Alzheimer’s disease (AD) is the most common cause of dementia, accounting for 60% to 80% of cases worldwide. 1 The pathologic hallmark of the disease is the accumulation of extracellular beta amyloid plaques and intracellular tau filaments, ultimately leading to neuronal death. The current approved treatments slow down the progression of the disease, but do not stop the neurodegeneration caused by it. The past 2 decades have witnessed repeated failures of clinical trials using disease-modifying therapies targeting amyloid. 2 These failures have prompted a major rethinking of the approach, with the general consensus being that potential treatments would work ...

Purpose To measure low perfusion areas (LPA) and focal perfusion loss (FPL) in the peripapillary retina using optical coherence tomographic angiography (OCTA) in glaucoma. Design Prospective observation study. Participants Forty-seven primary open angle glaucoma (POAG) patients and 36 normal subjects were analyzed. Methods One eye of each subject was scanned using AngioVue 4.5-mm OCTA scan centered on the disc. En face nerve fiber layer plexus angiogram was generated. Using custom software, capillary density map was obtained by computing the fraction of area occupied by flow pixels within each superpixel containing 21×21-pixels. The low-perfusion map is defined by local ...

Objective To investigate the intraocular lens position and refractive outcomes following cataract surgery and phacovitrectomy using swept-source anterior segment optical coherence tomography (SS-ASOCT). Design Retrospective case series Subjects Patients underwent cataract surgery (Group A; 34 eyes), phacovitrectomy without gas tamponade (Group B; 20 eyes), and phacovitrectomy with gas tamponade (Group C; 22 eyes). Methods Various parameters associated with the anterior chamber and lens were measured by SS-ASOCT (CASIA2®) before and after surgery. Axial lengths were measured by optical biometry (IOLMaster). The refraction (spherical equivalent) was measured 1 week and 1 month after surgery. Main Outcome Measures Refractive outcomes and the ...

Purpose To prospectively determine the relationship of optical coherence tomography angiography (OCTA) metrics to diabetic retinopathy (DR) progression and development of diabetic macular edema (DME). Design: Prospective, observational study. Participants Two hundred and five eyes from 129 patients with diabetes mellitus followed up for at least 2 years. Methods All subjects underwent OCTA with a swept-source OCT (DRI-OCT Triton, Topcon, Inc, Tokyo, Japan). Individual OCTA images of superficial capillary plexus (SCP) and deep capillary plexus (DCP) were generated by IMAGEnet6. After quality check, automated measurements of foveal avascular zone (FAZ) area, FAZ circularity, vessel density (VD) and fractal dimension (FD ...

Purpose To evaluate the relationship between optical coherence tomography (OCT) features and the progression to late age related macular degeneration (AMD) in the fellow eyes of patients enrolled in the 24-month HARBOR study (NCT00891735) for neovascular AMD. Design post hoc analysis of a phase 3 multicenter, prospective, randomized, double-masked, active treatment-controlled clinical trial. Participants Evaluable subjects (N=501) with macular neovascularization (MNV) secondary to neovascular AMD and early or intermediate AMD in the fellow eye. Methods Volume OCT scans from 501 fellow eyes of 501 patients with MNV were reviewed. Baseline OCT features that were assessed included intraretinal hypereflective foci ...

Objective To review the published literature on the use of swept-source optical coherence tomography (SS-OCT) for evaluating the lamina cribrosa in glaucoma. Methods A PubMed and Cochrane Library literature search initially conducted on March 3, 2017 and updated on June 26, 2018 yielded a total of 64 articles. Articles that were reviews or that were not published in English were excluded, and 29 were found to fit the inclusion criteria. The panel methodologist then assigned a level of evidence rating to each study. Fifteen studies were rated level III, 14 studies were rated level II, and no studies were rated ...

Objective To report the frequency and severity of optical coherence tomography (OCT) retinal thickness measurement errors and to describe parameters that predict these errors. Design Observational case series. Participants Two hundred consecutive patients undergoing OCT imaging. Methods One eye (primary) from each of 200 consecutive patients undergoing Stratus OCT imaging (Carl Zeiss Meditec, Dublin, CA) with radial lines or fast macular thickness-based acquisition protocols was selected for review by 2 graders. On each of the line scans, graders evaluated the position of the automated retinal boundary lines (inner retinal surface and retinal pigment epithelium band) used by the OCT machine ...

