Macular Holes: Symptoms, Causes and What You Need to Know

Overview

A macular hole is a retinal problem which I see frequently in my clinic. As the name suggests, this condition is a small hole which develops at the macula. The macula is the central part of the retina which is responsible for fine and high quality vision. Symptoms of visual loss and distortion can start quite suddenly when a macular hole occurs, and therefore be worrying for patients. The surgery I perform for macular hole is highly successful (over 90%) in repairing the hole and improving vision. This article will help you understand what a macular hole is, describe the macular hole causes, symptoms that can occur and the importance of early diagnosis and subsequent treatment.

What Is a Macular Hole

A macular hole is a small hole which develops at the macula which is at the back of the eye. In the early stages of macular hole development, the vision might not be affected. However, over time, as the hole increases in size, macular hole symptoms such as blurred central vision and reading distortion usually occur.

Macular holes are classified according to their appearance on an OCT scan. This is a specialised scan I perform on patients who attend my clinic in order to give very high definition detail of their macula. An OCT scan allows me to identify conditions such as macular hole, epiretinal membrane (macular pucker), age-related macular degeneration and diabetic retinopathy, which can sometimes present with similar symptoms. The OCT scan of a macular hole has a characteristic appearance which allows a severity (or staging) to be performed as well as physically being able to measure the size of the hole. This assessment of severity and size is important because it can determine whether treatment should be offered or if observation in the first instance might be a better option. It is not possible to determine the stage or size of the macular hole, and therefore the long term visual prognosis, on the basis of symptoms alone.  

Early Warning Signs to Look Out For

Most people with a macular hole, or an early macular hole, report symptoms such as central vision distortion, blurred central vision, distortion when reading and difficulty recognising faces. Of note, this condition does not cause eye pain or any visible changes at the front of the eye, such as redness. The symptoms of macular hole are quite non-specific, and can be seen with other conditions such as age-related macular degeneration, macular pucker, epiretinal membrane, and macular oedema. For these reasons, if any of the above symptoms occur, it is important to have an eye check and consider seeing a vitreoretinal surgeon, like myself. Vitreoretinal surgeons specialise in the management and treatment of diseases that affect the vitreous and retina, such as a macular hole.

What Causes a Macular Hole

The most common cause of a macular hole is natural ageing. This is because, with time, the jelly inside the eye (known as the vitreous) undergoes changes such as liquefaction. These changes cause it to pull on the retina and macula. Most of the time, the vitreous then detaches from the macula, in a process called posterior vitreous detachment (PVD). However, when this detachment is occurring, sometimes the vitreous attachment to the macular is too strong which results in the pulling of a hole. This can be thought of like pulling bluetack off a wall and in some instances pulling off a flake of paint or small fragment of the wall.
There are some rarer causes of macular hole such as trauma to the eye, previous eye surgery, retinal detachment and inflammation in the eye (uveitis). However, it is important to note that the vast majority of time, macular holes develop due to natural ageing changes in the eye, which are not the result of anything you may have done to your eye.

How Macular Holes Are Diagnosed

A macular hole is first noted on careful clinical examination of the retina using a slit-lamp microscope. It is then confirmed, with its staging and size measured using an OCT scan. This is a rapid (less than 10 second) non-invasive scan which uses light to visualise the microstructure of the macula and retina. When I perform an OCT scan, it also allows me to determine whether the hole is partial thickness or full thickness of the macula. This is an important distinction because it usually determines whether or not surgery is recommended.

How Macular Holes Are Treated

I see many patients with macular holes and the treatment options are a well established part of retinal care. In clinic, I take time to explain the diagnosis, showing patients their scans, so that they understand the condition and why or when treatment is required. Most people with macular holes need surgery. Sometimes, people with a very early small macular hole or a partial thickness macular hole, may not need surgery and instead I may recommend a period of close observation. This is because partial thickness holes often do not cause any significant changes in vision and some small holes may resolve on their own without treatment.

If surgery is recommended, in simple terms, the goal of surgery is to close the macular hole. This occurs in approximately 90% of surgical cases and therefore the odds are good. If the macular hole closes, the vision usually improves, meaning the central vision is better than before surgery, usually with less distortion and the eyes tend to work better together. It is important to be aware that the vision after macular hole surgery does not tend to return to how it was before the macular hole problem had started due to the damage that occurs in the eye during the macular hole formation. Most patients report some long-term minor distortion of vision, but this is usually quite mild and does not tend to cause much problem with day to day activities.

Surgery can be performed with you awake (under local anaesthetic), under sedation or under general anaesthetic (asleep). The procedure involves keyhole surgery to access the back of the eye (macula). The vitreous jelly is removed in a safe way, and then a small membrane, called the inner limiting membrane (ILM) is peeled from around the macular hole. This is a delicate procedure that I perform with microforceps, with the thickness of the ILM being approximately 1micrometer. For context, the thickness of a human hair is usually at least 20 times thicker than the ILM.

The end of the surgery involves a gas bubble being injected into the eye in order to help improve the chance of surgery being successful in closing the macular hole. For the first few days after surgery, patients are usually asked to posture face down (or looking down) so that the gas bubble pushes against the macula inside the eye. Such posturing is thought to increase the chance of surgical success. Gas affects the way light travels through the eye and therefore for a few weeks after macular hole surgery, the vision will be blurred. Patients often describe this as a feeling of looking under water. This is normal. Over a few weeks, the gas bubble absorbs, and the vision improves. It means the visual recovery after macular hole surgery can take a few weeks, and whilst this is inconvenient, there is not usually significant pain.

How Vision Changes Can Affect Everyday Activities

The vision changes from macular hole can significantly affect everyday activities. This is because the macula is the central part of the retina which is involved in fine vision for tasks such as reading, recognising faces, and using screens. The visual distortion and blurred vision from a macular hole can also affect how the eyes work together, meaning difficulties judging distances and depth perception. This can cause problems with driving and walking down stairs, for example.

In the majority of cases, I recommend surgery for a macular hole because the vision tends to worsen with time as the hole increases in size which results in gradual further worsening of the vision.

When Is It Too Late to Treat a Macular Hole

It is unusual for a macular hole to be too late to offer treatment. However, the longer the hole has been present, the lower the chance of surgery being successful and therefore the worse the long term visual prognosis. With time, holes tend to slowly increase in size causing further loss of vision and poor central vision. Even those with large holes can undergo surgery, and I discuss this fully with my patients so they are fully informed about the options.

Summary

A macular hole is a condition that I commonly encounter in my clinic. It tends to cause blurred central vision and distorted vision. In most cases I recommend a surgical procedure in order to repair the hole, which carries a success rate of approximately 90%.

As with many other conditions of the retina, early diagnosis is important because earlier treatment usually results in better visual outcomes. If you develop new eye symptoms such as reduced vision, distorted central vision, floaters, flashing lights, or shadows in your vision, it is important to be checked by an eye expert to see if there is any problem that needs addressing before it worsens. If you would like to read more about macular conditions and their treatments, you can find further information on the retina page.

Mr Neffendorf is an experienced consultant vitreoretinal surgeon. One of his specialist interests is macula hole because this formed a major part of his academic thesis at King’s College London. Specifically, this included different treatment options for different macular holes. He has also published and presented many academic papers on macular holes. In his day to day practice, he is heavily involved in teaching the next generation of vitreoretinal surgeons to perform surgery on macular holes.