Macular Hole

What is Macular Hole?

Macular hole (MH) is a disease of the eye, specifically affecting the vitreous and retina. It results in a partial or full-thickness defect, or hole, in the central part of your retina called the macula. There wasn’t much known about this condition until the early 1990s. However, in the last two decades, our understanding and approach to diagnosing and treating macular holes have greatly improved.

We now have a new classification system based on both the appearance and the underlying disease process of the vitreoretinal interface (the point where the vitreous humor and retina meet). This has greatly improved our understanding of how macular holes form. Today, diagnosing a macular hole and monitoring the recovery after treatment, both by examination and using a special imaging technique called optical coherence tomography (OCT), has become definitive.

This condition often affects the central pit of the macula (fovea), leading to symptoms like metamorphopsia (distorted vision) and visual deprivation, which are the common symptoms when patients first seek help. The encouraging news is that these might be reversible after successful surgery that closes the macular hole.

What Causes Macular Hole?

A macular hole is a condition that is often unexplained or related to a syndrome known as vitreomacular traction. The macular hole can be linked to different types of conditions in the macula, which is the part of your eye responsible for sharp, central vision. Some of these conditions are:

* After laser eye treatment
* After certain eye surgeries
* Epiretinal membrane (a thin layer of tissue over the retina)
* Polypoidal choroidal vasculopathy (an eye disorder that causes vessels under the retina to bulge)
* Hypertensive retinopathy (damage to the retina caused by high blood pressure)
* Diabetic retinopathy (damage to the retina caused by diabetes)
* Vitelliform dystrophy (an inherited eye disorder that affects the retina)
* Ruptured retinal arterial macroaneurysm (a burst blood vessel in the eye’s retina)

Some less common related conditions are:

* Central retinal artery occlusion (a blockage of the blood flow in the eye’s central retinal artery)
* Retinitis pigmentosa (a group of genetic disorders that lead to loss of vision)
* Alport syndrome (a genetic condition that affects hearing and kidney function)
* Valsalva retinopathy (damage to the eyes from high pressure)
* Stargardt disease (an inherited eye disorder that affects young people)
* Syphilis

Additionally, certain eye conditions can make someone more likely to develop a macular hole. For example, people with myopia (near-sightedness) with or without a bulging area in the back of the eye (posterior staphyloma) might be more susceptible. In some cases, a macular hole can lead to a detached retina, and there are various methods now being tried to close the hole.

Injury is also a common cause of a macular hole, especially in younger people. Sometimes, a macular hole caused by injury can heal on its own. If it doesn’t, it may require surgery. If a macular hole is not linked to another condition, it’s simply referred to as a primary macular hole. On the other hand, if it’s connected to another condition, it’s known as a secondary macular hole.

Risk Factors and Frequency for Macular Hole

An idiopathic macular hole, a condition affecting the eye, typically occurs in one eye at a time. Cases where it affects both eyes vary greatly, ranging from just 2% to as high as 28% of incidents, although there is no known associated systemic condition. Females are more often impacted by this condition, with a ratio of 3 females to every male affected. This tends to occur in the sixth or seventh decade of life.

While the average age of people with this condition is over sixty years, a myopic (nearsighted) and traumatic macular hole can appear at any age. The prevalence of macular holes differs from place to place, with 3.3 out of every 1000 people in the Baltimore eye study having a macular hole, compared to just 0.2 out of every 1000 people in Australia.

In a study conducted in the United States, it was found that the incidence of macular holes was 7.8 persons per 100,000 population per year. Another study noted a cumulative incidence of 41.1 cases per 100,000 person-years. The connection between different systemic risk factors and the macular hole have been examined, but no strong associations have been found.

