What is a retinal detachment?
A retinal detachment is a separation of the retina from its attachments to its underlying tissue within the eye. Most retinal detachments are a result of a retinal break, hole, or tear. These retinal breaks may occur when the vitreous gel pulls loose or separates from its attachment to the retina, usually in the peripheral parts of the retina. The vitreous is a clear gel that fills 2/3 of the inside of the eye and occupies the space in front of the retina. As the vitreous gel pulls loose, it will sometimes exert traction on the retina, and if the retina is weak, the retina will tear. Most retinal breaks are not a result of injury. Retinal tears are sometimes accompanied by bleeding if a retinal blood vessel is included in the tear.
Once the retina has torn, liquid from the vitreous gel can then pass through the tear and accumulate behind the retina. The build-up of fluid behind the retina is what separates (detaches) the retina from the back of the eye. As more of the liquid vitreous collects behind the retina, the extent of the retinal detachment can progress and involve the entire retina, leading to a total retinal detachment. A retinal detachment almost always affects only one eye. The second eye, however, must be checked thoroughly for any signs of predisposing factors that may lead to detachment in the future.
What are the signs and symptoms of a retinal detachment?
Flashing lights and floaters may be the initial symptoms of a retinal detachment or of a retinal tear that precedes the detachment itself. Anyone who is beginning to experience these symptoms should see an eye doctor (ophthalmologist) for a retinal exam. In the exam, drops are used to dilate the patient's pupils to make a more detailed exam easier. The symptoms of flashing lights and floaters may often be unassociated with a tear or detachment and can merely result from a separation of the vitreous gel from the retina. This condition is called a posterior vitreous detachment (PVD). Although a PVD occurs commonly, there are no tears associated with the condition most of the time.
The flashing lights are caused by the vitreous gel pulling on the retina or a looseness of the vitreous, which allows the vitreous gel to bump against the retina. The lights are often described as resembling brief lightning streaks in the outside edges (periphery) of the eye. The floaters are caused by condensations (small solidifications) in the vitreous gel and frequently are described by patients as spots, strands, or little flies. There is no safe treatment to make the floaters disappear. Floaters are usually not associated with tears of the retina.
If the patient experiences a shadow or curtain that affects any part of the vision, this can indicate that a retinal tear has progressed to a detached retina. In this situation, one should immediately consult an eye doctor since time can be critical. The goal for the ophthalmologist is to make the diagnosis and treat the retinal tear or detachment before the central macular area of the retina detaches.