What is a macular hole?

RetinaRest

A macular hole is a tiny hole in the centre of the macula, usually less than half a millimetre across. Unfortunately, this part of the macula (the fovea) provides the most detailed vision. As a result, patients with a macular hole usually cannot read with the affected eye. If the other eye is unaffected, this may not be noticeable. All too often, though, the poor vision in the affected eye interferes with the better eye. Many patients with a macular hole close the affected eye when they read or are trying to look at a distant or small object.

The cause of a macular hole is unknown, but it is widely thought to be due to a physical pulling open of a hole by the back of the vitreous gel. This vitreous gel normally fills the back of the eye and is in contact with the whole of the retina, including the macula. The back of the vitreous gel, when still in contact with the macula, is believed to pull outwards and away from the centre of the macula. Over a period of time, this pops a hole open in the centre of the macula (fovea). Sometimes people notice this as it happens; others notice it at a later stage. Some people are unaware of a visual problem until they close the better eye or visit an optometrist. The hole progressively gets bigger but generally does not progress to complete loss of vision. Most patients see the top letter on the vision test chart or better.

There are two areas of vision affected by macular holes, which are related to the two areas of abnormality in a macular hole. You are likely to be shown an OCT scan by your surgeon; this is a cross-sectional image of your macula and there is usually an obvious gap in the retina (macular hole) and an area on each side where the macula is thicker than normal. The black areas within the macular retinal image are where there is excess fluid in the retina. The macular hole itself usually results in a total loss of central vision and the thickened area outside causes vision to be blurred and distorted around the central missing area in your vision.

In the earliest stages of development, a small proportion of macular holes, at the earliest stages, will close on their own. However, most patients' macular holes have passed this point by the time they are first seen by vitreoretinal surgeons, leaving surgery as the only realistic option for improving vision. More than 9 out of 10 macular holes are closed with surgery, with almost all seeing less distortion or blurring off-centre. About 7 or 8 out of 10 patients also see more in the central area of their vision.