This is a review of 290 patients who underwent excision of orbital cavernous venous malformations (OCVM) between 1970 and 2021, looking to identify the risk factors for a poor visual outcome following surgery. Intraconal lesions were classified as Group I, being free of the apex, or Group II which were wedged into the apex. Overall, 85% of lesions were intraconal, and 12% were Group II, wedged into the apex. Surgical approaches were via a lateral osteotomy (130), lower swinging eyelid (73) or upper lid / medial (87). Intraoperative classification described the OVCM as spongy, or fibrous, the latter often showing adherence to surrounding structures. 85% of Group II were fibrous compared to 46% of Group I. A poor visual outcome was defined as loss of three or more Snellen lines, or an acuity of counting fingers or worse. Overall, 6.9% had a poor visual outcome, with 4.1% losing all vision, all of which had intraconal lesions, comprising 5% of all Group I lesions and 30% of Group II. Predictors of a poor visual outcome were a preoperative relative afferent pupillary defect (RAPD) with a relative risk (RR) of 2.9, apical location (RR5.8), inferior to the optic nerve (RR3.3), fibrous consistency (RR6.7) and a low intraoperative diastolic blood pressure (RR2.8). This is a large series which emphasises the risk of visual loss when operating on lesions in close proximity to the optic nerve, particularly those with a fibrous / adherent nature.
Complications of orbital cavernous venous malformation excision
Reviewed by James Hsuan
Incidence and risk factors for poor postoperative visual outcome after excision of orbital cavernous venous malformations.
