A macular hole is a small break in the macula, located in the centre of the eye’s light-sensitive tissue called the retina. The macula provides the sharp, central vision we need for reading, driving, and seeing fine detail. A macular hole can cause blurred and distorted central vision. Macular holes are related to ageing and usually occur in people over age 60.
What are the symptoms of a macular hole?
Macular holes often begin gradually. In the early stage of a macular hole, people may notice a slight distortion or blurriness in their straight-ahead vision. Straight lines or objects can begin to look bent or wavy. Reading and performing other routine tasks with the affected eye become difficult.
What causes a macular hole?
Most of the eye’s interior is filled with vitreous, a gel-like substance that fills about 80% of the eye and helps it maintain a round shape. The vitreous contains millions of fine fibres that are attached to the surface of the retina. As we age, the vitreous slowly shrinks and pulls away from the retinal surface. Natural fluids fill the area where the vitreous has contracted.
In most cases, there are no adverse effects. Some patients may experience a small increase in floaters, which are little “cobwebs” or specks that seem to float about in your field of vision. However, if the vitreous is firmly attached to the retina when it pulls away, it can tear the retina and create a macular hole. Also, once the vitreous has pulled away from the surface of the retina, some of the fibre can remain on the retinal surface and can contract.
This increases tension on the retina and can lead to a macular hole. In either case, the fluid that has replaced the shrunken vitreous can then seep through the hole onto the macula, blurring and distorting central vision. Macular holes can also occur in other eye disorders, such as high myopia (nearsightedness), injury to the eye, retinal detachment, and, rarely, macular pucker.
Can the other eye be affected?
If a macular hole exists in one eye, there is a 10-15% chance that a macular hole will develop in your other eye over your lifetime. The ophthalmologist will discuss this with you.
How is a macular hole diagnosed?
An ophthalmologist who suspects a macular hole may:
- Visual acuity test to measure vision at a distance.
- Visual field test to evaluate your central vision.
- Dilated pupil examination to see the inside of the eye with an ophthalmoscope
- Retinal scan: An optic coherence tomography test (OCT) is a non-invasive, high-resolution retinal scan.
What are the current treatments options for a macular hole?
Although some macular holes can seal themselves and require no treatment, surgery is necessary in many cases to help improve vision. In this surgical procedure (called a vitrectomy) the vitreous gel is removed to prevent it from pulling on the retina and replaced with a bubble containing a mixture of air and gas. The bubble acts as an internal, temporary bandage that holds the edge of the macular hole in place as it heals. Surgery is performed under local anaesthesia and often on an outpatient basis.
Following surgery, patients must remain in a face-down position, normally for a day or two but sometimes for as long as two to three weeks. This position allows the bubble to press against the macula and be gradually reabsorbed by the eye, sealing the hole. As the bubble is reabsorbed, the vitreous cavity refills with natural eye fluids. Maintaining a face-down position is crucial to the success of the surgery, because this position can be difficult for many people. It is important to discuss this with your doctor before surgery.