About cataracts

What exactly is a cataract?

Our eyes consist primarily of water and protein, and as we age, the eye’s protein can clump together and cloud the lens. In a healthy eye the protein is spread evenly, creating a clear lens, allowing light to pass onto the retina at the back of the eye. As light passes through the lens, a sharp and focused image is produced on the retina. This image is processed through the optic nerve to the visual system of the brain.

If the lens is not able to focus light onto the retina because of clumps of protein, it is not able to produce a sharp image. The clouded lens scatters light rather than transmits it to the retina resulting in blurry or hazy vision, a symptom known as opacification.

It may help to think of the natural lens in the eye as being clear like a window in the lounge of your house. With a bad cataract this window becomes fogged and the view outside is difficult to see.  

What causes cataracts?

Natural aging is the most common cause of cataracts. However, there are other less common causes for cataracts, these include:

Congenital – While it is rare babies can be born with cataracts, or these can develop in children in the early years.

Traumatic – Cataracts may result from a significant injury to the eye. 

Secondary – Cataracts can result from the use of some medications, the most common example being steroids. Some general health conditions may cause cataracts – the most common is diabetes. Cataracts can also form due to many other eye diseases such as uveitis (inflammation in the eye) or be a side effect of other eye surgeries/procedures.

Is there anything I can do to prevent cataracts?

While cataracts are typically part of the natural aging process, there may be some actions you can take to prevent the development of cataracts. These include an annual eye check-up that allows your optometrist to monitor any early signs of cataracts (as well as any other conditions such as macular degeneration or eye disorders). Some lifestyle factors may increase the risk of cataracts, such as smoking, excessive drinking and excessive exposure to sunlight. People who have diabetes or have experienced previous eye injuries are also at a greater risk of developing cataracts.

Are cataracts painful?

Cataracts form slowly over time and do not cause pain or discomfort. Because of this, most people will be unaware they have a cataract until it starts to affect vision.

What are the symptoms of cataracts?

Cataracts do not tend to impede vision in the early stages. As cataracts develop, patients can experience several symptoms, including:

  • Blurry or hazy vision and changes in contrast
  • Difficulty driving at night due to haloes/starbursts around lights
  • Sensitivity to light (particularly very bright sunlight)
  • Difficulty reading 

At some point the cataract can become so dense it will become difficult to carry out everyday tasks and will severely compromise quality of life. 

How are cataracts treated?

Cataracts cannot be treated with glasses, contact lenses or laser eye surgery. It will not go away on its own – surgery is the only treatment

Cataract surgery is one of the most commonly performed and most effective surgeries in New Zealand. Advances in technology have meant that almost all patients will have their vision restored following cataract surgery and, in some cases, will have reduced reliance on glasses.

What does cataract surgery involve?

Cataract surgery involves removing the eye’s natural lens and replacing it with a clear artificial lens that focuses the light clearly onto the retina again to restore vision. A keyhole incision is made in the front of the eye to reach the cataract. The cataract is broken up, removed, and the replacement intraocular lens (IOL) is inserted. The surgery is typically performed under local anaesthetic and carried out by one of our eye specialists in an operating theatre at a dedicated eye care facility.

What can I expect after cataract surgery?

Prior to your surgery, your eye specialist will talk to you about your visual requirements and use technology to help you choose which strength and type of artificial intraocular lens (IOL) is best suited to achieve your vision goals. Because of this, you can expect to experience improved clarity of vision post-surgery and depending on the type of IOL chosen, reduced need for glasses. 

Cataract surgery gives patients more independence too. For example, many patients regain improved eyesight to the point that they can regain their driver’s license. You can also expect improved colour vision, more confidence to drive at night and often reduced need for glasses.

Is cataract surgery safe?

Cataract surgery techniques and equipment have been refined over the last 40 years to the point where it is now regarded as one of the safest and most cost-effective operations in the world. The sheer improvement in your quality of life after restored vision is well worth the investment! As with all surgery there are risks however. Your eye specialist will fully discuss these risks with you before you proceed to surgery.

