Macular hole

An untreated macular hole results in poor central (reading) vision then central blindness due to a hole at the very centre of the retina.

There was a time, not so long ago, that this condition was regarded as untreatable, and it was also a significant cause of legal blindness. In recent years, advances in technology with respect to vitrectomy micro surgery has turned the situation around.

 All our “detailed vision” is supplied by the tiny central retina area, called the macula. A macular hole, which is basically a tiny hole in the macula of the eye, causes devastating loss of central vision if not treated.

Macular holes tend to occur in those over 60 years of age and are slightly more common in females.

 The cause

The natural shrinkage of the vitreous which happens naturally with age is often the cause of a macular hole developing. Macular holes are caused by traction from the vitreous and often by traction from an underlying thin layer of scar tissue, which pulls on the retina in such a way that it causes a break (hole) in the retina. The same traction causes the macular hole to slowly enlarge.

The cure: macular hole surgery

The cure for a macular hole is vitrectomy surgery combined with removal of the vitreous and underlying layer of scar tissue (contracted internal limiting membrane). This removes the traction forces that are keeping the hole open. A large gas bubble is infused into the eye at the time of surgery, to help seal the macular hole. The bubble floats, therefore to put the “bubble in the trouble” (i.e. tamponade the macula with the flotation force of the gas bubble and hence cause closure of the macular hole), posturing with a head down position is required. To enable the gas bubble to work, the patient is asked to posture in a face down position for 30 up to 50 minutes out of every hour for the first five to seven days post-operatively. This surgery can be performed under local anaesthesia or general anaesthesia, depending on the patient and the anaesthetist’s choice. The surgery is performed as a day case.

The gas bubble

Having the gas bubble in the eye does not harm the eye but it does prevent you from seeing. During the post operative period, the gas bubble will get smaller and will disappear on its own. During this time a line will be seen which moves as you move the eye. As you move the eye up and down, the gas bubble will move around and this will change the vision, usually obscuring the vision when you look straight down. The gas bubble and normal intraocular fluid are acting like a spirit level within the eye. This line will gradually travel upwards over a period of weeks and eventually will disappear. Whilst the gas bubble is getting smaller, the gas bubble tends to break into multiple little bubbles (which is not a cause for concern). Whilst the gas bubble is in the eye, you should not travel to high altitudes (e.g. aircraft, mountains) due to the fact that it will expand at high altitude.

The benefits

When the macular hole seals, the visual distortion is alleviated and the central vision will improve. Dr Bourke’s audited results are that the hole seals in 99% of cases in Dr Bourke’s series.

Potential complications

In those patients who have not already had cataract surgery, most will develop a cataract within a few years of this surgery, which may require cataract extraction. A retinal tear is a possible complication (5%), and this is searched for and treated at the time of surgery with laser. It is very rare for a treated tear to cause problems, but if a tear does not adequately seal, it can result in a retinal detachment, which can decrease vision and does require further surgery. Complications that can occur in any intraocular surgery such as a haemorrhage and infection are extremely rare (1 in 5000). Please ensure that when you are posturing you do not put weight on the inner elbow for too long (the “funny bone” area). This can result in compression of the nerve and weakness of the fingers.

 Tips

• Talk to Dr Bourke’s reception staff regarding posture beds.
• Due to the time spent posturing while you are recovering, you may want to look into the possibility of obtaining some “talking” books for entertainment. These are available from local bookstores and most council libraries.

Amsler Grid Self Testing

Using an Amsler Grid to self-test your eyes will not only help detect symptoms of macular degeneration, but also macular hole symptoms as well. Today, the success rate for treating macular holes with vitrectomy surgery is extremely high, particularly if it’s detected early.

Dr Robert Bourke

Dr Bourke explains what a macular hole is.

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