Vitreo-Retinal Surgery

Retinal detachment occurs when the thin lining at the back of your eye called the retina begins to pull away from the blood vessels that supply it with oxygen and nutrients.

Without prompt treatment, it will lead to blindness in the affected eye. 

Warning signs and symptoms

Most people will experience warning signs that indicate their retina is at risk of detaching before they lose their sight. These include:
• the sudden appearance of floaters – black dots, specks or streaks that float across your field of vision (usually only one eye is affected)
• a cobweb effect of lots of little floaters – others report a single large black floater that looks like a housefly
• sudden short flashes of light in the affected eye lasting no more than a second
• blurring or distortion of your vision

Without treatment, sight in the affected eye will start to deteriorate. Most people describe this as a shadow or "black curtain" spreading across their vision.

Retinal detachment usually only occurs in one eye. If your eye is affected, there is an up to one in 10 chance that retinal detachment will happen in your other eye.

Causes

The retina lies at the back of your eye and sends signals to the brain, allowing it to see. Without a blood supply, the nerve cells die which leads to a loss of sight.

Retinal detachment is most often the result of the retina becoming thinner and more brittle with age and pulling away from the underlying blood vessels.

It can also be caused by a direct injury to the eye, but this is less common.

Diagnosis

If your GP suspects retinal detachment, it is likely you will be referred to an eye specialist (ophthalmologist), usually on the same day. The ophthalmologist will study the back of your eye with an ophthalmoscope (a magnifying glass connected to a light) and a slit lamp (a microscope that magnifies the eye while you rest your head on a chin rest). If there is a poor view of the retina, an ultrasound scanmay also be used. 

Treatment

The quicker retinal detachment is treated, the less risk there is of permanently losing some or all of your vision in the affected eye. Most detached retinas can be successfully reattached with surgery. There are a number of different types of surgery available, depending on the individual.

It can take months to fully recover from surgery on your eye. During this period you may have reduced vision, which means you may not be able to do some of your usual activities, such as driving or flying.

Some people's eyesight does not fully return after surgery and they have permanently reduced peripheral (side) or central vision. This can happen even if the retina is reattached successfully. This risk is higher the longer the detachment was left untreated.

Who is affected?

Retinal detachment is rare. Only one in every 10,000 people will develop it in any given year in the UK.

As retinal detachment is associated with ageing, most cases affect older adults aged between 60 and 70. Retinal detachment caused by an injury can affect people of any age, including children.

A macular hole is a small gap that opens up at the centre of the retina, in an area called the macula.

The retina is the light-sensitive film at the back of the eye. In the centre is the macula – the part responsible for central and fine detail vision needed for tasks such as reading. In the early stages, a macular hole can cause blurred and distorted vision. Straight lines may look wavy or bowed, and you may have trouble reading small print.

After a while, you may see a small black patch or a "missing patch" in the centre of your vision. You won't feel any pain and the condition doesn't lead to a total loss of sight. Surgery is usually needed to repair the hole (see below). This is often successful, but you need to be aware of the possible complications of treatment. Your vision will never completely return to normal, but it's usually improved by having surgery. Why does it happen?

We don't know why macular holes develop. The vast majority of cases happen spontaneously (without an obvious cause). They most often affect people aged 60-80, and are twice as common in women as men.

One possible risk factor is a condition called vitreomacular traction. As you get older, the vitreous jelly in the middle of your eye starts to pull away from the retina and macula at the back of the eye. If some of the vitreous jelly remains attached, it can lead to a macular hole.

A few cases may be associated with:
• retinal detachment – when the retina begins to pull away from the blood vessels that supply it with oxygen and nutrients
• severe injury to the eye
• being slightly long-sighted (hyperopic)
• being very short-sighted (myopic)
• persistent swelling of the central retina (cystoid macular oedema)

What should I do?

If you have blurred or distorted vision, or there's a black spot in the centre of your vision, see your GP or optician as soon as possible. You'll probably be referred to an ophthalmologist (a specialist in eye conditions).

If you do have a macular hole and you don't seek help, your central vision will probably get gradually worse. After a year, you'll be unable to read even the largest print on an eye test chart.

There's evidence that relatively early treatment (within months) gives a better outcome in terms of improvement in vision. There's a very small chance the hole may close and heal by itself, so for this reason, Mr Woodcock may want to monitor its progression before recommending treatment.

What is the treatment and how successful is it?



