© gilaxia - Getty ImagesRetinal detachment is a serious eye condition where the retina - the layer of tissue at the back of the eye that is light-sensitive - pulls away from the tissue surrounding it. Sometimes known as a detached retina, this is a serious eye condition that requires prompt treatment. There are a number of possible causes of retinal detachment (RD), with the most common being due to age or an eye injury.
Retinal detachment is a serious eye condition where the retina - the layer of tissue at the back of the eye that is light-sensitive - pulls away from the tissue surrounding it. Sometimes known as a detached retina, this is a serious eye condition that requires prompt treatment.
Dr Roger Henderson looks at retinal detachment causes, symptoms and potential treatment options:
What is the retina?
When light enters the eye it is focused by the lens onto the back of the eye - the retina. The retina then produces an image that is sent to the optic nerve which transports the picture to the brain and we then 'see' that image. If the retina becomes damaged in any way, our vision is affected and any image is altered.
The retina is made up of two layers, called an inner and outer layer. The inner layer contains cells called rods and cones - the so-called 'seeing' cells' - which react to light and send electrical impulses to the brain along the optic nerve.
Rod cells help us see in the dark whereas cone cells help us see in daylight and also form our colour vision. The outer layer, called the RPE (retinal pigment epithelium) sits next to the rods and cones, helping to nourish them and filter harmful substances away from reaching these sensitive cells.
Retinal detachment causes
There are a number of possible causes of retinal detachment (RD), with the most common being due to age or an eye injury. RD is typically classified into three main types:
. Tractional
In this type, scar tissue pulls on the retina to detach it, and is usually caused by damage to the blood vessels at the back of the eye from diabetes.
. Rhegmatogenous
This is the most common type and occurs when a break or hole appears in the retina. This then allows fluid in the eye to seep in between the two retinal layers and separate them. Usually triggered by being over the age of 40, other risk factors for this type of RD include being near-sighted, having a previous history of RD and if you have Marfan's syndrome. The most common cause of a retinal break or hole is called a posterior vitreous detachment, where the jelly-like substance that fills the eye (the vitreous) shrinks and pulls away from the retina, causing RD in about 15 per cent of cases.
. Exudative
This type of RD occurs when fluid builds up behind the retina, pushing it away - but not tearing it - from the back of the eye. Common causes include old age, inflammation, extremely high blood pressure and injury.
© Ivan-balvan - Getty ImagesRetinal detachment
Retinal detachment risk factors
Anyone can suffer from a retinal detachment but you are more likely to have one with increasing age as well as any of the following:
- Severe nearsightedness
- An eye injury
- Cataract surgery
- A family history of retinal detachment, or a previous episode of RD
- Thinning along the retinal edges (lattice degeneration)
- Diabetic retinopathy (a diabetic condition where blood vessels at the back of the eye are affected)
Retinal detachment symptoms
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If only a small part of the retina is affected, or if any tear is very small then there may be no symptoms and the condition is only picked up at a routine eye check. If more of the retina is affected however, you may find that your vision is not as sharp as normal and you may also experience other symptoms such as:
. Flashing lights
Notice in over half of people with RD, these are usually more noticeable in dim light or in the periphery (side) of your vision. This is typically an early warning sign of impending RD, and is probably caused by the retina being 'tugged' before any full detachment occurs.
. Floaters
These are extremely common - most people experience them as moving back dots or tiny squiggles that 'float in your vision - and their presence is usually harmless and not an indication of RD. However, an increase in their number or size can be an indication of early detachment.
. Altered vision
Any sudden alteration to your vision should always be treated as a medical emergency, and in RD this can present as cloudy vision or visual loss usually described as being like a curtain coming down over the sides or middle of the visual field.
Symptoms of RD usually present quickly and require urgent treatment since the longer it is left the more of the retina can become detached, increasing the risk of permanent loss of vision or even full blindness. The sooner it is treated, the better the outcome.
Retinal detachment diagnosis
Your GP or eye specialist will put some drops into the eye which dilates (widens) the pupil at the front of the eye, allowing for an easier examination of the back of the eye. These can cause a temporary blurring of your eyesight but this wears off after a few hours. A special ophthalmoscope is then used to look at the back of the eye, which is often also photographed - this is painless.
It is uncommon for further tests to be required but if the doctor is unable to clearly see the back of the eye (such as with a cataract causing clouding in the eye) an ultrasound scan or special eye scan called optical coherence tomography may be needed.
Retinal detachment treatment
This depends on the type of retinal detachment you have, and how much of the retina is affected. In all cases, the sooner treatment occurs the better the outcome. This is especially important in trying to prevent any RD reaching and affecting the macula, which is the central and most important part of the retina.
All treatments aim to try to 'stick' the retina and RPE together again, as well as sealing any tears to prevent them extending and worsening. Several procedures are possible and your specialist will discuss which is most appropriate for you - and more than one may be used - but the options here are:
?? Freezing treatment (cryopexy) or laser surgery
This can be done in a hospital outpatient clinic under local anaesthetic, and may be all that is required if no fluid has crept behind a retinal tear. The aim is to 'weld' the retinal layers back together and in doing so, seal any break and can be done either with a fine laser or a freezing probe.
?? Scleral buckling
Done under either a local or general anaesthetic, this procedure can be done in addition to freezing or laser treatment, and involves stitching a small piece of silicone over the retinal tear, as well as sometimes draining off any fluid that has built up behind the retina to help the silicone attach more firmly. (This is called scleral buckling because the outer wall of the eye - the sclera - is pushed or 'buckled' inwards). The silicone is left in the eye permanently, and at the operation a gas bubble may be injected into the eye to help keep the retina firmly attached. This bubble then slowly disperses over a few weeks.
?? Pneumatic retinopexy
Done under local anaesthetic, this procedure works well for a small tear that is simple to close. A tiny bubble of gas is injected into the eye which then presses against the retina, causing the tear to close. For this to work, you have to keep your head still and in the position of being forward and down for a few days or longer to help keep the bubble in the right area of the eye. Some people find this almost impossible and extremely tiresome to do, which is why this type of treatment is not suitable for everyone.
?? Vitrectomy
This is a type of surgery done under a local or general anaesthetic and involves removing the vitreous humour gel from the eyeball and replacing it with a gas liquid or oil to push the retina back into place. A scleral buckle procedure may also be performed at the same time, and after some weeks the gas naturally disperses and is replaced by the normal eye fluid.
After any of these treatments you will be prescribed steroid and antibiotic eye drops, and sometimes drops to lower the pressure in the eye. The effectiveness rate of treatment is around 90 per cent, especially if any detachment is caught early.
Retinal detachment outlook
This depends on a number of factors including how much of the retina is involved, how long the detachment has been present, what has caused it and whether the macula of the eye is involved. With no macula involvement and early treatment of an RD then good restoration of vision can reasonably be expected.
However, if the macula has detached then this success rate drops to around 40 per cent. In general, up to 90 per cent of retina procedures are successful although more than one procedure may be needed to achieve this, and it may take several months for normal vision to return.
Last updated: 10-03-2021