About epiretinal membrane

How is epiretinal membrane treated?

Not all cases of epiretinal membranes will require surgery. Treatment can range from no action at all (apart from close monitoring) to eye surgery. Vitrectomy surgery will be recommended for patients who experience blurry vision or vision distortion that might affect their daily activities and quality of life.

How can you test for epiretinal membrane?

At Southern Eye Specialists we take an eye scan using an Optical Coherence Tomography machine, which generates a cross-section image of the retina and epiretinal membrane. This confirms the diagnosis and helps your eye specialist determine the severity of the epiretinal membrane and best treatment option.

Why does epiretinal membrane occur?

The condition can affect up to 10 per cent of the population aged 60 years and over. While epiretinal membrane is most commonly linked with natural aging changes in the vitreous gel it can also be related to inflammation, previous eye surgery, retinal tears or blockage of the blood vessels.

What is vitrectomy?

Vitrectomy surgery is the procedure used to remove the epiretinal membrane. The procedure is usually highly successful in improving vision and reducing distortion. The surgery involves making keyhole incisions in the white of the eye, removing the vitreous and then peeling the epiretinal membrane off the retina with forceps. Vitrectomy is typically performed under local anaesthetic as a day surgery. The surgery will be performed by your eye specialist in an operating theatre at a dedicated eye care facility.

How does an epiretinal membrane affect vision?

The small part of the retain called the macula is a delicate and intricate part of the eye, composed of 10 layers that are all inter-connected and precisely located. Epiretinal membranes consist of scar-forming tissue which can contract, similar to the process the occurs in a skin scar. As the epiretinal membrane contracts it causes the delicate macula to become swollen. This leads to blurred vision and, as the membrane pulls the layers of the macula out of place, vision distortion.

About glaucoma

What exactly is glaucoma?

Glaucoma is the name given to a group of related diseases in which the eye’s optic nerve is damaged. The damage is slowly progressive, so is easy to go unnoticed – but once the optic nerve is damaged, it cannot be repaired. Glaucoma is typically caused by excessive eye pressure, which can be detected before any serious damage by regular check-ups.

How does glaucoma start?

A normal healthy optic nerve has about a million nerve fibres, which come from the retina (the seeing membrane at the back of the eye), and transfer the images to the brain for processing. When glaucoma develops, these nerve fibres start to die off and, if enough nerve tissue is lost, the vision starts to be affected.

Am I at risk of glaucoma due to my age?

Your eyes should be examined and tested for glaucoma regularly once you reach your 40s. From 40 to 50 eyesight should be tested every 5 years. From 50 to 60 this test should be 3 years, and from 60 onwards it should be every 2 years. If you have glaucoma risk factors you should be tested every 1-2 years after the age of 40.

What other risk factors are there for glaucoma?

If you have high eye pressure (intraocular pressure) there is a greater risk of developing glaucoma. Other risk factors include having a family history of glaucoma, certain medical conditions (diabetes, heart disease, high blood pressure and sickle cell anemia) and being extremely farsighted or nearsighted. As you get older there is also a greater risk of having glaucoma. If you have taken corticosteroid medications (especially eyedrops) for a long time, have had a significant eye injury, or after certain types of eye surgery, there may also be an increased risk.

Is there any type of glaucoma that needs early diagnosis?

Acute angle-closure glaucoma has symptoms that include a severe headache, eye pain, blurred vision and nausea. If these occur you should promptly go to Southern Eye Specialists or the nearest emergency department.

How do I get a glaucoma test?

Glaucoma is most commonly picked up during an appointment with an optometrist. Optometrists are well known for prescribing glasses, but during a comprehensive eye examination will also check for eye diseases, including a glaucoma. This examination will include measuring the eye pressure and possibly a visual field test.

What is the main method for treating glaucoma?

Prescribed eye drops are the best way of keeping Intraocular Pressure (IOP) down. This is a long-term treatment – if you stop using the medication your IOP will rise again and cause more irreversible damage. That’s why it’s very important to use your eye drops every day, and especially so on the days you visit your eye specialist – as they’ll need to determine whether your IOP is low enough with treatment.

