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

Abstract

Purpose of review 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. Recent findings 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. Summary 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.

Chronic chiasmal compression and persistent visual field defect without detectable changes in optical coherence tomography of the macular ganglion cell complex

“…More interesting, is that there were no detectable changes in the macular GCC, including no differences between the nasal and temporal sextants in each eye and no differences between the eyes. Chiasmal compression is well-known to cause more thinning of the nasal portion of the macular GCC, 2 , 4 , 5 but this was not the case here. This was likely a result of only analyzing the macular GCC rather than elsewhere in the retina and the possibility that a only a mild amount of thinning occurred, which may have been below the level of detection of OCT 8 …”

“…OCT of the RNFL and macular GCC has become an important aspect of the pre-treatment evaluation of pituitary tumors and is recommended by the Congress of Neurological Surgeons’ guidelines 1 . Not only does OCT help in determining prognosis, it also allows for earlier diagnosis since OCT parameters typically precede visual field changes in chronic chiasmal compression 2 . Danesh-Meyer et al first reported that 15% of patients undergoing resection of parachiasmal tumors had normal visual field testing, but a thin RNFL as detected with OCT 3 .…”

“…Optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) are recommended when evaluating patients with sellar masses and visual symptoms 1 . OCT helps with prognostication in patients undergoing surgery and also allows for the early diagnosis of chiasmal compression since it has become well-recognized that OCT changes usually precede early visual field defects in patients with chronic chiasmal compression 2, 3, 4. OCT of the macular GCC is important to include in the evaluation of these patients since it is thought to allow for even earlier detection of anterior visual pathway changes compared to the RNFL 2 , 4 , 5 .…”

“…OCT helps with prognostication in patients undergoing surgery and also allows for the early diagnosis of chiasmal compression since it has become well-recognized that OCT changes usually precede early visual field defects in patients with chronic chiasmal compression 2, 3, 4. OCT of the macular GCC is important to include in the evaluation of these patients since it is thought to allow for even earlier detection of anterior visual pathway changes compared to the RNFL 2 , 4 , 5 . We present a case of chronic chiasmal compression from a pituitary adenoma with an initial monocular visual field defect that responded promptly to medical treatment.…”

Using the Thickness Map from Macular Ganglion Cell Analysis to Differentiate Retinal Vein Occlusion from Glaucoma

“…Thinning of the peripapillary retinal nerve fiber layer (RNFL), which is mainly composed of axons of the retinal ganglion cells, provides an important diagnostic clue of glaucoma. However, many other diseases also involve RNFL thinning, such as compressive optic neuropathy, ischemic optic neuropathy, and hypertensive retinopathy [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. RVO is one of them [ 9 ].…”