Hearing that you have a hole in the macula can be alarming, even if you’re not entirely sure what that means. Fortunately, macular holes are not overly common, with an estimated incidence of just under 8 new cases per 100 000 people per year. Also, fortunately, treatment of a hole in the macula tends to be highly successful with retinal surgery by a retinal specialist.
What is the Macula?
The macula is a specific part of the retina, the light-sensitive tissue found inside the eyeball. At the centre of the macula, there is a dip in the tissue called the fovea, where we find the highest density of cone photoreceptors. Unlike rod photoreceptors, cones are able to discern colours and also work optimally in bright lighting. For these reasons, the macula is responsible for:
- Colour perception
- Central vision
- Fine detail discrimination
- Daytime sight
We use our macula and fovea for a variety of daily tasks, such as reading, writing, driving, watching TV, and recognising faces. Damage or disruption to this part of the retina, such as due to a hole in the macula, can therefore be quite debilitating.
What Causes a Hole in the Macula?
Macular holes are literally that – a break or hole in the macula region of the retina. Most macular holes involve the fovea, resulting in a significant impact on your central sight.
Macular holes can be classed as full-thickness holes involving a break through all the layers of the retina or partial holes (also known as lamellar holes). A lamellar macular hole involves distortion or break of the inner fovea while the outer retinal layers remain intact.
The vast majority of macular holes are known as idiopathic, meaning the condition occurred spontaneously without any known cause. There is often an association with a natural age-related change to the vitreous gel inside the eyeball, known as a posterior vitreous detachment. A posterior vitreous detachment occurs when the vitreous gel liquefies and loses its solid molecular arrangement. As it liquefies and slowly collapses, it can pull on points of attachment to the retina, including at the macula. This tugging, commonly called traction, is thought to create a hole in the macula. However, while everyone experiences a posterior vitreous detachment, not everyone will develop a macular hole. Also, while macular holes in both eyes are not impossible, it is highly uncommon despite both eyes undergoing a vitreous detachment. If there is a strong adhesion between the macula and the vitreous, you may need treatment with vitrectomy surgery to remove the vitreous gel.
Other causes of macular holes can include as a result of fluid swelling from other conditions, such as diabetic retinopathy or severe trauma to the eye.
Several risk factors have been associated with the development of macular holes. One study reported that:
- Female gender has been found to be at a 64% increased risk compared to males
- Asian patients have a 117% increased risk compared to Caucasians
- The mean age of study participants who developed a macular hole was 62 years old
In addition to gender and age, other risk factors include:
- Myopia condition (short-sightedness)
- Ocular inflammation
- Epiretinal membrane (a membrane that forms over the surface of the macula, which can contract and cause traction on the tissues beneath)
It is not possible to take steps to prevent a macular hole. However, it helps to be aware of the symptoms, so you know to seek attention from an eyecare professional early. Symptoms of a macular hole involve distortion or loss of your central sight. It can be difficult to notice this on one side, especially if your sight is still sharp in the other eye. In fact, you may not even realise you have an issue with the macula until you attend a routine check-up at your optometrist.
Retinal Surgery for Macular Holes
Not all macular holes need to be treated with retinal surgery. Some specialists will choose just to closely monitor a lamellar hole associated with sharp sight rather than jumping straight into vitrectomy surgery as there is a chance the hole will self-seal, and there are risks associated with retinal surgery.
However, full-thickness macular holes are typically treated with vitrectomy surgery, often sooner rather than later. Vitrectomy surgery involves surgical removal of the vitreous gel from the eyeball. This allows the vitreous to fully detach from the retina and stop pulling at it. Once the vitreous has been removed, the surgeon injects a bubble of inert gas into the space. This gas expands and pushes against the edges of the macular hole to encourage it to close, similar to stitches. Over time, the gas is absorbed and disappears.
Restoration of your central sight after retinal surgery can take some time, depending on a few factors, including how long you’ve had the macular hole. In some cases, your vision may never be as sharp as it was prior to the hole; however, treatment is still important to prevent your sight from deteriorating further. After a vitrectomy, you will be required to position yourself face-down so that the gas bubble maintains contact with the macula. However, the duration of this posture is under debate, so your retinal specialist will advise you, according to the latest research, if you need a vitrectomy.
Call us today on (03) 9070 3580 for a consultation.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.
Incidence of and Risk Factors for Developing Idiopathic Macular Hole Among a Diverse Group of Patients Throughout the United States.