A vitrectomy is a surgical procedure performed by an ophthalmologist in which the gel-like fluid in the back of the eye (the vitreous humour) is removed and replaced with an artificial solution. It may be performed if the vitreous has become cloudy, or to repair diseases in the back of the eye (the retina).
What is the vitreous humour?
The vitreous humour (commonly called just “the vitreous”) is the fluid that fills most of the eye. It is contained in the space between the lens and the retina.
The fluid of the vitreous is mostly water (in fact it is 99% water), but is significantly less viscous than water due to the salts, sugars, cells and collagen fibres contained in it. Unlike the aqueous humour, the vitreous humour is not continually produced and drained.
Diagram showing an eye in cross-section. Note the location of the vitreous humour.
Why would a vitrectomy be performed?
There are many eye diseases that may require a vitrectomy to be performed. Some examples include:
• Bleeding inside the eye: This is called vitreous hemorrhage, and occurs when blood leaks from the surrounding structures in the eye. Sometimes, this blood is naturally cleared from the vitreous, but in other instances a vitrectomy may be required to clear the vitreous of the blood.
• Infection: Infection of the eye can occur from injury or as a complication from other eye surgery. Sometimes, the infection can become severe; this is known as endophthalmitis. In the past, endophthalmitis frequently resulted in loss of the eye, however today a vitrectomy can treat endophthalmitis and result in a good outcome.
• Foreign bodies in the vitreous: A vitrectomy may be required to remove foreign objects in the eye.
• Macular holes: recall that the macula is the central portion of the retina responsible for our sharp, central vision. Sometimes, a “hole” can develop in the macula.
• Retinal detachment: Vitrectomy may be used to treat a retinal detachment if it is severe and/or other treatment options have failed.
• Diseases of the retina: Some diseases of the retina, such as diabetic retinopathy or pre-retinal membrane fibrosis, may be treated by vitrectomy if the diseases is severe.
• Complications from other eye surgeries: During cataract surgery, the natural lens (that has become cloudy) in the eye is replaced by an artificial lens. Sometimes during the surgery, pieces of the lens may detach and “drop” into the vitreous gel. A vitrectomy is usually required to retrieve these lens fragments.
Diagram showing a large retinal detachment. Such a severe retinal detachment would likely require vitrectomy to repair.
Diagram showing proliferative diabetic retinopathy. The vitreous hemorrhage shown will obstruct vision. If the hemorrhage is severe, a vitrectomy may be required to restore vision.
How is the surgery performed?
Prior to surgery, patients are given special drops that prepare the eye for surgery. These drops dilate the pupil to allow the surgeon to better see the eye and also numb the eye so that the surgery is comfortable for the patient.
Next, tiny incisions (less than 2 mm) are made in the eye through which the surgical instruments are inserted. Surgical instruments include:
• A light source: this helps the surgeon visualize the back of the eye during surgery. Sometimes, the surgeon may use special contact lenses as well to focus light on the back of the eye
• A vitreous cutter: this is a special tool that breaks apart the vitreous and sucks it out so it can be replaced with new fluid
• An infusion line: this maintains the shape of the eye by replacing lost vitreous with a saline solution.
When all instruments are in place, the vitreous is removed and replaced with the saline solution. In addition, if other eye diseases are present in the back of the eye, they will be treated during the surgery as well.
Animation showing the basic steps of vitrectomy surgery. In this case, vitrectomy is being performed to remove an opacity in the vitreous. Click on the picture to start the animation. To restart the animation, press REFRESH in your web browser.
Who performs a vitrectomy?
A vitrectomy is usually performed by an ophthalmologist who has completed medical school, residency training in ophthalmology plus further training in vitreo-retinal surgery.
How long does a vitrectomy take?
Usually, a vitrectomy takes between 1 and 2 hours. However, since a vitrectomy may be performed to treat a variety of eye diseases, the time it takes is highly variable.
What are the complications from surgery?
Like all surgeries, there is always a risk that there will be a complication from surgery. The most common complications from vitrectomy include cataracts and retinal detachments. A less common but more severe complication is an infection of the eye (endophthalmitis).
Fortunately, most of these complications are rare and easily treated if they do occur.
How well does someone see after a vitrectomy?
A vitrectomy may be performed to treat a variety of eye diseases. The outcome of surgery depends on the underlying disease as well as many other factors. In most cases, vision is significantly improved after surgery.