• Idiopathic macular hole usually impacts one eye at a time.
• Cases of both eyes being affected range from 2% to 28%.
• Females are more likely to have this condition, with a ratio of 3 females for every male affected.
• It typically occurs when an individual is in their sixties or seventies.
• Myopic and traumatic macular holes can occur at any age.
• In the Baltimore eye study, 3.3 out of every 1000 people had a macular hole. Meanwhile, in Australia, the number is 0.2 out of every 1000 people.
• The incidence in the US was found to be 7.8 persons per 100,000 population per year.
• A separate study showed a cumulative incidence of 41.1 cases per 100,000 person-years.
• No strong association has been found between systemic risk factors and the macular hole.

Signs and Symptoms of Macular Hole

An idiopathic macular hole is a condition that usually affects older adults, particularly women, mostly between 60 and 70 years old. This painless condition gradually reduces central vision and can sometimes cause distorted vision. In the early stage of a macular hole, a person’s vision might not be drastically affected, yet it worsens as the hole progresses.

• A partial-thickness hole leads to a minor decrease in vision.
• A full-thickness macular hole, on the other hand, significantly reduces vision.

A red central spot seen through an examination with a slit lamp and +90D/+78D fundus viewing lenses typically confirms a full-thickness macular hole. There are two simple exams using a slit lamp and a laser-aiming beam that can help differentiate between a full-thickness hole and a pseudo hole. When using a thin slit-lamp beam during the eye test, patients with a full-thickness hole usually report a gap or break in the line. In contrast, people with pseudo holes might report the line appearing thinner in the middle or bending without a break. With a varied-sized laser-aiming beam projected on the eye’s centre, patients can detect it in cases of a pseudo hole but not in cases with a macular hole.

• Other signs linked with this condition include an epiretinal membrane, thinning, cystoid changes, and complete posterior vitreous detachment (PVD).
• Retinal pigment epithelium changes and vitreomacular traction (VMT) might also exist.
• Depending on how advanced the hole is, there might be visible yellowish fluid around it and yellow spots in the centre.

It’s also key to examine the other eye for similar changes. If PVD is present, there’s a lower chance of a macular hole forming if one hasn’t already.

Testing for Macular Hole

Diagnosing macular hole (MH), a condition that mainly affects older people, often begins with a thorough eye examination. However, if you also have other age-related conditions like cataracts, which can make your eye’s lens cloudy, the process can sometimes be more difficult for your eye doctor.

Optical coherence tomography (OCT) is an important tool used to confirm the diagnosis of a macular hole. OCT provides a detailed image of the eye, similar to a cross-section or 3D scan, and can show a macular hole and other potential abnormalities like epiretinal membrane (ERM) or vitreomacular traction (VMT), which can both affect your vision. The OCT test can also provide useful information before and after treatment to see how well it’s working. Sometimes, doctors use specific measurements from the OCT to predict how likely your condition is to improve.

Fundus fluorescence angiography is another test that might be used. This test shows a bright spot in the center of the eye due to a “window defect,” where there’s missing tissue that blocks light. Doctors usually only need to do this test if they suspect other diseases are also present, or if they need to figure out why you’re losing vision more quickly than expected.

One way to tell the difference between a true macular hole and a similar-looking condition known as a pseudo hole is macular microperimetry. This test, which uses a special device known as a scanning laser ophthalmoscope, can also track changes in your vision over time. Another test that can be used is the Amsler grid test, but it’s not always as reliable for diagnosing a macular hole.

Treatment Options for Macular Hole

If you’ve been diagnosed with a macular hole (MH), there are different stages of the condition and each stage requires a specific type of treatment. The treatment plan depends on the interaction between the back part of your eye’s vitreous (a jelly-like substance inside your eye) and the surface of your retina (a thin layer at the back of your eye that captures light). After 1989, an eye surgery called vitrectomy was introduced as a potential treatment option. Over the years, this treatment has evolved with the development of new tools, medications, and techniques such as dyes for staining certain parts of the eye and using materials to fill the gap in the macular hole.

