When to use gas, oil, or air in vitreous (vitrectomy) surgery?

From the Guidelines

Gas tamponade, specifically SF6, is the preferred choice for vitrectomy in cases of idiopathic macular holes, due to its high closure rate of 98% 1. When deciding between gas, oil, or air in vitrectomy, several factors must be considered, including the type of retinal condition, patient compliance with post-operative positioning, and the need for a second surgery.

• Gas tamponade is ideal for macular holes, with SF6 providing a high closure rate, as seen in a recent study 1.
• Silicone oil may be used for patients who cannot maintain face-down positioning, but it requires a second operation for removal and may result in anatomic and visual outcomes that are not as good as those with gas tamponade 1.
• Air tamponade and internal limiting membrane (ILM) peeling can also achieve high closure rates, but this may not be as effective for larger macular holes 1. Key considerations in the decision-making process include:
• The size of the macular hole, with larger holes potentially requiring longer positioning or alternative tamponade methods 1
• Patient comfort and ability to maintain post-operative positioning, as face-down positioning can be uncomfortable and may lead to complications 1
• The need for a second surgery to remove silicone oil, which may be a consideration for some patients 1
• The potential risks and benefits of each tamponade method, including the risk of cataract progression and the importance of a good post-operative gas fill 1

From the Research

Tamponade Agents in Vitrectomy

The choice of tamponade agent in vitrectomy depends on various factors, including the type of retinal detachment, the presence of proliferative vitreoretinopathy (PVR), and the surgeon's preference. The following are some guidelines based on the available evidence:

• Air vs. Gas: A study published in 2022 2 compared the outcomes of filtered air and sulfur hexafluoride (SF6) gas tamponade in patients undergoing primary pars plana vitrectomy for uncomplicated rhegmatogenous retinal detachment with inferior breaks. The results showed no significant difference in single-surgery anatomical success rates and final visual recovery between the two groups.
• Gas vs. Silicone Oil: A randomized clinical trial published in 1992 3 compared the outcomes of vitrectomy with silicone oil or sulfur hexafluoride gas in eyes with severe PVR. The results showed that silicone oil was associated with better visual acuity and macula attachment rates compared to gas. However, another study published in 1997 4 found that silicone oil and perfluoropropane gas were equal in most respects for the management of retinal detachments with PVR.
• Type of Gas: A systematic review and meta-analysis published in 2022 5 compared the outcomes of different tamponade agents, including air, gas (SF6, C2F6, and C3F8), and silicone oil, in patients undergoing vitrectomy and internal limiting membrane peeling for idiopathic macular holes. The results showed no significant difference in anatomic closure rates between studies using SF6 compared to either C3F8 or C2F6.

Indications for Each Tamponade Agent

Based on the available evidence, the following are some indications for each tamponade agent:

• Air: May be used for uncomplicated rhegmatogenous retinal detachment with inferior breaks 2.
• Gas: May be used for retinal detachments with PVR, including those with severe PVR 3, 4, 6. The choice of gas type (SF6, C2F6, or C3F8) may depend on the surgeon's preference and the specific clinical scenario.
• Silicone Oil: May be used for retinal detachments with severe PVR, particularly those with a high risk of redetachment 3, 4, 6. Silicone oil may also be used in cases where a longer-acting tamponade is desired.

Some key points to consider when choosing a tamponade agent include:

• The type and severity of the retinal detachment
• The presence of PVR and its severity
• The surgeon's preference and experience
• The potential risks and benefits of each tamponade agent, including the risk of complications such as cataract formation, glaucoma, and retinal redetachment.