Purpose To report the 3-year assessment of feasibility and usefulness of microscope-integrated intraoperative OCT (iOCT) during ophthalmic surgery. Design Prospective, consecutive case series. Participants Adult participants undergoing incisional ophthalmic surgery with iOCT imaging who consented to be enrolled in the Determination of Feasibility of Intraoperative Spectral-Domain Microscope Combined/Integrated OCT Visualization during En Face Retinal and Ophthalmic Surgery (DISCOVER) study. Methods The DISCOVER study is a single-site, multisurgeon, institutional review board-approved investigational device prospective study. Participants included patients undergoing anterior or posterior segment surgery who underwent iOCT imaging with 1 of 3 prototype microscope-integrated iOCT systems (i.e., Zeiss Rescan ...

Purpose To examine the natural history of vitreomacular traction syndrome (VMTS) in the absence of other ocular comorbidities. Design Retrospective clinical case series. Participants A total of 183 eyes of 159 patients diagnosed with VMTS with no other ocular comorbidity. Methods Patients with VMTS were identified from an OCT database at Moorfields Eye Hospital, London. Sequential OCT scans and patient notes were reviewed over a minimum period of 6 months. Data collected included patient demographics, best-corrected visual acuity, and OCT features of vitreomacular adhesion. Contingency tests and binary logistic modeling were used to identify baseline predictors of stability and progression ...

Ocular imaging has been heavily incorporated into glaucoma management and provides important information that aids in the detection of disease progression. Longitudinal studies have shown that the circumpapillary retinal nerve fiber layer is an important parameter for glaucoma progression detection, whereas other studies have demonstrated that macular parameters, such as the ganglion cell inner plexiform layer and optic nerve head parameters, also are useful for progression detection. The introduction of novel technologies with faster scan speeds, wider scanning fields, higher resolution, and improved tissue penetration has enabled the precise quantification of additional key ocular structures, such as the individual retinal ...

Optical coherence tomography (OCT) is increasingly used to obtain objective measurements of the retinal nerve fiber layer (RNFL), optic nerve head, and macula for assessing glaucoma progression. Although OCT has been adopted widely in clinical practice, uncertainty remains concerning its optimal role. Questions include: What is the best structure to measure? What quantity of change is significant? Are structural changes relevant to the patient? How are longitudinal measurements affected by aging? How can changes resulting from aging be differentiated from true progression? How best should OCT be used alongside visual fields, and how often should OCT be performed? Recent studies ...

Optical coherence tomography angiography (OCTA) studies in primary open-angle glaucoma have consistently demonstrated reduced microcirculation in the superficial optic nerve, 1 peripapillary retina, 2 , 3 and the macula 4 , 5 of glaucoma patients. These studies clearly demonstrate the superior resolution of OCTA compared with prior methods that were used to measure ocular blood flow (OBF) or its surrogates. How will OCTA help the glaucoma clinician now and in the future? What else must we learn before achieving more practical usefulness from OCTA for glaucoma? First, OCTA will supplement current glaucoma diagnostic tools to aid in the early detection of glaucoma ...

Assessing pupil size can be challenging in dim light, especially in dark brown eyes. This evaluation is facilitated by the infrared camera of the Heidelberg Spectralis Optical Coherence Tomography (OCT) system (Heidelberg Engineering, Heidelberg, Germany), which gives a bright pupillary reflex. Figure 1 shows a 67-year-old woman with metastatic breast cancer. Her pupils were difficult to see clinically (Fig 1 A ), and flash photography before (Fig 1 B ) and after (Fig 1 C ) 0.5% apraclonidine drops did not show reversal of her anisocoria very clearly. Using the Spectralis system it was much easier to see that her anisocoria was ...

Purpose Optical coherence tomography has been a technological breakthrough in the diagnosis, treatment, and follow-up of many ocular diseases, especially retinal and neuro-ophthalmologic pathologic conditions. Until now, several controversies have arisen over the specific cell types that the bands observed in the OCT represent, especially over the 4 outer retinal bands. Design To correlate the 4 outer hyperreflective bands observed in the OCT with the histologic structures using human retinal sections and immunocytochemistry at the fovea level. Participants Eyes from human donors. Methods Vertical cryosections of human retinas were immunostained with antibodies specific for cones photoreceptors, bipolar cells, mitochondria, M ...

To the Editor: We read with interest the article by Sung et al. 1 In this observational study, the authors concluded that the most distinct difference between the 2 subgroups in the cluster analysis was trabecular–ciliary process angle (TCA) and that the position of the ciliary body is important in subclassifying primary angle closure. However, there are several limitations that may affect the results. First, in the study, the authors reported that gonioscopy and image analysis using ImageJ was all conducted by a single researcher. These 2 measurements, however, both can be influenced by observers' subjectivity. To reduce influence ...

