Endoscopic transnasal orbital decompression for visual failure due to sphenoid wing meningioma.

Objective: To review a group of patients with sphenoid wing meningioma and visual impairment. The technique and results for endoscopic transnasal decompression of the orbital apex is presented.

Methods: Patients presenting between 1993 and 2004 with visual impairment due to sphenoid wing meningioma were identified. All patients had full ophthalmic assessment, automated visual field testing, and appropriate orbital imaging. Patients with clinical evidence of significant progression in visual impairment (loss of acuity, reduced colour discrimination, or field deterioration) underwent endoscopic transnasal orbital decompression. Methods: Assessment of visual function (Snellen acuity, Ishihara colour perception, and visual field testing), together with other measures of orbital structure and function (ocular balance, ductions, and exophthalmometry).

Results: Twelve patients (all women) presented to the Orbital Clinic between the ages of 38 and 71 years (mean 42.6; median 48.5 years) and with symptoms for an average of 32 months (3-102 months; median 22). The most common symptom was swelling and proptosis, in 11 (91%) patients, and subjective deterioration of vision had been noted in six cases (50%). Eight right orbits (67%) were affected and the preoperative acuity varied between Snellen 6/5 and counting fingers, with visual field impairment in all cases. There was an average of 5.0 mm of axial proptosis (range 5-9 mm; median 5). Endoscopic decompression was without complication in all cases. With a follow-up interval of 33.9 months (range 5-80; median 26 months), there was a subjective and objective improvement in visual functions-with Snellen acuity improving between 1 and 4 lines in seven patients, reduction in relative afferent pupillary defect in 10/12 patients, and improved visual field testing. There was a 2.3 mm reduction in proptosis (1-4 mm; median 3 mm) with less lid swelling, improved ocular balance and motility in four patients, and slightly worse diplopia in one patient. Three patients required further procedures: one had ipsilateral middle meatal antrostomy for retained secretions at 18 months and two had strabismus surgery. Three patients underwent fractionated radiotherapy for large tumours, or for late tumour growth and recurrent visual impairment.

Conclusions: Orbital decompression by transnasal endoscopic ethmoidectomy appears to alleviate optic nerve compression due to sphenoid wing meningioma, with a reasonable relief of the condition for some years. Some patients will require later radiotherapy for progressive tumour growth or visual failure.