Optical coherence tomography angiography (OCTA) is a non-invasive, depth-resolved imaging tool for the appraisement of retinal vascular changes. Since its introduction, the understanding of diabetic retinopathy, age-related macular degeneration, central serous retinopathy and other diseases has been enriched on many fronts. Its dye-less imaging property maps retinal as well as deeper choroidal vasculature in quick succession with good reproducibility. Hence, it can play an important role in the diagnosis and management of optic nerve-related diseases as well. A detailed literature review for its role in non-arteritic anterior ischemic optic neuropathy, papilledema, optic disc drusen, papillitis, hereditary optic neuropathies, central nervous ...

Intraoperative optical coherence tomography (iOCT) enables real-time visualization of ocular structures during surgery and enhances our understanding of intraoperative dynamics. iOCT aids in decision making during various anterior segment surgeries, and its efficacy and feasibility in anterior lamellar keratoplasty and endothelial keratoplasty is well established. The landmark DISCOVER study observed that iOCT altered the surgeon decision in 38% of cases undergoing lamellar keratoplasty and provided guidance regarding the need for secondary surgical intervention. iOCT also finds an application in phacoemulsification wherein it helps to assess corneal incisions, intralenticular pressure, and posterior capsule integrity during nuclear emulsification. iOCT aids in the ...

With the advent of spectral-domain optical coherence tomography (SD-OCT), imaging of the posterior segment of the eye can be carried out rapidly at multiple anatomical locations, including the optic nerve head (ONH), circumpapillary retinal nerve fiber layer (cp-RNFL), and macula. There is now ample evidence to support the role of SD-OCT imaging of the macula for detection of early glaucoma. Macular SD-OCT measurements demonstrate high reproducibility, and evidence on its utility for detection of glaucoma progression is accumulating. We present a comprehensive review of macular SD-OCT imaging emerging as an essential diagnostic tool in glaucoma.

The choroid is the vascular coat of the eye,and its role has been studied in multiple chorioretinal disorders. The recent advancements in choroidal imaging techniques including enhanced depth imaging optical coherence tomography (EDI-OCT), swept source (SS-OCT), enface OCT and OCT angiography have facilitated an in-depth analysis of choroid. The gradual shift from manual to automated segmentation and binarization methods have led to precise and reproducible measurements of choroidal parameters. These qualitative and quantitative parameters, called choroidal imaging biomarkers, have evolved over the past decade from a simple linear subfoveal choroidal thickness to more complex 3 dimensional (3-D) choroidal reconstruction ...

Diabetic retinopathy (DR) is a primary cause of visual impairment worldwide. Diabetes mellitus may be associated with ophthalmoscopically nonvisible neurovascular damage that progresses before the first clinical signs of DR appear. Reduction of the inner neuroretinal layer thickness on macular optical coherence tomography (OCT), reduced contrast sensitivity primarily at low spatial frequencies, abnormal results in color vision and microperimetry tests, and a prolonged implicit time recorded by multifocal electroretinography have been proposed for detection of early functional and nonvisible structural neuroretinal changes. Vascular abnormalities such as changes in the retinal vessels caliber, architectural indices, and blood flow have been investigated ...

We enjoyed reading the recent article regarding acute macular neuroretinopathy (AMN) by Pellegrini et al in Surv Ophthalmol. 2017;62:882-5 1 . Recently, we published a similar case of a young woman with bilateral AMN 2 , and like your case, the spectral-domain optical coherence tomography (SD-OCT) was instrumental to the diagnosis especially since the visual fields and multifocal electroretinogram (mfERG) were completely normal in our case. Our case, like yours, also had a normal fundus examination lacking the classic “flower petal” macular appearance that generally accompanies AMN as well as normal automated visual fields 2 .

Corneal dystrophies are categorized according to the International Committee for Classification of Corneal Dystrophies (IC3D) classification, and their treatment depends on the affected structures and layer of the cornea. Therefore, estimating the depth and extent of the morphological changes due to the specific dystrophy is crucial when deciding between different treatment options. Besides superficial laser treatments and penetrating keratoplasty, minimal invasive lamellar keratoplasties such as Descemet membrane endothelial keratoplasty), deep anterior lamellar keratoplasty, or Descemet stripping automated keratoplasty have become increasingly popular to exchange the specific opaque layers in dystrophic eyes. To determine the morphological changes of the cornea in ...

Optical coherence tomography angiography (OCT-A) is a new imaging modality that provides non-invasive characterization and quantification of the microvasculature in different retinal conditions. The purpose of this paper is to give an updated review of the features of dry age-related macular degeneration investigated by means of new generation OCT-A. We searched PubMed and Medline using the terms “optical coherence tomography angiography” associated with “age-related macular degeneration”, “drusen”, “reticular pseudodrusen,” and “geographic atrophy” and reviewed publications up to January, 2017.

Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging technique that generates real time volumetric data of chorioretinal vasculature and its flow pattern. With the advent of high-speed optical coherence tomography, established en-face chorioretinal segmentation, and efficient algorithms, OCTA generate images that resembles an angiogram. The principle of OCTA involves determining the change in backscattering between consecutive B-scans and then attributing the differences to the flow of erythrocytes through retinal blood vessels. OCTA has shown promise in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age- related macular degeneration (AMD) and retinal vascular occlusions. It quantifies vascular ...

Various important findings related to the development and progression of idiopathic macular holes (MHs) have been described using optical coherence tomography (OCT) since Gass first described the stages of MH development using biomicroscopy in 1988 and 1995. We believe that a system for classifying and staging MHs should reflect the degree of disease status and its progression and have value not only from a practical point of view (by predicting the chance of closure or visual recovery) but also provides researchers and clinicians with insights into the pathogenesis and disease progression of MH. These data pave the way for the ...

There are now many devices that acquire data about the cornea: shape, power, pachymetry at any desired point of the cornea, corneal hysteresis, flap thickness (in LASIK procedures), endothelial cell count and morphology, and so forth. We review the literature on corneal assessment techniques and devices available in clinical practice. Specifically, we discuss slit lamp biomicroscopy, specular microscopy, ultrasound pachymetry, confocal microscopy, very-high-frequency digital ultrasound biomicroscopy, optical coherence tomography, Placido disk-based keratoscopy, slit-scanning elevation topography, Scheimpflug imaging, and dynamic applanation procedures—all of which can be used to assess the morphology of the cornea. In addition, we present a critical ...

Because glaucomatous damage is irreversible early detection of structural changes in the optic nerve head and retinal nerve fiber layer is imperative for timely diagnosis of glaucoma and monitoring of its progression. Significant improvements in ocular imaging have been made in recent years. Imaging techniques such as optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy rely on different properties of light to provide objective structural assessment of the optic nerve head, retinal nerve fiber layer and macula. In this review, we discuss the capabilities of these imaging modalities pertinent for diagnosis of glaucoma and detection of progressive ...

Optical coherence tomography (OCT) is a cross-sectional, three-dimensional, high-resolution imaging modality that uses low coherence interferometry to achieve axial resolution in the range of 3–20 μm. Two OCT platforms have been developed: time domain (TD-OCT) and spectral (or Fourier) domain (SD/FD-OCT). Visante anterior segment OCT (Carl Zeiss Meditec) is a TD-OCT widely used for anterior segment imaging. The SD-OCT systems with both posterior and anterior segment imaging capabilities include the RTVue, iVue (Optovue), the Cirrus (Carl Zeiss Meditec), and the Spectralis (Heidelberg Engineering, Inc.). Each of the SD-OCTs has a wavelength in the range of 820–879 nm ...

Seventy percent of the blood flow to the eye goes to the choroid, a structure that is vitally important to the function of the retina. The in vivo structure of the choroid in health and disease is incompletely visualized with traditional imaging modalities, including indocyanine green angiography, ultrasonography, and spectral domain optical coherence tomography (OCT). Use of new OCT modalities, including enhanced depth imaging OCT, image averaging, and swept-source OCT, have led to increased visualization of the choroidal anatomy. The correlation of these new anatomical findings with other imaging modalities results increases understanding of many eye diseases and recognises of ...

Abstract: Age-related macular degeneration (AMD) is the leading cause of severe visual loss in people aged 50 years or older in the developed world. In recent years, major advances have been made in the treatment of AMD, with the introduction of anti-angiogenic agents, offering the first hope of significant visual recovery for patients with neovascular AMD. In line with these advances, a new imaging modality—optical coherence tomography (OCT)—has emerged as an essential adjunct for the diagnosis and monitoring of patients with AMD. The ability to accurately interpret OCT images is thus a prerequisite for both retina specialists and ...

Abstract: All optic nerve pathologies, including the glaucomas and disorders such as non-arteritic ischemic optic neuropathy, affect the appearance of the optic nerve head. Morphological examination of the optic nerve head in a qualitative and quantitative manner is therefore clinically mandatory. With the advent of modern imaging modalities such as confocal scanning laser tomography and optical coherence tomography, new diagnostic avenues have opened up to further refine the examination. The new imaging devices are now becoming a major adjunct to the diagnosis and long-term management of optic nerve head pathology; before it is possible to identify an abnormal optic disk ...

Abstract: We describe the abnormalities seen in the mid periphery and posterior pole of two patients with multifocal vitelliform macular distrophy as evaluated by high-definition spectral domain optical coherence tomography (HD-OCT). In patient 1, HD-OCT scans revealed, in the central area, a thicker and more reflective layer compared with the normal macula, located between the retinal pigment epitelium and the interface of the inner segment /outer segment, corresponding to the Verhoeff‘s membrane. Moreover, HD-OCT macular scans, as well as C-scans, revealed a slight hyper-reflective lesion just above an area of reduced reflectivity between the photoreceptor layer (interface of the ...