How can I protect myself from glaucoma?

1. Get regular eye examinations – especially if you are over 40.
2. Check your family history as glaucoma will often run in families.
3. Look after your eyes. Wearing eye protection helps prevent injury, which can increase the chance of glaucoma.
4. Exercise. Regular exercise can reduce eye pressure, which reduces the risk of glaucoma.
5. If you are diagnosed with glaucoma, use the prescribed eye drops regularly and as directed by your ophthalmologist. These significantly diminish the chance that your high eye pressure will lead to glaucoma.

Can children get glaucoma?

Yes, they can but it is very rare. It may be present from birth or it can develop in their first few years. This is often cause by drainage blockages in the eye or an underlying medical condition.

How is glaucoma detected?

The damage glaucoma causes to the optic nerve can be detected in two ways, either by the way the nerve is working (such as problems with vision) or by abnormal changes in the structure of the nerve. To achieve this analysis we will generally use OCT scanning and Visual Field Test (VFT).

What is OCT scanning?

Optical Coherence Tomography (OCT) is an imaging test that provides us with a detailed view of the optic nerve head and retina. The OCT machine uses specific light waves to take a cross-section picture of the retina (similar to how an ultrasound uses sound waves).

What will happen in my OCT scan?

An OCT scan is painless and takes around 15 minutes. Dilating eye drops are administered first (which means you can’t drive for two to three hours afterwards). While the scan is taking place you will be asked to fix your vision on a bright light for short intervals. Following the scan you can view your test results with your eye specialists.

Why is this test so helpful?

In the past, deterioration was assessed by careful clinical examination, drawings or sometimes with digital photos. OCT can detect changes over time, and the scan can help determine how much your eye pressure needs to be lowered to halt further damage. This is why we recommend an initial baseline OCT scan for most cases of glaucoma, even if no further tests are done.

What is a Visual Field Test?

A Visual Field Test (VFT) is designed to assess the health of the peripheral vision. VFT is used to detect blind spots (scotomas) and other visual field defects that may indicate certain eye conditions. This test establishes a baseline that can then be used to assess any changes over time and guide the treatment of glaucoma.

Why is a VFT so important?

When glaucoma damages your eyes, it affects your peripheral vision first, almost always without you being aware of any symptoms. If glaucoma is not treated you may slowly and silently lose all peripheral vision. By the time central vision is affected and you notice a problem, the damage to the nerve fibres is already very severe, potentially resulting in irreversible blindness at the end stages. Because glaucoma is typically a slow and gradual disease, the VFT result can help assess damage and changes over time and establish the effectiveness of treatment.

What will happen in my VFT?

The Visual Field Test (VFT) takes around 10 minutes. It is in a quiet and darkened room, where a specialised technician will instruct you on what to do. One eye is tested while the other eye is covered. You are asked to look into a large dome-shaped machine with your eye focused on a central light. The light will vary in brightness and will appear off to the side of your vision. The test requires you to push a button whenever you see a light. The machine then analyses your results and provides the eye specialist with a map of your visual field.

How often will I have a VFT?

Your first VFT becomes your baseline. After this we will test you every 4 – 12 months, as instructed by your ophthalmologist. By comparing subsequent testing to your baseline result we can measure how well your treatment is working.

Where can I find out more about glaucoma?

Either speak to one of our nurses here, talk to your local optometrist or GP or go to Glaucoma NZ for further information.

About macular degeneration

Can I see for myself if my retina or macula shows any signs of damage before I have symptoms?

No. It is impossible to examine your own retina, the light-sensitive lining at the back of the eye. You need to get a full eye examination from an eye specialist where the pupil is dilated, giving a clear view of the retina and macula.

Is macular degeneration painful?

No, it never causes physical discomfort as we are unable to feel any sensation from our retina. That’s why you need someone to check your retina – macular degeneration can occur without you being aware of any visual symptoms.

