Vitrectomy: why we do it, how it is done, and what to expect afterwards

When patients hear the name of this operation for the first time, it often surprises them: "Removing the vitreous? Can the eye live without it?" It is a reasonable question. This is one of the most common retinal operations, and we do it for very different reasons: retinal detachment, a hole in the macula, bleeding in the eye in people with diabetes, and more. In this article we explain what happens during the operation, and why recovery can differ so much from one patient to another.

What is the vitreous, and why do we remove it?

The vitreous is a clear, jelly-like substance that fills the inside of the eye behind the lens and is attached to the surface of the retina. It matters while the eye is developing, but an adult eye works well without it, because the natural fluid the eye produces fills the space after the operation.

We remove it because it may itself become the cause of the problem, or block the way to treating it:

• It pulls on the retina, causing a tear and a detachment, or pulls on the macula and causes a hole.
• It fills with blood, as in bleeding inside the eye in people with diabetes, blocking vision.
• It blocks access to the retina, so the surgeon cannot remove a membrane from its surface or repair a detachment until it has been removed.

Which conditions is the operation used for?

The operation is used for a wide range of conditions. In a series of hundreds of operations, the most common reasons included a membrane on the macula, troublesome floaters, traction detachment in diabetes, vitreous hemorrhage, macular hole, retinal detachment, removal of silicone oil, and a dislocated intraocular lens (Khan et al., 2018).

Each of these reasons has its own story. We explain some of them in detail in our articles on macular hole and epiretinal membrane, retinal detachment surgery, flashes and floaters, and a dislocated intraocular lens.

How is the operation done?

This operation was first described in the early 1970s (Machemer et al., 1971), and its instruments have advanced greatly. Today it is usually done through three very small openings in the white of the eye, each less than a millimeter across (Khan et al., 2018), and it usually needs no stitches (Hu et al., 2009).

The operation generally follows these steps:

1. Anesthesia: usually local, around the eye, with sedation; sometimes general, depending on the case and the patient.
2. Inserting the instruments: a fine light source, a delicate instrument that cuts and removes the vitreous, and a tube that infuses fluid to keep the shape of the eye during surgery.
3. Removing the vitreous, then treating the reason for the operation: sealing a tear with laser, removing a membrane from the macula, removing blood, or other steps.
4. Filling the eye at the end of the operation with fluid, gas, or silicone oil, depending on the case.

In a series of hundreds of operations done with some of the smallest instruments currently used, vision improved on average after surgery, and complications were few across different conditions (Khan et al., 2018).

Why does the surgeon leave gas or oil in the eye?

In some operations, such as for retinal detachment and macular hole, the surgeon needs something to press on the retina from the inside until it heals. This is either a gas bubble, which is absorbed on its own within weeks, or silicone oil, which stays until it is removed in another operation.

Each has important instructions the patient must know precisely, especially gas, which rules out flying and some types of anesthesia. We have a separate article on each: the gas bubble after retinal surgery and silicone oil in the eye.

What can you expect after surgery?

Recovery differs a great deal depending on the reason for the operation and what was left in the eye at the end:

• If the operation ended with fluid only, vision starts to improve within days to weeks.
• If it ended with gas, vision is very poor at first and improves gradually as the gas is absorbed. The surgeon may ask for a particular head position.
• If it ended with silicone oil, vision stays relatively limited as long as the oil is in the eye.

In the first days it is normal to have redness, a gritty feeling, and mild discomfort that gradually eases. The doctor prescribes drops for inflammation and to prevent infection.

It is important to separate two things: anatomical success (the retina reattached, the hole closed, or the blood removed) is one thing, and final vision is another. Vision after surgery depends mainly on the original disease and how long the retina was affected before surgery.

What are the real complications?

Cataract: the most common

If your eye still has its natural lens and you are over 50, a cataract is expected to develop faster after the operation. In a study of patients operated on for a membrane on the macula, a cataract became visually significant, or had already been removed, in 80 out of every 100 operated eyes, compared with 24 out of every 100 of the patients' other eyes (Cherfan et al., 1991). It developed about six times faster in people over 50, and faster when gas was used (Thompson, 2004).

In people with diabetes, however, the need for cataract surgery after vitrectomy was lower in one study (Smiddy and Feuer, 2004). We explain what is specific to this cataract operation in our article on cataract surgery after vitrectomy.

Raised eye pressure

Eye pressure may rise in the first days after surgery. In a large series, a temporary rise occurred in about 11% of eyes (Khan et al., 2018). A small study found a sustained rise needing follow-up in a proportion of patients, even after uncomplicated operations (Cabuk and Cekic, 2021). That is why the doctor measures the pressure at follow-up visits.

Infection inside the eye

This is one of the most serious complications, but it is very rare. In a study of more than 3,000 operations, it occurred in roughly one case only (Hu et al., 2009), and in another series it occurred after about 1 in 400 operations (Khan et al., 2018).

Retinal tears or detachment

Tears can occur in the retina during surgery, and the surgeon treats them at the same time. But a retinal detachment can occur later in a small proportion of patients. In a study of people operated on for floaters, a detachment occurred after about 2.5% of operations (Tan et al., 2011).

Questions patients often ask

Will I live without the vitreous?

Yes. The adult eye does not need it to work, and the natural fluid the eye produces fills its place after the operation.

Is the operation painful?

It is not painful during surgery, thanks to the anesthesia. Afterwards discomfort is usually mild and eases within days. Severe or increasing pain needs an immediate call to the doctor.

When can I go back to work?

That depends on the type of work, what was left in the eye at the end of the operation, and whether a head position is needed. Your surgeon will decide for your case.

Will I need cataract surgery afterwards?

If you are over 50 and your eye still has its natural lens, this is very likely in the following years (Cherfan et al., 1991; Thompson, 2004). Sometimes the surgeon performs both operations together, depending on the case.

Summary

Vitrectomy is not a treatment for one disease; it is the route by which the surgeon reaches the retina to treat many diseases. Recovery depends on the original disease and on what is left in the eye: fluid, gas or oil. It is important for patients to know the real complications before surgery, chief among them the development of a cataract, to follow the instructions afterwards, and to know the signs that need an immediate call to the doctor.

This information is for health education and does not replace a medical examination.