Vitrectomy surgery

A macular hole can often be repaired using an operation called a vitrectomy, with inner limiting membrane (ILM) peel and gas. If you've had the hole for less than a year, there's around a 90% chance the operation will be successful in closing it. More than 70% of people successfully treated will be able to read two or three additional lines on a standard vision chart, compared to before the operation.

Even if surgery does not achieve this degree of improvement, your vision will at least become stable, and you may find you have less distortion of vision.

In a minority of patients, the hole doesn't close despite surgery, and the central vision can continue to deteriorate. However, a second operation can still be successful in closing the hole.

Ocriplasmin injection

If a macular hole is caused by vitreomacular traction, it may be possible to treat it with an injection of ocriplasmin into the eye. The injection helps the vitreous jelly separate from the back of the eye and allows the macular hole to close. This treatment is successful at closing a macular hole in around 40% of cases.

The injection takes a few seconds and you'll be given local anaesthetic  as eye drops or an injection, so you won't feel any pain. You'll also be given eye drops to dilate your pupil, so the ophthalmologist can see the back of your eye.

An ocriplasmin injection is usually only available in the early stages, while the macular hole is less than 400 micrometres wide, but causing severe symptoms.

Ocriplasmin can cause some mild side effects, which usually go away, such as:

• temporary discomfort
• floaters
• flashing lights
• dimming of vision
• yellow tinge to the vision

A small number of people may develop more severe side effects, such as a noticeable loss of vision, enlargement of the macular hole or retinal detachment.

Surgery is usually needed to correct macular hole enlargement or retinal detachment. You won't be able to drive after the injection, as the eye drops cause your vision to be blurry. However, you should have normal, comfortable vision the day after.

If the ocriplasmin injection fails to close the macular hole, which happens in around 60% of cases, vitrectomy surgery will be needed to close the macular hole and improve the vision.

What does vitrectomy surgery involve?

Macular hole surgery is a form of keyhole surgery performed under a microscope. Three small incisions (one millimetre in size) are made in the white of the eye and very fine instruments are inserted.

First, the vitreous jelly is removed (vitrectomy) and then a very delicate layer (the inner limiting membrane) is carefully peeled off the surface of the retina around the hole, to release the forces that keep the hole open. The eye is then filled with a temporary gas bubble, which presses the hole flat onto the back of the eye to help it seal.

The bubble of gas will block the vision while it's present, but it slowly disappears over a period of about four to eight weeks.

Macular hole surgery usually takes 45-90 minutes and can be done while you're awake (under local anaesthetic) or asleep (under general anaesthetic). Most patients opt for a local anaesthetic, which involves a numbing injection around the eye, so no pain is felt during the operation.

You may be able to go home the same day, but most patients need to stay in hospital overnight.

What can I expect after the operation?



Temporary poor vision

With the gas in place, the vision in your eye will be very poor – a bit like having your eye open under water.

Your balance will be affected and you'll have trouble judging distances, so be aware of steps and kerbs. You may have problems with activities such as pouring liquids or picking up objects.

In the 7-10 days after the operation, the gas bubble slowly shrinks. As this happens, the space that was taken up by the gas fills with the natural fluid made by your eye and your vision should start to improve.

It generally takes six to eight weeks for the gas to become absorbed and for vision to improve.

Mild pain or discomfort

Your eye may be mildly sore after the operation, and will probably feel sensitive. Contact your ophthalmologist immediately or go to your nearest eye accident & emergency (A&E) department if at any time:
• you're in serious pain
• your vision gets worse than it was on the day after the surgery

Protective dressing

When you wake up, your eye will be padded with a protective plastic shield taped over it. The pad and shield can be removed the day after the operation.

Getting home

If you've had a general anaesthetic, you will not be able to leave the hospital unless a responsible adult is there to help you get home.

Medication

You'll usually be prescribed two or three types of drops to take after surgery:

• an antibiotic
• a steroid
• a pupil-dilating agent

You'll be seen again in the clinic about two weeks after the operation and if all is well, the drops will be reduced over the following weeks.

Do I need to position myself face down after the operation?

Once at home, you may have to spend several hours during the day with your head held still and in a specific position, called posturing. The aim of lying or sitting face down is to keep the gas bubble in contact with the hole as much as possible, to encourage it to close.

There's evidence that lying face down improves the success rate for larger holes, but it may not be needed for smaller holes.

If you're asked to do some face-down positioning, your head should be positioned so 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. Your doctor will advise you on whether you need to do this and, if so, for how long. You may find it helpful to read Moorfields Eye Hospital's instructions for post-operative posturing (PDF, 1.7Mb).