For Stage 1 macular holes, doctors usually monitor the condition since there’s a roughly 50% chance it will resolve on its own without need for surgery. However, if there’s a significant drop in vision or if the condition lasts for a long time, doctors may recommend surgery.

For Stage 2 and 3 macular holes, there’s a chance (between 4 to 11.5%) that the macular hole will close by itself. If not, surgery under local anesthesia is typically the preferred option. The main surgery is known as Pars-plana vitrectomy (PPV). This process involves creating a small incision to remove the vitreous gel from inside the eye following which several other steps are performed such as separating the back part of the vitreous from the optic disc. After this, most of the vitreous near the macula is removed. Following this, the surgeon will also remove the internal limiting membrane (ILM). All these steps are aimed to reduce the interactions between the vitreous and the retina, that can complicate the healing process after the surgery.

If you have a Stage 4 macular hole, the aforementioned procedure, minus the separation of the vitreous, is still followed since this separation has already happened in this stage of macular hole.

In order to make the surgery safer and more precise, dyes such as indocyanine green (ICG), trypan blue (TB), and brilliant blue G (BBG), are used to stain the ILM. This staining helps the surgeon better visualize the area they need to work on. Depending on the surgeon’s judgement, they might peel the stained ILM to ensure a successful closure of the macular hole and to prevent it from reopening.

Once the ILM is successfully removed, a “tamponade” effect is created by injecting a vitreous substitute such as a gas into the eye. This procedure helps to close the macular hole by pushing against the retina. Different types of gases can be used for this purpose. After the surgery, maintaining the correct head position is very important as it ensures that the gas bubble stays in contact with the macular hole, aiding the healing process.

If the patient can’t maintain the required head position or needs to travel by air soon after the procedure, silicone oil may be used instead of gas.

What else can Macular Hole be?

New improvements in eye scanning technology (OCT) have made it easier to tell the difference between a specific eye condition that affects the center of the retina (macular hole) and other similar, small eye issues that often occur with old age. These conditions can all appear as small, round, red spots in the center of the eye and cause blurry central vision. Doctors need to consider the following possibilities:

• A superficial membrane on the retina with a false macular hole (Epiretinal membrane with a macular pseudo hole)
• Dot-sized bleeding in the innermost part of the retina (Central foveal dot hemorrhage)
• An incomplete macular hole (Lamellar macular hole)
• A condition where the vitreous (gel in the eye) pulls on the retina (Vitreomacular traction syndrome)
• Small deposits in the retina (Foveal drusen)
• A specific pigment disorder affecting the center of the retina (Central areolar pigment epitheliopathy)
• Eye damage caused by sun exposure (Solar retinopathy)
• A small growth of new blood vessels involving the retina’s center (Small choroidal neovascular membrane involving center)
• A condition involving fluid buildup under the retina (Small central serous chorioretinopathy involving center)
• Swelling in the macula due to fluid leakage (Cystoid macular edema)

What to expect with Macular Hole

Before eye surgery for macular holes (MHs), doctors use several methods to predict how successful the procedure might be. These methods have become more accurate thanks to the use of Optical Coherence Tomography (OCT), a type of eye scan.

Certain factors can generally suggest a successful result before the operation. For instance, a naturally occurring macular hole often heals better than one due to injury or myopia (short-sightedness). It’s also typically better if the symptoms have been present for less time, if the patient’s vision is good before the operation, if the hole is in an early stage and small, and if several specific measurements taken from the OCT scan meet certain criteria.

These OCT measurements include the Hole Forming Factor (HFF), which measures the shape of the hole – a value above 0.9 is usually a good sign, while a value below 0.5 is not as promising. The Macular Hole Index (MHI) measures the height of the hole relative to its width – an MHI greater than 0.5 is usually favorable. The Diameter Hole Index (DHI) compares the narrowest part of the hole to the width of the base – a DHI LESS than 0.5 is generally a good sign. The Tractional Hole Index (THI) compares the tallest part of the hole to its narrowest diameter – a THI greater than
1.41 indicates a better prognosis. If the retina shows fluid-filled areas, this usually bodes well for recovery.

