The role of optical coherence tomography in the evaluation of compressive optic neuropathies

Optical coherence tomography (OCT) is a noninvasive imaging tool routinely used in ophthalmology that provides cross-sectional images of the retina. Compression of the anterior visual pathways results in progressive thinning of the retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) and this review will highlight the utility of OCT in evaluating patients with this condition.

The RNFL and macular GCC have been found to highly correlate with visual function in patients with compressive optic neuropathies. Preoperative RNFL and macular GCC thickness have emerged as the most reliable and consistent prognostic factors for visual recovery after surgery. Patients with an otherwise normal neuroophthalmic examination, including automated perimetry, may have macular GCC or RNFL thinning as the only manifestation of compression, enabling compressive optic neuropathies to be diagnosed at an earlier stage and managed accordingly.

Recent findings indicate that OCT is an important tool in the evaluation of patients with compressive optic neuropathies, particularly for prognosis in patients with visual field defects and diagnosis in patients with preserved or mildly reduced visual function. Anatomical changes detected by OCT may precede visual loss and allow for earlier diagnosis and presumably better visual outcomes.