- What are they?
- What is the cause?
- What is the prognosis?
- How are they diagnosed?
- Is there a treatment?
What are they?
Floaters are symptoms that people recognize as spots suspended or floating in their field of vision. Many patients describe these as a glob, a strand, a fly, pepper grains, or a web in their vision. They are best visualized against a white background and continue to float past the center vision after an eye movement. Flashes are like streaks of lightening that recur several times a day for several days or longer.
What is the cause?
Most people experience floaters when the gel (vitreous) in the cavity of the eye peels from the retina (which lines the back of the eye wall). Peeling of the vitreous gel (posterior vitreous detachment) is a normal age-related change that usually occurs after the age of 50. The vitreous gel can peel earlier in eyes that are very nearsighted, that recently underwent surgery, or have had a significant traumatic injury. Another common cause of floaters is vitreous hemorrhage – blood within the cavity of the eye. The blood may appear as pepper grains, dark strings, or areas of missing vision. Flashes are usually caused by pulling on the retina by the gel (vitreous) in the eye cavity. The pulling stimulates the nerve cells in the retina. The nerve cells then fire, sending a signal to the brain that the individual perceives as a flash of light. Therefore, light flashes may be a symptom of intermittent traction on the retina. If the traction on the retina is great, a retinal tear can develop.
What is the prognosis?
The prognosis depends on the cause of the symptoms. A floater due to peeling of the vitreous gel without an associated retinal tear has an excellent prognosis. The floater is annoying, but not dangerous, and usually becomes less apparent in several months. However, floaters or flashes related to a retinal tear would be more serious, because the retinal tear could progress to a retinal detachment. Likewise, a floater perceived as pepper grains might indicate the presence of vitreous hemorrhage, which increases the likelihood of a retinal tear. Since a patient cannot determine whether the floater is complicated by a retinal tear, the best way to improve the prognosis is to have a dilated examination of the eye.
How are they diagnosed?
A thorough eye examination, including dilation of the pupils, is advisable in patients with new onset floaters or flashes. The objective is to determine the cause of the floaters and/or flashes. Some patients with floaters and flashes have an undiagnosed retinal tear or retinal detachment. Both warrant prompt diagnosis and treatment, if present.
Is there a treatment?
Uncomplicated floaters and flashes do not require treatment. Only those patients whose examination reveals a retinal tear, retinal detachmen or other vision-threatening abnormality need treatment. If a retinal tear is present, it is our objective to diagnose and treat it as soon as possible – before it progresses to a retinal detachment. Treatment of a retinal tear usually involves laser or cryo (freezing) to seal down the edges of the tear (like spot welding). There are several methods to treat a retinal detachment and they are more invasive than the treatment for retinal tears. For that reason, prompt evaluation of the retina when experiencing new onset floaters or flashes is imperative.