I suffer from watery or dry eyes. Does this mean I have the wet or dry form of macular degeneration?

The front of the eye gives us no indication of what happening at the back or vice versa. Symptoms such as bloodshot eyes, dry or itchy eyes and watery eyes have no relationship to the retina. Any disease or damage to the retina does not affect the front of the eye in any way.

Why don't new spectacles help?

Spectacles help our vision by ‘assisting’ the natural lens inside the eye to better focus the image onto our retina at the back of the eye. If the retina is damaged, as with MD, it cannot ‘take a good picture’ regardless of how strong the lens or spectacles are.

Do any other eye diseases such as cataract, glaucoma or diabetic retinopathy have an impact on MD?

No. Other eye diseases or complaints have no impact on the incidence, severity or outcome of macular degeneration. Of course, other eye conditions may also have impact on your vision, potentially adding to or exacerbating the visual problems caused by MD. However they do not affect the actual disease process.

Is it 'normal' to experience visual hallucinations?

It is common for people with severe MD, where most central vision is gone, to experience strange visual symptoms. It is the brain trying to make sense of or “fill in the gap” caused by the damage of MD. These symptoms can be mildly irritating or quite distressing – in the case of those who experience vivid, random images of everyday objects or scenes at the most inappropriate times. Be assured you are not going crazy – it just seems like it – and images often settle down with time. Please discuss your concerns with your eye specialist.

What is meant by ‘degeneration’?

When we use the term degeneration to describe something in the body, it means a gradual breaking down of tissues resulting in reduced function of the parts affected. We are all familiar with the medical term arthritis; it means the degeneration or wearing out of our joints. Likewise macular degeneration is a wearing out of our macula.

What other kinds of macular degeneration are there?

Age-related is the most common form of the disease, affecting those over 50 years of age. Younger people can get other special forms of macular degeneration and these are mainly inherited.

What are some examples of non age-related MD?

There are a number of other retinal diseases classified as dystrophies, including Stargardt’s disease and Best’s Macular Dystrophy.

These have a different disease process to macular degeneration and involve the retinal receptors, or cells, degenerating. Macular dystrophies are inherited and the majority are diagnosed before the age of 30 years.

My vision is good but my doctor says I have the early signs of MD - what does that mean?

Macular degeneration is a progressive disease. It begins in the special layer of cells known as the retinal pigment epithelium (RPE), which lies underneath the retina. Early changes can be detected by your doctor when they examine your eyes. These changes appear as drusen or pigment changes and suggest that you may go on to visual loss.

What is the difference between dry and wet MD?

Dry MD is more common qne 9 out of 10 patients with MD have the dry type. Dry MD varies in severity and rate of progression – so not all patients with dry MD will experience severe vision loss. In this condition there is slow degeneration and loss of the photoreceptors (cones) at the macula which leads to reduced vision. The progression of dry MD can be slowed by quitting smoking, dietary changes, or vitamin supplements.

Any patient with dry MD, even mild disease, can suddenly ‘convert’ to wet MD. It occurs in about 1 in 10 patients with dry MD. The mild damage occurring in dry MD can promote a healing response that causes new blood vessels to grow under the retina. Unfortunately, these abnormal blood vessels don’t help, and instead they leak and bleed causing swelling of the macula, hence the name ‘wet’ MD.

The change to wet MD occurs suddenly and the damage to vision occurs much more quickly – without treatment most people with wet MD will lose all central vision over the course of a year. However, early treatment with injections of anti-VEGF medication into the eye blocks the healing response and reduces swelling and bleeding of the macula, This is very effective at improving or stabilising vision.

I have had dry MD for years. Does this mean I'm going to get wet MD too?

The progression of macular degeneration is different in each person. Some people have only the dry form for decades and never develop the wet form. However, if you have the dry form, even if very mild, you are at risk of developing wet MD. This is why it is so important to use the Amsler Grid regularly to check for any changes that might indicate a change from dry to wet MD.

No one else in my family has MD. Why did I get it?

