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    1. Axial Length Variation Impacts on Superficial Retinal Vessel Density and Foveal Avascular Zone Area Measurements Using Optical Coherence Tomography Angiography

      Axial Length Variation Impacts on Superficial Retinal Vessel Density and Foveal Avascular Zone Area Measurements Using Optical Coherence Tomography Angiography

      Purpose : To evaluate the impact of image magnification correction on superficial retinal vessel density (SRVD) and foveal avascular zone area (FAZA) measurements using optical coherence tomography angiography (OCTA). Methods : Participants with healthy retinas were recruited for ocular biometry, refraction, and RTVue XR Avanti OCTA imaging with the 3 × 3-mm protocol. The foveal and parafoveal SRVD and FAZA were quantified with custom software before and after correction for magnification error using the Littman and the modified Bennett formulae. Relative changes between corrected and uncorrected SRVD and FAZA were calculated. Results : Forty subjects were enrolled and the median (range) age of the ...

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    2. Author Response: Gap in Capillary Perfusion on Optical Coherence Tomography Angiograph

      Author Response: Gap in Capillary Perfusion on Optical Coherence Tomography Angiograph

      We appreciate the valuable comments from Huang and Sha 1 regarding our recent article. 2 Their comments raise an important point about image artifacts in optical coherence tomography angiography (OCTA). Image artifacts in OCTA are common and physicians should be aware of this problem. 3 As reported elsewhere, it is difficult to evaluate precise vascular abnormalities when macular edema is present. 4 Thus, in the current study, we described our OCTA protocol in cases in which macular edema persisted. 2 In eyes with persistent macular edema, OCTA was performed within 2 months after the last anti-VEGF treatment, when the macular ...

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    3. Gap in Capillary Perfusion on Optical Coherence Tomography Angiography

      Gap in Capillary Perfusion on Optical Coherence Tomography Angiography

      We read with great interest the recent article by Tsuboi et al.1 The authors used optical coherence tomography angiography (OCTA) and a threshold technique to evaluate correlations between persistent macular edema associated with branch retinal vein occlusion (BRVO), and the macular perfusion status in the superficial (SCP) and deep (DCP) capillary plexus. They found that the gap between the SCP and DCP (i.e., specifically the presence of isolated vessels in the SCP existing simultaneously with capillary loss in the DCP) was associated with persistent macular edema. We congratulate the authors for their excellent work and would like to ...

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    4. The Impact of Lens Opacity on SD-OCT Retinal Nerve Fiber Layer and Bruch's Membrane Opening Measurements Using the Anatomical Positioning System (APS)

      The Impact of Lens Opacity on SD-OCT Retinal Nerve Fiber Layer and Bruch's Membrane Opening Measurements Using the Anatomical Positioning System (APS)

      Purpose : To evaluate the impact of lens opacity on retinal nerve fiber layer thickness (RNFLT) and Bruch's membrane opening (BMO) measurements. Methods : Fifty-nine randomly selected patients without any other relevant ocular pathology undergoing elective routine cataract surgery in two specialized eye clinics were enrolled. RNFLT, BMO area, and BMO minimum rim width (BMO-MRW) were assessed with the Heidelberg Engineering Spectralis OCT using the anatomical positioning system (APS) prior to and 1 day after cataract surgery using a ring scan at different eccentricities of the disc (3.5, 4.1 and 4.7 mm). Lens opacity was quantified using densitometry ...

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    5. Repeatability and Reproducibility of Retinal Blood Flow Measurement Using a Doppler Optical Coherence Tomography Flowmeter in Healthy Subjects

      Repeatability and Reproducibility of Retinal Blood Flow Measurement Using a Doppler Optical Coherence Tomography Flowmeter in Healthy Subjects

      Purpose : To evaluate the repeatability and reproducibility of retinal blood flow (RBF) measurements in humans by using new auto-alignment and measurement software in a commercially available Doppler optical coherence tomography (DOCT) system. Methods : The DOCT flowmeter assessed the intrasession repeatability and the intersession and interobserver reproducibility of the RBF measurements. For intrasession repeatability, the coefficients of variation (CVs) of five repeated RBF measurements were calculated at the retinal arteries and veins in 20 normal eyes of 20 healthy volunteers. For intersession reproducibility, two sets of three measurements obtained by one observer on 2 different days were compared. For interobserver reproducibility ...

