Macular hole: A break in the central vision

The macula is the structure in the central part of the retina that controls frontal vision, allowing us to see in detail and in colour. When a circular opening develops in the macula, this is called a macular hole. Here, Ms Guzaliya Safiullina, leading consultant ophthalmic surgeon, provides an expert insight into a macular hole.

What is a macular hole?

A macular hole is a break in the central retina. It is usually less than 1 mm in size, but due to its central situation, it causes a central vision gap, while preserving the peripheral vision intact. It is usually the result of delayed and difficult vitreous gel detachment that causes a traction (pulling) over the central retina (called the macula), which resembles a ‘hole’ and thus, the name.

What causes a macular hole?

The main cause is a delayed and difficult process where the vitreous gel pulls away and separates from the retina. The human vitreous gel is attached to the retina at a young age and it is mainly composed of collagen and water. The gel is believed to have some nutritional function at the early stages of human life, but has no crucial nourishing function to the retina in adult life. As we age, the gel becomes more liquid, resulting in the gel’s separation from the retina.

Over the years, as our gel gradually degenerates, it tends to be detached from the retina, on average, at the age of 62. The vitreous degeneration and detachment from the retina are inevitable as they are a normal part of ageing.

Most people’s vitreous gel detaches easily with no complications or incidence of a macular hole or significant tractions. However, some people will have a very strongly attached ‘young’ gel that has difficulties becoming detached naturally from the retina and sometimes, starts pulling away a little too strongly and a little too long over several months. This persistent tractional (pulling) force over the central retina produces a vitreomacular traction syndrome first and then consecutively, a macular hole as a result. This occurs without any apparent variation on diet or lifestyle that delays or accelerates the vitreous gel detachment. This makes it difficult to predict whether the vitreous will detach spontaneously and easily or if it will remain attached and pull during some period of time.

What happens if a macular hole is left untreated?

An untreated macular hole becomes larger in size and deteriorates into central vision loss. A small proportion of untreated macular holes are found to be involved in causing a detached retina.

When possible, the surgical treatment of a macular hole is always recommended, even for the latest stages of a macular hole when a very modest visual improvement is expected with a successful surgery. The main reason for this is that a macular hole closure always improves the anatomical stability of the macula, which reduces the risk of retinal detachment from the macular hole. Second, most of the surgically-closed macular holes are shown to improve the eccentric vision (next to the macular hole retina, in the nearby area), which allows the healthy retina around the macular hole to partially take over the function of the centrally-damaged retina.

In general, an average improvement of one to three lines on visual charts is to be expected after a successful surgical intervention for the macular hole.

What are the treatments for a macular hole? What is the success rate of these treatments?

The most successful treatment is surgery. In an expert retinal surgeon’s hands, a macular hole surgery has a 95 to 99 per cent success rate.

Are there any possible complications with macular hole surgery?

All intraocular surgeries are estimated to have a 1:1000 infection - 1:5000 risk of choroidal bleed rates. Blood hypertension and blood thinning treatments need to be controlled pre-operatively in order to prevent a choroidal bleed related to the eye surgery.

A classic 20G (larger, compared to modern incision) is associated with a slight increased risk of retinal detachment. A modern 25G (much thinner compared to the classic 20G one) vitrectomy surgery, decreases the risk of retinal detachment significantly and makes the vitrectomy for macular hole surgery a safe and efficient procedure.

What are the alternative treatments to surgery?

For vitreomacular traction and the early stages of a macular less than 400 microns without the presence of an epiretinal membrane, an intravitreal injection of Ocriplasmin, called Jetrea, was used during the past few years in many countries. This substance liquified the vitreous and accelerated the gel’s liquefaction to help it become detached.

However, the UK’s leading vitreoretinal units reported concerns about an increased incidence of retinal detachment, which has now made this treatment be offered in certain indicated cases only.

If you wish to receive the utmost quality ophthalmology care for a macular hole, don't hesitate to visit Ms Safiullina's Top Doctors profile today.