The vitreous is a gel-like material attached to the retina at several points along the back of the eye. If the vitreous becomes detached from the retina, it could have no effects, it could cause flashing lights or floaters or it could create a retinal tear or detachment--which requires urgent care by an eye doctor. Multiple things can cause posterior vitreous detachments, from aging to surgical procedures.
Age
As a person gets older, the gel-like material in the vitreous begins to liquefy in the center. Eventually the vitreous will collapse in on itself, pulling the vitreous free from its attachments on the retina or at the optic nerve. According to the Eye Digest website, posterior vitreous detachments occur in less than 10 percent of people under the age of 50 but they occur in more than 60 percent of persons who are 70 years old or older.
Trauma
Trauma to the eye can also cause a posterior vitreous detachment. A blow to the eye causes traction on the vitreous and can pull the vitreous away from the retina. In the textbook "Vitreoretinal Surgery," Thomas Williamson reports that trauma can be a factor in posterior detachments occurring in people younger than 40 years old.
Nearsightedness
Because the eyes of nearsighted or myopic people are longer than the average eye, these people are at a higher risk of developing a posterior vitreous detachment. A 2004 study by S. Hayreh and J. Jonas in the journal "Ophthalmologica" found statistical evidence that posterior vitreous detachments are associated with nearsightedness.
Infection or Inflammation
Infection in the rear portion of the eye can cause inflammation. According to M. Haddrill on the All About Vision website, this inflammation can cause the vitreous to liquefy as well; this leads to the gel in the vitreous collapsing and the vitreous pulling away from the retina of the eye. Conditions like uveitis--which is an inflammation of the vitreous--can cause a poster vitreous detachment as well.
Surgery
As noted by the Academy of Ophthalmology on the Eyecare America website, people who have had cataract surgery are at higher risk of developing a posterior vitreous development. Patients who have had a specific type of laser surgery called a YAG laser after cataract surgery are also at risk for posterior vitreous detachments.
References
- The Eye Digest: Flashes and Floaters
- "Ophthalmologica"; Posterior vitreous detachment: clinical correlations; S.S. Hayreh, J.B. Jonas; 2004.
- Eye Surgical-Medical Associates: Posterior Vitreous Detachment (PVD) and Retinal Tears
- All About Vision: Eye Floaters, Flashes and Spots
- "Vitreoretinal Surgery"; T.H. Williamson; 2008
