Optical coherence tomography (OCT) is a noninvasive imaging technology using the optical reflectivity of tissues capable of detecting quantitative and qualitative biomarkers of age-related macular degeneration (AMD) that cannot be similarly recognized in conventional imaging . We systematically searched PubMed and Embase databases to identify relevant articles to this subject. A fixed-effect or random-effect model was applied for the meta-analysis based on the heterogeneity level. In addition, subgroup analyses, meta-regression, publication bias, and quality assessment were also performed. Twenty-five studies with 1632 cases and 1445 healthy controls in total were included. Our results revealed that, when compared to controls, AMD subjects ...

Imaging is an integral part of the evaluation and management of retinal disorders. Each imaging modality has its own unique capabilities and can show a different aspect or perspective of disease. Multimodal retinal imaging provides a wealth of substantive and insightful information; however, the integration of all this complex data can be overwhelming. We discuss the applications and the strengths and limitations of the many different retinal imaging tools that are approved for clinical use. These modalities include color fundus photography, widefield imaging, fundus autofluorescence, near infrared reflectance, optical coherence tomography angiography, and en face optical coherence tomography. We also ...

Recent developments in high-resolution optical coherence tomography allow evaluation of even the slightest changes of choroidal thickness in various disorders, including migraine. In this review, we analyze the choroidal thickness measurements reported in various studies that compare results between migraineurs and healthy individuals. We searched PubMed, Scopus, and EMBASE to identify relevant literature reporting choroidal thickness in the migraineurs' different macular regions compared with healthy controls. A fixed-effects or random-effects model was applied for the meta-analysis based on the heterogeneity level. Moreover, subgroup analyses, meta-regression, publication bias, and quality assessment were also performed. We identified ten studies involving 580 migraineurs ...

Diabetic macular edema (DME) is a leading cause of vision loss among people with diabetes. Optical coherence tomography (OCT) allows for accurate assessment and early detection of DME. Meta-analyses on DME prevalence diagnosed with OCT are lacking. We performed a meta-analysis to assess the global prevalence of OCT-diagnosed DME. We searched five electronic databases (EMBASE, CINAHL, Web of Science, Scopus, and MEDLINE) on May 29, 2020 and updated the search on March 19 and June 22, 2021. The quality of retrieved studies was evaluated using the Joanna Briggs Institute Checklist for Prevalence Studies. A random-effects model was used to pool ...

An important goal of advancements in ocular imaging algorithms and devices has been to improve the image acquisition and resolution of deeper ocular tissues, namely the choroid and its vasculature that are otherwise inaccessible to direct clinical examination. These advancements have contributed to the understanding of the pathophysiology of a number of ocular inflammatory conditions. We focuse on the imaging characteristics of clinical conditions where imaging the choroid has improved or radically changed the understanding of the disease, has helped in differentiation of phenotypically similar but distinct lesions, and where imaging features have proven vital formonitoring disease activity. The last ...

Optical coherence tomography angiography (OCTA) provides a noninvasive method to obtain angiography of the chorioretinal vasculature leading to its recent widespread adoption. With growing number of studies exploring the use of OCTA, various biomarkers have been described to quantify vascular characteristics using various techniques. We summarize biomarkers currently described for retinal and choroidal vasculature OCTA systems and the methods used to obtain them. We presents a critical review of these methods and key findings in common retinal diseases andalso appraise future directions, including application of artificial intelligence in OCTA angiolytics.

Studies reporting alteration in retinal thickness using optical coherence tomography (OCT) have been performed in different populations and various degrees of refractive error, producing inconsistent results. Therefore, we performed a meta-analysis to evaluate the alterations in retinal OCT measurements in myopic and hyperopic patients compared to controls. Evaluation of different retinal layers’ thickness may have significance for developing novel approaches for preventing, diagnosing, and treating refractive errors and their complications. We searched PubMed and EMBASE to identify articles that reported OCT measurements of different retinal layers and regions, including macular, foveal, parafoveal, perifoveal, foveolar, ganglion cell complex (GCC), retinal nerve ...

Diagnostic investigation on pachychoroid spectrum disease (PSD) has been growing along with the rapid advancement of imaging technology. In optical coherence tomography (OCT)-based studies, choroidal thickness profile, luminal and stromal choroidal ratio, and abnormalities in the neurosensory retina have demonstrated various patterns in different clinical entities related to PSD. The emerging role of OCT angiography (OCTA) has been expanded to involve the quantitative analysis of the OCTA parameters in different clinical entities of PSD and to evaluate the choriocapillaris signal void and vessel density as indicators of choriocapillaris ischemia. OCTA has broadened our knowledge in characterization and assessment of ...

The vascular system of the ocular surface plays a central role in infectious, autoimmune, inflammatory, traumatic and neoplastic diseases. The development, application, and monitoring of treatments for vascular abnormalities depends on the in vivo analysis of the ocular surface vasculature. Until recently, ocular surface vascular imaging was confined to biomicroscopic and color photographic assessment, both limited by poor reproducibility and the inability to image lymphatic vasculature in vivo . The evolvement and clinical implementation of innovative imaging modalities including confocal microscopy, intravenous, and optical coherence tomography–based angiography now allows standardized quantitative and functional vascular assessment with potential applicability to automated ...

Optical coherence tomography angiography (OCTA) images the layers of retinal and choroidal vasculature in the absence of an injectable dye. Since its introduction, OCTA has been utilized in various posterior segment diseases, including central serous chorioretinopathy (CSCR). We provide a comprehensive review of OCTA's application to CSCR published between 2014 and 2020.

Artificial Intelligence (AI) is an unstoppable force that is starting to permeate all aspects of our society as part of the revolution being brought into our lives (and into medicine) by the digital era, and accelerated by the current COVID-19 pandemic. As the population ages and developing countries move forward, AI-based systems may be a key asset in streamlining the screening, staging, and treatment planning of sight-threatening eye conditions, offloading the most tedious tasks from the experts, allowing for a greater population coverage, and bringing the best possible care to every patient. This paper presents a review of the state ...

Glaucoma is a chronic and progressive optic neuropathy characterized by the death of retinal ganglion cells and corresponding visual field loss. Despite the growing number of studies on the subject, the pathogenesis of the disease remains unclear. Notwithstanding, several studies have shown that the lamina cribrosa (LC) is considered an anatomic site of glaucomatous optic nerve injury, thus having a key role in the pathophysiology of glaucoma development and progression. Different morphological alterations of the LC have been described in vivo in glaucomatous eyes after the evolution of optical coherence tomography (OCT) devices. The most relevant findings were the reduction ...

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 ...