There is clearly a genetic component and your risk of MD is higher if there are other family members who have it. Much of MD research is focused on identifying the genes involved and figuring out why some people get it and others don’t. It appears some genes predispose to developing MD, whilst others can be protective, and your unique combination of these genes gives the overall risk of developing MD. Unfortunately, we don’t yet have all the answers to this question yet.

Factors other than family history/genetics also contribute to the development of MD. You may have developed it because of age or lifestyle factors such as diet, smoking, high blood pressure or exposure to ultraviolet light. Smoking is the biggest modifiable risk factor. Smokers are 3 times more likely to develop MD and tend to develop MD 10 years earlier than non-smokers.

For more information and support visit the Macular Degeneration New Zealand website at https://www.mdnz.org.nz/

Macular Degeneration New Zealand has a variety of information sheets on MD you can download or you can order them to be delivered for free – follow this link https://www.mdnz.org.nz/services-1-1

About macular hole

What are the symptoms of a macular hole?

In the early stages of macular hole formation your vision becomes blurred and distorted. If the hole progresses, a blind spot develops in the central vision. Side vision remains normal, and there is no pain. It is uncommon for a macular hole to occur in both eyes.

What treatment will I need if I have a macular hole?

A macular hole cannot be treated by medication or laser. Instead it will require a surgery known as vitrectomy. Vitrectomy involves the removal of the transparent vitreous that fills the centre of the eye. The membranes that hold the macular hole open are removed, and the pulling that caused the macular hole is released allowing the hole to close.

Will my vision return after macular hole surgery (vitrectomy)?

The macula hole must close for vision to improve so it is good news that holes close 95 times out of 100 with surgery. If the hole closes, 7 out of 10 patients will have a significant improvement in vision. Distortion is a common symptom of macular hole and, although this invariably improves after surgery, it is likely that some distortion will persist even after successful closure of the macular hole. The best improvements in vision tend to occur in people with smaller holes that have been present for only a short period of time.

Why will I have to lay face down after surgery?

The aim of face down posturing is to keep the gas bubble in contact with the macular hole as much as possible to encourage it to close. Whether you are required to posture, and for how long, will depend on the size of the macular hole and the preferences of your eye surgeon. While there is evidence that posturing improves the surgery success for larger holes it may not be needed for smaller holes.

If you are asked to perform face down posturing, your head should be positioned so that the tip of your nose points straight down to the ground. This could be done sitting at a table or lying flat on your stomach on a bed or sofa. You should try to remain in this position for around 50 minutes in each hour for the duration advised by your eye surgeon. A short break of 10 minutes can be taken every hour to allow eating, trips to the bathroom etc.

If face down posturing is not prescribed, you will generally be advised to avoid lying flat on your back for around one week after surgery.

Can I get a macular hole in my other eye?

On average 1 out of 10 people with a macular hole will develop the same problem in their other eye. A careful examination by your eye surgeon will be able to tell you if you have risk of developing a hole in your other eye.

About pterygium

How do I know if I have a pterygium?

A pterygium is clearly visible as a raised, red growth in the inside corner of the eye. It may continue to grow over the cornea (clear front window of the eye) and across the pupil. A pterygium may also cause:

  • Redness and inflammation
  • Blurred vision if the pterygium distorts the shape of the cornea or encroaches over the pupil
  • Dryness, itching or a burning sensation
  • A feeling that there is a foreign object in the eye 
Do I need treatment for a pterygium?

In many cases no treatment is needed. Eye drops or ointments can be used to reduce the inflammation if the pterygium causes redness and irritation. Surgery is only required if the ptergyium causes reduced vision or is threatening to do so, or is causing persistent discomfort. Some patients request the removal of pterygium for cosmetic reasons.

How can I prevent a pterygium?

The best way to avoid developing a pterygium is to limit your eyes’ exposure to the environmental factors that can cause the condition. This includes sunlight, wind and dust. Always wear good-quality sunglasses and a hat when outdoors, wear eye protection in dusty conditions, apply artificial tears when in dry conditions and avoid exposure to toxic chemicals.

