Posterior Vitreous Detachment
Flashes and floaters are among the most common symptoms described to eye doctors. In the majority of cases, these symptoms represent a series of benign changes within the eye, usually related simply to age. Rarely, they may be associated with retinal damage which may require treatment, and therefore all new flashes and floaters merit a visit to a physician for evaluation. The following discussion will explain the details of these changes.
Most of the eye, which is essentially a hollow sphere, is filled completely by a clear structure called the vitreous. This vitreous, which is composed primarily of water and long strands of suspended molecules, is fairly solid when we are young, with the consistency of loose Jello. As we age, the vitreous gel begins to break down into its components, becoming more liquid with clumping of the strands, a process known as syneresis. These clumps are the first “floaters” which most people recognize. They are often described as small spots or hairs which seem to move or float around as the eye moves. As the breakdown of the vitreous gel continues, it begins to lose its attachment to the retina, the thin film which lines the inside of the eye. Flashes, often seen as brief bursts of light in the periphery of vision, occur as the retina is stimulated by the loosening vitreous. Eventually, the vitreous separates from the retina, often with the development of new, large floaters as the semi-solid gel now floats freely within the eye. This final separation of vitreous from retina is known as a posterior vitreous detachment, or PVD. (See diagram at right)
The entire process of vitreous detachment is generally nothing more than a nuisance, with larger floaters occasionally interfering with vision, causing transient blurring. Rarely, however, the separation of vitreous and retina can cause problems. In some cases, the vitreous is abnormally adherent to the retina. Rather than simply peel free, it clings tightly to the retina, leading to a retinal hole or tear. Vitreous fluid can then pass through the tear and collect beneath the retina, separating it from the wall of the eye. This is known as a retinal detachment. (See diagram at left)
The new onset of either flashes or floaters in an eye should be evaluated by an eye doctor within a few days. While relatively uncommon, a retinal tear can be easily treated with a brief, painless laser procedure, preventing the development of a retinal detachment. Once a significant retinal detachment occurs, more involved surgery is usually necessary to repair the damage.
If you experience the onset of multiple flashes, new floaters- particularly numerous small floaters, or a veil or curtain in the periphery of your vision, please call for an appointment. We will perform a thorough evaluation and, if necessary, arrange for treatment. Click the contact us link for information about scheduling your visit.