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Direct Exchange of PerfluoroCarbon Liquid for Silicone Oil: A Surgical Technique to Control Pressure and Avoid
Maxwell P Treacy1, Marcus P Conway2, Mohammad Al Hammoud3
1Moorefields Eye Hospital, Ophthalmology Department, London, England, Medical Optics, Ophthalmology Department, Dublin, Ireland, and Royal Victoria Eye and Ear Hospital, Ophthalmology Department, Dublin, Ireland.
Background/Purpose:
Perfluorocarbon heavy liquid (PFCL) is used in vitreoretinal surgery to flatten the unsupported detached retina before insertion of silicone oil in cases of giant retinal tear or relaxing retinectomy. Direct exchange of PFCL for silicone oil is recommended to reduce retinal slippage when compared with fluid-air exchange, but it is commonly regarded as a difficult procedure. We describe our technique for direct PFCL-silicone oil exchange using a 20-gauge drainage cannula, reliably avoiding the complications of retinal slippage and high intraoperative intraocular pressure.
Methods:
We present a consecutive case series of patients undergoing PFCL-oil exchange and explain, using Poiseuille's equation for laminar fluid flow through a cannula, the rationale for using a 20-gauge drainage cannula rather than smaller gauges to avoid high intraocular pressure.
Results:
Twenty-six patients underwent PFCL-oil exchange from February 1, 2019, to September 30, 2019. There was no intraoperative retinal slippage or pressure-related complications. Postoperatively 20 patients underwent oil removal. Six suffered retinal redetachment, and 14 remained attached. The vision postoil removal ranged from 6/6 to hand movements.
Conclusion:
We are confident that the PFCL-oil exchange technique described here is reliable and safe. The use of a 20-gauge drainage cannula is recommended regardless of vitrectomy gauge.
