The eye is rather like a ball filled with a fluid called vitreous gel. This fluid is very jelly like and gradually shrinks and shrivels with age. In a normal eye, the vitreous gel is attached to the optic nerve head at the back of the inside of the eye, and as the gel shrinks, this attachment will eventually break. This is known as a Posterior Vitreous Detachment and is essentially a normal and common ageing process.
When the vitreous detaches, most people are aware of the sudden appearance of vitreous floaters, like black or grey spots that float in front of your vision. These can be quite large and may be disconcerting, and are sometimes accompanied by flashes of light out in the edge of vision, usually only noticeable in the dark.
In a small number of people, probably about 1 in a 1000, as the vitreous detaches it can drag on the retina and cause a Retinal Detachment. This is potentially serious and needs the urgent attention of an eye surgeon.
So, a posterior vitreous detachment on its own is not sight threatening, but because of the risk of retinal detachment, everyone who presents with the sudden onset of flashes and / or floaters must be examined very carefully to exclude a retinal detachment.
What should I expect?
Patients will be offered an immediate appointment.
When we examine a patient who complains of flashes or floaters we will use eyedrops to dilate the pupils of both eyes. This permits a much better view of the inside of the eye but will leave the eye quite blurry and very sensitive to bright lights for several hours. You may be unable to drive during this time.
The inside of the eye will be examined very carefully and if there are signs of damage to the retina you will normally be referred directly to eye casualty for urgent assessment.
Even if there are no signs of damage to the retina, our examination cannot see all of the inside of the eye and so you may be referred to an eye specialist routinely, just to confirm the diagnosis, and for a more in-depth examination. Sometimes we will offer to do a follow up appointment if it is more convenient for you and if your doctor agrees.
The Standard Warning!
Everyone who has recently had a Posterior Vitreous Detachment is given the following advice in case they develop a retinal detachment.
If the floaters get worse or ff the flashes get worse or if your vision is generally getting worse and in particular if you get the appearance of a ‘curtain’ or ‘shadow’ in your vision; you should seek medical advice urgently.
Eye casualty is located in the Claremont Wing of the Royal Victoria Infirmary in Newcastle and is normally open 8.30am to 4.30pm weekdays, and 8.30am to 11.30 am on Saturdays. At other times contact your usual out of hours medical service.
Will the floaters go away?
The floaters will usually break up a bit in time and become less troublesome, and most people begin to ignore them, but they rarely disappear completely.
What about my other eye?
In most people, the other eye in time will develop a vitreous detachment, and they will require the same sort of examination.
Flashes & floaters are usually as a result of normal age –related changes but as they can occur due to serious problems everyone with these symptoms must be examined as soon as possible to exclude potentially sight threatening damage.
If you are unable to attend your optometrist, then you should consult your family doctor or attend eye casualty.
NHS Direct is a useful source of advice outside of normal hours.
Useful telephone numbers:
Eye Casualty (RVI switchboard ask for Eye Casualty): 0191 2336161
NHS Direct: 0845 4647 www.nhsdirect.nhs.uk