- What is it?
- Are there different types?
- What are the symptoms?
- What is the cause?
- What is the prognosis?
- How is it diagnosed?
- Is there a treatment?
What is it?
A retinal detachment is a separation of the retina from the back wall of the eye. The retina should be attached to the back wall of the eye just like wallpaper is attached to a wall. The retina, the thin layer that lines the back of the eyeball, acts as a receiver for what we see. Light enters through the front of the eye and is focused onto the retina in the same way light enters a camera through the lens and is focused onto its receiver. The retina receives the image that we perceive. If the retina comes loose from the wall of the eye, it is detached, and a part of the vision from that eye will be absent.
Are there different types?
Yes. Retinal detachments can be partial or total, just like wallpaper can be separated from just a corner of a wall or from the entire wall. Retinal detachments can also be classified by how long they are present (recent versus chronic) or whether they developed because of pulling (traction), leakage (exudative), or because of a tear (rhegmatogenous). Most retinal detachments in diabetics are due to pulling (traction), whereas most detachments in other individuals are due to a retinal tear.
What are the symptoms?
Most retinal detachments begin with symptoms of flashes and floaters, because these symptoms are associated with a retinal tear – and most retinal detachments start with a retinal tear. Floaters are spots which patients perceive to be suspended or floating in their field of vision. Many patients describe these as a glob, a strand, a fly, pepper grains, or a web in their vision. They are best visualized against a white background and continue to float past the center vision after an eye movement. Flashes are like streaks of lightning which recur several times a day for several days. Retinal detachments which begin in the peripheral retina cause loss of peripheral (or surround) vision. These can gradually progress to involve the central vision, resulting in a central and peripheral blind spot which blocks the vision. Rarely, retinal detachments begin in the central retina, and these cause central visual loss – inability to read, recognize faces, or thread a needle. If the retina becomes totally detached, the vision can go down to the level where a person sees only movement or light in the affected eye.
What is the cause?
Most retinal detachments develop after the gel (vitreous) in the cavity of the eye peels from the retina. Peeling of the vitreous gel (posterior vitreous detachment) is a normal age-related change that usually occurs after the age of 50. The vitreous gel can peel earlier in eyes that are very nearsighted, that recently underwent surgery, or have had a significant traumatic injury. A retinal tear can develop during the peeling of the gel due to an abnormal adhesion between the gel and the retina. A retinal tear allows fluid in the eye cavity to go through the tear to the space behind the retina where it can push the retina off the wall of the eye. Another type of retinal detachment is called tractional and occurs most often in eyes with severe diabetic retinopathy. Tractional retinal detachments result from contraction of scar tissue in front of the retina. The scar tissue pulls the retina forward into the eye cavity, causing separation of the retina from the back wall of the eye.
What is the prognosis?
All retinal detachments are different. In general, if a retinal detachment can be fixed before the macula has detached, the visual prognosis is good. On the other hand, if the macula is already detached, the prognosis for visual improvement is related to the length of time the macula has been detached. Even after fixing a retinal detachment involving the macula, the vision usually does not return as good as it previously was, although it can be very close to normal. Retinal detachments that are chronic (longstanding) have a worse prognosis for visual return. Some partial retinal detachments, particularly those associated with traction, may never progress and some can be safely observed without treatment. It is also important to note that a patient with a retinal detachment in one eye has a higher than usual risk of developing a retinal detachment in the other eye.
How is it diagnosed?
Retinal detachments are best diagnosed by an eye doctor. Diagnosis requires the use of dilating drops and a comprehensive eye exam to thoroughly view the retina.
Is there a treatment?
A small minority of retinal detachments can be observed for progression or treated with laser in the office. Most retinal detachments require surgery to reattach the retina to the back wall of the eye. The surgical procedures to correct a retinal detachment include scleral buckle, vitrectomy, and pneumatic retinopexy. Each works best under certain circumstances. Treatment may be 90% effective in simple recent detachments, but only 50% effective in more complex and longstanding cases.