Myodesopsia: the familiar eye floaters
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Have you ever been in a very bright environment, seen something like a fly passing across your vision and tried unsuccessfully to brush it away? Repeating this over and over again? Yes, these are myodesopsias, the familiar eye floaters, and they are inside your eye. Here we explain what they are and what to do when they appear.
What are eye floaters?
The vitreous humour is the gel-like substance that fills the eye cavity behind the natural lens and in front of the retina. As we age, the vitreous humour can change in consistency, forming small cavities and opacities in the form of floating particles that cast shadows on the retina, giving rise to the perception of floaters. These opacities appear gradually and in limited numbers, so they should not be numerous.
With age, this gel-like substance loses its consistency and separates from the retina, causing what is known as posterior vitreous detachment which leads to the sudden appearance of a central cobweb. At that point, the patient may also see flashes or streaks of light. These raise strong suspicion of a retinal tear or break and therefore require a thorough examination of the back of the eye. A tear in the retina has a high probability of leading to retinal detachment, a disease that can devastate vision if left untreated.
What other causes can produce eye floaters?
Besides age, the second most common cause of floaters occurs in patients who are short-sighted because of the particular shape of their eyeball; floaters can be numerous in these patients.
Other common instances of seeing floaters occur in patients who have had cataract surgery, because more light reaches the retina after removal of the cataractous lens, and in those who undergo a posterior capsulotomy, because remnants of the capsule can remain floating in the front part of the vitreous.
Finally, other less common but no less important causes include haemorrhages, particularly in patients with diabetes, inflammation inside the eye and tumours.
Currently, there is no treatment to eliminate floaters. At first, patients generally describe them as constant and very bothersome, but over time they usually become intermittent and disappear depending on the lighting conditions.
If you suspect you have eye floaters and need ophthalmic advice, please get in contact with us.