Floaters and Flashes: Retinal Tears, and Posterior Vitreous Detachment

“Floaters” is the term used by ophthalmologists to describe symptoms of opacities in a patient’s vision. When the individual adjusts their gaze and moves their eyes, these opacities continue to move beyond the time when the patient’s eyes stop moving. That is to say that the opacities “float” beyond the time when the eye stops moving. The words used by patients to describe such symptoms are often “cobwebs,” “gnats,” or “circles.” If the opacities are caused by red blood cells, then patients may also recognize a reddish tinge to the floaters.

How do floaters and flashes develop?

The cause of floaters is typically thought to be from a natural aging process of the vitreous gel which occupies the internal aspect of the eyeball. In patients older than 50, it is not uncommon for the vitreous gel to separate from the back of the eye in conjunction with this aging process. This process is called a posterior vitreous detachment (PVD). As the posterior vitreous separates from the retina, it may tug on the retina, causing the brain to interpret this tugging as light flashes. The description of flashes that are more ominous is when the patient says the lights are bright (usually white), in the periphery, and induced by eye movement.

Why does your ophthalmologist want to know if you have floaters and flashes?

In patients with an acute onset of floaters and/or flashes, there may be an associated tear in the retina. A tear in the retina is the reason your ophthalmologist will recommend a detailed examination of the retina, as retinal tears often lead to retinal detachment. If retinal tears are caught early, then laser photocoagulation or cryopexy can often be done as an office procedure to significantly reduce the chance of progressing to retinal detachment.

If the process progresses to retinal detachment, then surgical intervention in an operating room is often recommended. Although floaters may affect visual function, the common recommendation is observation as your retina specialist would expect the floater symptoms to abate with time. However, retinal detachments can cause permanent vision loss even if fixed surgically, so prompt medical attention is recommended if you experience sudden onset of floaters and/or flashes.