The protective effect of ophthalmic viscoelastic devices on endothelial cell loss during cataract surgery: a meta-analysis using mixed treatment comparisons
Van den Bruel A., Gailly J., Devriese S., Welton NJ., Shortt AJ., Vrijens F.
BACKGROUND/AIMS: To compare ophthalmic viscoelastic devices (OVDs) in protecting the cornea from endothelial cell loss during cataract surgery. METHODS: A systematic review yielded 21 randomised controlled trials including 1769 patients. OVDs were classified according to the Arshinoff classification. Traditional pairwise meta-analyses were performed for each direct comparison. Mixed treatments comparisons (MTC) analysis was also performed to combine all direct and indirect comparisons. The outcome measure was loss in endothelial cell density 3 months after surgery. RESULTS: Direct comparison meta-analysis showed that viscoadaptives lead to a lower loss in cell density compared with very low viscosity dispersives, and compared with super viscous cohesives. The soft shell technique, a combination of viscous cohesives and medium viscosity dispersives, showed a lower loss compared with viscous cohesives, but was not compared with the other treatments. The MTC analysis shows that comparing all treatment options together, all mean differences were ≤ 100 cells/mm(2). The probability of being the best treatment option is 80% for viscoadaptives and 18% for the soft shell technique. CONCLUSION: Viscoadaptives may be superior to the other OVDs, but absolute differences in loss in endothelial cell density are <100 cells/mm(2).