Overview 

A macular hole is an opening in the centre of the macula within the retina. If the macula has been damaged, daily activities like driving, watching television, reading, or even recognising faces might become hard. Macular holes are seen in approximately 3 in every 1,000 people over the age of 55, and are more common in people assigned female at birth (AFAB) than in people assigned male at birth (AMAB).

Macular holes are thought to occur from an abnormal adhesion and traction of the jelly or vitreous humour that normally fills the eyeball cavity, on the retinal surface.¹ The jelly usually fills the eye cavity and touches the retinal surface. 

The jelly becomes weaker, shrinks, and detaches from the retina's surface with age.² This process is termed posterior vitreous detachment or PVD, which usually occurs in most people as they age. In some people, however, the vitreous humour is attached abnormally to the retina's surface. In people with this form of attachment, when the jelly detaches, there is abnormal traction or pulling of the retina, and the jelly often takes a small amount of retina with it, leaving a round defect in the plane of the retina.

The macular hole is typically located at the centre of the macula. As this area is responsible for detailed visual function, any abnormalities here can impact vision significantly.

Risk factors

Risk factors for macular holes include:³

• Ageing
• People AFAB
• Eye trauma
• Being very nearsighted
• Previous eye surgeries or eye inflammation
• History of a retinal tear or detachment
• Diabetes
• Retinal venous occlusions
• Inflammation in the eye (uveitis)

Causes

Prevention of the formation and development of macular holes is not possible yet, as most cases develop without any apparent cause.  A macular hole in one eye further increases the risk of one growing in the other eye by 5% to 15%.

The following conditions may increase the possibility of the appearance of macular holes:¹

• Vitreal traction: Traction of the retina from tugging by the vitreous. The vitreous refers to the "gel" inside of the eye
• Trauma/injury: Some young individuals develop a macular hole secondary to blunt trauma
• Diabetic eye disease
• High degree of myopia (nearsightedness)
• Macular pucker: A layer of scar tissue that forms over the macula and may cause wrinkling of the retina by warping and contracting
• Retinal detachment 

Genetics, environmental factors, and systemic causes don't seem to play a part in the development of macular holes.

Types 

Macular holes are classified into primary and secondary. A  primary macular hole develops without any related medical condition, surgical history or trauma to the eye. Thus it is unrelated to another disorder. A secondary macular hole, on the other hand, occurs with or owing to another disease or condition such as trauma or inflammation of the eye (uveitis).¹

There are a couple of ways to classify macular holes. These are called staging systems. One system has four stages (Gass biomicroscopic classification), with the first being the least severe and the fourth, being the most severe. A newer system categorises the stage of a macular hole as one of three, depending on imaging test findings. The eye care provider will provide information about the severity of the hole.

Stages

• Stage 1a: Yellow spot. This finding is not specific to macular holes but may also represent other conditions like central serous chorioretinopathy, cystoid macular oedema, and solar maculopathy 
• Stage 1b: Occult hole – doughnut-shaped yellow ring (200-300 μm) centring the foveola (a part of the retina). Of these, up to 50% progress to stage 2 
• Stage 2: Full-thickness macular hole (<400 μm). Pre-foveolar cortex usually separates eccentrically, creating a semi-transparent opacity (often larger than the hole) and the yellow ring disappears. Progression to stage 3 is usual
• Stage 3: holes >400 μm associated with partial vitreomacular separation
• Stage 4: Complete detachment of the vitreous from all of the macula and the optic disc

Signs and symptoms

During the early stages of the macular hole, distortion and blurred vision are common. It inhibits one's ability to read. The straight lines appear wavy. Gradually, it involves breaks in the central vision. Even though a macular hole may occur in either eye, it most often begins initially with one. Thus, patients do not feel the loss of vision early. If not treated, it may result in a detached retina, which is a sight-threatening condition.²

Sudden flashes of light, floating specks, or a veil-like dimming of vision can indicate a detached retina.

Diagnosis

Diagnosis is usually made clinically using a detailed medical history. However, the following may be useful:^1,4

• Optical coherence tomography has been very useful in predicting prognosis through the high-resolution cross-sectional image of the retina
• Fluorescein angiography can be useful in differentiating the macular hole from other conditions, including cystoid macular oedema and choroidal neovascularisation. Classically, it reveals a window defect early in the angiogram, which does not expand with time, without any leakage or pooling of dye
• Amsler grid abnormalities may be seen, but plotting small central scotomas (visual field abnormalities) is usually difficult⁵

Treatment 

Vitrectomy is the most common treatment for macular holes. This surgical procedure halts the pulling on the retina caused by the vitreous gel, and with most gas-bubble placements in the eye, the edges of the macular hole are kept closed until they heal.

This can include patients being positioned face down for several days and sometimes up to 2 weeks, depending on the characteristics of the macular hole. This allows the bubble to slowly dissolve and fill in with natural eye fluids.

Vitrectomy has a good success rate, as sight is regained in over 90% of cases. Many of these patients regain at least some of their lost vision. Potential complications of the surgery include cataract formation, retinal detachment, infection, glaucoma, bleeding, and re-opening or persistence of the macular hole in less than 10% of cases. Another treatment used in certain patients with macular holes involves intravitreal injection of ocriplasmin (Jetrea). This medication could relieve vitreous traction by tugging on some macular holes.

In those few cases, when the macular hole is small and has no significant bearing on visual acuity, physicians may not recommend any treatment. The course of progression or natural healing of the macular hole can be observed and followed accordingly. Regular eye follow-up examinations, as determined by the eye doctor, are then needed to catch and treat problems early.^7,8

Post operation effects

Patients may be advised to lie face down for some days after the surgery, this 'posturing' helps the eye heal properly. Other post-surgery effects include temporary poor vision, discomfort, mild pain, etc.

Precautions

The eye will be padded with a shield for protection after the operation. This should be removed the next day, or as advised by the physician. Other precautions are:

• Do not rub your eye
• Wear an eyepatch
• Avoid swimming, as this may help to prevent infection through the water
• Avoid strenuous exercise
• Avoid eye makeup
• Take medication as prescribed
• Avoid flying or travelling to high elevations

Recovery

This gas bubble disappears with time after surgery. Our natural eye fluids replace the bubble during the healing. The recovery may take several weeks.

Complications 

One of the more common side effects, though rare, following surgery for a macular hole is an infection of the cataract. The majority of people often need to go under cataract surgery after vitrectomy surgery. In the event of failure, you might have to redo the surgery, usually when the hole doesn't seal. 76% of cases require cataract extraction within two years of macular surgery.⁶

Other problems include: 

• Retinal detachment
• Iatrogenic retinal tears
• Macular retinal pigment epithelium changes
• Enlargement of the hole
• Macular light toxicity
• Postoperative intraocular pressure spikes
• Endophthalmitis
• Reopening of an initially successfully closed hole
• Retinal pigment epithelial abnormalities

Prognosis 

The prognosis remains good in cases where the patient has received early treatment or the hole is tiny. Without treatment, the patient can lose much of the clear central vision but peripheral or side vision will be preserved. 

The success rate for vitrectomy surgery is over 90%. Surgery is generally successful when the hole is smaller and more recent. However, the amount of regained vision may vary.

Summary 

With the deterioration of central vision, a macular hole can greatly impact daily activities. Fortunately, the treatment is very effective, with a high success rate following surgery. Early diagnosis is necessary, to prevent further loss of vision (especially in older adults). This requires regular eye exams and timely medical intervention. If appropriately cared for, the outcomes are promising regarding good vision and quality of life.