Air versus gas tamponade in retinal detachment surgery

Objective: To compare the outcome of air tamponade with gas tamponade in primary vitrectomy for the treatment of rhegmatogenous retinal detachment (RRD). Methods: We examined the records of 524 cases of 523 patients that underwent primary vitrectomy for RRD with air or sulphur hexafluoride 20% gas tamponade and a follow-up of at least 3 months, excluding cases with inferior retinal breaks. Results: 318 cases were treated with gas and 128 cases with air. Overall, vitrectomy led to an attached retina after a single operation in 85.1% of cases. Eyes treated with air had an 81.0% chance of primary success and those treated with gas had an 86.9% success rate (p=0.083, NS, χ² test). Involvement of lower retinal quadrants in the retinal detachment was revealed as a significant confounding factor. After correction for this confounder using a multivariate logistic regression model, air versus gas tamponade became a statistically significant determinant for success rate (OR 1.97; p=0.012). In a sub-analysis, eyes with a retinal detachment that involved the inferior quadrants had significantly lower primary success rates when using air tamponade (69.6%), compared to gas tamponade (84.7%; p=0.009, χ² test). Conclusions: Gas tamponade is superior to air tamponade in retinal detachment cases with involvement of the lower quadrants. These results suggest that air tamponade should only be used in retinal detachments that are restricted to the superior quadrants. Further prospective study is needed to confirm these findings, and to address functional outcome.