Macular Holes
Macular Holes
It can be very scary if vision in one of your eyes suddenly becomes blurry and distorted, as may happen with development of a macular hole.
To understand how macular holes, occur, it’s important first to know a little about eye anatomy. The macula, where holes sometimes develop, is a very small spot in the centre of the back of the eye (retina). Light focuses to a sharp point at the macula, which is the only area of the eye that sees crystal clear, colour vision (such as for driving or recognizing faces).
The macula also is full of light-sensitive cells called cones. The entire rest of the retina is made up of photosensitive cells called rods that see black and white shading, shape and movement (such as for night vision and side vision).
Macular Hole
Because macular holes often are related to aging processes, they are more likely to develop if you are over age 60. Also, women have a slightly higher risk for macular holes than men.
When a macular hole develops, most people notice a sudden decrease in vision in one eye.
Macular holes, tears and cysts are not the same as another age-related eye disease called macular degeneration, which also occurs more frequently among those over age 60.
Macular holes can occur due to:
- Vitreous shrinkage and/or separation
- Diabetic eye disease
- High amounts of near-sightedness (myopia)
- Macular pucker
- A detached retina
- Best’s disease (inherited condition causing macular damage)
- Eye injury
Macular Hole Caused by Vitreous Shrinkage And/or Separation
The back of your eye is filled with a rather thick, gel-like material called the vitreous humour (also called the vitreous body or the vitreous) that helps your eye keep its shape. The clear vitreous shrinks and becomes more liquid with aging, causing it to slosh around.
Because the vitreous is attached to the retina with tiny strands of cells, it can pull on the retina as it shrinks. Sometimes, this shrinkage can tear off a small piece of the retina, causing a hole. If this missing piece of retina is in the macula, it’s called a macular hole.
Another direct cause of macular holes due to vitreous shrinkage is when the strands stay attached to the retina and break away from the vitreous. These strands can contract around the macula, causing the macula to develop a hole from the traction.
In either case, fluid develops where the vitreous shrinks to fill the spaces. This fluid can seep into a macular hole, causing blurred and distorted vision.
Macular Hole Progression
Left untreated, a macular hole can worsen over time. Macular holes occur in three stages:
- Foveal detachments — about 50 percent worsen without treatment.
- Partial-thickness holes — about 70 percent worsen without treatment.
- Full-thickness holes — most worsen without treatment.
A macular hole sometimes can resolve without intervention, but most should be treated to prevent permanent vision loss.