Seeing dots & lines
You are definitely not seeing things. They are called floaters and are common as we age. However, these can become an emergency if later on a retinal tear or detachment occurs.
BY: Eleanor Yap
You are seeing flying lines or dots in your field of vision and you wonder what is happening. These are called floaters and commonly occur as we age. But when should red flags come up?
Ageless Online speaks to Dr Gavin Tan, consultant, Vitreo-retina service, Singapore National Eye Centre (SNEC), to explain why floaters occur and when a more serious problem such as a retinal tear or detachment can happen:
What exactly are spots and floaters, and why do they occur?
Floaters are flying lines or dots that you may sometimes see moving in your field of vision. You usually see floaters when you are looking at a plain bright background, such as a blue sky. The inside of your eyeball is filled with a clear transparent jelly-like fluid called the vitreous.
Floaters result from the normal ageing process where the vitreous degenerates and liquefies. During this degenerative process, tiny clumps of gels or cellular debris will accumulate in the liquefied vitreous. These cast shadows on the retina, the image-sensing layer of the eye, giving the perception of floaters appearing in front of the eye.
Will they fade over time and become less bothersome? What are some ways people can deal with these floaters and dots?
As the vitreous continues to degenerate and liquefy, the floaters will become less obvious. Furthermore, the visual centre in the brain will begin to ignore these chronic floaters with time and as a result most people will notice them less, and less often. Floaters and flashes are caused by ageing and cannot be prevented.
What is the significance of flashes, which are associated with floaters?
Once the vitreous liquefies, the peripheral vitreous gel, which was attached to the retina, will pull on the retina. As a result, you may see what looks like flashing lights or lightning streaks. These are called flashes. You may have experienced this same sensation if you have ever been hit in the eye and seen “stars”. The flashes of light can appear off and on for several weeks or months. Like floaters, flashes are generally harmless and require no treatment.
However, sudden new onset flashes should be assessed by your ophthalmologist in order to rule out more serious problems. Some neurological (brain) conditions such as migraines can also cause the perception of flashes. Therefore if your flashes are associated with other neurological symptoms such as headaches, you should consult a doctor.
When do these floaters and flashes become a medical emergency?
Floaters and flashes are only a matter of concern if the degenerated vitreous pulls away from the retina and tears it. The retina is the inner light-sensing layer of the eye responsible for image perception. The traction on the retina can result in the perception of light flashes or photopsia. Tearing of the retina can also cause bleeding or release of pigment and cellular debris in the eye, and may appear as new floaters.
Retinal tears if untreated may develop into a retinal detachment, which can cause vision loss and blindness. Therefore, it is important to see your eye doctor when you see a sudden onset of many new floaters or flashes.
Can you explain more what a retinal tear or detachment is?
The retina is the light-sensitive tissue lining the back wall of your eye. This thin layer can be torn by the age-related contraction of the vitreous or by other causes such as trauma. Retinal detachment occurs after a tear in the retina develops, allowing fluid to pass through the break and eventually separating the retina from the wall of the eye.
Over time, the detachment may cause the retina to lose contact with the nutrient supply of the eye and it will stop functioning. This is when you lose your vision. Therefore, if not treated early, retinal detachment may lead to partial or complete permanent loss of vision.
Who are particularly at risk for this?
Your risk increases if you:
- Are over 40 years old.
- Have had retinal detachment in one eye previously.
- Have myopia (shortsightedness).
- Have family history of the retina detachment.
- Have had previous intraocular eye surgery.
- Had sustained severe eye injury or trauma in the past.
How many cases has SNEC dealt with last year of retinal tears or detachments particularly for those 50 and above?
We perform retinal detachment surgery on more than 300 cases every year. About 60 percent would be in patients aged 50 years and older.
If one has a retinal tear or detachment, what are the current and new treatments?
The current treatment for retinal tears without detachment is laser photocoagulation. Laser photocoagulation can seal retinal tears by using a laser light to burn the edges of the retinal tear. The resultant scarring will adhere the retina to the underlying tissue permanently.
Surgical repair is necessary once a retinal detachment has occurred. There are two types of surgeries to deal with this. A scleral buckle involves sealing the retinal tears with a silicone material, which is placed around the sclera (the tough white protective tissue of the eyeball).
The second type of operation is a vitrectomy for more complex cases of retinal detachments. A vitrectomy involves removing the vitreous (the jelly-like substance in the eye cavity) and filling the eye with a gas bubble to hold the retina in place, giving it time to heal. Patients will be required to position themselves in a certain way at home for a while after the surgery to allow the gas bubble to float upwards and flatten the retina.
Occasionally, more than one operation may be required. The degree of vision that returns six months after successful surgery will vary. At SNEC, over 95 percent of all retinal detachments are reattached after treatment. More than 85 percent require only one surgery to reattach the retina.
What are some ways to prevent a retinal tear or detachment besides a yearly check-up on the eyes?
You can’t change the risk factors for retinal tears such as age and shortsightedness. Avoiding eye trauma is the only modifiable risk factor for tears and detachment. Therefore, the key is to diagnose retinal tears early and treat them before they result in detachments that cause permanent visual loss.
You should seek early medical attention for an eye examination if you have acute or new onset floaters and flashes, or a sudden increase in previous stable floaters, as this may be the early sign of a retinal tear. Any persistent blurring of vision associated with flashes and floaters also requires early eye examination. This will allow your ophthalmologist to diagnose and treat your eye condition before any permanent damage is done. Even if a retinal detachment has occurred, early surgery will improve the eventual visual outcome for the patient.
(** PHOTO CREDITS: SNEC)