Macular Hole

A macular hole occurs when a hole or gap forms, usually in the center of the macula. The macula is the most sensitive part of the retina and is crucial for sharp central vision.

Symptoms of a macular hole include blurring of central vision, or visual distortion (seeing straight lines as abnormally curved or "wavy").

There are no proven preventive measures for this condition.

What causes macular holes?

Macular holes usually occur due to stress on the macula. When we are young, the vitreous (the clear gel-like substance in the eye) is attached to the retina and macula. As we age, at some point in our lives, the vitreous will usually detach from the macula and the posterior retina, which is called a posterior vitreous detachment (PVD). PVD can cause symptoms of floaters and flashes for a few weeks, but in most cases does not cause any major problems. However, in some patients, the process of PVD causes stress on the macula, causing a macular hole to form.

Another cause of macular holes is high myopia (short-sightedness), where the elongation of the eyeball causes stretching and thinning of the retina, and puts stress on the macula, causing a hole to form.  Occasionally, macular holes can also be caused by physical trauma to the eye.

Macular Hole

Optical coherence tomography (OCT) scan showing a Macular Hole 

The best way to diagnose the problem is through an eye examination. Your ophthalmologist will administer eye drops to enlarge (dilate) the pupils temporarily so that they can examine the retina and macula. Usually, you will also undergo an optical coherence tomography (OCT) scan, which will provide a detailed cross-sectional image of the macula, which confirms the diagnosis of a macular hole. An OCT scan is very fast and convenient. The light beam used for scanning is painless, and unlike X-rays, it does not involve any radiation.

Most full-thickness macular holes will require surgical treatment. Surgery for macular holes involves a vitrectomy, a form of "keyhole" surgery that uses small instruments to enter the eye to remove the vitreous gel. In most cases, the innermost thin layer of the retina is peeled off, to relieve stress on the macula and to allow the hole to close.  Usually, a gas bubble is injected into the eye at the end of surgery, to replace the vitreous gel, and to maximise the chances of success.

The rates of surgical success and improvement in vision vary from person to person and ranges from 60% to 80%. The likelihood of hole closure and the amount of vision improvement depend on the size of the hole, and how long the symptoms and hole have been there for, prior to surgery.

Following surgery, if a gas bubble was injected, your doctor may instruct you to maintain a specific head position (usually face-down) for up to two weeks after surgery, and you would also need to avoid air travel until the gas bubble dissolves. The eye will refill naturally with fluid over time.

Eye drops will be dispensed after surgery, and should be used as prescribed. Good eye hygiene and avoiding injury to the operated eye are important to reduce infection and problems after surgery.