What Is A Detached Retina? What Causes A Detached Retina?

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Main Category: Eye Health / Blindness
Article Date: 12 Nov 2009 - 0:00 PST

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The retina is a thin layer of nerve cells lining the inside back wall of the eye. The retina is essential to see properly. It turns the light that enters the eye into an image by sending a message along the optic nerve to the brain.

When this layer becomes separated from the inner wall of the eye, it is called retinal detachment. The retina peels away from its underlying layer of support tissue. If this is not treated, it usually leads to blindness in the affected eye. Retinal detachment is a medical emergency requiring prompt surgical treatment to preserve vision.

According to Medilexicon's medical dictionary, retinal detachment is "loss of apposition between the sensory retina and the retinal pigment epithelium."

Fortunately, retinal detachment often has clear warning signs. Seeing an ophthalmologist (eye specialist) as soon as warning signs appear, early diagnosis and treatment of retinal detachment can save vision.

Retinal detachment normally occurs in only one eye.

Retinal detachment is rare and can affect anyone but is more common in people who:

• are short-sighted
• have had complicated cataract surgery in the past
• have suffered an important blow or injury to the eye in the past
• have diabetes

Usually, the retina becomes detached if there are one or more holes in it. Retinal detachment can be treated with surgery to seal the holes and reattach the retina.

What are the signs and symptoms of a detached retina?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor notice. For example, pain may be a symptom while a rash may be a sign.

Retinal detachment is painless. Almost always visual symptoms appear before it occurs. Warning signs include:

• Shadow, veil or black curtain over a portion of the visual field
• Sudden appearance of floaters, small bits of debris in the field of vision (dark spots or strings that seem to float before the eyes)
• Sudden blur in vision
• Sudden flashes of light in one or both eyes
• Vision may become cloudy as small blood vessels bleed

Seek immediate medical attention if suddenly there is an increase in floaters or flashes of light in the visual field.

Often, people do not realize the urgency of the warning signs of retinal detachment and hope that symptoms will disappear. In some cases, symptoms temporarily weaken only to be followed by a loss of vision over the next few days or weeks. At the stage of advanced retinal detachment, surgery is not always successful and vision loss may be permanent.

It is normal to see the occasional floater, but floaters and flashes may be a sign of retinal detachment.  These signs do not always mean the retina has detached. Prompt treatment for retinal detachment minimizes damage to the eye.

What are the causes of retinal detachment?

There are several common causes of retinal detachment.

Holes or tears in the retina.

This often occurs when the retina becomes thin, particularly among people who are short-sighted. When the retina has holes in it, fluid in the eye can leak underneath the retina and separate it from the lining of the eye.

Conditions and injuries, such as:

• Advanced diabetes
• Complications of surgery for cataract
• Trauma
• An inflammatory disorder, such as sarcoidosis or cytomegalovirus retinitis
• Sagging or shrinkage of the jelly-like vitreous that fills the inside of the eye

Retinal detachment cannot be caused by heavy lifting or by straining your eyes. 


Posterior vitreous detachment (PVD)


This common condition is also called vitreous collapse. With age, vitreous may change in consistency and shrink or become more liquid. PVD usually does not cause serious problems, but it can cause visual symptoms (flashes of sparkling lights when eyes are closed, floaters).

Most retinal tears caused by PVD lead to retinal detachment if left untreated. Detachments that go undetected and untreated can progress and eventually involve the entire retina, causing complete loss of vision in the affected eye.

What are the risk factors of retinal detachment?

A risk factor is something which raises the likelihood of developing a disease or condition. For example, obesity increases the risk of developing diabetes type 2; therefore, obesity is a risk factor for diabetes.

The following factors increase the risk of retinal detachment:

• A family history of retinal detachment
• Aging (retinal detachment is more common in people older than age 40)
• Extreme nearsightedness (myopia)
• Previous eye surgery (such as cataract removal)
• Previous retinal detachment in one eye
• Previous severe eye injury or trauma
• Weak areas on the sides of the retina

How is retinal detachment diagnosed?

By looking at the retina with an ophthalmoscope, an ophthalmologist (eye specialist) may be able to see a retinal hole, tear or detachment.

If blood in the vitreous cavity blocks the view of the retina, an ultrasound examination may provide useful information.

What is the treatment for retinal detachment?

If retinal detachment has occurred, the only way of reattaching the retina is with surgery. Without it, a complete loss of vision is almost certain.

Surgery for retinal tears


When a retinal tear or hole has not yet progressed to detachment, the following procedures may be recommended:

• Laser surgery (photocoagulation). A laser beam is directed through a contact lens or ophthalmoscope designed for this procedure. The laser makes burns around the retinal tear, and results in scarring tissue. This procedure requires no surgical incision and causes little irritation to the eye. 