If face-down posturing isn't advised, you may simply be told to avoid lying on your back for at least two weeks after the surgery.

Sleeping

You'll need to sleep with your head on one side, resting on an ear. You may be asked to avoid sleeping on your back for at least one month after your operation, to make sure the gas bubble is in contact with the macular hole as much as possible.

If you can't lie on your side, you should sleep propped up with pillows so you're at a 45-degree angle.

If you have concerns about sleeping positions, speak to your doctor or nurse.

Am I able to travel after macular hole surgery?

You must not fly or travel to high altitude on land while the gas bubble is still in your eye (up to 12 weeks after surgery).

If you ignore this, the bubble will expand at altitude, causing very high pressure inside your eye. This will result in severe pain and permanent loss of vision.

Can I drive after the operation?

No – the gas bubble will still be present in your eye for six to eight weeks after your surgery, so during this time you can't drive a vehicle of any sort.

None of these exclusions apply once the gas has fully absorbed. You'll notice the bubble shrinking and will be aware when it has completely gone.

How much time will I need off work?

Most people will need at least two weeks off work, although this will depend to an extent on the type of work you do and the speed of recovery. Discuss this with Mr Woodcock.

What are the possible complications of macular hole surgery?

It's unlikely that you'll suffer harmful effects from a macular hole operation.

However, you should be aware of these six possible complications:
• Failure of the hole to close. This happens in 1-2 out of 10 patients. If the hole fails to close, your vision may be a little worse than before the surgery. It's usually possible to repeat the surgery. 
• Cataract. This means the natural lens in your eye has gone cloudy. You'll almost certainly get a cataract after the surgery, usually within a year, if you've not already had a cataract operation. The cataract may be removed at the same time the hole is being repaired.
• Retinal detachment. The retina detaches from the back of the eye in 1-2% of patients having macular hole surgery. This can potentially cause blindness, but it's usually repairable in a further operation.
• Bleeding. This occurs very rarely, but severe bleeding within the eye can result in blindness.
• Infection. This is also very rare, occurring in an estimated 1 in 1,000 patients. Infection needs further treatment and could lead to blindness.
• Raised eye pressure. An increase in pressure within the eye is quite common in the days after macular hole surgery, usually due to the expanding gas bubble. In most cases, it's short-lived and controlled with extra eye drops or tablets to reduce the pressure, protecting the eye from damage. If the high pressure is extreme or becomes prolonged, there may be some damage to the optic nerve as a result. 

How successful is macular hole surgery?

The most important factor in predicting whether the hole closes as a result of surgery is the length of time the hole has been present.

If you've had a hole for less than six months, there's about a 90% chance your operation will be successful (9 in 10 operations will successfully close the hole).

If the hole has been present for a year or more, this success rate drops to about 60%. Most people have some improvement in vision after they've recovered from the surgery. At the very least, the operation normally prevents your sight from getting any worse.

Mr Woodcock will speak to you in more detail about what results you can expect from the surgery.

Even if surgery doesn't successfully correct your central vision, a macular hole never affects your peripheral vision, so you'd never go completely blind from this condition. 

Can I develop a macular hole in my other eye?

After carefully examining your other eye, your surgeon should be able to tell you the risk of developing a macular hole in this eye. In some people this is extremely unlikely, in others there's a 1 in 10 chance of developing a macular hole in the other eye.

It's very important to monitor any changes in the vision of your healthy eye and report these to your eye specialist, GP or optician urgently.

How does it differ from age-related macular degeneration?

A macular hole isn't the same as macular degeneration, although they affect the same area of the eye and can sometimes both be present in the same eye.

Age-related macular degeneration is damage to the macula, leading to the gradual loss of central vision. It's unclear what causes it, but getting older, smoking and a family history of the condition are known to increase your risk.

Epiretinal membrane is a disease of the eye in response to changes in the vitreous humor or more rarely, diabetes. It is also called macular pucker. Sometimes, as a result of immune system response to protect the retina, cells converge in the macular area as the vitreous ages and pulls away in posterior vitreous detachment (PVD). PVD can create minor damage to the retina, stimulating exudate, inflammation, and leucocyte response. These cells can form a transparent layer gradually and, like all scar tissue, tighten to create tension on the retina which may bulge and pucker (e.g., macular pucker), or even cause swelling or macular edema. Often this results in distortions of vision that are clearly visible as bowing when looking at lines on chart paper (or an Amsler grid) within the macular area, or central 1.0 degree of visual arc.

