What is the macula?
The macula is the area of retina at the very centre and is responsible for very fine vision, the macula gives you your central vision. Diseases of the macula cause what we call a scotoma ie a black / blurred area in the centre of your vision. It may also cause distortion ie wavy lines.
What is a macula hole?
A Macula hole is a defect in the retina at the macula in the shape of a circle. The retina in this circle no longer works as it is missing. This means you may have difficulty recognising faces and also reading. You may not notice the problem with both eyes open.
What causes it?
No one knows the exact cause but it is thought that the hole is caused by the vitreous gel pulling on the retina and causing a hole to form. This only affects the central vision and does not cause blindness.
It is more common in women and tends to affect only one eye. The risk to the other eye of developing a macula hole is 10-20%.
What can be done?
Surgery for macula holes is very successful. Recent advances have enabled us to perform this procedure without prolonged face down positioning, I currently suggest 3 days. A recent audit of my results showed that over 90% of holes closed and 66% of patients gained vision.
What is involved in surgery?
This entails a vitrectomy (removal of the vitreous), peeling of a very fine membrane (the internal limiting membrane) and insertion of a gas bubble into the eye. The theory is that the traction from the vitreous gel is removed and the gas bubble floats against the hole to encourage closure.
What happens after surgery?
In order for the gas bubble to press on the macula hole the patient is requested to ‘position’ face down ie with the nose pointing at the floor (either sitting up with head on a pillow or lying face down) for 45mins per hour ie 15 mins rest per hour. This positioning is done at home for 3 days. You will be asked to put drops in for at least 4 weeks and your vision will be blurred for at least 2 weeks.
The first post operative visit is at 2 weeks then 6 weeks, 3 and 6 months.
What is the success rate and risks?
The success rate of surgery is approx. 90% but is dependent on many factors, mainly the size of the hole and how long it has been there. Once the hole closes approximately 2/3rds of patients notice some visual improvement.
The risks of surgery are small, the main complication being:
detached retina < 5%
loss of vision < 0.1%.
Most patients develop a cataract and this is treated in the routine way.
However if you already have a cataract both operations can be done together.