Posterior Vitreous Detachment
The vitreous humor is a clear gelatinous solid that fills the back central part of the eye. It is present from birth. As we age, the solid vitreous gel begins to liquefy. We reach a point in our lives, usually in our 50’s, where the vitreous gel liquefies enough to become detached from the posterior retina. When this separation occurs, most patients notice a large round floater with small string like extensions. The spot, when seen, is freely mobile. It is seen best against a light background such as a white wall or blue sky. It is noticeable most with eye movement. The floater initially moves in the opposite direction of the eye movement and then slowly floats back towards central vision. Patients report a generalized blur, or fogginess, that occurs with a vitreous separation. Many feel that there is something on the surface of their eye or on their glasses, which they try to blink away or try to clean unsuccessfully.
As the vitreous separates from the retina, flashing lights can be seen. The flashing is the same as lightening flashes seen off to one side; or the flash of a camera. The retina does not have any pain fibers in it. It is only capable of sensing light when stimulated. The tugging of the vitreous on the retina produces the flashes of light.
A vitreous separation does not occur all at once. The vitreous slowly separates from the back of the eye over approximately six to eight weeks. As the vitreous separation continues, the flashing decreases in intensity and can completely resolve. Occasional rare flashes seen when in the dark and looking from one side to the other are not concerning. As the vitreous separation continues, the floaters tend to settle to the bottom part of the eye and become less noticeable and bothersome.
When a new posterior vitreous detachment occurs, we recommend a dilated eye exam as soon as possible, usually the day of the new symptoms or early next morning if they occurred during the night. Depending on the appearance of the vitreous separation, a one-week follow-up exam and sometimes a secondary three-to-four week follow-up exam are scheduled as needed.
Retinal Holes or Tears
The majority of vitreous separations occur without causing damage to the retina. With some vitreous detachments, an area of vitreous can be firmly attached to the retina and cause either a retinal hole or a retinal tear. These are often associated with a large number of flashing lights and/or a large number of individual small and round floaters (usually dozens to hundreds) along with the large floaters from the vitreous detachment.
If a new retinal hole or tear is found soon after its formation, either laser treatment or cryopexy (freezing treatment) can be used to encircle the hole or tear and prevent the risk of a retinal detachment. Timing of the treatment is critical and reporting symptoms immediately is important.
If a posterior vitreous detachment, with symptoms, causes a hole or tear and treatment is required, postoperative instructions will be given following the procedure.
The signs of a vitreous detachment, potential retinal hole, retinal tear, and a retinal detachment are very similar. Only a dilated eye evaluation can tell the difference between them and the potential need for treatment. The onset of new floaters in an eye, the significant increase in the number of pre-existing floaters, new flashing lights, or loss of any peripheral vision should be reported immediately, so a prompt evaluation can be performed.
Our office phone (502-589-1500) is answered 24 hours a day, seven days a week. Do not hesitate to call because symptoms have occurred at night or over a weekend or a holiday. We prefer that you call us so that we can speak to you and decide when an evaluation should be scheduled. Do not go to an emergency room if you have visual changes. You will wait for hours in the emergency room and will be told that you need to see an eye doctor. Please call us at the onset, so we can determine if you have a problem that needs to be seen and how rapidly that needs to occur.