Emulsification of Different Viscosity Silicone Oil in Complicated Retinal Detachment Surgery: A Randomized Double-Blinded Clinical Trial

OBJECTIVE: To study silicone oil (SO) emulsification, anatomic and visual outcome after complicated retinal detachment surgery by pars plana vitrectomy (PPV) with intraocular SO tamponade, comparing between low and high viscosity SO. DESIGN: Randomized, double-blinded, controlled trial. PATIENTS AND METHODS: Patients with complicated retinal detachment who had been surgically treated by PPV and intraocular SO tamponade were randomly divided into low viscosity (Group 1) or high viscosity (Group 2). Main Outcome Measures were rate of silicone oil emulsification, anatomic retinal reattachment and visual outcome, assessed at 1,3,6,9 and 12 months. RESULTS: One hundred patients were divided into 50 patients in each group. The rate of silicone oil emulsification in Group 1 (63.64%) was higher than Group 2 (40%), but the difference was not statistically significant (p = 0.08). Rates of anatomic retinal reattachment were 88% in Group 1 and 90% in Group 2 (p = 0.76). For functional visual outcome, final best-corrected visual acuity (BCVA) at Month 12 compared with the baseline BCVA was improved vision 52% in Group 1 and 58% in Group 2 (p = 0.82). CONCLUSION: SO emulsification rate in low viscosity group is non-significantly higher than high viscosity group, but results in a comparable reattachment rate and final visual recovery. Emulsification in both groups is detected at as early as 1 month and mostly within 3 months. We recommend using either low or high viscosity SO in complicated retinal detachment surgery and removing it as early as possible to prevent the consequent serious complications. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02988583.