  
  
• Freezing (cryopexy). Cryopexy uses intense cold to freeze the retina around the retinal tear. After a local anesthetic a freezing probe is applied to the outer surface of the eye directly over the retinal defect. This freezes the area around the hole, leaving a delicate scar that helps secure the retina to the eye wall. This procedure is used for hard-to-reach tears, generally along the retinal edge. It may result in redness and inflammation of the eye for some time.

Surgery for retinal detachment


There are three different surgical procedures used to repair a retinal detachment. They may be done in conjunction with photocoagulation or cryopexy. The type, size and location of any retinal detachment will determine which surgical approach is recommended. Generally, these surgeries successfully treat more than 90 percent of cases of retinal detachment. Sometimes a second treatment is necessary. It may be done under a general or a local anesthetic and may require a hospital stay of one or two days.

Pneumatic retinopexy: This outpatient procedure is recommended for a relatively uncomplicated detachment with the tear located in the upper half of the retina. It is usually done under local anesthesia. The procedure often starts with cryopexy to treat the retinal tear. A bubble of expandable gas is injected into the vitreous cavity. Over the next several days, the gas bubble expands, sealing the retinal tear by pushing against it and the detached area that surrounds the tear. The retina is able to reattach itself to the back wall of the eye. The gas eventually disappears after several weeks.

Scleral buckling: Fine bands of silicone rubber or sponge are stitched onto the outside white of the eye (the sclera) in the area where the retina has detached. Laser or freezing treatment is used to scar the tissue around the retina. The bands can be left on the eye and should not be noticeable after the operation.

Vitrectomy: The vitreous (jelly-like substance) from the inside of the eye is removed and replaced with either a gas or silicone bubble. This holds the retina in position from the inside. Tiny dissolving stitches are used to close the wound.

Tears and holes can be treated before detachment develops. Retinal holes or tears can be sealed using either lasers or cryotherapy (freezing treatment). These procedures can be used after scleral buckling, to seal a detached retina to the wall of the eye, or as a treatment on its own (using local anesthetic) to seal a small hole or tear and prevent retinal detachment from happening. Both lasers and cryotherapy work by making the eye create scar tissue that seals the hole or the gap between the detached retina and lining of the eye.

After the procedure, the patient will be asked to keep their head in a certain position and to avoid travel by air for a while.

Possible complications

There is a small chance of developing complications during or after surgery. There are not common and can usually be treated. They include:

• a cataract (cloudy lens)
• allergy to the medicine used
• bleeding inside the eye
• bruising around the eye
• double vision
• high pressure or swelling inside the eye (glaucoma)
• immune system reaction that affects the other eye (this is extremely rare)
• infection in the eye (although, this is very rare)
• more holes in the retina

Sometimes, more than one operation may be needed to fix the retina. Surgery is not always successful in reattaching the retina. Vision after surgery depends in part on whether the central part of the retina (macula) was affected by the detachment before surgery, and for how long.

Vision may take many months to improve after repair of a complicated retinal detachment. Some people do not recover any lost vision.

Results of surgery


Retinal detachment can cause loss of eyesight in the portion of the field of vision that corresponds to the detached part of the retina. This can greatly change lifestyle. There are some ways to cope with impaired vision:

• At home. Proper light at home for reading and other activities.
  
  
• Help of others. Inform friends and family members about vision problems so that they can help.
  
  
• Safer home. Eliminate rugs and other tripping hazards within the home.
  
  
• Special glasses. Optimize vision with glasses that are specifically prescribed for the effects of retinal detachment. Keep an extra pair of glasses in the car.
  
  
• Talking to others with impaired vision. Online networks, support groups and resources for people with impaired vision can be helpful.
  
  
• Transportation. Vans and shuttles, volunteer driving networks, or ride shares are available for people with impaired vision.

Recovering from retinal detachment 

After the operation, eyelids may feel itchy and sticky. There may be some bruising around the eye. Any discomfort should go away after a couple of days. Simple painkillers can be recommended to relieve the discomfort.

A day after the operation, eye drops will be given to reduce the swelling and prevent infection. It is important not to rub the eye while it heals, which will usually take two to six weeks.  Vision will be very blurry for a while. This is only temporary.

Eyesight cannot always be completely restored. This depends largely on how much of the retina was detached and for how long.

Any of the following symptoms after the operation should be cause for alarm:

• A very painful eye.
• Loss of vision.
• Increasing redness in the eye.

How is retinal detachment prevented?

There is no way to prevent retinal detachment. However, being aware of the warning signs of a detached retina is essential: an increased number of floaters, bright flashes of light, or a shadow or curtain falling across visual field. Contact your ophthalmologist immediately if you notice any of the warning signs of retinal detachment, particularly if you are over the age of 40, if there is family history of detached retina, or you are extremely nearsighted.

Written by Stephanie Brunner (B.A.)
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today