During the operation, the prognosis for healing can be improved with micro-incision vitrectomy surgery (a minimally invasive surgical procedure) and by using specific staining and gas bubble techniques, although some are controversial.

After the operation, certain factors can help recovery: maintaining a face-down position can assist in closing larger macular holes, and the integrity of the layers of the retina can affect results. The type of closure of the hole also influences the prognosis: an intact nerve-sensitive layer of the retina linked to the hole (type 1 closure) predicts a good outcome, whilst the presence of a defect in this retina layer (type 2 closure) may lead to unfavorable results.

Possible Complications When Diagnosed with Macular Hole

Macular hole surgery can lead to a variety of complications. These include general issues that can occur with any eye surgery, including infection in the eye, sympathetic ophthalmia (a form of inflammation), release of blood into the eye, high or low eye pressure, and recurrent issues with the eye’s cornea.

Possible problems specific to pars plana vitrectomy, a type of surgery involved in treating a macular hole, can include different types of cataract, retinal break, retinal detachment, and blood in the vitreous part of the eye. There might also be inflammation in the eye, neovascularization (new, weak blood vessels growing), and a type of glaucoma.

Certain complications may occur because of internal limiting membrane (ILM) staining and peeling. Some of the dyes used can be toxic to certain cells in the eye, causing complications. Also, removing the ILM sometimes leads to irregularities in the retinal surface.

Complications related to macular hole surgery:

• Infection in the eye, sympathetic ophthalmia, intraocular hemorrhage, glaucoma, hypotony, and recurrent corneal erosion.
• Nuclear sclerotic cataract, intraoperative cataract, retinal break, retinal detachment, and vitreous hemorrhage, among others.
• Toxic effect of dyes used for ILM and irregularities in the retinal surface after ILM peeling.

After surgery, visual defects may occur. Though the chances of these developing are decreasing due to improvement in surgical techniques. There’s also a risk of the macular hole reopening, but this risk has also decreased over time thanks to better surgical methods.

Non-ocular (not related to the eye) complications might also occur, including nerve damage due to the position held during the postoperative period.

Side effects of a specific drug called Intravitreal Ocriplasmin can include reduction in visual acuity, reduction in peripheral vision, retinal arterial attenuation, problems with the lens, loss in a certain layer of the retina and abnormal pupil reaction.

Side effects of Intravitreal Ocriplasmin:

• Reduction in visual acuity
• Reduction in peripheral vision
• Retinal arterial attenuation
• Problems with the lens
• Loss in a certain layer of the retina
• Abnormal pupil reaction

Recovery from Macular Hole

The position of your head after a surgery to fix a macular hole (a small break in the macula, the part of your eye responsible for detailed, central vision) is crucial to how well you recover. The goal is to keep the area around the macular hole free from fluid interaction to maintain it in a dry state using what’s called a gas tamponade – a bubble of gas to block off the hole. Often, if the hole is small, you won’t need to keep your face down as long as the gas bubble is big enough to block off the hole properly.

Keeping your face down after the operation can considerably help close a macular hole that is less than 400 micrometers in diameter.

Your doctor will advise you about the negative impact of air travel on expansile gases (gases used for blocking off the hole). In these situations, an alternative may be to use silicone oil instead.

Preventing Macular Hole

It’s important for the doctor to explain to the patient about the factors that can affect the outlook of their condition and the chances of the hole in their eye’s macula closing up. However, even if the hole does close up, this doesn’t always mean that the patient’s vision will fully recover. A treatment called gas tamponade is sometimes used, and patients who receive this treatment should avoid travelling by plane. Additionally, patients should be aware that their vision may worsen drastically immediately after treatment, but this will gradually improve over time depending on the type of gas used in the treatment.