The retina is the curved, back layer of the eye and is covered in light-sensitive cells that recognise shape, colour and pattern.
When a person has a detached retina, it means the retina has separated from the back of the eye. Without treatment, retinal detachment may worsen until the retina is completely detached and unable to send information down the optic nerve to the brain. This results in blindness. Around one in 10,000 people are affected by some degree of retinal detachment, with older people having a higher risk.
Retinal detachment can only be repaired with surgery. If left untreated, your vision will most likely worsen beyond repair. It is important to see an eye specialist as soon as you experience symptoms.
Retinal detachment surgery involves reattaching the retina to the back of the eye and sealing any breaks or holes. If there is a break or hole in the retina, fluid can collect beneath it and weaken the attachment.
The retina is the innermost layer of the wall of the eye and is made up of light-sensitive cells known as rods and cones, which detect shape, colour and pattern. The rod-shaped cells respond to dim light, while the cone-shaped cells recognise colour.
The retina is supported on the inside by the jelly-like vitreous, which fills the eyeball behind the lens. On its outer side, the retina is attached to the choroid, or middle layer, which is rich in blood vessels. Nerve fibres leaving the retina bundle together to form the optic nerve.
Light enters the eye through the pupil and is focused by the cornea and the lens so that a crisp picture can fall on the retina. The optic nerve then relays information to the brain.
Symptoms of retinal detachment
The symptoms of retinal detachment include:
- Blurry vision
- Bright lights or sparks, particularly in the periphery (outer edges) of the visual field
- Areas of darkness, shadow or shade in the visual field
- Loss of vision.
A retinal tear may be accompanied by the sensation of flashing lights in the affected eye. If there is bleeding into the vitreous gel, there may also be showers of dark ‘floaters’ and blurred vision. As the retina detaches, it often causes a dark shadow – like a curtain or veil – in the peripheral vision, which usually progresses to complete vision loss.
See your doctor or eye specialist immediately if you experience any of these visual disturbances. A retinal detachment needs prompt corrective surgery to prevent permanent damage to your eyesight.
Causes of retinal detachment
Retinal detachment is caused by small tears or splits in the retina that allow fluid inside the eye to seep through and separate the retina from its underlying tissue. The most common cause of retinal tears is the shrinking of the vitreous, the thick and jelly-like substance that fills the eyeball and keeps it firm. As the vitreous retracts, it can pull the retina away from the back of the eye.
Small beads of blood may be experienced as a fresh batch of floaters. However, a large tear may lead to a complete and sudden loss of vision. Less commonly, little splits may be the result of eye injury or inflammation.
Near-sighted people, those who have had cataract surgery and anyone who has had a severe eye injury are at higher risk of retinal breaks, but the most common cause is age-related shrinkage of the vitreous gel, which may lead to tearing at a weak point in the retina.
Once a tear or hole develops in the retina, fluid can collect underneath it and start to separate the retina from the choroid, resulting in a detachment. When this happens, the retina can no longer function and vision is lost.
The effect on eyesight depends on the location and severity of the detachment. For example, if the retina detaches at its centre (macula), the person may lose their central vision.
Risk factors for retinal detachment
Some people are more likely than others to experience retinal detachment. Risk factors include:
- Family history of the condition
- Prior eye surgery, such as cataract surgery
- Eye injury
- Advancing age
- Prior retinal detachment in the other eye.
Complications of retinal detachment
If left untreated, the retinal detachment can permanently affect the person’s vision or lead to blindness. Other possible complications include:
- Bleeding into the eyeball (which will cloud the vitreous)
- Build-up of pressure inside the eyeball
- Cataract formation.
Diagnosis of retinal detachment
Retinal detachment is diagnosed using a range of eye tests, including:
- Vision tests
- Examination of the retina
- Ultrasound scan.
Treatment for retinal tears
Treatment options to close up retinal tears and prevent retinal detachment may include:
- Photocoagulation – laser surgery. A laser is used to seal the tears by burning the retina. This makes scar tissue form. A scar helps to anchor the retina to the back of the eye
- Cryopexy – ‘freeze’ treatment. A small, extremely cold instrument called a cryoprobe prompts the retina to produce scar tissue. This tissue seals the tear, and helps to anchor the retina to the back of the eye.
