pm

Contact numbers:

Parramatta:02 9635 7077
Castle Hill: 02 9634 6364 Penrith: 02 4731 1811
Lasik Clinic: 02 9635 6964

Free Lasik
Consults are available.

	1. Why Choose Us?	4. All About Eyes
	2. Our Doctors	5. Sponsored Clinical Trials Department
	3. Our Services	6. News

4. ALL ABOUT EYES

There are many diseases that affect the eyes. The following are a few of the many types treated at Marsden. Follow the hyperlinks to find out more about them. If you have concerns about your eye condition, please call any of our rooms to arrange a consultation.

1.		Anatomy of the Eye
2.		Cataracts
3.		Diabetic Eye
4.		Lasik
5.		Macular Degeneration
6.		Dry Eyes
7.		Glaucoma
8.		Squints
9.		Flashes/Floaters
10.		Diseases of the cornea

4.1 Anatomy of the Eye

A guide to the many parts of the human eye and how they function.
The ability to see is dependent on the actions of several structures in and around the eyeball. The graphic below lists many of the essential components of the eye's optical system.

When you look at an object, light rays are reflected from the object to the cornea,

which is where the miracle begins. The light rays are bent, refracted and focused by the cornea, lens, and vitreous. The lens' job is to make sure the rays come to a sharp focus on the retina. The resulting image on the retina is upside-down. Here at the retina, the light rays are converted to electrical impulses, which are then transmitted through the optic nerve, to the brain, where the image is translated and perceived in an upright position!

Think of the eye as a camera. A camera needs a lens and a film to produce an image. In the same way, the eyeball needs a lens (cornea, crystalline lens, vitreous) to refract, or focus the light and a film (retina) on which to focus the rays. If any one or more of these components is not functioning correctly, the result is a poor picture. The retina represents the film in our camera. It captures the image and sends it to the brain to be developed. The macula is the highly sensitive area of the retina. The macula is responsible for our critical focusing vision. It is the part of the retina most used. We use our macula to read or to stare intently at an object.

4.2 Cataracts

What is a cataract?
It is a clouding of the normally clear lenses of the eye. It can be compared to a window that is frosted or yellowed. There are many misconceptions about cataract. It is NOT a film over the eye, caused by overusing the eyes, spread from one eye to the other, a cause of irreversible blindness.

Symptoms of cataracts include a painless blurring of vision, glare, light sensitivity, poor night vision, double vision in one eye, needing brighter light to read, fading or yellowing of colours. The most common type of cataract is related to the aging of the eye. Other causes that may be related includes, injury to the eye, medical problems such as diabetes, family history, medications especially steroids, long-term unprotected exposure to sunlight, previous eye surgery, and unknown factors.

A thorough eye examination by your ophthalmologist can detect the presence of a cataract as well as any other conditions that may be causing blurred vision or other eye problems. How quickly the cataract develops varies among individuals and may even be different between two eyes. Most age related cataracts progress gradually over a period of years. Surgery should be considered when cataracts cause enough loss of vision to interfere with your quality of life or your daily activities. It is not true that cataracts need to be matured or ripped before they can be removed or that they are required to be removed just because they are present.

To find out more about Cataract Surgery please click on the following link:
Marsden Eye Surgery Centre / Cataract Surgery

YAG LASER
The YAG laser is a surgical instrument that emits a short pulsed, high energy light beam that can be precisely focused by computer to cut, vaporize, or fragment tissue. The YAG laser is used to treat posterior capsular opacification, a clouding of the remaining capsular tissue that develops postoperatively in as many as half of cataract removal operations. The tissue is vaporized with carefully controlled pulses of the YAG laser, and the surgery is performed on an outpatient basis.

4.3 Diabetic Retinopathy

Patients who suffer from diabetes are at a high risk of developing retinal changes that can in some cases lead to blindness. These changes include such things as new blood vessels forming which have weak walls and often lead to haemorrhages. They can also get what is called Drusens: these are like calcium deposits on the retina. Also these patients develop cataract at a much earlier age, so they will always be a potential cataract patient.

www.visionsimulator.com

4.4 Lasik

Laser assisted in situ keratomilleusis (LASIK) is a type of refractive surgery that permanently changes the shape of the cornea to correct.

Types of Refractive Error:

Myopia is when your eye is longer than usual or the cornea and lens have too much focusing power, light rays focus in front of the retina instead of on it. Myopia or nearsightedness means you have a hard time seeing objects at a distance.

Hyperopia is when your eye is shorter than usual, or the cornea and lens lack the necessary focusing power, light rays focus beyond the retina. Hyperopia or farsightedness means you cant see close objects clearly. A young person may be mildly farsighted but unaware of it because the lens is flexible and compensates for the error by bringing the light rays forward and onto the retina.

