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Optical Coherence Tomography (Oct) and Fundus Fluorescein Angiography (FFA) in Neuro-Ophthalmology
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Ramandeep Singh, Deeksha Katoch, Mohit Dogra, Basavaraj Tigari, Simar Rajan Singh, Sahil Jain, Bruttendu Moharana, Sabia Handa, Mangat R. Dogra
OCT is being used by neuro-ophthalmologists to precisely localize the damage, nail down the diagnosis, give a prognosis of visual recovery, and to assess treatment. FFA is an invasive tool, with clear advantages of showing vascular blood supply of the anterior part of optic nerve, and retina. Hence its use in understanding and diagnosing disorders of blood vasculature is irreplaceable. OCT-angiography (OCTA) (dyeless angiography) is becoming increasingly popular and may be able to replace FFA entirely in the future.
Peri-operative Investigations
Published in Pradeep Venkatesh, Handbook of Vitreoretinal Surgery, 2023
Optical coherence tomography (OCT) has been a game changer in the management of a multitude of retinal disorders. It has provided objectivity to the treatment response, enabled better understanding of macular pathologies, and improved the ease and safety of follow-up. While the role of OCT in the medical management of macular disorders is well established, the same cannot be said of its role in the surgical management of macular disorders. Discussion on the importance of OCT to surgical decision making revolves largely around its ability to confirm a diagnosis [e.g., lamellar hole from full thickness macular hole, myopic foveoschisis, vitreomacular traction]. However, preoperative OCT has a strong potential to enable several micro-surgical steps to be carried out with greater precision, safety, and surety.
Apparent Sudden Visual Loss: An Essential Approach
Published in Amy-lee Shirodkar, Gwyn Samuel Williams, Bushra Thajudeen, Practical Emergency Ophthalmology Handbook, 2019
Ultrasonography (known as a B-scan [brightness-scan]) can be helpful in differentiating disc oedema and disc drusen, as the latter may appear reflective (see Figure 9.1). Fundus autofluorescence and fundus fluorescein angiography (FFA) can also be useful adjuncts. Optical coherence tomography (OCT) is a non-invasive imaging modality providing a cross-section of the retina. This can be performed centred on the disc and one can assess if a ‘lazy V’ pattern of the subretinal hyporeflective space (more in keeping with papilloedema) or a ‘lumpy bumpy’ pattern (more in keeping with disc drusen) is evident (see paper by Johnson et al. Arch Ophthalmol. 2009, for further reading – reference below).
Uveitis-Glaucoma-Hyphema Syndrome: Clinical Features and Differential Diagnosis
Published in Ocular Immunology and Inflammation, 2022
Massimo Accorinti, Maria Carmela Saturno, Maria Pia Paroli, Daniele De Geronimo, Marta Gilardi
The diagnosis of UGH was made based upon clinical features, including an history of cataract surgery and IOL implantation, the presence of inflammation in the anterior chamber with an intraocular pressure ≥ 24 mmHg, the presence of hyphema or hematic/pigmented cells in the anterior and/or posterior chamber and an evident (clinically diagnosed or detected by ultrabiomicroscopy) contact between the IOL and the iris or the haptic of the IOL and the ciliary body. All patients underwent a complete ophthalmic evaluation that included best- corrected visual acuity, anterior and posterior segment evaluation with a slit-lamp, Goldmann tonometry, indirect ophthalmoscopy after pupil dilation and ultrabiomicroscopy (UBM). Optical coherent tomography (OCT) was performed if necessary. In presence of severe media opacities precluding OCT, the procedure was performed immediately after their resolution. The clinical features of the patients were recorded from their chart at baseline and after achieving a resolution of UGH. The amount of flare and cells in anterior chamber and vitreous opacities was graded following the SUN criteria.11
Retinal nerve fibre layer and ganglion cell layer thickness changes following intravitreal aflibercept for age-related macular degeneration
Published in Cutaneous and Ocular Toxicology, 2022
Betul Onal Gunay, Cenap Mahmut Esenulku
The SD-OCT analysis findings (RNFLT, GCLT, CMT, and SFCT) were recorded at baseline and at 1, 3, 6, and 12 months for the present study. One experienced technician performed OCT imagings. A 12° circle scan centred on the optic nerve was used to quantify the peripapillary RNFL. Mean RNFLT and supero-nasal (91–135°), supero-temporal (46–90°), temporal (316–45°), infero-temporal (271–315°), infero-nasal (226–270°), and nasal (136–225°) RNFLT was provided by the software module in the device. The automated segmentation protocol of the Spectralis OCT was used to measure central GCLT and 1 mm intervals to the superior, temporal, inferior, and nasal locations from the area delineated between the outer border of the macular RNFL and the inner border of the inner plexiform layer. Central retinal thickness was examined using the retinal thickness map analysis protocol with five Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. SFCT measurements were done using enhanced depth imaging OCT mode. SFCT was determined manually with calliper vertical line perpendicular to the retina from the outer surface of the hyper-reflective line corresponding to Bruch’s membrane to the line of the inner surface of the sclera. Two masked experienced observers (BOG and CME) assessed the automated segmentation profile and manually corrected the existing misalignment.
Optical Coherence Tomography Angiography of Inflammatory Choroidal Neovascularization Early Response after Anti-VEGF Treatment
Published in Current Eye Research, 2020
Wenyi Tang, Jingli Guo, Wei Liu, Gezhi Xu
OCTA volumes of 3 × 3 mm were obtained using AngioVue OCTA device (RTVue XR AVANTI, Optovue, Fremont, CA, USA) with split-spectrum amplitude-decorrelation technology. The outer retina layer was automatically segmented by AngioVue software between Bruch’s membrane and the inner nuclear layer/outer plexiform layer junction. CNV-related abnormal blood flow signals on this layer are easy to distinguish since it is devoid of blood vessels in healthy eyes. The CNV areas on the outer retina were manually selected (‘selected area’) via the outermost vessels by two independent qualified measurers (T.W.Y and G.J.L) using embedded software. The ‘flow area’ value was then automatically calculated according to the flow signals within the selected area. Measurements of these two parameters that disagreed by over 10% were adjudicated through a second measurement. Central macular thickness (CMT), measured from the internal limiting membrane to the RPE, was averaged in a 3-mm-diameter circular zone centered on the fovea using the embedded software. Patients underwent OCTA and SD-OCT scans sequentially: 1 day before injection (t0), 1 day (t1), 1 week (t2), 2 weeks (t3), and 1 month (t4) after the injection.