Silicone oil in the eye after retinal surgery: why it is used, when it is removed, and its risks

"The doctor told me there is oil in my eye after the operation and that it will be removed in a few months. Will the oil stay in my eye all that time? Is it dangerous? And why didn't he use gas like other patients?" These are natural questions, because having "oil" inside the eye seems strange at first. In fact, silicone oil is a very important tool in difficult retinal surgery, but it needs regular follow-up, and its removal is usually planned for the right time.

Why is oil put in the eye at all?

At the end of a vitrectomy, the surgeon may need something that presses on the retina from inside and holds it in place until it heals. The two best-known options are gas and silicone oil.

Gas is absorbed on its own within days to weeks and needs no operation to remove it. Oil stays in the eye until it is removed, giving the retina longer support. That is why it is usually preferred in more difficult cases. In a series of patients treated with oil, the most common reasons were retinal detachment with scar tissue (proliferative vitreoretinopathy), advanced diabetic retinopathy, and eye injuries (Honavar et al., 1999).

In a clinical trial in retinal detachment with severe scarring, oil gave better results than one type of short-acting gas: the macula was attached in about 80% of eyes versus 60%, and a larger proportion of patients had better vision (Silicone Study Group, 1992). But the researchers explained that this difference was not seen when oil was compared with another, long-acting gas (Silicone Study Group, 1992). In other words, the choice between oil and gas depends on the case and on the patient's circumstances, such as their ability to keep a head position, or their need to travel.

What can I expect while the oil is in my eye?

• Vision: usually remains relatively limited while the oil is in the eye, and improves after removal in many patients if the retina is healthy.
• Travel: some hospitals advise not flying for two weeks after surgery unless the surgeon allows it (Moorfields Eye Hospital NHS Foundation Trust, 2020). So ask your surgeon before any trip. We explain the danger of gas and flying in our article on the gas bubble after retinal surgery.
• Regular follow-up: the most important thing we monitor is eye pressure.

Why do we care about eye pressure with oil?

Raised eye pressure is one of the most common complications of silicone oil. In a study of more than 250 eyes, pressure rose in about half of the eyes after surgery, mostly within the first week (Jabbour et al., 2018). In complicated retinal detachments, raised pressure persisted for a long time in a larger proportion, and it was controlled in most of them with drops, removal of the oil, or glaucoma surgery, while it remained hard to control in some (Honavar et al., 1999).

This does not mean that everyone with oil in the eye will develop glaucoma, but it explains why pressure-check appointments must not be missed, even if the eye feels comfortable.

Other problems that can occur with oil

• Breakdown of the oil into small droplets (emulsification): over time part of the oil may turn into very small bubbles. In one study this happened in about 7% of patients before the oil was removed (Tayyab et al., 2023). Emulsification has been linked to difficulty controlling eye pressure (Honavar et al., 1999).
• Cataract: usually develops after vitrectomy in general in people over 50 (Cherfan et al., 1991). We explain what is specific to cataract surgery in these eyes in our article on cataract surgery after vitrectomy.
• Corneal and optic nerve problems with long-term oil: in a few patients the oil stays in for more than a year because their condition is very complicated. In a study of these patients, some developed corneal problems, and the optic nerve was affected in about 28% of them (Morphis et al., 2012). That is why it is usually preferable not to leave the oil in longer than necessary.

When is the oil removed?

The oil is usually removed after several months, once the surgeon is confident that the retina has healed firmly (Moorfields Eye Hospital NHS Foundation Trust, 2020). There is no single duration that suits every patient. In a study of more than 200 patients, the oil was removed after about 10 months on average, and the risk of redetachment was not linked to how long the oil had stayed in, with a minimum of about 3 months in that study (Jonas et al., 2001).

Removing the oil is usually a relatively simple operation compared with the first one (Moorfields Eye Hospital NHS Foundation Trust, 2020).

Can the retina detach again after the oil is removed?

Yes, and this is one of the most important things for a patient to know before removal. In the study mentioned above, the retina detached again after oil removal in about a quarter of patients (Jonas et al., 2001). The risk was higher in those who had more previous failed detachment operations, those with poorer vision before removal, and depending on the original reason for surgery (Jonas et al., 2001). In other words, much of this risk reflects how difficult the case was in the first place, which is why oil was used.

Unexplained vision loss: rare but recognized

In a proportion of patients, vision drops while the oil is in place or after it is removed, without a clear cause on examination or scans. In a study of patients whose oil was removed, this happened in about 11%, and it was linked to raised eye pressure while the oil was in place and to emulsification of the oil (Oliveira-Ferreira et al., 2020). In a small series of one specific type of case (detachment that had not reached the macula, mostly caused by very large retinal tears), the rate was much higher, and the researchers advised surgeons to tell patients about this possibility and to remove the oil as soon as appropriate (Barth et al., 2023).

The cause of this phenomenon is still not fully understood (Ruggeri et al., 2026). We mention it not to frighten anyone, but because patients have a right to know the real risks, and to understand why the surgeon is careful about follow-up and about not leaving the oil in longer than necessary.

Questions patients often ask

Can the oil stay in my eye forever?

In most patients the oil is removed after several months. But in a few very complicated cases, it may be left in for a long time as a last resort, with careful monitoring for complications (Morphis et al., 2012).

Will my vision come back after the oil is removed?

Vision improves in many patients after removal if the retina is healthy, but final vision depends on the original disease and the state of the macula, and complications such as redetachment can occur (Jonas et al., 2001).

Why did the doctor use oil for me and gas for another patient?

Because the choice depends on how difficult the case is, whether there is scar tissue, the patient's ability to keep a head position, and their need to travel (Silicone Study Group, 1992). No single approach suits every case.

Can I feel the oil inside my eye?

You do not usually feel it. But if you notice pain or redness that is getting worse, or a sudden drop in vision, call your doctor.

Summary

Silicone oil is an important tool in complicated retinal surgery, because it supports the retina for longer than gas. But it is not something to be "forgotten" in the eye: it needs regular checks of eye pressure, and its removal is usually planned after several months. It is important for patients to know, before the oil is removed, that the retina can detach again in a proportion of patients, and that final vision depends mainly on the original disease. We make sure each patient understands this whole picture, so they can follow their condition with awareness and confidence.

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