Surgical procedures for retinal detachment
There are various methods available to reattach the retina, including:
- Pneumatic retinoplexy – this is the simplest repair of a detachment, but it is not suitable for everyone. The retinal surgeon injects a gas bubble into the vitreous cavity and treats the tear(s) with either laser or cryotherapy (freezing). The bubble presses the retina flat against the wall of the eye and the laser or freezing sticks the retina down. For this to happen, it is important you follow the surgeon’s instructions about keeping your head in the correct position after the surgery. The gas gradually disappears over the days or weeks following the surgery
- Scleral buckling – the surgeon treats the retinal tear with cryotherapy. Then the surgeon drains the fluid under the retina and sutures (sews) a specially shaped piece of silicone rubber to the outer wall of the eye (the sclera). The silicone creates an indent, which closes the tear and holds it in place while the cryotherapy seal has time to form. The scleral buckle is permanent
- Vitrectomy surgery – under an operating microscope, the surgeon removes the vitreous using very fine instruments. They treat any tears with laser or cryotherapy and fill the eye with gas or silicone oil. It is important to follow instructions about post-operative head positioning to allow the retina to stick down. You will experience temporary poor vision while your eye is filled with gas. However, if the surgery is successful, your vision will improve as the gas reabsorbs and is replaced with your eye’s own clear fluid. If your eye is filled with silicone oil, you will still be able to see, although the image will tend to be out of focus. Silicone oil is usually removed after a few months. Occasionally, the retinal surgeon may decide to leave it in your eye indefinitely.
Immediately after surgery for retinal detachment
After the operation, you can expect:
- Your eye will be covered with an eye pad and perhaps a protective eye shield.
- You may need to stay in hospital overnight or, occasionally, for longer.
Self-care after surgery for retinal detachment
Be guided by your surgeon, but general suggestions for care of your eye after the operation include:
- Your eye may be sore for several weeks, although this is less likely following a vitrectomy, in which modern fine-gauge instruments are used.
- Your vision will be blurry – it may take some weeks, or even three to six months, for your vision to improve.
- Your eye may water.
- Expect a ‘gritty’ feeling on the surface of your eye if stitches have been used.
- Avoid rubbing or pressing on your eye.
- You may need to wear an eye pad for protection at night while your eye is healing.
- Be sure to follow all directions for medications, such as eye drops.
- Avoid vigorous activity for some weeks following surgery.
- Obey all instructions on head positioning.
- See your surgeon immediately if you experience severe pain.
Complications of surgery for retinal detachment
Risks and complications depend on the procedure used, but can include:
- The formation of cataracts (loss of clarity of the lens of the eye)
- Glaucoma (raised pressure in the eye)
- Haemorrhage (bleeding) into the vitreous cavity
- Vision loss
- Loss of the eye, although modern surgical techniques make this very unlikely.
Long-term outlook after surgery for retinal detachment
In most specialist centres, around nine out of 10 retinal detachments are successfully repaired with a single operation. In the remaining cases, the retina detaches again and needs another operation. The final success rate is over 95 per cent. After treatment, your vision may improve over the next few months, but often some vision loss is permanent. Usually, you will need a change of prescription glasses.
Whether or not your vision returns depends not only on the success or failure of the operation, but also on the duration, extent and location of the detachment. For example, if your macula (the part of the retina responsible for central vision) has detached, it is unlikely that your full vision will ever return, even if the operation is successful.
Where to get help
- Your doctor
- Eye specialist
- Retinal surgeon
- Royal Victorian Eye and Ear Hospital Tel. (03) 9929 8666
Things to remember
- The retina is the curved back layer of the eye and is covered in light-sensitive cells.
- Retinal detachment means the retina has separated from the back of the eye.
- Retinal detachment surgery involves reattaching the retina to the back of the eye and sealing any breaks or holes in the retina.
- The treatment success rate is high, with around nine out of 10 retinas able to be reattached.
- Older people are at higher risk of retinal detachment.
- If left untreated, a detached retina can cause permanent damage to your eyesight.