Posterior Vitreous Detachment: Everything You Should Know About Flashes and Floaters
What Floaters Can Look Like
Floaters and flashes are a common problem the majority of the population will suffer at some point in their lives. Generally, they are completely normal and a part of the natural aging process. But on rare occasions they can be a warning sign for a vision-threatening condition—retinal detachment.
What is the Vitreous?
The vitreous is a gel-like fluid in the back of the eye, behind the iris and lens. It gives the eye its rigidity and keeps the retina pressed against the back wall of the eye. The vitreous is attached to the retina in two places: the optic nerve and the ora seratta, but it may stick to the retina in other places, as well.
The vitreous gets its consistency from being 99% water. The other components are vitrosin (a type of collagen), phagocytes, hyalocytes of Balazs and hyaluronic acid.
Phagocytes are white blood cells (part of the immune system) that clean the vitreous of any foreign debris, and the hyalocytes of Balazs recycle the hyaluronic acid. There are no blood vessels feeding the vitreous. All blood vessels in the back of the eye are contained within the retina.
How Age Affects the Vitreous: Flashes and Floaters
As we age, the vitreous liquefies and loses its gelatinous consistency due to the break down of vitrosin (collagen) and hyaluronic acid.
When the collagen breaks down, it sometimes forms chunks in the form of strings, worms, blobs, cobwebs and other shapes that float in the watery vitreous.
These “floaters” can be annoying, obstruct the vision, and are most noticeable against a white or solid background like the sky. They are sometimes accompanied by flashes of light, resembling a camera flash, in the periphery of the vision.
These flashes are caused by the vitreous collapsing and tugging at the retina, which causes the retinal neurons to fire, registering a flash of light in the brain. This collapse is called a posterior vitreous detachment.
Slit Lamp View of a Retinal Detachment
Occasionally, the vitreous can pull too hard on the retina and cause it to rip, leading to a retinal tear. These tears, if not treated, will allow fluid to build up underneath the retina (the typical immune response to injury) and create a retinal detachment.
Flashing lights and floaters do not necessarily mean you have a retinal detachment, and can often be mistaken with an ocular migraine. If you have these symptoms, you should see your ophthalmologist as soon as possible. The ophthalmologist will be able to catch a retinal tear before you can see it in your vision.
Do you, or someone you know, have floaters and flashes?
Asteroid hyalosis is a somewhat rare condition affecting about one in 200 people and usually only affects one eye. It is named for the calcium-lipid particles that float around in the vitreous collagen. These particles clump together in large chunks, giving the appearance of asteroids in space.
This condition typically affects humans, dogs, cats and chinchillas. When it appears in humans the patient does not typically see the asteroid bodies, but may still have some floaters. Upon examination, asteroid hyalosis can easily seen via the slit lamp in even an undilated eye (see video below).
There is no known cause for asteroid hyalosis, although it is often associated with diabetes, hypertension, and high cholesterol.
Treatments for Floaters
There are two treatments currently available for floaters. The first is a vitrectomy. This procedure is done on patients who have a retinal detachment, or large floaters that completely obstruct a portion, or all, of their vision when it floats into view.
The vitreous is removed and the vitreous cavity is filled with silicon oil. In the case of retinal detachment, a gas bubble is placed in the eye.
This surgery is not recommended for minor or annoying floaters. There is a long recovery time, and vision may not improve for three to six months after surgery.
The procedure is also quite invasivel, carrying a large risk for infections such as endophthalmitis, a nasty infection that can cause permanent vision loss in less than 24 hours. Most surgeons will only perform a vitrectomy on a patient with a vitreous hemorrhage or retinal detachment due to the surgery's invasive nature and risks of permanent vision loss.
The second treatment for floaters is laser treatment. There is only one surgeon in the U.S. who has the experience to treat floaters with laser. He is also the one who developed the technique; his name is Dr. John Karickhoff, and he practices in Virginia.
Dr. Karickhoff uses a YAG (Yttrium, Aluminium and Garnet) laser to vaporize the floaters. The technique takes about 20 minutes, and two treatments are usually needed.
The most important thing to remember is if you have just one or two floaters and flashes occasionally, there is really no reason to worry. If you notice a sudden increase in floaters, your one or two floaters turn into considerably more, and you notice the flashes have become more frequent, you should see your ophthalmologist right away.
Have you, or someone you know, ever had a posterior vitreous detachment, or a retinal detachment?
This content is for informational purposes only and does not substitute for formal and individualized diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed medical professional. Do not stop or alter your current course of treatment. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
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© 2012 Melissa Flagg COA OSC