Astigmatism occurs when the curve of the cornea is uneven – steeper in one direction than the other - like the shape of an egg or the back of a spoon. This uneven curve causes light rays to focus on many points on the retina, distorting both near and far vision.

Presbyopia or "aging eye" causes close objects to appear blurry. It usually begins around age 40 when the lens begins to harden and lose its elasticity. This refractive error is usually corrected with bifocals or reading glasses. Nearsighted people with presbyopia can often read without glasses but farsighted people will probably need reading glasses.

4.5 Macular Degeneration (AMD)

This is often a complaint of elderly patients. The macula is an area on the retina that is clear of blood vessels, it is where we get our colour and clearest vision. However as we get older and the eye ages, the macula sometimes develops new blood vessels, as these vessels grow over the macular area, the vision is reduced. Patients often complain of straight lines becoming "bent" and they have areas of "black hole" in their central vision. This is often due to a haemorrhage of the new vessels. This deprives the sensitive retinal tissue of oxygen and nutrients that it needs to function and thrive. As a result, the central vision deteriorates. Age-related macular degeneration (ARMD) is a degenerative condition of the macula (the central retina).




	This demonstrate wavy lines on the Amsler Grid




	This example demonstrates what a patient with advanced macular degeneration sees

What causes macular degeneration?
Macular degeneration may be caused by variety of factors. Genetics, age, nutrition, smoking, and sunlight exposure may all play a role.

Signs and Symptoms

•		Loss of central vision. This may be gradual for those with the dry type. Patients with the wet type may experience a sudden decrease of the central vision.
•		Difficulty reading or performing tasks that require the ability to see detail
•		Distorted vision (Straight lines such as a doorway or the edge of a window may appear wavy or bent.)

Detection and Diagnosis
Eye physicians usually diagnose AMD. Vision testing, Amsler grid test, ophthalmoscopy, fundus photography and fluorescein angiography are some common tests performed during a retinal exam.

Treatment
There is no proven medical therapy for dry macular degeneration. In selected cases of wet macular degeneration, laser photocoagulation is effective for sealing leaking or bleeding vessels. Unfortunately, laser photocoagulation usually does not restore lost vision, but it may prevent further loss.

Recently, photodynamic therapy has proven to be effective in stopping abnormal blood vessel growth in some patients with wet AMD. This new type of laser treatment is far less damaging than laser photocoagulation and is the treatment of choice in many cases.

Early diagnosis is critical for successful treatment of wet macular degeneration. Patients can help the doctor detect early changes by monitoring vision at home with an Amsler grid.

Nutrition and macular degeneration
Several recent studies have indicated a strong link between nutrition and the development of macular degeneration. It has been scientifically demonstrated that people with diets high in fruits and vegetables (especially leafy green vegetables) have a lower incidence of macular degeneration. More studies are needed to determine if nutritional supplements can prevent progression in patients with existing disease.

Tips for AMD patients
If you've been diagnosed with AMD, making a few simple lifestyle changes could have a positive impact on the health of your retina.

•		Monitor your vision daily with an Amsler grid. By checking your vision regularly, changes that may require treatment can be detected early.
•		Take a multi-vitamin with zinc. (check with your eye physician for a recommendation). Antioxidants, along with zinc and lutein are essential nutrients, all found in the retina. It is believed that people with AMD may be deficient in these nutrients.
•		Incorporate dark leafy green vegetables into your diet. These include spinach, collard greens, kale and turnip greens.
•		Always protect your eyes with sunglasses that have UV protection. Ultraviolet rays are believed to cause damage to the pigment cells in the retina.
•		Quit smoking. Smoking impairs the body’s circulation, decreasing the efficiency of the retinal blood vessels.
•		Exercise regularly. Cardiovascular exercise improves the body’s overall health and increases the efficiency of the circulatory system.

These are a few tips to make reading easier:

•		Use a halogen light. These have less glare and disperse the light better than standard light bulbs.
•		Shine the light directly on your reading material. This improves the contrast and makes the print easier to see.
•		Use a hand-held magnifier. A drugstore magnifier can increase the print size dramatically.
•		Try large-print or audio books. Most libraries and bookstores have special sections reserved for these books.
•		Consult a low vision specialist. These professionals are specially trained to help visually impaired patients improve their quality of life. After a personalized consultation, they can recommend appropriate magnifiers, reading aids, practical tips, and many resources.

