Abstract
Purpose :
The anterior visual pathways may be affected by meningiomas originating within the optic nerve sheath, in the area of the optic canal, anterior clinoid, or tuberculum. Advances in imaging (CT and MRI) now permits diagnosis, often without need for biopsy. Improvements in quantitation of psychophysics (automated perimetry static perimetry), anatomic assessment (OCT assessment of nerve fiber layer thickness and ganglion cell segmentation analysis) have dramatically improved our ability to make a diagnosis and assess the level of damage. Surgical approach can still be effective in decompressing pressure on the optic nerve and chiasm. If the optic nerve sheath is involved, surgery has been generally replaced by fractionated radiation therapy.
Methods :
A retrospective review of 31 patients with optic nerve and chiasmal involvement of meningiomas with follow-up of up to 34 years was reviewed.
Results :
While most patients were identified with progressive visual loss, some lesions were picked up fortuitously when imaging was done for other reasons. Visual acuity was variable ranging from 20/20 or better to NLP. The advent of quantitative retinal and optic nerve assessment has shown variable results. Long-term compression can lead to significant optic atrophy and corresponding nerve fiber layer thinning, but compression at the orbital apex can mask previous damage due to swelling of the optic nerve fibers (“green disease”). More recent introduction of ganglion cell analysis by segmentation algorithm may allow distinction of preceding and irreversible damage. Natural history of meningiomas affecting the anterior visual pathways is quite variable with some stable over decades while others progress over months to years. Surgical decompression and, perhaps more importantly, fractionated radiation therapy may play a role in improving and prolonging visual function.
Conclusions :
Meningiomas are a common cause of optic nerve dysfunction. Judicious use of fractionated radiation therapy and surgical decompression may be helpful in improving and protecting visual function. The advent of OCT is an important addition, particularly with ganglion cell analysis for detecting the severity of damage. In spite of substantial damage, psychophysical improvement may still occur with treatment.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.