Diagnosis and treatment

What does the operation involve?

The surgery to repair a macular hole is called a vitrectomy. It's done by a specialist eye surgeon.

The procedure usually takes about 30 to 60 minutes. Most often, we do it under local anaesthetic. This means your eye is numbed, and you stay awake but comfortable. You won't see the details of what's happening, but you might be aware of bright lights. Sometimes, we may use a general anaesthetic, where you are asleep. Your surgeon will discuss the best option for you.

1. During the vitrectomy:
   Tiny incisions: The surgeon makes three very small cuts (less than 1mm) in the white part of your eye. These usually don't need stitches.
2. Removing the vitreous gel: A tiny instrument is used to remove the jelly-like substance (vitreous gel) from the middle of your eye. This is replaced with a clear saline solution during the surgery.
3. Peeling the membrane: The surgeon may peel a very thin, innermost layer of the retina called the internal limiting membrane (ILM). This helps to relieve any pulling forces on the macula and encourages the hole to close.
4. Gas bubble: At the end of the surgery, a special gas or air bubble is put inside your eye. This bubble acts like an internal bandage, gently pressing on the edges of the macular hole to help it close and heal. The gas bubble will gradually disappear over time (see 'Types of Gas and What to Expect').
5. During the vitrectomy procedure the medicine Triamcinolone
   Acetonide may be used as an aid to visualise the vitreous. This medicine is being used as an “unlicensed product” but has been used at Moorfields for this purpose for decades. For more information visit our pages on unlicensed medicines, or discuss with your clinician if you have any questions.

What are the benefits of surgery?

The main aim of surgery is to close the macular hole and improve your central vision, especially your reading vision.

• High success rate for closure: For most macular holes, there is a very high chance (around 90-95%) that the hole will close after one operation. Success rates are generally better for smaller holes and those that haven't been present for a long time.
• Improved vision: Many patients (over 70%) experience an improvement in their central visual acuity, often by 2 or 3 lines on a vision chart.
• Reduced distortion: The wavy or distorted vision often improves
  significantly once the hole is closed.
• Stabilisation: Surgery prevents the hole from getting larger and your vision from getting worse due to the macular hole.

Vision improvement can be slow. It may take many months, sometimes up to a year, to see the full benefit of the surgery. Complete restoration of vision is not possible, especially for larger or long-standing holes.

Anaesthesia for your operation

Most operations for macular holes are performed under a local anaesthetic, which means you will be awake throughout your operation. We will inject local anaesthetic into the area around your eye to numb your eye and prevent you from feeling any pain during the operation. You will not be able to see details of what is happening, but you might be aware of the bright lights or movement in the operating theatre. During the operation, we will ask you to lie as flat as possible and keep your head still.

General anaesthesia, under which you are asleep for the whole operation, is rarely used for macular hole surgery. If you require a general anaesthetic, you will need to follow specific instructions about eating and drinking prior to your operation.

Your operation

The operation to repair your macular hole is called a vitrectomy and usually takes about an hour. Whichever form of anaesthetic you chose, we will give you eye drops before your operation to enlarge your pupils. The surgeon will then make tiny openings in your eye and remove the vitreous (the jelly-like substance) from inside. Your eye is then filled with a bubble of special gas, which presses against the macula and seals the hole.

If we put a gas or air bubble in your eye you must not fly for the periods of time specified below. This is because the gas or air bubble will expand in size and can lead to raised pressure inside your eye, leading to visual loss.

We use three types of gases:

• C3F8 which is long acting and can stay in your eye for up to 12 weeks.
• SF6 which can stay in your eye for up to four weeks.
• C2F6 which can stay in your eye for up to eight weeks.
• Air – which can stay in your eye for up to two weeks.

You will be told after your surgery which type of gas bubble was used. The surgeon might put small stitches in your eye to close up the opening. The stitches dissolve naturally over about four to six weeks. At the end of the operation, we usually put a pad and shield over your eye to protect it. These will be removed the morning after your surgery.

After your operation – how your eye will feel

Your eye will feel uncomfortable, gritty, and itchy. It might appear red or bruised and the vision is likely to be very poor at first. This is normal for seven to 14 days. We will give you eye drops to reduce inflammation and to prevent infection, and will explain how and when you should use them. You can also take paracetamol for pain relief as advised on the packet. Please do not rub your eye. Your eye will take between two and six weeks to heal, but your vision might continue to improve for several months.

Your vision

Your vision will be very poor with the gas in your eye. As the gas disperses and is replaced by your eye’s natural fluid, you will begin to see a line, which wobbles in your vision, like a spirit level. You will be able to see above the line, but the vision will be fuzzy underneath. This line will continue to ease downwards until only a tiny bubble is left and finally, it too will disappear.

It is important to note that the gas can react with another gas called nitrous oxide, which can cause problems in your eye if any is administered. Nitrous oxide is commonly used during childbirth and in A&E as pain relief. Please tell the midwife or A&E staff treating you (or ask your family to) that you have gas in your eye and that they should not administer any nitrous oxide. Should you need a general anaesthetic for any reason during this time it is important that you also tell the anaesthetist that you have had surgery and gas in your eye.

Posturing

This is the hardest part of the recovery following your surgery, but the most important. If we put gas or silicone oil in your eye, we usually ask you to “posture” for up to seven days. This means lying or sitting in a position that keeps your face down (so that the bubble floats up and presses the retina into position while it is healing).

Your surgeon will advise you if it is necessary for you to posture after your surgery, and will give you another information to show you how to do this.