What is posterior vitreous detachment?
The middle of the eye is filled with a clear, jelly-like substance called the vitreous. The vitreous is attached to the retina, particularly in certain areas such as the vitreous base and the optic nerve. As we age, the vitreous becomes watery, less jelly-like and begins to detach and move away from the retina at the back of the eye (posterior means back). This is a normal ageing process known as posterior vitreous detachment (PVD).
PVDs are very common.
By the age of 65, almost 75 per cent of people will develop a PVD.
PVD can occur at an earlier age in certain conditions.
A posterior vitreous is different to a retinal detachment, although the two can be related.
Although it can cause some frustrating symptoms, PVD won’t cause you pain or change the way your eye works.
Symptoms of posterior vitreous detachment
The most common symptom of PVD is a sudden increase or change in floaters. You may also notice flashes of light. The symptoms of PVD will change over time and usually settle down over about six months. Occasionally, the floaters caused by the PVD can last for a year or longer.
What are floaters?
Floaters can take many different forms, shapes, and sizes. You may see them as dots, circles, lines, clouds, or cobwebs in your vision. Sometimes, floaters can move around quickly. At other times it can feel like they hardly move at all. You may find floaters are more obvious in bright light or on a sunny day.
Floaters can be due to condensations of the jelly-like substance in the vitreous from the PVD. These cast a shadow on the retina and are seen as floaters. Other causes of floaters include inflammation and infection, so it’s important to have an eye exam to exclude these conditions.
Many people have floaters even if they don’t have PVD or an eye condition. Floaters generally will become less noticeable with time as your brain learns to ignore them.
Flashes of light
Flashes of light occur when the vitreous pulls away from the retina, tugging on it. The retina reacts by sending a small electrical signal to your brain. You see this as short, small, flashes of light.
In the long term, you are unlikely to see these flashes because once the vitreous has fully pulled away, it no longer tugs on the retina.
Posterior vitreous detachments can be associated with other more serious conditions which have similar symptoms but require urgent attention. The only way to tell whether these floaters and flashes have been caused by PVD or something else is to have your eyes examined by an optometrist or ophthalmologist. They’ll advise you when to return for review appointments and any additional symptoms to look out for.
Diagnosis of PVD
PVD is diagnosed by a comprehensive eye examination with an optometrist or ophthalmologist. Your eye health professional may dilate (enlage) your pupils using eye drops to examine the retina at the back of your eye. After your pupils have been dilated, it’s normal for your eyes to be blurry and sensitive to light for a few hours. You shouldn’t drive while your eyes are still dilated.
Retinal photographs are commonly used as part of the eye examination. They provide a detailed image of your retina and a basis for comparison for future eye exams.
Treatment and complications of PVD
In most cases, PVD is non-sight threatening and there’s no recommended treatment.
In some rare cases, the vitreous pulling away from the retina can cause a retinal tear or traction at the macula. If these occur, your ophthalmologist may suggest treatment including laser or a vitrectomy to prevent vision loss. When you have your PVD examined by the ophthalmologist, they will look for any complications and will advise you of symptoms to look out for.
Coping with posterior vitreous detachment
You may find floaters frustrating as they get in the way of seeing things and can make activities, such as reading, more difficult. You may find it helpful to look to the side and back to what you were looking at as this can sometimes move the floater out of your direct field of vision.
Making things bigger can also help while you have floaters so that you’re able to see things around the blank spots the floaters cause. Sunglasses may also help make floaters less noticeable in bright conditions.
Most people find that over time the floaters become less of a problem and they don’t need any special adaptations.
Ask your eye health professional whether your PVD will restrict any of your daily activities – in most cases it won’t. However, you may find that some activities make your floaters more noticeable. This is due to the movement of the activity rather than a change in your eye, so you may want to wait until your floaters have settled down.
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