The eye is a hollow spherical structure. Internally, a delicate sheet of nerve tissue called the retina lines the wall of the eye like wallpaper. The central cavity of the eye is filled with a sticky gel called the vitreous. Over time, the vitreous gel tends to liquefy in its center, creating liquid pockets surrounded by the more formed gel. Eventually, with enough degeneration within the vitreous gel, the filamentous scaffold collapses and the vitreous separates from the retina. This event is called a posterior vitreous detachment (PVD) and is a normal event occurring in most people sometime between 40-70 years of age. A PVD will often occur at an earlier age in people who are nearsighted or have undergone cataract surgery.
Flashes of light are also a common symptom of a PVD. When the vitreous pulls on the retina – to which it is attached – the photoreceptors are mechanically stimulated. If the vitreous gel is abnormally adherent to the retina or the retina is weak in a certain area a retinal tear can occur as the gel separates and pulls away from the retina. Once a retinal tear develops there is a significant risk of the liquid vitreous going through the break and detaching the retina from the back wall of the eye. If a retinal tear can be discovered before a retinal detachment develops it can be treated with the laser to seal the break and prevent a retinal detachment. If you have new symptoms of a PVD (new floaters, flashes of light, shower of spots or a curtain or shade in your vision) it is important to have a prompt and thorough examination of the retina.
Retinal Detachment is when the retina floats away from its normal position. Retinal detachment, should it occur, requires surgical correction. There are a variety of procedures that might be used, depending upon the nature of the specific patient’s problem. One of the more common treatments involves injecting a bubble into the center of the vitreous (“Pneumatic Retinopexy”). The bubble pushes the retina back into position where the retinal tear can be sealed with laser. For more complex cases there are other more involved surgeries available. These surgeries are highly successful at reattaching the retina, and usually succeed at preserving useful vision.