Development of cystoid macular edema after uneventful cataract surgery in eyes with a history of vitrectomy using silicone oil versus gas tamponade

Background/Objectives: The purpose of this study is to investigate whether history of silicone oil tamponade may predispose to the development of cystoid macular edema (CMO) following uneventful post-vitrectomy cataract surgery. Subjects/Methods: This is a retrospective study that was conducted at a single academic institution. Records of patients who underwent pars plana vitrectomy (PPV) with or without silicone oil tamponade and subsequent cataract surgery between 2017–2020 were reviewed. Macular optical coherence tomography (OCT) findings up to 4 years after surgery were assessed. Results: A total of 95 eyes were included. Forty-one eyes underwent cataract surgery and had a history of PPV with silicone oil tamponade (Group 1). Fifty-four eyes underwent cataract surgery by phacoemulsification and had a history of PPV with gas tamponade (Group 2). Average follow up time after cataract surgery was 41.1 months. In Group 1, the incidence of OCT-detected CMO was 39.0%, compared to 27.8% in Group 2 (p = 0.247). The incidence of clinically significant CMO in Group 1 was 22.0%, compared to 18.5% in Group 2 (p = 0.679). The duration of CMO was significantly longer in Group 1 (p = 0.041) and cases were less likely to resolve by the last follow up visit (p = 0.040). Conclusions: The incidence of OCT-detected or clinically significant pseudophakic CMO is not significantly different between eyes with prior PPV with gas tamponade versus silicone oil tamponade. However, CMO after uneventful cataract surgery may have a prolonged course if there is history of silicone oil tamponade, requiring longer treatment.