A 7-year-old boy presented with decreased vision in the right eye to 20/300. He had longstanding 20/400 vision in the left eye due to a congenital scar. His examinations revealed right anterior chamber and vitreous inflammation, as well as optic disc and macular edema with diffuse irregular retinal pigmentation.

A 66-year-old woman with a 450-μm diameter macular hole (MH) in her right eye underwent vitrectomy, internal limiting membrane (ILM) peel with inverted ILM flap, and perfluoropropane (C3F8) gas tamponade. Inverted ILM flaps may improve outcomes for holes larger than 400 μm; however, confirming proper ILM placement is difficult after air-fluid exchange.

A 48-year-old woman presented with peripapillary chorioretinal atrophy and cilioretinal artery in the left eye without other findings (Fig 1A). Optical coherence tomography angiography (OCTA) through full-thickness retinal segmentation (Fig 1B) showed intact retinal perfusion. The cilioretinal artery arose from the temporal margin of the optic nerve and coursed into the retina, resembling a hook.

Identification and characterization of patients with diabetic macular edema (DME) are important for individualizing treatment and optimizing outcome. We investigated optical coherence tomography (OCT) biomarkers for DME treated by intravitreal dexamethasone (DEX) implant.

Purpose Appearance of geographic atrophy (GA) on color photography (CP) is preceded by specific features on spectral-domain optical coherence tomography (SD OCT). We aimed to build SD OCT–based risk assessment models for 5-year new onset of GA and central GA on CP. Design Prospective, longitudinal study. Participants Age-Related Eye Disease Study 2 Ancillary SD OCT study participants with age-related macular degeneration (AMD) with bilateral large drusen or noncentral GA and at least 1 eye without advanced disease (n = 317). Methods For 1 eye per participant, qualitative and quantitative SD OCT variables were derived from standardized grading and semiautomated segmentation ...

A 50-year-old woman with a history of rheumatoid arthritis and macular hydroxychloroquine toxicity presented for a routine eye examination. An incidental loop vessel of the inferior prepapillary arteriole was readily apparent on examination (Fig 1 A ). Three-dimensional optical coherence tomography (OCT; Avanti, Optovue, Fremont, CA) demonstrated the elevation of this vessel into the vitreous (Fig 1 B ). The vessel was also captured on OCT-angiography (Fig 1 C ) with segmentation of the superficial retina and vitreous interface demonstrated by the B-scan image (inset). Retinal loop vessels are a common incidental finding on ophthalmic examination, but they can also be associated with ...

The clinical applications of handheld optical coherence tomography (OCT) imaging (Bioptigen, Morrisville, NC) for retinoblastoma continue to evolve and include characterization of small tumors, tumor recurrences, evaluation of seeding, and retinal anatomy. OCT was performed at staging examination of the left eye in a 13-month-old child diagnosed with bilateral retinoblastoma (Group C right eye, Group D left eye) demonstrated normal foveal architecture, preretinal dusting of small hyper-reflective seeds, and a hollow reflective cystic structure floating above the retina, with shadowing posteriorly, which correlated clinically with a large translucent spherical seed in the vitreous cavity (Fig 1, asterisk).

A 50-year-old woman with a history of rheumatoid arthritis and macular hydroxychloroquine toxicity presented for a routine eye examination. An incidental loop vessel of the inferior prepapillary arteriole was readily apparent on examination (Fig 1 A ). Three-dimensional optical coherence tomography (OCT; Avanti, Optovue, Fremont, CA) demonstrated the elevation of this vessel into the vitreous (Fig 1 B ). The vessel was also captured on OCT-angiography (Fig 1 C ) with segmentation of the superficial retina and vitreous interface demonstrated by the B-scan image (inset). Retinal loop vessels are a common incidental finding on ophthalmic examination, but they can also be associated with ...

Purpose To detect macular perfusion defects in glaucoma using projection-resolved optical coherence tomography (OCT) angiography. Design Prospective observation study. Participants A total of 30 perimetric glaucoma and 30 age-matched normal participants were included. Methods One eye of each participant was imaged using 6 × 6–mm macular OCT angiography (OCTA) scan pattern by 70-kHz 840-nm spectral-domain OCT. Flow signal was calculated by the split-spectrum amplitude-decorrelation angiography algorithm. A projection-resolved OCTA (PR-OCTA) algorithm was used to remove flow projection artifacts. Four en face OCTA slabs were analyzed: the superficial vascular complex (SVC), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and all-plexus ...