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    6. Biomechanical Responses of Lamina Cribrosa to Intraocular Pressure Change Assessed by Optical Coherence Tomography in Glaucoma Eyes

      Biomechanical Responses of Lamina Cribrosa to Intraocular Pressure Change Assessed by Optical Coherence Tomography in Glaucoma Eyes

      Purpose : The purpose of this study was to measure change in anterior lamina cribrosa depth (ALD) globally and regionally in glaucoma eyes at different intraocular pressures (IOP). Methods : Twenty-seven glaucoma patients were imaged before and after IOP-lowering procedures using optical coherence tomography. The anterior lamina was marked in approximately 25 locations in each of six radial scans to obtain global and regional estimates of ALD. ALD and its change with IOP were compared with optic disc damage, nerve fiber layer thickness, and visual field loss. Results : Variables associated with deeper baseline ALD included larger cup/disc ratio, thinner rim area ...

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    7. Quantitatively Measured Anatomic Location and Volume of Optic Disc Drusen: An Enhanced Depth Imaging Optical Coherence Tomography Study

      Quantitatively Measured Anatomic Location and Volume of Optic Disc Drusen: An Enhanced Depth Imaging Optical Coherence Tomography Study

      Purpose : Optic disc drusen (ODD) are found in up to 2.4% of the population and are known to cause visual field defects. The purpose of the current study was to investigate how quantitatively estimated volume and anatomic location of ODD influence optic nerve function. Methods : Anatomic location, volume of ODD, and peripapillary retinal nerve fiber layer and macular ganglion cell layer thickness were assessed in 37 ODD patients using enhanced depth imaging optical coherence tomography. Volume of ODD was calculated by manual segmentation of ODD in 97 B-scans per eye. Anatomic characteristics were compared with optic nerve function using ...

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    8. Automated Staging of Age-Related Macular Degeneration Using Optical Coherence Tomography

      Automated Staging of Age-Related Macular Degeneration Using Optical Coherence Tomography

      Purpose : To evaluate a machine learning algorithm that automatically grades age-related macular degeneration (AMD) severity stages from optical coherence tomography (OCT) scans. Methods : A total of 3265 OCT scans from 1016 patients with either no signs of AMD or with signs of early, intermediate, or advanced AMD were randomly selected from a large European multicenter database. A machine learning system was developed to automatically grade unseen OCT scans into different AMD severity stages without requiring retinal layer segmentation. The ability of the system to identify high-risk AMD stages and to assign the correct severity stage was determined by using receiver ...

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    9. The Evolution of the Plateau, an Optical Coherence Tomography Signature Seen in Geographic Atrophy

      The Evolution of the Plateau, an Optical Coherence Tomography Signature Seen in Geographic Atrophy

      Purpose : Histologic details of progression routes to geographic atrophy (GA) in AMD are becoming available through optical coherence tomography (OCT). We studied the origins and evolution of an OCT signature called plateau in eyes with GA and suggested a histologic correlate. Methods : Serial eye-tracked OCT scans and multimodal imaging were acquired from eight eyes of seven patients with GA and plateau signatures over a mean follow-up of 7.7 years (range, 3.7–11.6). The histology of unrelated donor eyes with AMD was reviewed. Results : Drusenoid pigment epithelial detachment (PED) on OCT imaging progressed into wide-based mound-like signatures with ...

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    10. Gap in Capillary Perfusion on Optical Coherence Tomography Angiography Associated With Persistent Macular Edema in Branch Retinal Vein Occlusion

      Gap in Capillary Perfusion on Optical Coherence Tomography Angiography Associated With Persistent Macular Edema in Branch Retinal Vein Occlusion

      Purpose : To evaluate correlations between persistent macular edema associated with branch retinal vein occlusion (BRVO) and the macular perfusion status in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) using optical coherence tomography angiography (OCTA). Methods : Retrospective, case-control study. Twenty patients with BRVO followed for 12 months or more were enrolled. Persistent macular edema was defined as central retinal thickness exceeding 300 μm that persisted or recurred less than 3 months after the final treatment. We compared two groups (i.e., seven eyes with persistent macular edema and 13 eyes without macular edema). The macular perfusion status was ...

