Risk factors for visual loss after excision of orbital cavernous venous malformations: a systematic review

Background Orbital cavernous venous malformations (OCVMs) are the most common primary orbital mass lesion and presenting symptoms are usually secondary to a mass effect. Surgical excision presents unique challenges and vision loss is a rare, but devastating, complication. This review aims to identify risk factors for vision loss with excision of OCVMs. Method A systematic search of the databases PubMed/MEDLINE, Embase and CENTRAL was performed to May 2024, prior to data collection and risk of bias analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. 16 articles fulfilled the inclusion criteria. Results These studies identified apical location and strong adherence to apical structures, including the optic nerve, as characteristics carrying a higher risk of postoperative vision loss. Symptoms and signs with a poor visual prognosis included preoperative visual loss, relative afferent pupillary defect, optic disc abnormality and choroidal folds. Intraoperative risk factors include prolonged vascular handling and traction on the optic nerve, as well as low intraoperative diastolic blood pressure. Central retinal artery occlusion was the most common cause of vision loss. Conclusion There are several risk factors for poor visual outcome after excision of OCVMs. Surgical and anaesthetic teams should remain cognisant of these factors, and be willing to adapt their intraoperative management as required. Further large-scale prospective studies might aid the development of management guidelines.