The back cavity of the inner eye is filled with clear jelly called vitreous. When the vitreous jelly undergoes the natural aging process it deteriorates and becomes liquid. As the eyeball moves, small pockets of liquid vitreous can move around as well inside the vitreous cavity. This movement causes the vitreous to pull on the retina.
Normally the vitreous is only loosely adherent to the retina and easily peels away from the retina during vitreous degeneration. This event is called a posterior vitreous detachment (PVD) and again is a normal event occurring in most people.
However, occasionally, the vitreous is so adherent to the retina and pulls so hard on it that it creates a tear. If this tear is along a blood vessel of the retina this may cause bleeding into the vitreous (called a vitreous hemorrhage) which could lead to a shower of floaters which cloud the vision. Acute retinal tears with or without flashes and floaters pose a risk because fluid can enter through the tear under the retina and lift the retina off, causing a retinal detachment, much like damp wallpaper peeling from the wall. Since PVDs are usually the initiating event of most retinal detachments, a detailed peripheral retinal examination should be performed when PVD symptoms occur. Retinal tears may be sealed with lasers or cryotherapy (a freezing treatment), or both, to prevent retinal detachment. These treatments are usually painless and seal the retina to the wall of the eye. Both of these procedures create a scar to seal the retina to the back of the eye. This prevents fluid from traveling through the tear and under the retina, and is thought to be helpful in preventing a retinal detachment.
What are the symptoms of Retinal Tears and Detachments?
Retinal tears and detachments generally offer the following painless symptoms:
- New Floaters: The presence of some floaters is common because the vitreous is not
completely transparent or uniform in consistency. However, a sudden increase in the
number and size of floaters perceived in your vision is a warning sign that a retinal tear
could be in progress.
- Flashes: The sudden appearance of flashes in vision may indicate that the vitreous material
is pulling away from or tugging on the retina, which could be the first stage of a retinal
tear or detachment.
- Shadow or curtain over vision: The onset of a growing, dark shadow or the appearance of
a curtain over a portion of the vision in one eye may be an indication of a retinal
detachment. These symptoms usually occur in the peripheral (side) vision. The growing
shadow results from the increasing area of retinal tissue being pulled away from the back
wall of the eye and no longer able to react to light.
- Decreased vision: Another common symptom of a retinal tear or detachment is a sudden decrease in vision.
If you experience flashes or floaters then you should notify your ophthalmologist immediately. An eye examination with dilated pupils will allow the determination of the source of your symptoms, as well as a recommendation for the appropriate treatment. Prompt treatment can often minimize the damage to your eye.
For minor detachments or tears of the retina, a simple procedure may be done in your doctor's office. In most cases, if you have a hole or tear in your retina but your retina is still attached, your doctor may use photocoagulation (laser). This binds the retina to the underlying tissue, ensuring that detachment will not occur and preventing vitreous fluid from leaking through the tear. In cases where a laser cannot be used, a cryoprobe is used to freeze the tissue around the tear rather than burning it. In more severe cases, you will need surgery to repair a detached retina.
Follow-up examination are important even after treatment or surgery. This allows a doctor to ensure that your eyes are not developing any further problems and that the retina is intact.