Perfluoropropane was the worst of the three gases for routine detachment

Design

registry cohort study with propensity-score matching and weighted regression, prespecified equivalence margins

Population

7,466 eyes (anatomical) and 5,734 (visual) after low-to-moderate complexity primary rhegmatogenous detachment repair, 2012 to 2024

Primary outcome

single-operation anatomical success and postoperative visual acuity

Effect

C3F8 0.10 logMAR worse than C2F6 (95% CI 0.07 to 0.14); cystoid macular oedema OR 2.72 vs SF6

A registry analysis drew on British and Eire Association of Vitreoretinal Surgeons and EURETINA data from 2012 to 2024, comparing sulphur hexafluoride, perfluoroethane and perfluoropropane in low-to-moderate complexity primary rhegmatogenous retinal detachment: 7,466 eyes for anatomical outcomes and 5,734 for visual, matched on propensity score with prespecified equivalence margins.

Vision was where the gases separated. C2F6 and SF6 were indistinguishable (mean difference -0.01 logMAR, 95% CI -0.04 to 0.01). C3F8 was worse than both - 0.10 logMAR worse than C2F6 (0.07 to 0.14) and 0.09 worse than SF6 (0.04 to 0.13). It also carried more cystoid macular oedema than SF6 (OR 2.72, 1.13 to 6.57) and more raised intraocular pressure than C2F6 (C2F6 versus C3F8 OR 0.41, 0.24 to 0.68). On single-operation anatomical success, estimates leaned towards C2F6 - against SF6 OR 1.19 (0.97 to 1.48) and against C3F8 OR 1.28 (1.01 to 1.65) - while C3F8 showed no advantage over SF6 at all (OR 0.83, 0.58 to 1.13).

For uncomplicated detachment the practical message is to stop reaching for the longest-acting gas by default. Its longer tamponade buys nothing anatomically here and comes with worse acuity, more macular oedema and more pressure trouble, alongside the weeks of poor vision and positioning restrictions the patient lives with. Reserve C3F8 for the cases where its duration is the reason you chose it - inferior breaks, extensive proliferative change - and use SF6 or C2F6 for the rest.

• Default to SF6 or C2F6 in low-to-moderate complexity primary detachment
• Reserve C3F8 for cases where prolonged tamponade is specifically indicated
• Warn patients on C3F8 about the higher pressure risk and check it more closely
• Watch for cystoid macular oedema postoperatively after C3F8
• Weigh the weeks of restricted vision and air travel against an anatomical benefit that was not demonstrated

Why it matters

The longest-acting gas is chosen for safety margin, and on these data it costs vision without buying anatomical success.

Don't overread it

Registry data with propensity matching, not a randomised comparison; the gas was chosen by the surgeon for reasons the model may not capture.

The statistics, in plain English

A 0.10 logMAR difference is about one line on the chart - small for one patient, meaningful across a service. The anatomical comparisons are the weaker half: C2F6 against SF6 at OR 1.19 with an interval from 0.97 to 1.48 includes no difference, so 'favoured' means the estimate leaned that way, not that a benefit was shown. Propensity matching cannot remove the reason a surgeon chose a long-acting gas - harder cases attract C3F8 - and residual confounding by complexity plausibly explains part of the worse vision.

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