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    11. Choroidal Vascular Flow Area in Central Serous Chorioretinopathy Using Swept-Source Optical Coherence Tomography Angiography

      Choroidal Vascular Flow Area in Central Serous Chorioretinopathy Using Swept-Source Optical Coherence Tomography Angiography

      Purpose : To report the choroidal vascular flow area in eyes with central serous chorioretinopathy (CSC) compared with healthy subjects and unaffected fellow eyes using swept-source (SS) optical coherence tomography (OCT) angiography. Methods : Prospective case series of 19 eyes of 19 consecutive patients affected by CSC, compared with 15 unaffected fellow eyes and 20 eyes of 10 healthy subjects. Patients underwent SS-OCT angiography in order to evaluate the choroidal vascular flow area of choriocapillaris (CC) and deeper choroidal layers. Results : The choroidal vascular flow area was higher in eyes with CSC than in control eyes (53.4 ± 5.8% vs. 49 ...

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    12. Retinal Microvasculature and Visual Acuity in Eyes With Branch Retinal Vein Occlusion: Imaging Analysis by Optical Coherence Tomography Angiography

      Retinal Microvasculature and Visual Acuity in Eyes With Branch Retinal Vein Occlusion: Imaging Analysis by Optical Coherence Tomography Angiography

      Purpose : To investigate microvascular changes in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with resolved branch retinal vein occlusion (BRVO) and their association with best-corrected visual acuity (BCVA). Methods : Eighty-five eyes (82 consecutive patients) with BRVO after resolution of the macular edema were retrospectively evaluated. All patients underwent optical coherence tomography angiography (OCTA) for assessment of microvascular changes, including capillary telangiectasia, microaneurysm, and disruption of the foveal avascular zone (FAZ). The areas of vascular perfusion and FAZ in the SCP and DCP were quantitatively evaluated. Best-corrected visual acuity was measured on the same day as ...

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    13. Alterations of the Foveal Avascular Zone Measured by Optical Coherence Tomography Angiography in Glaucoma Patients With Central Visual Field Defects

      Alterations of the Foveal Avascular Zone Measured by Optical Coherence Tomography Angiography in Glaucoma Patients With Central Visual Field Defects

      Purpose : To investigate whether the area and shape of the foveal avascular zone (FAZ) as assessed by optical coherence tomography angiography (OCTA) are altered in glaucomatous eyes with central visual field defects (CVFDs). Methods : A total of 78 patients with open-angle glaucoma with central or peripheral visual field defects (PVFDs) confined to a single hemifield were studied retrospectively. Foveal avascular zone area and circularity were measured using OCTA images from the superficial retinal layer. Central retinal visual field (VF) sensitivity using Swedish Interactive Threshold Algorithm 24-2 VF and macular ganglion cell–inner plexiform layer (mGCIPL) thickness were measured. The FAZ ...

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    14. Underlying Microstructure of Parapapillary Deep-Layer Capillary Dropout Identified by Optical Coherence Tomography Angiography

      Underlying Microstructure of Parapapillary Deep-Layer Capillary Dropout Identified by Optical Coherence Tomography Angiography

      Purpose : To characterize the microstructure underlying the parapapillary deep-layer microvasculature dropout (MvD) identified by optical coherence tomography (OCT) angiography (OCTA) in eyes with primary open-angle glaucoma (POAG). Methods : Parapapillary MvD was defined as a focal sectoral capillary dropout without any visible microvascular network identified in deep-layer en face images obtained using swept-source OCTA. The peripapillary microstructure was characterized in 188 POAG patients with MvD in the parapapillary deep layer. Twelve radial optic nerve images were obtained using swept-source OCT to examine the peripapillary structure and measure the juxtapapillary choroidal thickness (JPCT). The JPCT was also measured in 72 age-matched POAG ...

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    15. Comparison Between Spectral-Domain and Swept-Source Optical Coherence Tomography Angiographic Imaging of Choroidal Neovascularization

      Comparison Between Spectral-Domain and Swept-Source Optical Coherence Tomography Angiographic Imaging of Choroidal Neovascularization

      Purpose : The purpose of this study was to compare imaging of choroidal neovascularization (CNV) using swept-source (SS) and spectral-domain (SD) optical coherence tomography angiography (OCTA). Methods : Optical coherence tomography angiography was performed using a 100-kHz SS-OCT instrument and a 68-kHz SD-OCTA instrument (Carl Zeiss Meditec, Inc.). Both 3 × 3- and 6 × 6-mm 2 scans were obtained on both instruments. The 3 × 3-mm 2 SS-OCTA scans consisted of 300 A-scans per B-scan at 300 B-scan positions, and the SD-OCTA scans consisted of 245 A-scans at 245 B-scan positions. The 6 × 6-mm 2 SS-OCTA scans consisted of 420 A-scans per B-scan at ...

