is a disorder of the
Eye in which the
Retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to
Vision Loss and
Blindness .
The retina is a thin disc-shaped layer of light-sensitive tissue on the back wall of the eye. Its job is to translate what we see into
Neural impulses and send them to the brain via the
Optic Nerve . Occasionally, injury or trauma to the eye or head may cause a small tear in the retina, which allows fluid to seep through, and peel it away like a bubble in wallpaper.
- - A rhegmatogenous retinal detachment occurs due to a hole, tear, or break in the retinal that allows fluid to pass into the subretinal space between the sensory retina and the retinal pigment epithelium.
- - An exudative retinal detachment occurs due to inflammation or injury that results in fluid accumulating underneath the retina without the presence of a hole, tear, or break.
- - A tractional retinal detachment occurs when epiretinal fibrovascular tissue, caused by an injury or inflammation, pulls the sensory retina from the retinal pigment epithelium.
The risk of retinal detachment in otherwise normal eyes is around 5 per 100,000 per year
Detachment is more frequent in the middle-aged or elderly population with rates of around 20 per 100,000 per year [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14644727&query_hl=22 .
The lifetime risk in normal eyes is about 1 in 300
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- Retinal detachment is extremely common in those with severe or extreme Myopia (above 5-6 Diopters ), as their eyes are longer and the retina is stretched thin. The lifetime risk increases to 1 in 20 {Link without Title} . Myopia is associated with 67% of retinal detachment cases. Myopic patients are often younger than non-myopic ones.
- Tractional retinal detachments can also occur in patients with proliferative disease {Link without Title} . In proliferative retinopathy, abnormal blood vessels (neovascularization) grow within the retina and extend into the vitreous. In advanced disease, the vessels can pull the retina away from the back wall of the eye causing a traction retinal detachment.
Although retinal detachment usually occurs in one eye, there is a 15% chance of developing it in the other eye, and this risk increases to 25-30% in patients who had cataracts extracted from both eyes
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People who suffer from retinal detachment feel no pain. A retinal detachment is commonly preceded by a
Posterior Vitreous Detachment which gives rise to these symptoms:
- flashes of light (photopsia) - very brief in the extreme temporal (outside away from the nose) part of vision
- a sudden dramatic increase in the number of Floaters
- a ring of floaters or hairs just to the temporal side of the central vision
- a slight feeling of heaviness in the eye
Although most posterior vitreous detachments do not progress to retinal detachments, those that do produce the following symptoms:
- a dense shadow that starts in the peripheral vision and slowly progresses towards the central vision
- the impression that a veil or curtain was drawn over the field of vision
- straight lines (scale, edge of the wall, road, etc.) that suddenly appear curved (positive Amsler Grid test)
- central Visual Loss
There are several methods of treating a detached retina which all depend on finding and closing the holes (tears) which have formed in the retina.
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: Scleral Buckle surgery is a common treatment in which the eye surgeon sews one or more silicone bands (plombs, tyres) to the outside of the eyeball. The bands push the wall of the eye against the retinal hole, closing the hole and allowing the retina to re-attach. The bands do not usually have to be removed. A recent study found that the encircling band used in the repair of retinal detachments may elongate the eye and considerably increase myopia {Link without Title} .
:This is another method of repairing a retinal detachment in which a gas or Silicone oil bubble is injected into the eye. The bubble floats to the area of the detachment where it must remain to apply light pressure against the hole. The Surface Tension of the air/water or oil/water interface seals the hole in the retina, and allows the Retinal Pigment Epithelium to pump the subretinal space dry and pull the retina back into place. When the gas bubble is used, patients may have to keep their heads tilted for several days to keep it in contact with the retinal hole. This often makes the treatment impractical when the retinal tear occurs in the lower part of the eyeball.
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:Vitrectomy is an increasingly widely used treatment for retinal detachment in countries with modern healthcare systems. It involves the removal of the vitreous gel using keyhole surgery combined with filling the eye with a gas bubble.
: Cryotherapy (freezing) and Laser photocoagulation are treatments used to create a scar around the retinal hole to prevent further fluid from accumulating behind the retina and the retina from re-detaching. Cryopexy can be used to seal anterior retinal tears; photocoagulation to seal posterior breaks.
After treatment, patients gradually regain their vision, although the
Visual Acuity may not be as good as it was prior to the detachment, particularly if the
Macula was involved in the area
of detachment. However, if left untreated, total
Blindness can occur in a matter of days.
Retinal detachment can be prevented in some. The most effective way of preventing retinal detachment is educating people to seek ophthalmic medical attention if they suffer symptoms suggestive of a
Posterior Vitreous Detachment {Link without Title} . Early examination allows detection of retinal tears which can be treated with laser or cryotherapy. This reduces the risk of retinal detachment in those who have tears from around 1:3 to 1:20.
There are some known risk factors for retinal detachment. There are also many activities which at one time or another have been forbidden to those at risk of retinal detachment, with varying degrees of evidence supporting the restrictions.
Cataract surgery is a major cause, and can result in detachment even a long time after the operation. The risk is increased if there are complications during cataract surgery, but remains even in apparently uncomplicated surgery. The increasing rates of cataract surgery, and decreasing age at cataract surgery, will inevitably lead to an increased incidence of retinal detachment.
Trauma is a less frequent cause.
Activities which cause direct trauma to the eye (boxing, kick-boxing, karate and others) can cause a particular type of retinal tear called a retinal dialysis. This type of tear can be detected and treated before it develops into a retinal detachment. For this reason governing bodies in some of these sports require regular ophthalmic examination.
Individuals prone to retinal detachment due to a high level of myopia are encouraged to avoid activities where there is a risk of shock to the head or eyes, although without direct trauma to the eye the evidence base for this may not be convincing
{Link without Title} . Some doctors recommend avoiding activities that
increase pressure in the eye, including diving, skydiving, lifting heavy weights, again with little supporting evidence. Activities that involve sudden acceleration or deceleration also increase eye pressure and are discouraged by some doctors. These include bungee jumping
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