Abstract: To present spectral domain optical coherence tomography (OCT) findings during treatment in a case of acute isolated cilioretinal artery occlusion (CLRAO) reversed with intravenous systemic administration of mannitol and carbogen inhalation. Close monitoring with OCT thickness topographic map and cross section scans, every 12 hours, during treatment and till complete reversal of retinal nerve fiber layer edema. Fundus photography and fluorescein angiography (FFA) were used to illustrate occlusion and recanalization. After 72 hours of therapy, visual acuity improved from counting fingers (CF) to 7/10, Snellen’s chart. Consecutively OCT scans showed that the initial macular edema was gradually restored to typical 72 hours of treatment initiation. FFA performed after treatment confirmed recanalization of the cilioretinal artery. Early intervention with the combined intravenous administration of mannitol and carbogen inhalation can reverse acute onset loss of vision due to CLRAO. The reflectivity of retinal layers differs significantly regarding stages of acute CLRAO. In our case report increased reflectivity of the innermost layers of the retina was illustrated and a corresponding reduction in the outer retina and the retinal pigment epithelium and choriocapillaris layers. Macular thickness follow-up data recorded the course of intracellular edema to normal.
Background: To measure the anterior and posterior segment structural features of acute primary angle-closure (APAC) eyes.
Methods: A total of 36 subjects with unilateral APAC were recruited in this study. The ocular biometric characteristics were measured by anterior segment optical coherence tomography (AS-OCT) and swept source optical coherence tomography (SS-OCT), respectively at baseline, 2 weeks, and 1 month after surgical intervention.
Results: At baseline, when compared with the fellow eyes, APAC-affected eyes showed significantly greater corneal thickness (P=0.004), shallower anterior chamber depth (ACD) (P<0.001), smaller anterior chamber area (ACA) (P=0.013), angle opening distance at 750 μm from the scleral spur (AOD750) (P=0.002), trabecular–iris space area at 750 μm from the scleral spur (TISA750) (P=0.033), angle recess area (ARA) (P=0.014), and iris area (IARE) (P=0.003), less iris curvature (ICURVE) (P=0.003), and larger lens vault (LV) (P=0.030). After intervention, the corneal thickness was significantly decreased at 1 month (P<0.001), while ACD, ACA, and AOD750 were significantly increased at 2 weeks and 1 month (all P<0.017). Changes in ACD were correlated with decreasing LV (P<0.05). The posterior segment parameters did not change over the 4-week period.
Conclusions: When compared with the fellow eyes, APAC-affected eyes had greater corneal thickness, shallower anterior chamber, narrower angle, less ICURVE, and larger LV. After intervention, the corneal thickness was decreased, while the shallower anterior chamber was relieved to some extent.
Abstract: Optical coherence tomography (OCT) is a technology that is widely used to assess structural abnormalities in the retina for a variety of pediatric conditions. The introduction of this instrument has allowed for widespread access to minimally invasive standardized, reproducible quantified structural assessments of the optic nerve and retina. This has had important implications in pediatric optic neuropathies, populations in whom monitoring of disease activity is essential to making treatment decisions. OCT has had particular relevance for inflammatory optic neuropathies, as onset of an inflammatory optic neuropathy may herald the onset of a chronic inflammatory disorder of the central nervous system (CNS) such as multiple sclerosis, neuromyelitis optica spectrum disorder (aquaporin 4 antibody positive), and myelin oligodendrocyte glycoprotein (MOG) associated disorders. This paper will focus on the application of OCT technology to this group of disorders in pediatrics. After reviewing pediatric-specific anatomic and practical issues pertinent to OCT, we will review knowledge related to the use of OCT in inflammatory pediatric optic neuropathies, with a focus on structural outcomes and their correlation with functional outcome metrics.
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: Optical coherence tomography (OCT) is a widely used non-invasive medical imaging technology that has revolutionized clinical care in ophthalmology. New developments, such as OCT angiography (OCTA) are expected to contribute even further to the widespread use of OCT-based imaging devices in the diagnosis and monitoring of patients with ophthalmic diseases. In recent years, many of the disadvantages such as limited field of view and imaging artefacts have been substantially reduced. Similar to the progress achieved in the assessment of retinal disorders, OCT is expected to change the approach to patients seen in the neuro-ophthalmology clinic. In this article, we review the technical features of OCT and OCT-based imaging techniques, highlighting the specific factors that should be taken into account when interpreting OCT in the field of neuro-ophthalmology.
Abstract: Effective and safe electrical stimulation of the retinal ganglion cells is at the heart of retinal prosthesis design. However, the effectiveness and safety demand of the electrical stimulation is often at odds against each other. Besides, the nerve fiber layer above retinal ganglion cells limits the spatial resolution of stimulation. Also, current retinal prosthesis still cannot selectively activate the ON or OFF visual pathways, thus cannot relay the correct luminance information to the brain. With decades of development, the stimulation protocol for retinal implants began to tackle these problems. We believe that a novel design of electrical stimulation scheme, combined with gene therapy technique, can improve the selectivity and spatial resolution of retinal implants and further lower the damage caused by electric stimulation.
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.
Abstract: Ischemic optic neuropathies are among the most common causes of sudden vision loss, especially in patients over age 50. The cause and prognosis of these disorders, and in particular non-arteritic anterior ischemic optic neuropathy, is poorly understood, and treatments remain poor in terms of restoring or preserving vision. Optical coherence tomography (OCT) and OCT angiography have allowed us to identify early and late structural changes in the optic nerve head and retina that may assist in predicting visual outcomes and may lead to greater understanding of pathogenesis and thus the development of effective medical interventions.
