It’s a description I’ve heard many times in my practice – worms, spiders, flies – and they usually indicate the same problem: floaters.
Floaters typically appear when tiny pieces of the eye’s gel-like vitreous break loose within the inner back portion of the eye. When we’re born and through our youth, the vitreous has a gel-like consistency. As we age, the vitreous begins to dissolve and liquefy to create a watery centre.
Some undissolved gel particles will occasionally float around in the more liquid centre of the vitreous. These particles can take on many shapes and sizes to become floaters. This can sometimes be disturbing as the floaters shift as we move our eyes and head.
One or more floaters may appear as lines or cobwebs. But if the numbers increase from a few to many, or if you see flashes of light or “falling stars”, or worse a “black curtain”, you should seek an ophthalmologist’s opinion as such signs may indicate a tear in the retina – the layer of nerves that send visual impulses to your brain telling you what you see.
Most of the time, these floaters do not cause problems except to fill our time trying to chase away these disturbing images. I’ve seen my grandmother try to swat a fly that she says is always flying around her.
Needless to say that can prove unsettling, but there is hope because floaters slowly fade, and you rarely see them unless you’re looking at bright light or a clear blue sky.
Risk of getting floaters
Floaters are age-related, so it may be seen quite commonly in individuals over the age of 50. But individuals who are near-sighted may notice it earlier in life.
It’s also common for people who’ve experienced trauma or injury to the eye, and even for patients who’ve undergone cataract surgery.
All this goes to show that floaters are quite common.
An October 2015 study published in the journal Ophthalmology revealed that, among people who experienced the sudden symptom of eye floaters and/or flashes of light, 39.7% had a posterior vitreous detachment (PVD) and 8.9% had a torn retina.
Other research has shown that up to 50% of people with a retinal tear will subsequently develop a detachment of the retina, which could lead to significant vision loss.
In cases of retinal tear or detachment, treatment must take place as soon as possible so that an eye surgeon can reattach the retina and restore function before vision is lost permanently.
PVDs are far more common than retinal detachments and are often not emergencies, even when floaters appear suddenly.
Some vitreous detachments can also damage the retina by tugging on it, leading to a tear or detachment.
Light flashes, known as photopsia, can occur when your retina receives non-visual (mechanical) stimulation, which can happen when it is being tugged, torn or detached. These light flashes may appear as lightning bolts, flickering lights or random sparks.
Causes of floaters
As mentioned above, PVDs are common causes of floaters. Far less commonly, these symptoms can be associated with retinal tears or detachments that may be linked to PVDs.
But what leads to vitreous detachments in the first place?
As the eye develops, the vitreous gel fills the inside of the back of the eye, pressing against the retina and attaching to its surface.
Over time, the vitreous becomes more liquefied in the centre. This sometimes means that the central, more watery vitreous cannot support the weight of the heavier, more peripheral vitreous gel.
The peripheral vitreous gel then collapses into the central, liquefied vitreous, detaching from the retina (like jelly that’s not properly formed separating from the inside of a mould or bowl, leaving tiny chunks behind).
Eye floaters resulting from a PVD are then concentrated in the more liquid vitreous found in the interior centre of the eye.
It’s estimated that more than half of all people will experience a PVD by age 80. Thankfully, most of these PVDs do not lead to a torn or detached retina.
Light flashes during this process mean that traction is being applied to your retina while the PVD takes place.
Once the vitreous finally detaches and pressure on the retina is eased, the light flashes should gradually subside.
Treatment for floaters
In most cases, treatment is not necessary as these floaters will fade over time.
In the past, the only treatment for eye floaters was an invasive surgical procedure called a vitrectomy.
In this procedure, some or all of the vitreous is removed from the eye (along with the eye floaters within it) and is replaced with a sterile clear fluid.
But the risks of a vitrectomy usually outweigh the benefits for eye floater treatment.
These risks include surgically-induced retinal detachment and serious eye infections. On rare occasions, vitrectomy surgery can cause new or more floaters.
For these reasons, most eye surgeons do not recommend vitrectomy anymore to treat eye floaters and spots.
Recently, a laser procedure called laser vitreolysis has been introduced that is a much safer alternative to vitrectomy for eye floater treatment.
In this in-office procedure, a laser beam is projected into the eye through the pupil and is focused on large floaters, which breaks them apart and/or frequently vapourises them so they disappear or become much less bothersome.
However, it is always best to first and foremost get an opinion from your ophthalmologist, who will do a routine eye examination to rule out any problems like holes and tears in your retina.
If there are none, there’s simply no need for any treatment at all.
So, once you know the floaters will cause no problems, you can eventually learn to ignore them, and trust me when I say you will see them less often.