A macular hole is a retinal problem whereby a hole develops in the macular region which is the part of the eye used for central vision. Symptoms of macular hole include blurred, distorted vision and sometimes a dark spot may appear in the centre of the vision, causing letters or words to be missed when reading (a scotoma). It is more common in the elderly and in women, though it can occur in both sexes. Previous trauma may also cause development of a macular hole. The underlying cause is thought to be due to a fine membrane around the macular region which undergoes centrifugal traction resulting in macular hole formation.
Surgery is very successful in closing the macular hole and improving vision. Some small, early macular holes may improve spontaneously without treatment and are therefore best observed and monitored with regular follow-ups. Once the macular hole begins to enlarge and vision is affected, surgery is recommended to close the hole. If the hole is not treated, it may enlarge with time leaving a larger dark spot in the centre of vision, causing further potentially permanent deterioration in vision. There is also an approximately 10% risk of the other eye developing the same condition.
Surgery for macular holes involves vitreoretinal microsurgery where very fine microsurgical instruments are inserted inside the eye and the vitreous jelly is removed. The fine inner retinal membrane which causes the macular hole is also removed. Special dyes are used to delineate these membranes and assist removal of the traction. A gas bubble is used to tamponade the macular hole which is absorbed over four to eight weeks and replaced with the eyes’ own fluid. The success rate of macular hole closure is excellent at 95% or higher. Once the hole is closed, the distortion in vision should improve and the level of vision should also improve (in approximately 70 – 80% of cases). Macular hole surgery may be combined with cataract surgery if a cataract is present at the time of macular hole diagnosis.
Some macular holes may require further surgery if the initial surgery is not successful in closing the hole. The degree to which this occurs, depends on the length of time that the hole has been present and the size of the hole at presentation. Macular holes which have been present for a long period of time may have poorer prognosis and may not be able to be closed.
Following surgery, vision will be initially blurred due to the gas bubble and the dilating eye drops. For the first two weeks following surgery, face down posturing is required for forty-five minutes in the hour; the other fifteen minutes are used to perform normal daily tasks. Face down positioning chairs are availabe to assist with positioning.
While macular hole surgery is successful in closing most macular holes, one should be aware that occasionally there are problems which can arise following surgery. Complications such as retinal tears or retinal detachment may develop during or following surgery and further surgery would be required to correct these. Infection and haemorrhage can occur but they are very rare risks. It should be noted that cataract surgery may be required some time after macular hole surgery due to increased cataract development after vitrectomy.
There has been development in intravitreal therapy (Jetrea) as a treatment option to close macular holes and reduce traction without surgery. It should be noted that the success rate of Jetrea injections is significantly less than that of surgery and has possible complications, including loss of vision.