What happens if I need surgery for my pterygium?

Occasionally, surgery is required to remove the growth. This is performed as day surgery and should only take around 30 minutes. The procedure is performed under local anaesthetic to paralyse and numb the eye and the area around it. The growth is removed and a small piece of tissue from underneath the eyelid is grafted into the space left by the removed growth. Read more about surgery for pterygium here.

About retinal detachment

What causes retinal detachment?

A retinal detachment is caused by a tear of the retina. Retinal tears are most commonly caused by a process called posterior vitreous detachment (PVD). This can occur spontaneously in people who are short-sighted (myopic) or after an injury to the eye.

PVD is the final stage of the ageing process of the vitreous gel the fills the main cavity of the eye. The vitreous gel collapses to the point that it pulls away from the retina, often causing flashes and floaters. Although most people who develop PVD suffer no damage to the eye, in some cases the vitreous gel will not separate cleanly and pulls on the retina, causing a tear to occur.

What is the treatment?

There are several different surgical procedures that can be employed to fix a retinal detachment, with many factors contributing to the choice of which technique to employ. The most common technique is vitrectomy surgery but other options include pneumatic retinopexy and scleral buckling surgery.

Do floaters mean I have retinal detachment?

Flashes and floaters are a common sight for many people and don’t necessarily mean retinal detachment. A ‘floater’ is a catch-all term for the specks, threads, or cobweb-like images that occasionally drift across the line of vision. Flashes are sparks or strands of light that flicker across the visual field. Both are usually harmless. However the sudden appearance of new or increased flashes and floaters are strong reasons to see your eye specialist urgently.

What are the symptoms?

Symptoms of retinal detachment include flashes of light, sudden onset of floaters (little spots like specks of dirt in your vision), a new dark shadow in the peripheral vision, and sudden loss of vision. If you experience any of these issues, it is advisable to seek urgent medical attention.

About watery eye (epiphora)

What causes epiphora?

Epiphora is most commonly a result of a tear drainage duct not working properly or the eye producing more tears than necessary. Epiphora can also be a symptom of issues such as conjunctivitis, trauma to the eye, or in some cases, dry eye.

Epiphora can also be due to issues with the nasolacrimal system, responsible for drainage of the tears from the eye surface. Inflamed eyes, dry eyes, allergies and thyroid eye disease can all contribute to the overproduction of tears, and a variety of treatments are available, from lubricants and eye drops to eye surgery in more serious cases.

Why do we produce tears?

Tears are a mixture of water, salt, protein and mucus and are continually produced to keep the eye moist and healthy. Tears originate from small glands within the eyelids. When you blink, the eyelid moves tears across the cornea to the punctum—little openings on the eyelid which drain the tears to the back of the nose. Humans produce tears to keep eyes moist, wash away irritants or debris and help protect the eye from infection.

Is epiphora dangerous?

Watery eye is a common symptom and can be associated with lots of other eye conditions. While epiphora is not serious in most cases, you should speak to your eye specialist if you experience constant watering eyes.

My child has epiphora, what does this mean?

Before a child reaches 12 months, a small membrane at the end of the nasolacrimal duct (which drains tears) should open. In some cases, the membrane does not open and it may be necessary for the child to undergo a small procedure under general anaesthetic where a probe is passed along the passageway open the duct. Epiphora is common among children and occurs in up to 30 per cent of infants.

How is epiphora treated?

The treatment will be very different depending on if the problem is over production of tears or reduced tear drainage. The underlying cause of the over production of tears needs to be identified and treated. For example, if dry eye is the cause, lubricant eye drops and eyelid cleaning techniques may be recommended.

Epiphora caused by reduced tear drainage typically requires a procedure or surgery for treatment. The exact treatment will depend on the location of the blockage. It might involve a narrow probe introduced into the tear drainage hole (punctum) and injection of salty water, or a minor eyelid surgery under local anaesthetic. In more severe cases, there may be a blockage in the nasolacrimal duct and a dacryocystorhinostomy operation under general anaesthetic may be necessary.