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    16. Wide-Field En Face Swept-Source Optical Coherence Tomography Features of Extrafoveal Retinoschisis in Highly Myopic Eyes

      Wide-Field En Face Swept-Source Optical Coherence Tomography Features of Extrafoveal Retinoschisis in Highly Myopic Eyes

      Purpose : To evaluate the features of extrafoveal retinoschisis (EFRS) in highly myopic eyes detected by swept-source optical coherence tomography (SS-OCT). Methods : In this retrospective case series, 89 eyes of 65 patients with high myopia and coexisting EFRS were included. The participants underwent a comprehensive ophthalmologic examination, including visual acuity, ocular biometry, refraction, and perimetry. Three-dimensional wide-field scans were obtained with SS-OCT, and en face images were reconstructed with custom software. En face OCT features of EFRS were determined by two ophthalmologists masked to clinical characteristics. The associations of EFRS subtypes with ocular biometry and other OCT changes were evaluated as ...

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    17. Preventing Corneal Calcification Associated With Xylazine for Longitudinal Optical Coherence Tomography in Young Rodents

      Preventing Corneal Calcification Associated With Xylazine for Longitudinal Optical Coherence Tomography in Young Rodents

      Purpose : Spectral-domain optical coherence tomography (SD-OCT) is widely used in clinical ophthalmology and recently gained popularity in laboratory research involving small rodents. Its noninvasive nature allows repeated measurements, thereby decreasing the number of animals required. However, when used at a conventional dosage, xylazine (an α2-adrenoceptor) can cause irreversible corneal calcification, especially among young rodents. In the present study, we test whether corneal calcification associated with xylazine is mediated by the α2-adrenoceptor. Methods : Our study tested Sprague-Dawley rats, Long-Evans rats, and CD-1 mice (postnatal day [P]14). Retinal images were captured by SD-OCT. Quantitative PCR (qPCR) was used to study gene ...

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    18. Quantitative Retinal Optical Coherence Tomography Angiography in Patients With Diabetes Without Diabetic Retinopathy

      Quantitative Retinal Optical Coherence Tomography Angiography in Patients With Diabetes Without Diabetic Retinopathy

      Purpose : To compare optical coherence tomography (OCT) angiographic parameters in retina and choriocapillaris between control subjects and diabetic patients without diabetic retinopathy (NDR). Correlations were studied between OCT angiography parameters, retinal structure parameters, and systemic characteristics in all subjects. Methods : Sixty-two patients were included in the study: control subjects ( n = 33) and patients with NDR ( n = 29). Optical coherence topography angiographic parameters were as follows: vessel density (%) (in superficial, deep retinal vessel plexus and in choriocapillary layer) and foveal avascular zone (FAZ) area (mm 2 ) in superficial and deep retinal vessel plexus of parafovea. Split-spectrum amplitude decorrelation angiography (SSADA) software ...

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    19. Optical Coherence Tomography Angiography Analysis of the Foveal Avascular Zone and Macular Vessel Density After Anti-VEGF Therapy in Eyes With Diabetic Macular Edema and Retinal Vein Occlusion

      Optical Coherence Tomography Angiography Analysis of the Foveal Avascular Zone and Macular Vessel Density After Anti-VEGF Therapy in Eyes With Diabetic Macular Edema and Retinal Vein Occlusion

      Purpose : To evaluate the changes in foveal avascular zone (FAZ) area and the retinal capillary density after a single intravitreal anti-VEGF injection for macular edema secondary to diabetic retinopathy or retinal vein occlusion. Methods : In this prospective noncomparative case series, 18 eyes of 15 patients with diabetic macular edema (13 eyes) or macular edema secondary to central retinal vein occlusion (5 eyes) were included. Optical coherence tomography angiography (OCTA) images were obtained, and retinal capillary vessel density and FAZ area were measured in the foveal and parafoveal regions at the level of the superficial (SCP) and deep retinal capillary plexus ...

