Retinal detachment
Retinal detachment describes an emergency situation in which a thin layer of tissue (the retina) at the back of the eye pulls away from its normal position.
How retinal detachment occurs
Retinal detachment can occur when the gel-like material (vitreous) leaks through a retinal hole or tear and collects underneath the retina.
Aging or retinal disorders can cause the retina to thin. Retinal detachment due to a tear in the retina typically develops when the vitreous collapses and tugs on the retina with enough force to create a tear.
Fluid inside the vitreous then finds its way through the tear and collects under the retina, peeling it away from the underlying tissues. The areas where the retina is detached lose this blood supply and stop working, so you lose vision.
Symptoms
- Sudden loss of vision
- Half sided or partial vision
But warning signs almost always appear before it occurs or has advanced, such as:
- The sudden appearance of many floaters — tiny specks that seem to drift through your field of vision
- Flashes of light in one or both eyes
- Blurred vision
- Gradually reduced side (peripheral) vision
- A curtain-like shadow over your visual field
Risk factors
- Aging — retinal detachment is more common in people over age 50
- Previous retinal detachment in one eye
- A family history of retinal detachment
- Extreme nearsightedness (myopia)
- Previous eye surgery, such as cataract removal
- Previous severe eye injury
- Previous other eye disease or inflammation
Aging-related retinal tears that lead to retinal detachment
As you age, your vitreous may change in consistency and shrink or becomes more liquid. Eventually, the vitreous may separate from the surface of the retina — a common condition called posterior vitreous detachment (PVD).
As the vitreous separates or peels off the retina, it may tug on the retina with enough force to create a retinal tear. Left untreated, fluid from the vitreous cavity can pass through the tear into the space behind the retina, causing the retina to become detached.
PVD can cause visual symptoms. You may see sudden new floaters or flashes of lights (photopsia). These may be visible even in daylight. The flashes may be more noticeable when your eyes are closed or you’re in a darkened room.
Myopia (Glasses for distant vision) and Retinal Detachment
Myopia itself does not cause a retinal detachment (RD) but it is a risk factor. This is one of the main contributing reasons. Myopic retinal degenerations like lattice, snail-track often seen. Lattice is associated with thin and fragile retinas as well as vitreous adhesion to the edges which makes a tear more likely.
The vitreous jelly also tends to be less viscous and this watery nature not only lends itself to being more likely to separate from the retina and cause a tear but also to more easily get under the retina when a tear develops and thus increase and accelerate the formation of an RD. Results showed eyes with mild myopia had a four-fold increased risk of retinal detachment compared with non-myopic eyes. Among eyes with moderate and high myopia, the risk increased 10-fold.
How is retinal detachment treated?
Small holes and tears are treated with laser surgery or a freeze treatment called cryopexy. These procedures are usually performed in the doctor’s OPD room. During laser surgery tiny burns are made around the hole to “weld” the retina back into place. Cryopexy freezes the area around the hole and helps reattach the retina.
Retinal detachments are treated with surgery. In some cases a scleral buckle, a tiny synthetic band, is attached to the outside of the eyeball to gently push the wall of the eye against the detached retina. If necessary, a vitrectomy may also be performed. During a vitrectomy, the doctor makes a tiny incision in the sclera (white of the eye). Next, a small instrument is placed into the eye to remove the vitreous, a gel-like substance that fills the center of the eye and helps the eye maintain a round shape. Silicon Oil or Gas is often injected to into the eye to replace the vitreous and reattach the retina; this agents pushes the retina back against the wall of the eye. After few months silicon oil can be removed.
With modern therapy, over 90 percent of those with a retinal detachment can be successfully treated, although sometimes a second treatment is needed. However, the visual outcome is not always predictable. The final visual result may not be known for up to several months following surgery. Even under the best of circumstances, and even after multiple attempts at repair, treatment sometimes fails and vision may eventually be lost. Visual results are best if the retinal detachment is repaired before the macula (the center region of the retina responsible for fine, detailed vision) detaches. That is why it is important to contact an eye care professional immediately if you see a sudden or gradual increase in the number of floaters and/or light flashes, or a dark curtain over the field of vision.