Vitreous detachment is typically seen in elderly individuals. The retina receives light signals and transmits them to the optic nerve which is connected to the back part of the brain, where light signals are interpreted and images are formed by the brain. The vitreous is composed of about 99% water and 1% collagen, hyaluronic acid, special substances and fibers that attach to the retina. It comprises about two-thirds of the eye.
The vitreous serves many functions:
- maintains the shape of the eye
- serves as a shock absorber
- cushions the eye against any blows or pressure applied to the eye
- helps keep the retina in contact with the membrane at the back of the eye
- enables transmission of light to the retina
Because the vitreous has the consistency of gelatin, like gelatin, it tends to dry out and shrink with age. As it shrinks, it often detaches from the retina. This is a very common occurrence in elderly people. Rates of vitreous detachment begin to increase in the fourth and fifth decade of life, and rates reach as high as 75% by the sixth decade of life and 86% by the ninth decade of life.
Usually vitreous detachment does not cause a serious problem. But it can. The vitreous is attached to the retina by a collection of fibers. As it shrinks and separates, the fibers do not always detach gently. In some cases they remain attached to the retina and pull on it. This can cause tears, holes or an entire detachment of the retina. Retinal tears, retinal holes and retinal detachments can cause serious vision problems, and, in some cases, even blindness. The vitreous can also liquefy during the process, known as “Synchysis.” Or it can collapse, known as “Syneresis.”
Causes and Risk Factors
Causes and risk factors for a vitreous detachment include the following: age, nearsightedness greater than six diopters, a history of cataract surgery, inflammation in the eye, bleeding inside the eye, blunt force trauma to the eye, and a previous vitreous detachment in the other eye within the preceding year. The condition is somewhat more common in women than in men.
The most common symptoms of a vitreous detachment are floaters and flashes. Floaters are small particles in the vitreous that are ordinarily stationary. As the vitreous pulls away from the retina, the floaters begin to move through the liquefying vitreous and new floaters may be created. They appear in the visual field as small spots or dots, or cobwebs, or a “swarm of bees” that seem to dash off if one tries to focus on them. Usually a vitreous detachment will be accompanied by a swarm of floaters that will then dissipate if the retina has not been damaged.
Flashes resemble lightning or fireflies or disco lights. The retina has no nerve signals for pain, but if parts of the vitreous tug on the retina, these tugs are interpreted as light signals by the retina. Flashes will also usually be plentiful during a vitreous detachment and will also usually abate if the detachment is non-problematic.
Less commonly, people may also experience a ring of floaters or flashes at the edge of the visual field. Or the edge of the visual field may appear gray and cloudy. This grayness may slowly creep in to encompass central vision as well.
Ordinarily, vitreous detachments are uncomplicated and require no treatment. But in 7% to 15% of cases, there will also be a retinal tear, a retinal hole or a retinal detachment. Such conditions are serious. If the vitreous exerts enough force on the retina to create only small tears, the retina will proliferate glial cells to attempt to heal the tears. In this case, the extra layer of cells can diminish vision. The risk of retinal detachment is greatest in the first six weeks following a vitreous detachment, but one can occur even several months after the event.
If you experience a sudden increase of flashes or floaters it is very important to see an opthalmologist immediately. If an uncomplicated vitreous detachment is underway, it can only be diagnosed through a close examination of the back of the eye done with dilation of the pupil. If it is uncomplicated, the opthalmologist will most likely suggest you return for another exam in four to six weeks to ensure a retinal tear or detachment has not also occurred.
Uncomplicated vitreous detachments require no treatment and the only residual effect will usually be a couple of additional floaters in the visual field. However, if a problem with the retina has developed, then a surgical procedure may be necessary to repair the retina. Retinal repairs can be done with lasers, with surgical implants or with cryopexy (freezing). An ophthalmologist can let you know what would be most appropriate in your case. The potential retinal problems associated with vitreous detachment are why an eye exam is urgent if you notice an increase in flashes or floaters. Retinal problems have a much better prognosis with early treatment, and left untreated, they can create serious and permanent vision problems.
Maintaining Eye Health
While vitreous detachment is a frequent occurrence in later life, it may be prevented or its effects may be mitigated by maintaining proper eye health. The lifestyle habits that maintain the rest of the body, such as attention to diet and exercise will also help to preserve vision. But you can also take supplements that have been specifically shown to help maintain eye health and/or to retard the aging process. A compound found in bilberries, known as anthocyanosides, has been shown in a number of studies to protect the eye and retina from damage. It has reversed early cataracts and given people with macular degeneration significant vision improvement. Other useful nutrients include tumeric, omega-3 fatty acids, lutein, zeaxanthin, astaxanthin, vitamin D3, alpha lipoic acid, grapeseed extract and gingko biloba.