Usually it occurs in one eye first, and may cause binocular diplopia or double vision if the image from one eye is too different from the image of the other eye. The distortions can make objects look different in size (usually larger = macropsia), especially in the central portion of the visual field, creating a localized or field dependent aniseikonia that cannot be fully corrected optically with glasses. Partial correction often improves the binocular vision considerably though. In the young (under 50 years of age), these cells occasionally pull free and disintegrate on their own; but in the majority of sufferers (over 60 years of age) the condition is permanent. The underlying photoreceptor cells, rod cells and cone cells, are usually not damaged unless the membrane becomes quite thick and hard; so usually there is no macular degeneration.

Surgery for epiretinal membrane

Surgeons can remove or peel the membrane through the sclera and improve vision by 2 or more Snellen lines. Usually the vitreous is replaced at the same time with clear (BSS) fluid, in a vitrectomy. Surgery is not usually recommended unless the distortions are severe enough to interfere with daily living, since there are the usual hazards of surgery, infections, and a possibility of retinal detachment. More common complications are high intraocular pressure, bleeding in the eye, and cataracts, which are the most frequent complication of vitrectomy surgery. Many patients will develop a cataract within the first few years after surgery. In fact, the visual distortions and diplopia created by cataracts may sometimes be confused with epiretinal membrane.

Prevention

There is no good evidence for any preventive actions, since it appears this is a natural response to aging changes in the vitreous. Posterior vitreous detachment (PVD) has been estimated to occur in over 75 per cent of the population over age 65, that PVD is essentially a harmless condition (although with some disturbing symptoms), and that it does not normally threaten sight. However, since epiretinal membrane appears to be a protective response to PVD, where inflammation, exudative fluid, andscar tissue is formed, it is possible that NSAIDs may reduce the inflammation response. Usually there are flashing light experiences and the emergence of floaters in the eye that herald changes in the vitreous before the epiretinal membrane forms.

Diabetic retinopathy is a common complication of diabetes. It occurs when high blood sugar levels damage the cells at the back of the eye (known as the retina). If it isn't treated, it can cause blindness.

It's important for people with diabetes to control their blood sugar levels. Everyone with diabetes who is 12 years old or over should have their eyes examined once a year for signs of damage.

All people with diabetes are at risk of getting diabetic retinopathy, but good control of blood sugar levels, cholesterol and blood pressure minimises this risk.

How diabetes can damage the retina

The retina is the light-sensitive layer of cells at the back of the eye. It converts light into electrical signals.

The signals are sent to the brain through the optic nerve and the brain interprets them to produce the images that you see.

To work effectively, the retina needs a constant supply of blood, which it receives through a network of tiny blood vessels. Over time, a continuously high blood sugar level can cause the blood vessels to narrow, bleed or leak. This damages the retina and stops it from working.

When the blood vessels in the central area of the retina (the macula) are affected, it's known as diabetic maculopathy.

Symptoms of diabetic retinopathy

During the initial stages, retinopathy does not cause any noticeable symptoms. You may not realise that your retina is damaged until the later stages, when your vision becomes affected. Vision loss will probably be permanent at this late stage, which is why diabetic eye screening is so important. If you have diabetes and start to notice problems with your vision, contact your GP or diabetes care team immediately.

Screening for diabetic retinopathy

As severe retinopathy can cause sudden blindness, it needs to be identified and treated as soon as possible.

The NHS Diabetic Eye Screening Programme aims to reduce the risk of vision loss in people with diabetes. This is done by identifying retinopathy at an early stage and ensuring that treatment is given to reduce or prevent sight damage.

Everyone with diabetes who is 12 years old or over is invited for screening once a year. The screening test involves examining the back of the eyes and taking photographs of the retina. Screening can detect diabetic retinopathy before you notice any changes to your vision.

Treating diabetic retinopathy

Treatment for retinopathy will depend on the stage the condition has reached.
For example, if retinopathy is identified in its early stages, you can prevent it from getting worse just by controlling your diabetes. If you have more advanced retinopathy, you may need to have laser surgery or injection therapy to prevent further damage to your eyes.

Preventing diabetic retinopathy

To reduce your risk of developing retinopathy, it's important to control your blood sugar level, blood pressure and cholesterol level. Good control will prevent diabetic complications in almost everyone.

Other steps that you can take to help prevent retinopathy include:

attending your annual screening appointment
informing your GP if you notice any changes to your vision (do not wait until your next screening appointment)
taking your medication as prescribed
losing weight (if you're overweight) and eating a healthy, balanced diet
exercising regularly
giving up smoking
controlling your blood pressure and cholesterol levels