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    20. Evaluation of the Anterior Segment Angle-to-Angle Scan of Cirrus High-Definition Optical Coherence Tomography and Comparison With Gonioscopy and With the Visante OCT

      Evaluation of the Anterior Segment Angle-to-Angle Scan of Cirrus High-Definition Optical Coherence Tomography and Comparison With Gonioscopy and With the Visante OCT

      Purpose : To evaluate the diagnostic performance of the anterior segment angle-to-angle scan of the Cirrus high-definition optical coherence tomography (HD-OCT) in detecting eyes with closed angles. Methods : All subjects underwent dark-room gonioscopy by an ophthalmologist. A technician performed anterior segment imaging with Cirrus ( n = 202) and Visante OCT ( n = 85) under dark-room conditions. All eyes were categorized by two masked graders as per number of closed quadrants. Each quadrant of anterior chamber angle was categorized as a closed angle if posterior trabecular meshwork could not be seen on gonioscopy or if there was any irido-corneal contact anterior to scleral spur ...

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    21. Macular Vascular Flow Area and Vascular Density in Healthy Population Using Optical Coherence Tomography Angiography

      Macular Vascular Flow Area and Vascular Density in Healthy Population Using Optical Coherence Tomography Angiography

      We read with interest the paper from Coscas et al. 1 regarding the normative data for vascular density in superficial and deep capillary plexuses of healthy adults assessed by optical coherence tomography angiography (OCT-A). The authors state that using the AngioVue OCT-A system (Optovue, Inc., Fremont, CA, USA), the total vascular density in superficial capillary plexus in healthy adults is 52.58 ± 3.22% and for the deep vascular density is 57.87 ± 2.82%. Optical coherence tomography angiography technology has some major limitations in clinical practice nowadays: variable segmentation, motion artifact, and project artifact. 2 We must take into ...

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      Mentions: Optovue Nidek
    22. In Vivo Observation of Lens Regeneration in Rat Using Ultra-Long Scan Depth Optical Coherence Tomography

      In Vivo Observation of Lens Regeneration in Rat Using Ultra-Long Scan Depth Optical Coherence Tomography

      Purpose : To evaluate morphologic changes of lens regeneration in rats in vivo after extracapsular lens extraction (ECLE) by ultra-long scan depth optical coherence tomography (UL-OCT). Methods : A total of 42 Sprague-Dawley rats were used in this study. We performed ECLE on the right eyes of animals in the surgery group ( n = 34). Biomicroscopy and UL-OCT scans were carried out for the surgery group immediately (within 1 hour postoperatively) and at days 1 and 3, weeks 1 and 2, and months 1, 2, and 3 postoperatively. After in vivo examination, three animals of the surgery group were euthanized at each time ...

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    23. Schlemm's Canal Expansion After Uncomplicated Phacoemulsification Surgery: An Optical Coherence Tomography Study

      Schlemm's Canal Expansion After Uncomplicated Phacoemulsification Surgery: An Optical Coherence Tomography Study

      Purpose : To evaluate the effects of phacoemulsification cataract surgery on Schlemm's canal (SC) using swept-source optical coherence tomography (OCT). Methods : Patients with a senile cataract were included. The SC area and diameter were checked by OCT at the baseline and 1 day, 1 week, 1 month, and 6 months after the cataract surgery. Multivariate linear regression analysis was performed for predictors of change in the mean SC area and diameter. Results : Twenty-five eyes (25 patients) were included in the final analysis. After the cataract surgery, there was a significant increase in the SC area and diameter, and a decrease ...

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    24. Benefit of Measuring Anterior Segment Structures Using an Increased Number of Optical Coherence Tomography Images: The Chinese American Eye Study

      Benefit of Measuring Anterior Segment Structures Using an Increased Number of Optical Coherence Tomography Images: The Chinese American Eye Study

      Purpose : The purpose of this study was to evaluate the benefit of analyzing an increased number of anterior segment optical coherence tomography (AS-OCT) images on measurement values of various anterior segment parameters. Methods : Subjects for this cross-sectional study were recruited from the Chinese American Eye Study (CHES), a population-based study in Los Angeles, CA. Thirty-two AS-OCT images were acquired from one eye each of 83 consecutive subjects. Sixteen parameters were analyzed in each image, including angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), trabecular iris angle (TIA), scleral spur angle (SSAngle), lens vault (LV), pupillary ...

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      Mentions: Rohit Varma UCLA
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