- What is it?
- Are there different types?
- What are the symptoms?
- What is the cause?
- What is the prognosis?
- How is it diagnosed?
- Is there a treatment?
What is it?
A macular hole is a defect or opening in the retinal tissue in the center of the macula. The macula is the part of the retina that provides us with the center of our field of vision – the part we need to read with, recognize faces, or thread a needle. Macular holes occur more frequently in women than men.
Are there different types?
Macular holes can be partial thickness or full thickness. Partial-thickness holes do not involve all the layers of the retina, while full-thickness holes do.
What are the symptoms?
Patients with a macular hole notice a central blur, which gradually progresses to a central blind spot in the affected eye. Since the macular hole is an area of missing tissue in the center of the retina, it results in an area of missing sight in the center of the vision. Imagine a ping-pong ball suspended in front of your eye, blocking your central sight. The side vision would be fine, but the central area would be missing. Symptoms are best appreciated when the better eye is covered and may not be noticeable with both eyes open.
What is the cause?
The vast majority of macular holes are idiopathic – meaning there is no known cause. We believe they occur when there is an abnormally strong adhesion or attachment between the gel in the eye cavity (vitreous) and the macula. When the gel begins its normal aging process of shrinkage, it pulls on the macula where it is firmly attached. If the pulling continues without the gel peeling free from the retina, the macula undergoes changes, resulting in a circular defect – the macular hole. This is comparable to fabric on your pants gradually thinning until a hole is present by the knee.
What is the prognosis?
Macular holes never result in total blindness – at the worst they cause a central blind spot. Eyes with a macular hole can become legally blind, but usually deteriorate no worse than 20/400 – the level of vision allowing us to see the large letter E at the top of the vision chart.
How is it diagnosed?
A comprehensive eye examination, usually with dilating drops, is necessary to diagnose a macular hole. Fluorescein angiography and OCT scan help confirm the diagnosis. A number of disorders can cause a central blind spot, and some are more urgent to treat than others. Any patient with a central blind spot should be evaluated as soon as possible.
Is there a treatment?
An operation called vitrectomy may successfully restore some of the lost central sight in patients with macular holes.