What Is Macular Hole?
The centre of the retina is called the macula, and when a small gap opens up in this area, it is known as a macular hole. The retina is situated towards the back of the eye, and is the thin film that processes light. The macula is responsible for intense focusing and detail vision that is required for tasks like reading.
A mild macular hole in the early stages can result in distorted vision, but as it escalates, you may experience what seems like a small black hole or missing part of your vision. This hole will appear in the centre of your line of vision, and although it won’t cause any pain, surgery is required to repair it. Although your vision will not return to 100% following treatment for a macular hole, you will see a substantial improvement as a result of having the surgery.
What Are The Causes?
The eye’s interior wall contains vitreous gel, a substance found in about 80 per cent of the eye. This gel disintegrates with time, which is normal and in most cases will not cause any adverse issues with your eyesight.
Some people may experience floaters, which are specks or spots that move across your field of vision, that are deposits of this vitreous gel. If the gel pulls away and is firmly attached to the retina however, this can result in the retina being torn, a process known as vitreomacular traction. As such, this can cause a macular hole to develop.
Macular holes can also develop as a result of eye disorders like near- sightedness, long-sightedness, retinal detachment, or in some cases even a trauma to the eye. A condition known as cystoid macular oedema, which is essentially a constant swelling of the central area of the retina, can also lead to a macular hole developing.
Macular holes most commonly affect people between the ages of 60 to 80, and occur twice as commonly in women than men. If a macular hole develops in one eye, then there is a 10-15 per cent chance that one will occur in your other eye at some point.
What Is The Treatment?
Some macular holes may heal without the need for surgery, but where this is found to be required, a procedure known as a vitrectomy is most commonly performed.
During this surgical procedure, the vitreous gel that naturally occurs in the eye is removed in order to prevent it pulling on the retina. As this is what gives the eye it’s round shape, a gas bubble will be put in place instead to prevent decompression. This bubble acts as a sort of internal short-term bandage to hold the edge of the macular hole in place while it heals.
This surgery is often performed on an outpatient basis under local anesthesia, and following the treatment, you will be instructed to follow a set of post-operative instructions that include posturing in order to help your retina heal.
It could also be that, where a macular hole has been caused by vitreomacular traction, an injection of Ocriplasmin is the preferred method of treatment. This injection is normally only used in cases where the hole is less than 400 micrometres wide, and yet is causing severe symptoms. This injection will ease the process of the vitreous jelly separating from the back of the eye and enable the macular hole to seal shut. The injection itself takes just a few seconds, and is carried out under local anaesthetic.
Your ophthalmologist will also insert drops to dilate the pupil so that they are able to clearly see the back of your eye. Ocriplasmin injections are successful in around 40 per cent of cases, although they may present some side effects such as floaters, flashing light, and a yellowish tinge developing in your vision. You may also experience pain and discomfort as a result of the injection. Should the injection fail to work, your ophthalmologist will turn to vitrectomy surgery as the next course of action.
How Is It Performed?
Macular hole surgery is keyhole surgery, meaning it is minimally invasive, and it is carried out as an outpatient procedure wherever possible. In some cases, you may have to stay in hospital overnight, but you should typically be able to leave the same day.
The procedure is carried out under a microscope, and can take anywhere between 45-90 minutes. Three tiny incisions measuring just one millimetre in size are made in the sclera (the white part of the eye) through which instruments are inserted to carry out the procedure. To start, the vitreous jelly is removed, and then a thin layer is peeled away from the surface of the retina around the macular hole, thus forcing it to stay open. The eye is filled with a temporary gas bubble, and while this will block the vision while present, it will disappear in the first couple of months after your procedure. This gas bubble is necessary in order to push the hole flat onto the back of the eye and help it seal.
What To Expect After Surgery
As you awake from your treatment, you may experience some discomfort, and may find that your eye has been fitted with a protective plastic shield. This protective dressing and shield can be removed the day following your operation.
You will not be able to drive yourself home after your treatment, and if you have had the procedure carried out under general anaesthetic, a responsible adult will need to collect you in order for you to be discharged. As the gas bubble will still be in your eye, your vision will be hazy, much like opening your eyes underwater. This is normal and will pass in the weeks following your treatment.
You may also experience difficulty with depth perception during this time. Over the next seven to 10 days, the gas bubble will shrink, and the natural fluids in your eye will return to the affected area thus restoring your vision. Generally speaking, the gas will be completely absorbed and out for your system within six to eight weeks. Your surgeon will normally prescribe you a number of eye drops to take following surgery, which can include antibiotics to prevent the onset of infection, along with steroids and a pupil-dilating agent as needed.
It is normal to experience mild pain, discomfort and a degree of sensitivity following the operation. However, if you experience severe pain or worsening of your vision, this could be a sign of complications. You should contact your ophthalmologist straight away and visit your nearest A&E department if the symptoms persist.
Once you are home, you may have to spend the majority of your day lying down on your front with your head held in a specific position.
This is known as posturing, and is done to keep the gas bubble in as close contact with the hole as possible, as this will encourage the macular hole to close. There is evidence to suggest that posturing results in a higher success rate for larger holes, whereas it may not be necessary for smaller holes. Should you be asked to do posturing, you will be instructed to keep your head down face towards the ground, whether lying on your front or sitting with your head facing downwards.
Posturing is not always necessary, so be sure to discuss with your Ophthalmologist whether or not posturing is required as part of your specific recovery programme. If it is, you should determine how long this will be required.
The sooner you undergo treatment for a macular hole, the better the chances of success.
If the hole has been present for six months or less, the success rate is around 90%. Should your hole have been present for a year or longer however, the success rate for a procedure falls to around 60%. The majority of patients will experience an improvement in vision once they have made a full recovery, and even if you still experience problems with your central vision, your peripheral vision will never be affected. Speak to your doctor to get an accurate idea of the results you can expect.
In most cases, a successful surgery will substantially heal your vision.
However, there can be potential complications, such as when the hole fails to close. While this only happens in roughly 1 or 2 patients out of 10, should it occur, your vision may be rendered worse than before the procedure. If this happens, it may be possible to repeat the surgery to rectify it. There is also the risk that cataracts could develop following the surgery, and that bleeding or infection can occur (the latter is rare, occurring in an in 1,000 patients).
Retinal detachment can occur in 1 to 2% of patients, while raised eye pressure is a more common complication following a macular hole surgery, normally caused by the expansion of the gas bubble. This is usually a temporary state, and it will decrease in size in the weeks following your surgery to release any pressure build-up you may experience.