Macular holes are a relatively uncommon cause of reduced vision. They can occur in a range of age groups but are more common in people in their sixties and seventies. Macular holes tend to occur more often in women than men.

What is a macular hole and how does it affect my vision?

In order to see clearly, light from an object has to be focused by the optical elements of the eye onto the retina. The retina is a thin layer, about the thickness of a piece of tissue paper, which is adherent to the inside wall of the eye.

There are certain parts of the retina, which perform different visual tasks. For example the retina towards the front of the eye is best used for detecting objects in the dark. Another small part of the retina is the macula. The macula is that part of the eye we use for such visual tasks as reading, driving, watching TV and other fine visual tasks. A hole in this part of the retina is called a macular hole.

How do macular holes from?

No one knows how holes develop in the macula. Some experts believe that the thin membrane lying on the surface of the retina can develop abnormal connections with the macula. It is thought that if these membranes contract the retina can become elevated and with continued traction a small tear in the retina may occur.

If this tear enlarges, a full thickness macular hole can develop. The evidence for this theory is attractive and many patients with macular holes have abnormal membranes in their eye and one can often see the macula is pulled forwards.

What are the risk factors for development of macular holes?

We have already mentioned that macular holes occur more commonly in women than men and that age is a factor. People with macular holes in one eye also have a greater risk of developing a hole in their other eye than unaffected individuals. It is not certain how many people develop a macula hole in their other eye and reports range from 5-20%.

Some reports have suggested there is a higher incidence of macular holes in women who have had a hysterectomy and who are on hormone replacement therapy. However, there are no reports suggesting discontinuing hormone replacement decreases the risks of hole development and most authorities do not advise stopping therapy.

Is there a treatment for macular holes?

During the mid 1990s, micro-surgical techniques were developed which have proved useful in some patients with macular holes.

It has been known for many years that the vitreous can be safely removed from eyes. In macular hole surgery the vitreous is first removed (vitrectomy). This enables the surgeon to access and remove the membranes holding the macular hole open. Once the traction is released the hole can be closed.

The success of the surgery is dependent on the hole remaining 'sealed'. It has been found a gas bubble placed in the eye at the end of the surgery will hold the macular hole closed providing the bubble is positioned against the macula.

How long is the recovery period?

Macular hole surgery can be performed under local or general anaesthesia. The eye may a feel a little gritty and uncomfortable following the surgery but pain is rare. For the first 10 days following the surgery the patient lies in face down position while the eye heals. This means at night the patient has to sleep on his or her stomach and during the day hold their head in such a position that their nose is directed towards the floor, that is FACE DOWN.

This difficult position has to be religiously adhered to for the operation to succeed and requires a commitment to adopt this posture for 23 hours out of every day. An hour off a day barely allows time for meals, dressing, going to the bathroom etc.

Although the gas bubble needs only to hold the retina in place for 10 days, the bubble usually takes up to six to eight weeks to disappear from the eye. During this time one is unable to fly in an aircraft (because of pressure problems). However 'posturing' is not required beyond the 10-day interval although it is best not to lie on one's back while the gas bubble is in the eye.

Success rate

Patients with macular holes can usually only see the top line on a standard visual acuity chart. With successful surgery vision is improved but it is rare to regain normal sight. Providing the macular hole stays closed, vision should improve to approximately half way down the vision chart. That is 6/12 or 20/40. Normal vision is 20/20.

The complications of macular hole surgery include failure to keep the macular hole closed, usually due to incorrect posturing. Other complications include cataract development, retinal tears and retinal detachments. Infection is rare but is another potential problem. Most of these listed complications require additional surgery and expense.

Unfortunately with such complex eye surgery if the complication is severe and not quickly treated the eye may become blind.

For further information and support talk to an optometrist or eye specialist. Optometrists are listed in the "Yellow Pages" of your telephone book. Eye specialists are listed with registered medical practitioners at the front of the white pages of your telephone book.

Original material provided by Auckland Eye, 2005. Reviewed by everybody.