Macular hole

The macula is a small area in the centre of the retina (the light-sensitive layer at the back of the eye), responsible for the detailed and central vision we need for activities such as reading and driving. A macular hole occurs when a tear forms in the central part of the retina. It can cause impaired vision, but in most cases can be cured by surgery.

People with macular hole will notice a difference in their central vision. Normally, one eye is affected, while the lateral (peripheral) vision remains unaffected.

Common symptoms may include:

• Blurred and distorted image;
• Straight lines appear twisted or curved;
• Difficulty reading, watching TV or working at close distances;
• A dark or empty spot in your central vision.

These symptoms will vary depending on the size and depth of the macula. You will not feel any pain and you will not lose your vision, but it is important to see an eye specialist if you notice these symptoms to ensure successful treatment.

It’s not always clear what causes macular hole, although it can be linked to other conditions such as:

• Prolonged swelling of the macula (known as cystoid macular oedema);
• Trauma to the eye;
• Retinal detachment;
• Toliaregia (hyperopia);
• Severe myopia (myopia).

Another cause is related to abnormalities in the vitreous, a gel-like fluid that fills the eye and is attached to the retina by many tiny fibres. As we age, the vitreous begins to shrink and move away from the retina – this is perfectly normal and usually does not cause any problems.

In most cases, the causes of macular hole formation are unknown, but it is thought that as the vitreous gelatinous mass moves from the back of the eye (a process called posterior vitreous detachment), the more strongly attached areas of the retina may start to pull on the macula, causing the hole to open.

If you experience any of the above symptoms, it is important to see an eye specialist as soon as possible. If they suspect that you may have a hole in your macula, they will refer you to a specialist (ophthalmologist) for further tests.

The ophthalmologist will use pupil dilating drops to allow a clear view of the back of the eye and perform an optical coherence tomography (OCT), which shows the thickness and structures of the retina in great detail. This will help to confirm or exclude the diagnosis of macular hole or other disorders.

If the specialist determines that you have a hole in your macula, treatment will be prescribed, if necessary, and the eye will be kept under observation for several months.

If the macular hole is at an early stage, ophthalmologists usually decide to monitor the eye for a while to see if its condition changes over time.

If treatment is needed, surgery is usually performed to repair the hole and improve your vision. However, in most cases your vision will not be the same as before.

Vitrectomy is the name given to surgery to correct a macular hole. The operation involves removing the gel mass in the vitreous and replacing it with a gas bubble to promote healing of the macular hole. Removing the vitreous prevents stretching of the retina and the bubble easily seals the hole, thus stimulating the healing process – similar to a bandage.

The gas bubble will interfere with your vision in the beginning, but over a few weeks the bubble will diminish and eventually disappear. During this time, your eye will naturally produce more fluid to take the place of the gas bubble.