MRI detection of residual perfluoro-n-octane after vitreoretinal surgery

Purpose. Utilization of MRI to determine if any residual PFO remains in the eye after BSS "wash-out" during vitreoretinal surgery and to establish the effectiveness of this surgical technique in the removal of perfluorocarbon liquid. Materials and Methods. Eight eyes status post vitreoretinal surgery with PFO for giant retinal tears and/or retinal detachment with proliferative vitreoretinopathy were examined by spin-echo T1- and T2- weight images. PFO had been removed from the eyes by air-fluid exchanged with concurrent PFO aspiration with the soft tip cannula. This was followed by injection of 0.5-1.0 cc of BSS to allow visualization of residual PFO which was then completely aspirated. Cadaveric human eyes injected with PFO were used as a control. Results. No evidence of residual PFO was identified by MRI in any of these eyes. Conclusions. Perfluorocarbon liquids (PFCLs) are frequently employed to facilitate vitreoretinal surgery in a variety of pathological conditions. However, animal studies have shown significant retinal toxicity to long-term retained PFCLs. These compounds show a distinctive characteristic flow void on spin echo T1-and T2- weighted imaging. Therefore, MRI is an excellent tool to detect residual PFCLs, especially when corneal or media opacities limit adequate ophthalmoscopy. The technique of air-fluid exchange followed by BSS "wash-out" resulted in complete removal of PFO in our patients and is a very effective method to insure thorough extraction of this PFCL.