The Clinical Utility of Ocular Coherence Tomography in Evaluation and Management of Skull Base Disorders

Ocular Coherence Tomography (OCT), aka Optical Coherence Tomography, is a non-invasive imaging test that uses light waves to capture micrometer-resolution, three-dimensional images from within the retina. OCT is based on low-coherence interferometry, typically employing near-infrared light. OCT provides near-microscopic resolution and has been employed as a clinical tool in the measurement of peripapillary retinal nerve fiber layer (RNFL) thickness and macular retinal ganglion cell (RGC) layer thickness. In our institution, in the management of thousands of patients, in conjunction with clinical neuro-ophthalmologic evaluation, we have found OCT provides additional useful information, leading to better management decisions, and useful diagnostic and prognostic information, leading to improvements in the counseling of patients and families regarding outcome expectations. RNFL thickness is diminished in the presence of atrophy, except in cases with optic nerve head edema (e.g., papilledema, optic nerve sheath infiltrative processes, some orbital tumors, or orbital venous congestive phenomena). RGC layer thickness is diminished in the presence of optic atrophy.

From January 2005 through August 2016, OCT was employed as a diagnostic tool in the evaluation and management of 2,215 patients seen in our Neuro-ophthalmology Department. Only a minority of the brain tumor and pituitary tumor patients underwent evaluation with OCT, but 195 of the 2,215 had a diagnosis of brain tumor and 76 had a diagnosis of pituitary tumor. 62 had a diagnosis of orbital tumor. 53 had a diagnosis of Idiopathic Intracranial Hypertension. The remainder of the 2,215 patients evaluated with OCT had other neurologic, systemic and ocular diseases or disorders.

OCT was found to be a clinically useful adjunctive test in the evaluation and management of increased intracranial pressure, orbital disorders, anterior skull base disease, and both anterior and posterior visual pathway disorders. Our clinical findings, recommendations and protocols will be presented.