Abstract: Hereditary, metabolic and toxic optic neuropathies cause bilateral, central vision loss and therefore can result in severe impairment in visual function. Accurate, early diagnosis is critical, as nutritional and toxic optic neuropathies may be reversible if identified early, and diagnosis of hereditary optic neuropathies can prevent unnecessary invasive workup, provide prognostic information, and allow for effective genetic counseling. Optical coherence tomography (OCT) is a valuable tool that aids in the diagnosis and prognostication of optic neuropathies as it allows for quantification of changes in the retinal ganglion cells (RGCs) and retinal nerve fiber layer (RNFL) over time. We review the characteristic clinical presentations of hereditary, metabolic and toxic optic neuropathies, with an emphasis on OCT findings.
Abstract: Optical coherence tomography (OCT) provides a non-invasive analysis of the retina in vivo. Lesions which compress the anterior visual pathway can cause anterograde and retrograde neuro-degeneration. Retrograde structural changes to the retina can be detected by OCT. Analyzing patterns of change on OCT can guide diagnostic and treatment decisions for lesions compressing the optic nerve and chiasm to minimize loss of visual function. From our review of current literature, it is clear that thinning of both the retinal nerve fiber and ganglion cell layers (GCLs) can indicate compression. These parameters correlate with visual function loss as detected by perimetry. Furthermore, these measurements have shown to be the most reliable biomarkers to date in predicting visual recovery after treatment of these compressive lesions.
Abstract: Focal intraretinal alterations have been studied to advance our understanding of the pathology of neurodegenerative diseases. The current literature involving focal alterations in the intraretinal layers was reviewed through PubMed using the search terms “focal alteration”, “region of interest”, “optical coherence tomography”, “glaucoma”, “multiple sclerosis”, “Alzheimer’s disease”, “Parkinson disease”, “neurodegenerative diseases” and other related items. It was found that focal alterations of intraretinal layers were different in various neurodegenerative diseases. The typical focal thinning might help differentiate various ocular and cerebral diseases, track disease progression, and evaluate the outcome of clinical trials. Advanced exploration of focal intraretinal alterations will help to further validate their clinical and research utility.
Abstract: Idiopathic intracranial hypertension (IIH) is a condition in which elevated pressure in the cerebrospinal fluid can lead to optic nerve head (ONH) dysfunction and subsequent visual impairment. Physicians are currently limited in their ability to monitor and manage this condition, as clinical symptoms and exam findings are often delayed in response to changes in intracranial pressure. In order to find other biomarkers of disease, researchers are using imaging modalities such as optical coherence tomography (OCT) to observe microscopic changes in the eye in this condition. OCT can create 2-dimensional and 3-dimensional high definition images of the retina of the ONH and has been used to study various conditions such as glaucoma and multiple sclerosis. Numerous studies have used OCT in IIH as well, and they have shown that certain retinal layers and the ONH change in thickness and shape in both the short and long term with intracranial pressure changes. OCT is a promising modality for clinical and scientific evaluation of IIH as it is a noninvasive and practical tool to obtain in depth images. This review will discuss how OCT can be used to assess a patient with IIH, both before and after treatment, along with its limitations and future applications.
