Orbital Compartment Syndrome without Evidence of Orbital Mass or Ocular Compression After Pterional Craniotomy for Removal of Meningioma of the Frontal Lobe: A Case Report and Literature Review

Background: Orbital compartment syndrome (OCS) is a rare post operative complication of Neurosurgery. It presents typically acutely with loss of vision, loss of pupillary reaction, and limitation of extraocular movement. The etiology of OCS is most typically associated with increased pressure from a mass lesion in the orbit compromising the blood supply of orbital structures. Emergent bedside decompression of the orbit by lateral canthotomy is indicated to quickly treat OCS in an attempt to save visual acuity and extraocular function. Case Description: We report a 76-year-old male patient whose magnetic resonance imaging of the brain demonstrated an anterior right frontal broad dural-based homogenously enhancing mass measuring 6.0 × 3.1 × 6.3 cm after he presented with 1-year of progressive cognitive dysfunction. A right-sided pterional craniotomy and resection of mass was performed under general anesthesia, with an uncomplicated intraoperative course. Postoperatively, the right eye was noted to have an afferent pupillary defect, complete ophthalmoplegia, ptosis, and significant resistance to retropulsion. Emergent ophthalmologic consultation confirmed the ocular examination, and the diagnosis of right OCS was suspected. A right lateral canthotomy and cantholysis was performed by the ophthalmologist at the bedside. The fundoscopic retinal evaluation was normal. Noncontrast computed tomography of the head demonstrated expected postoperative changes and mild edema of the right frontal lobe without evidence of acute hemorrhage. There was no retro-orbital hematoma, but the right extra-ocular muscles appeared edematous compared to the left. No light perception and ophthalmoplegia continued in the right eye. Conclusions: This case demonstrates that although very rare, OCS can occur without compression of the eye or an intra-orbital mass. Visual loss is a devastating complication. Constant vigilance to ensure adequate arterial and venous supply to the orbit, with great care to prevent external compression on the eye, hopefully, will continue to make this complication rare.