The vitreous is the jelly-like material that fills the large central cavity of the eye and helps to keep the eye round. It is 98% water and 2% proteins, which give a stiff consistency similar to double-strength gelatin. The vitreous has millions of tiny fiber connections to the retina, the light sensitive layer that lines the back of the eye.
As we age, the vitreous becomes liquefied and separates from its connection with the retina. This process culminates in a Posterior Vitreous Detachment or PVD. This separation is responsible for the characteristic flashes caused by the pulling of the vitreous gel on the retina and floaters caused by the reorganization of the fibrous elements. Patients may experience the flashes similar to a camera flash inside the eye and may notice the floaters as hair-like flecks that float across their vision. The primary cause of a PVD is the aging process but patients that are nearsighted or have trauma to the eye may experience a PVD at a younger age.
All patients who experience a recent onset of flashes or floaters should be carefully examined by an optometrist or ophthalmologist. Most of the time nothing unusual is found. The flashes eventually go away, and the floaters diminish and become less bothersome with time.
However, in some patients, the sticky attachments of the vitreous can create a retinal tear or pull on a blood vessel causing bleeding inside the eye. If left untreated, a retinal tear can cause a retinal detachment when the liquefied vitreous gel enters the space under the retina. A retinal tear can be treated with a laser procedure in the office to spot weld around the tear. A retinal detachment can be vision threatening and usually requires urgent surgery. The only way to definitively rule out a retinal tear or detachment is a careful dilated eye exam. Even if the first eye to experience a PVD has no evidence of a tear or detachment, the second eye to experience the PVD must also be examined carefully.