Instructions:

•		Use a bright reading light
•		Wear your reading glasses if appropriate
•		Hold the chart approximately 14-16 inches from your eye
•		Cover one eye
•		Look at the centre dot
•		Note irregularities (wavy, size, gray fuzzy)
•		Repeat the test with your other eye
•		Contact your ophthalmologist if you see any irregularities or notice any changes. http://www.mdfoundation.com.au




	Amsler Grid

4.6 Dry Eye Syndrome

Dry eye syndrome is one of the most common problems treated by eye physicians. Over ten million Americans suffer from dry eyes. It is usually caused by a problem with the quality of the tear film that lubricates the eyes.

Tears are comprised of three layers. The mucus layer coats the cornea, the eye's clear outer window, forming a foundation so the tear film can adhere to the eye. The middle aqueous layer provides moisture and supplies oxygen and other important nutrients to the cornea. This layer is made of 98 percent water along with small amounts of salt, proteins and other compounds. The outer lipid layer is an oily film that seals the tear film on the eye and helps to prevent evaporation.

Tears are formed in several glands around the eye. The water layer is produced in the lacrimal gland, located under the upper eyelid. Several smaller glands in the lids make the oil and mucus layers. With each blink, the eyelids spread the tears over the eye. Excess tears flow into two tiny drainage ducts in the corner of the eye by the nose. These ducts lead to tiny canals that connect to the nasal passage. The connection between the tear ducts and the nasal passage is the reason that crying causes a runny nose.

In addition to lubricating the eye, tears are also produced as a reflex response to outside stimulus such as an injury or emotion. However, reflex tears do little to soothe a dry eye, which is why someone with watery eyes may still complain of irritation.

Dry eye syndrome has many causes. One of the most common reasons for dryness is simply the normal aging process. As we grow older, our bodies produce less oil – 60% less at age 65 then at age 18. This is more pronounced in women, who tend to have drier skin then men. The oil deficiency also affects the tear film. Without as much oil to seal the watery layer, the tear film evaporates much faster, leaving dry areas on the cornea.

Many other factors, such as hot, dry or windy climates, high altitudes, air-conditioning and cigarette smoke also cause dry eyes. Many people also find their eyes become irritated when reading or working on a computer. Stopping periodically to rest and blink keeps the eyes more comfortable.

Contact lens wearers may also suffer from dryness because the contacts absorb the tear film, causing proteins to form on the surface of the lens. Certain medications, thyroid conditions, vitamin A deficiency, and diseases such as Parkinson’s and Sjogren’s can also cause dryness. Women frequently experience problems with dry eyes as they enter menopause because of hormonal changes.

Symptoms

•		Itching
•		Burning
•		Irritation
•		Redness
•		Blurred vision that improves with blinking
•		Excessive tearing
•		Increased discomfort after periods of reading, watching TV, or working on a computer

Treatments
When it comes to treating dry eyes, everyone's needs are a little different. Many find relief simply from using artificial tears on a regular basis. Some of these products are watery and alleviate the symptoms temporarily; others are thicker and adhere to the eye longer. Preservative-free tears are recommended because they are the most soothing and have fewer additives that could potentially irritate. Avoid products that whiten the eyes – they don't have adequate lubricating qualities and often make the problem worse.

Closing the opening of the tear drain in the eyelid




	Punctum Plug inserted

with special inserts called punctal plugs is another option. This works like closing a sink drain with a stopper. These special plugs trap the tears on the eye, keeping it moist. This may be done on a temporary basis with a dissolvable collagen plug, or permanently with a silicone plug.

There are also simple lifestyle changes that can significantly improve irritation from dry eyes. For example, drinking eight to ten glasses of water each day keeps the body hydrated and flushes impurities. Make a conscious effort to blink frequently – especially when reading or watching television. Avoid rubbing the eyes. This only worsens the irritation.

4.7 Glaucoma

Glaucoma is the overall name given to the condition in which the pressure in the eye is not at the correct level for the eye to function normally. People of all ages can get glaucoma, however people over 40 are usually more prone to this condition.

Why and how does it occur?
Each eye has its own "drainage" network, a plumbing network so as to allow the fluid in the eye to drain through and filter to the right places. In some eyes this network can become blocked and thus the fluid has difficulty flowing through so we see a rise in the pressure. Or some eyes produce too much fluid and again this will lead to a rise in the pressures. Each eye needs a certain pressure to function, rather like the pressures in car tyres, for each tyre to function correctly it must be kept at an optimal pressure, similar to our eyes.

Unfortunately for some, glaucoma can develop without the patients knowledge and going untreated can often lead to blindness. It is therefore important to ensure that if you have a family history of the disease that you get checked regularly. People over 40 should also be checked as a matter of routine and on a regular two year basis.

Early detection is the key to controlled glaucoma, damage caused by glaucoma most often cannot be reversed.

