What is a macular hole?
A macular hole is a condition affecting the central vision of one eye. Inside the eye is a structure called the retina. This a specialised layer of nerve cells that detect light, colour and motion and send information to the brain where the image is formed. The macular is an area of the retina responsible for central vision. This is high quality vision required for reading and recognising faces. Macular holes are rare. They usually occur as an aging change in the eye. Additionally, they can occur as a result of injury, inflammation or if the eye is very short sighted.
What are the symptoms of a macular hole?
Typically, a macular hole causes distortion of vision. The centre of an image may look
‘pinched in’, sometimes described as ‘hour-glass’, or ‘pin-cushion’ distortion. There may be a complete break seen in the centre of thin objects like lamp posts. These visual effects are more obvious when looking with the affected eye alone (not common in everyday life when both eyes are usually used together).
Sometimes macular holes are perceived as just a ‘blur’, or loss of clarity in the central
vision of one eye. Sometimes people have no symptoms and the macular hole is identified by a screening test.
What are the treatments for a macular hole?
Broadly, there are three options for macular hole treatment: Leave it alone (have no
treatment), injection therapy or surgery.
What happens if I have no treatment?
If the macular hole has been present for a very long period of time, and you are adjusted to it, or if you have no problems, you may decide to leave the macular hole alone. With time a macular hole will enlarge slightly and central vision can become more blurred, however this is not a condition that normally causes total blindness. Usually the condition only affects central vision.
Intravitreal injection treatment
A medicine called ocriplasmin can be given as an injection into the eye. This is performed with anaesthetic eye drops and goes through the white of the eye. This is
performed in a dedicate treatment room in clinic. The medicine dissolves attachments between the vitreous gel and the retina which may allow small macular holes to close without further treatment. It is not as effective as surgery, and if it does not work surgery is usually recommended.
The whole procedure takes about 10 minutes, the injection is a very brief part of
this. Eye drops are used to make the eye comfortable prior to injection.
Afterwards, there may be a few bubbles floating in the vision and the eye may feel a bit
gritty for a few days. The eye may be red after the injection which can last 1 or 2 weeks.
Serious risks from injection are rare. Surgery for complications such as infection,
retinal detachment or cataract occur in the order of 1 in 300 cases. Blindness from any cause occurs in the order 1 in 1000 cases.
The main problem with injection treatment is failing to close the hole which is more
common with larger holes and when surface epiretinal membrane is present. It is
usually reserved for patients with small macular holes who cannot undergo
surgery.
Surgical treatment for macular hole
Surgery has the best success rate for closing macular holes, working in 9 out of 10 cases
of small macular holes. This success rate drops for older larger holes (larger than 600 microns), in the order of 7 out of 10 holes closing that have been present for one year, and in the order of 5 out of 10 holes closing that are very large and longstanding.
Closing the macular hole often improves the distortion and allows both eyes to work better together. Whilst the vision may improve in the treated eye it doesn’t usually
return to normal.
If a hole doesn’t close with surgery a repeat operation can be performed- however, the
best success rates are with the first operation.
The operation is called vitrectomy surgery. This is microscopic keyhole surgery on the eye. It takes about 1 hour. Surgery is frequently performed under local anaesthetic, sometimes with additional sedation for relaxation and sometimes under general anaesthetic. This is discussed before arranging surgery.
During surgery the vitreous gel inside the eye is removed and a thin membrane is peeled off the surface of the retina. Finally a gas is injected into the eye where the vitreous gel was previously. The gas disappears by itself.