Macular Hole Surgery — Understand How Does It Work

A macular hole can be a concerning finding. You may not realise you even have one until you attend a routine check-up with your optometrist or ophthalmologist and realise one eye is not seeing as well as the other. Fortunately, macular hole surgery is more often successful than not at improving your sight, provided it’s initiated in time. Keep reading to learn more about macular holes and macular hole surgery.

What is a Macular Hole?

The macula is a part of the retina at the back of the eyeball. The retina, along with the macula, is made up of ten layers of different cells, which are responsible for detecting light, converting this into neural signals, and passing these signals through the optic nerve up to the visual areas of the brain. Specifically, the macula contains the highest density of cone photoreceptors; outside the macula area are mainly rod photoreceptors. Cone photoreceptors are best at:

• Discrimination of fine detail, such as reading or recognising faces
• Perceiving and discerning different colours 
• Sight in bright light conditions, such as daytime
• Central vision

A macular hole is exactly as it sounds – a hole in the macula area. Typically, this hole develops right in the centre of the macula, which is known as the fovea. In any given year, around 8 new cases per 100, 000 people are found. This break in the macula can either involve all the layers of the retina (a full-thickness macular hole) or just the inner layers (a partial or lamellar macular hole). 

The symptoms of a macular hole can be difficult to detect, especially if your other eye still has good sight. If you were to cover your unaffected side, you might notice:

• Distortion of objects or words when you look directly at them
• Straight lines appearing bent or wavy
• A missing piece in the centre of your sight

Prompt treatment, such as with macular hole surgery, offers the best chance of success and restoring your sight. 

Macular Hole Surgery

If you’re found to have a macular hole, your retinal specialist will make a decision about whether it’s likely to close on its own. Small, early-stage macular holes may be monitored for spontaneous closure, which happens in about 50% of cases. 

For macular holes that do need intervention, your specialist may suggest an injection of a drug known as ocriplasmin, which helps the vitreous gel inside the eyeball to separate from the underlying retina. This is relevant if your macular hole is caused by pulling or traction from a shrinking vitreous on the macula. 

If watching and waiting or an ocriplasmin injection is not a suitable treatment option for you, your retinal specialist will perform macular hole surgery, also known as a vitrectomy. A vitrectomy is normally performed under topical anaesthesia. The surgeon creates tiny keyhole incisions so that he or she can insert instruments into the eyeball. These tools are used to take out the vitreous gel as well as carefully peel off the innermost layer of the retina that was in contact with the vitreous surface, known as the inner limiting membrane.

After the vitreous and inner limiting membranes have been removed, a temporary bubble of inert gas is injected into the eyeball. This bubble serves to act like a bandage, pushing against the edges of the macular hole so that it can seal back in place. 

During your recovery from macular hole surgery, your specialist will need you to follow certain post-operative instructions to increase your likelihood of success. In the past, macular hole surgery was followed by very specific physical positioning during the recovery period. That is, patients were required to lie or sit face down so that the gas bubble would remain against the macula. At the moment, not all evidence points towards this being necessary for all patients undergoing macular hole surgery, but it can be useful in some situations for supporting visual recovery. Your retinal surgeon will advise you whether face-down posturing is recommended for you. 

Over the following week or two after your operation, you will find your sight in the affected eye is quite blurry. As the gas bubble slowly dissipates and the space in the eyeball is filled with natural fluids, your sight should begin to recover. It can take up to eight weeks for the gas to be fully absorbed. During this time, you will need to be more careful with tasks that rely on sight, particularly fine depth perception. This can include navigating curbs or uneven pavements, pouring drinks, and driving. 

During your recovery from macular hole surgery, your specialist will ask you to use two to three prescription eyedrops. These usually include an antibiotic to prevent infection, a steroid to control inflammation, and a medication that helps to manage the pressure inside the eyeball. Other general post-operative guidelines also include:

• Avoiding rubbing your eyes; you may be given a protective shield to wear
• Avoiding swimming or other sources of unsterile water, including the beach or saunas
• Avoiding strenuous exercise
• Avoiding applying cosmetics around the eyes

If macular hole surgery is performed within six months of developing the hole, the success rate of the procedure is around 90%. That is, 9 times out of 10, a vitrectomy is successful at closing the hole and restoring the sight.

Call us today on (03) 9070 3580.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner. 

References

Macular Hole – EyeWiki
https://eyewiki.aao.org/Macular_Hole

Macular Hole | National Eye Institute
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/macular-hole

Macular Hole.
https://www.nhs.uk/conditions/macular-hole/#:~:text=Vitrectomy%20surgery,success%20rate%20will%20be%20lower.