Who is at risk?
Anyone can get glaucoma however some people are at a greater risk of the disease especially if they have one of the following conditions:

•		A family history of glaucoma
•		Blood pressure
•		Diabetes
•		Migraine
•		Short sightedness
•		Cortisone drug use either past or present (steroids)
•		Eye trauma

People who find themselves in one of the above groups should be checked by the age of 35.

http://www.glaucoma.org.au

4.8 Strabismus (Crossed or turned eyes)

Strabismus is a visual defect in which the eyes are misaligned and point in different directions. The misalignment may always be noticeable, or it may come and go. One eye may be directed straight ahead, while the other eye is turned inward, outward, upward or downward. The turned eye may straighten at times and the straight eye may turn. Strabismus is a common condition among children, affecting about four percent but can also occur later in life. It occurs equally in males and females and may run in families. However, many people with strabismus have no relatives with the problem. When one eye turns, as in strabismus, two different pictures are sent to the brain. In a young child, the brain learns to ignore the image of the misaligned eye and sees only the image from the straight or best seeing eye. This causes loss of depth perception and binocular vision. Adults who develop strabismus often have double vision because the brain is already trained to receive images from both eyes and cannot ignore the image from the turned eye.

Treatment
Treatment goals for strabismus are to preserve vision, to straighten the eyes, and to restore binocular vision. Depending on the cause of the strabismus, treatment may involve repositioning the unbalanced eye muscles, removing a cataract, or correcting other conditions, which are causing the eyes to turn. After a complete eye examination, including a detailed study of the inner parts of the eye, an ophthalmologist can recommend appropriate optical, medical or surgical therapy. Covering or patching the good eye to improve vision in the amblyopic eye is often necessary.

Summary

•		Children do not outgrow strabismus
•		Treatment for strabismus is most effective when the child is young
•		Straightening of the eyes remains possible at any age and can result in improved side vision.
•		Treatment for strabismus may be non-surgical and include eye drops, exercises or glasses.
•		If surgical treatment is indicated, the earlier in life it is done, the better chance the child has of developing normal binocular vision.

4.9 Flashes and Floaters (Spots in your vision)

What are floaters?
You may sometimes see small specks or clouds moving in your field of vision. They are called floaters. You can often see them when looking at a plain background, like a blank wall or blue sky. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear jelly like fluid that fills the inside of your eye. While these objects look like they are in front of your eye, they are actually floating inside. What you see are the shadows they cast on the retina, the nerve layer at the back of the eye that senses light and allows you to see. Floaters can have different shapes, little dots, circles, lines, clouds or cobwebs.

Are floaters ever serious?
The retina can tear if the shrinking vitreous gel pulls away from the wall of the eye. This sometimes causes a small amount of bleeding in the eye that may appear as new floaters. A torn retina is always a serious problem, since it can lead to a retinal detachment. You should see your ophthalmologist as soon as possible if:

•		Even one new floater appears suddenly
•		You see sudden flashes of light

If you notice other symptoms like the loss of side vision, you should see your ophthalmologist

What causes flashing lights?
When the vitreous gel rubs or pulls on the retina, you may see what look like flashing lights or lightning streaks. You may have experienced this same sensation if you have ever been hit in the eye and seen "stars". The flashes of light can appear off and on for several weeks or months. As we grow older it is common to experience flashes. If you notice the sudden appearance of light flashes, you should visit your ophthalmologist immediately to see if the retina has been torn.

4.10 Diseases of the Cornea

This is a subspecialty area in Ophthalmology, which deals with problems affecting the outer parts of the eye. One very important component is the cornea, which is a transparent tissue in front of the pupil and is the "window of the eye". The clarity of the cornea is vital for vision and the role of the various parts of the anterior segment of the eye is to ensure the cornea remains clear. A range of infective, inflammatory, degenerative and congenital disorders may involve the ocular surface (eyelids, conjunctiva and adnexal organs such as the lacrimal gland) and / or the cornea resulting in eye symptoms such as pain, red eyes, excessive watering, and loss of corneal clarity and possibly visual loss.

These include:

•		Corneal Trauma
•		Corneal Scarring
•		Corneal Ulcer/ Corneal Erosions
•		Corneal Infections
•		Corneal Decompensation
•		Corneal Dystrophies such as Keratoconus and Fuch's Dystrophy.
•		Ocular Cicatricial Pemphigoid.
•		Pterygium
•		Dry Eye Syndrome
•		Contact- lens related problems.

Cornea specialists can offer a range of treatments, such as drug therapy, corneal surgery, anterior segment reconstruction surgery, corneal transplantation and laser refractive surgery.