Macular holes occur due to a localised attachment of the vitreous to the central macula which pulls on a specialised area called the fovea, creating a central defect. This reduces clarity dramatically in that eye. OCT examination makes the diagnosis of a macular hole very accurate, including the size of the macular hole which affects the surgical prognosis and potential vision after surgery.
Fortunately, contemporary macular hole surgery successfully closes the macular hole in approximately 95% of cases, although long-standing and large holes may require further surgery. Macular hole formation in highly myopic eyes (very short-sighted) can require very specialised techniques to close the hole.
In the majority of patients, early treatment results in restoration of virtually normal vision, although some people have a slight reduction in clarity and a small amount of distortion for a number of months. The final visual outcome can take up to 12-18 months to be achieved, after the macular hole closure, but the bulk of the improvement occurs within a month or 2.
The surgery for a macular hole is performed in the operating theatre where the scar tissue holding the hole open is released and a gas bubble is left in the cavity of the eye to hold the edges of the macular hole closed while it “heals”.
The gas bubble blocks vision for virtually 2 weeks and it is not possible to drive or fly during this period. After the 2 weeks or so, vision is usually close to normal and normal activities can be resumed.
As in macular pucker surgery, the intraocular manipulation causes physiological changes triggering progressive cataract formation. The advantage of combined cataract surgery with vitrectomy offers much faster visual rehabilitation for most patients. 2 weeks after the surgery, the gas bubble has gone and the hole is closed. 4 weeks later, any final glasses are prescribed. Surgery for the hole alone usually results in sub optimal clarity for many months, until cataract surgery is performed.
Macular Hole Surgery
Macular hole surgery is one of the great advances in eye surgery over the last two decades, with over 95% closed with one procedure. Driving and reading vision is regained in the vast majority of patients.
Macular holes develop within the area of sharp central (reading) vision. This small area – no more than half a millimetre across – is the most delicate part of the retina. The hole develops due to tension from the aging vitreous gel – usually occurring after the age of sixty. Macula holes can occur after severe blunt trauma to the eye but are rare. As macular holes are in nerve tissue just over a tenth of a millimetre thick, it is not possible to stitch or glue them back together. Instead, gas is used to fill the eye and support the hole while it repairs in much the same way as a plaster cast supports a broken bone. The gas is naturally resorbed within two weeks.
The microsurgery is performed in the operating theatre under sedation after complete local anaesthesia has been achieved. The abnormal vitreous gel is removed and a very delicate layer of scar tissue on the retinal surface is removed releasing any tension pulling the hole open.
Complications are uncommon apart from potentially rapid cataract development. If there is some cataract already present, cataract surgery is usually performed in combination with the vitreous surgery for the macular hole to resolve both problems in one admission. This avoids a second operation and speeds the return of clear vision significantly.
Serious complications such as retinal tears or retinal detachments occur in much less than 5% of cases. Other rarities such as damage from bright light, haemorrhages, severe glaucoma and peripheral vision loss can also occur. There is between a 1-3/1,000 risk of infection
In general, the sooner the hole is closed the greater the visual improvement. This is not urgent and a delay of 1-2 weeks is acceptable; but surgery is best performed as soon as convenient. Please note that you will not be able to drive for about 2 weeks due to the blurred vision so planning family and work commitments is sensible.
After the Surgery
Avoid sleeping on your back but no other specific positioning is needed. There is a lot on the internet about face down positioning but this does not improve success rates. The eye should be comfortable. Panadol should provide sufficient relief from any discomfort.
- You must call AProf Heriot if there is severe aching pain or perhaps attend the Eye and Ear hospital to check the eye pressure ( call them on 99298666).
- The gas gradually diminishes restoring a crescent of vision above the indistinct area. It can resemble looking over a rocking fish tank or wearing a diving mask with water in the bottom. Towards the end, the gas forms a bubble (or bubbles) seen as a round ball(s) that move with head movement in the bottom of the vision.
- Vision generally improves close or back to normal. The improvement after the first 2 weeks is considerable but improvement in clarity and any distortion continues for up to 12-18 months as the retina and brain fine-tune the image. It is important to recognise that macular holes may leave some irreversible damage to the area of sharp central vision particularly if they have been undetected for a while.
It is critical not to fly or rapidly drive up a mountain while the bubble is present.
It is also vital you tell the anaesthetist if an urgent operation is needed with general anaesthesia.
You must not drive until the vision in the operated eye is near normal.
Please leave the green warning wrist bracelet on until the bubble goes.