The retina is the nerve layer that lines the inside of the back of the eye. It senses light and sends images on to the brain. When the retina is separated from the layer beneath the retina that gives it nourishment, called the choroids, this is called retinal detachment. The retina does not work when it is detached. This is a very serious problem and, if untreated, almost always leads to blindness.
What are the causes and risks of the condition?
Most retinal detachments result from a hole or tear that develops in the retina. The tear allows fluid to leak through and get under the retina, separating it from the layer beneath, much like a blister. The most common reason for a break in the retina is when the vitreous or clear jelly that fills the middle of the eye shrinks and pulls on the retina. This may occur in one or more places.
After the development of the retinal tear, fluid passes through, lifting the retina off like wallpaper peeling off a wall. Many times this occurs spontaneously, especially in older persons in whom there may be weak spots from natural aging. Several conditions increase the possibility of retinal detachment. These include:
- a high degree of nearsightedness
- previous cataract surgery
- severe injury to the eye, or blunt trauma
- prior retinal detachment in the opposite ey
- family history of retinal detachment
- tiny or weak spots in the retina that are seen by an eye care professional
How is the condition diagnosed?
An eye care professional diagnoses a retinal detachment during an eye examination. The pupil is dilated and the raised retina can be seen using special lenses.
Long Term Effects
What are the long-term effects of the condition?
There are some risks to retinal detachment surgery. However, if left untreated, detachments can lead to permanent reduction or total loss of vision. The most common risks include infection, bleeding, increased pressure in the eye, and formation of a cataract.
Occasionally, a second operation may be needed if the first is unsuccessful. Vision may take months to improve and in some cases will never fully return. Some people do not recover any vision. For these reasons, it is especially important to visit the eye care professional at the first sign of any trouble.
What are the treatments for the condition?
If a retinal tear is found before a detachment has started, it should be treated immediately. Treatments include laser surgery or freezing the area to create a seal around the tear, preventing detachment from developing. In most cases, this will prevent detachment.
However, when fluid has already passed under the retina, lifting it, surgery is needed to put the retina back in its proper place. There are several procedures to fix the detachment. At the time of surgery other small tears without detachments around them may be treated as well.
In one type of surgery a gas bubble is injected into the vitreous space inside the eye. This bubble pushes the retina back into its normal position. The person will need to hold a certain head position for several days and the gas bubble gradually disappears.
Another procedure involves placing a band, called a scleral buckle, around the eye to indent the outer portion of the eye, allowing the retina to seat itself back in place. With this procedure the eye care professional drains the fluid from under the retina before the band is tightened.
With a third procedure, called a vitrectomy, the gel is removed from the eye and usually replaced with a gas bubble. The body's own fluid then gradually replaces the bubble as it dissolves. Sometimes the removal of the vitreous gel is combined with the scleral buckle procedure. Following surgery, eye drops are usually placed in the eye for several weeks.
Normal activity cannot be resumed until the eye care professional gives permission. People are usually required to avoid flying in an airplane or traveling up to high altitudes until the gas bubble is gone from the eye. This increase in altitude could cause a sudden rise in eye pressure, which is quite dangerous.
The overall success rate in reattaching the retina is 85%. If the central part of the retina called the macula is detached for any period of time, the vision will not return to normal even with successful reattachment of the retina. Usually glasses will be needed after the surgery.