Retinal Detachment
What is Retinal Detachment?
The retina is a light-sensitive layer of tissue that is located on the inside wall at the back of the eye. A Retinal Detachment is an uncommon but serious eye condition in which the retina pulls away from its normal position at the back of the eye, analogous to wall-paper peeling off a wall. As the retina is responsible for sending visual images to the brain via the optic nerve, when a detachment occurs, the vision becomes blurred. It is most often caused by a related condition called posterior vitreous detachment (PVD). In PVD, the retina is torn, allowing fluid to get under the retina. However it may also be caused by trauma, diabetes or an inflammatory disorder.
During a Retinal Detachment, bleeding from small retinal blood vessels may cloud the interior of the eye, which is normally filled with vitreous fluid. Central vision becomes severely affected if the macula, the part of the retina responsible for fine vision, becomes detached. Risk factors for retinal detachment include: increasing age, myopia (short sightedness), previous retinal disease, family history of retinal detachment, previous cataract surgery, trauma, previous retinal detachment in the other eye.
Symptoms
The most common symptoms are sudden onset of flashing lights visible in one eye, a sudden dramatic increase in the number of floating spots visible in one eye, or a grey curtain or veil across the vision. A shadow in the vision may start near the nose but can be seen anywhere in the vision.
Management
A Retinal Detachment can not be seen unless the eye is dilated. Diagnosis can be done by examining the retina in the consulting rooms with the aid of the following instruments:
- Ophthalmoscope
- Slit Lamp
- Ultrasound
Only after careful examination can your Ophthalmologist tell whether a retinal tear or early retinal detachment is present.
Retinal tears, not associated with Retinal Detachment, will usually need to be treated with claser surgery or rryotherapy (freezing), to seal the retina to the back wall of the eye. These treatments cause little or no discomfort and will usually prevent progression to a retinal detachment. In some cases retinal tears are closely monitored without treatment.
Surgery is the only effective treatment for Retinal Detachment. Immediate evaluation is critical to determine the best treatment approach, usually followed by prompt intervention.
Left untreated, Retinal Detachment can lead to permanent and severe vision loss.
There are a number of approaches to treating a Retinal Detachment. The decision of which type of surgery and anaesthesia to use (local or general), depends upon the characteristics of your detachment. In each of the following methods, your Ophthalmologist will also locate any retinal tears and use laser surgery or cryotherapy to seal the tear.
Scleral Buckle
A flexible band (scleral buckle) is placed around the eye to counteract the force pulling the retina out of place. The ophthalmologist will often drain the fluid under the detached retina from the eye, pulling the retina to its normal position against the back wall of the eye. This procedure is performed in an operating room.
Vitrectomy
Vitrectomy may be necessary to remove any vitreous gel which is pulling on the retina. This may also be necessary if the vitreous is to be replaced with a gas bubble. Your body’s own fluids will gradually replace this gas bubble, but the vitreous gel does not return. Sometimes a vitrectomy may be combined with a scleral buckle.
Silicone oil can also be used instead of the gas bubble to keep the retina attached postoperatively. The silicone will remain in the eye until it is removed (requiring a second surgery at a later date). This technique is advantageous when long term support of the retina is required or for those patients unable to position postoperatively (i.e. children). Unlike gas, patients are still able to see through clear silicone oil.
Any surgery has risks; however, an untreated retinal detachment will usually result in permanent severe vision loss or blindness. Some of the surgical risks include infection; bleeding; high pressure inside the eye; or cataract. Cataract is where the lens of the eye becomes hazy and is very common after vitrectomy surgery. Most retinal detachment surgery is successful, although on occasions more than one operation may be needed. If the retina cannot be reattached, the eye will continue to lose sight and ultimately become blind.
Important Notes
After Surgery
You can expect some discomfort after surgery. Your Ophthalmologist will prescribe any necessary medications for you and advise you when to resume normal activity. You will need to wear an eye patch for a short time. If a gas bubble was placed in the eye, your Ophthalmologist will recommend that you keep your head in special position for some time. If you have gas in your eye, your vision will be very blurry. It will seem like you are looking through a droplet of water.
DO NOT FLY IN AN AIRPLANE OR TRAVEL UP TO HIGH ALTITUDES UNTIL YOU ARE ADVISED BY YOUR OPHTHALMOLOGIST THAT THE GAS BUBBLE HAS GONE!
Recovery of vision may be quite slow, often taking many months. In some cases vision may return completely to normal, depending on the extent of the initial retinal detachment. In other cases, vision does not fully recover. Your Ophthalmologist can usually advise on likely outcomes. If your retinal detachment has been worsened by the formation of scar tissue (proliferative vitreoretinopathy) then the outlook for vision is significantly reduced.