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Higgins BE, Cull G, Gardiner SK. Assessment of Time Lag Between Blood Flow, Retinal Nerve Fiber Layer Thickness and Visual Field Sensitivity Changes in Glaucoma. Invest Ophthalmol Vis Sci 2024; 65:7. [PMID: 38564193 PMCID: PMC10996942 DOI: 10.1167/iovs.65.4.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/29/2024] [Indexed: 04/04/2024] Open
Abstract
Purpose This study investigates the temporal relationship between blood flow changes and alterations in retinal nerve fiber layer thickness (RNFLT) and mean deviation (MD) in individuals with glaucoma. Methods Blood flow, measured by mean blur rate in optic nerve head vessels (MBRv) and tissues (MBRt) using laser speckle flowgraphy (LSFG)-NAVI, was analyzed using structural equation models (SEMs). SEMs assessed whether the previous rate of one parameter predicted the current rate of the other parameter, adjusted for its own rate in the previous time interval. Data from 345 eyes of 174 participants were gathered from visits every six months. Results Rates of change of both MBRv and MBRt were significantly predicted by their own rate in the previous time interval and by the rate of change of MD in the previous time interval (P < 0.001 and P = 0.043, respectively), but not by the rate of MD in the concurrent interval (P = 0.947 and P = 0.549), implying that changes in MD precede changes in blood flow. Rates of change of RNFLT were predicted by their own previous rate and the rate of change of MBRv and MBRt in either the previous interval (P = 0.002 and P = 0.008) or the concurrent interval (P = 0.001 and P = 0.018), suggesting that MBR may change before RNFLT. Conclusions The evidence supports a temporal sequence where MD changes precede blood flow changes, which, in turn, may precede alterations in RNFLT.
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Affiliation(s)
| | - Grant Cull
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
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2
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Koprubasi S, Bulut E. Impact of obesity on peripapillary choroidal thickness, macular choroidal thickness, and lamina cribrosa morphology. Photodiagnosis Photodyn Ther 2023; 43:103724. [PMID: 37517426 DOI: 10.1016/j.pdpdt.2023.103724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023]
Abstract
BACKGROUND Obesity is known to be a significant risk factor for many ocular diseases. In order to understand the mechanism of obesity-related ocular diseases, we examined the lamina cribrosa morphology, peripapillary choroidal thickness (PPCT), and macular choroidal thickness (MCT) in obese women using optical coherence tomography (OCT). METHODS This comparative cross-sectional study included the right eyes of 72 obese women and 63 healthy women classified based on body mass index (BMI). Each participant underwent a thorough ophthalmological examination and enhanced depth (EDI) OCT imaging, including measurements of PPCT from a total of 12 regions, MCT from a total of 7 regions, Bruch's membrane opening (BMO), lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), intraocular pressure (IOP), and central corneal thickness (CCT). RESULTS The mean age and BMI of the obese group were 32.36±7.38 years and 35.11±4.39 kg/m², while those of the control group were 31.64±7.78 years and 20.88±1.72 kg/m² (p = 0.658, and p<0.001, respectively). PPCT N1000, PPCT N1500, PPCT S1500, and PPCT T1500 were statistically significantly thinner in the obese group than the control group (p values were 0.039, 0.012, 0.027, and 0.036, respectively). IOP and CCT were significantly higher in the obese group than the control group (p = 0.016, and p = 0.019, respectively). There was no statistically significant difference between the two groups in terms of MCT, BMO, LCT, and LCD. CONCLUSION We discovered thinning in the PPCT, which indicates microvascular abnormalities in the optic disc head. Microvascular alteration in the peripapillary region may be a potential initial event in the pathogenesis of several obesity-related ocular diseases, especially glaucoma.
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Affiliation(s)
- Sumeyra Koprubasi
- Department of Ophthalmology, Sancaktepe Sehit Prof. Dr. Ilhan Varank Training and Research Hospital, Istanbul, Turkey.
| | - Erkan Bulut
- Department of Opticianry, Vocational School of Health Services, Istanbul Gelisim University, Istanbul, Turkey
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3
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Gardiner SK, Cull G, Fortune B. Retinal Vessel Pulsatile Characteristics Associated With Vascular Stiffness Can Predict the Rate of Functional Progression in Glaucoma Suspects. Invest Ophthalmol Vis Sci 2023; 64:30. [PMID: 37335567 PMCID: PMC10284309 DOI: 10.1167/iovs.64.7.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/26/2023] [Indexed: 06/21/2023] Open
Abstract
Purpose Tissue stiffening and alterations in retinal blood flow have both been suggested as causative mechanisms of glaucomatous damage. We tested the hypothesis that retinal blood vessels also stiffen, using laser speckle flowgraphy (LSFG) to characterize vascular resistance. Methods In the longitudinal Portland Progression Project, 231 eyes of 124 subjects received LSFG scans of the optic nerve head (ONH) and automated perimetry every 6 months for six visits. Eyes were classified as either "glaucoma suspect" or "glaucoma" eyes based on the presence of functional loss on the first visit. Vascular resistance was quantified using the mean values of several instrument-defined parameterizations of the pulsatile waveform measured by LSFG, either in major vessels within the ONH (serving the retina) or in capillaries within ONH tissue, and age-adjusted using a separate group of 127 healthy eyes of 63 individuals. Parameters were compared against the severity and rate of change of functional loss using mean deviation (MD) over the six visits, within the two groups. Results Among 118 "glaucoma suspect" eyes (average MD, -0.4 dB; rate, -0.45 dB/y), higher vascular resistance was related to faster functional loss, but not current severity of loss. Parameters measured in major vessels were stronger predictors of rate than parameters measured in tissue. Among 113 "glaucoma" eyes (average MD, -4.3 dB; rate, -0.53 dB/y), higher vascular resistance was related to more severe current loss but not rate of loss. Conclusions Higher retinal vascular resistance and, by likely implication, stiffer retinal vessels were associated with more rapid functional loss in eyes without significant existing loss at baseline.
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Affiliation(s)
| | - Grant Cull
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
| | - Brad Fortune
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
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Gutiérrez Martín LC. Update on the diagnosis and treatment of normotensive glaucoma. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2023:S2173-5794(23)00078-6. [PMID: 37209720 DOI: 10.1016/j.oftale.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 04/19/2023] [Indexed: 05/22/2023]
Abstract
The increased Knowledge of the multifactorial origin of glaucoma, and especially the vascular involvement in normotensive glaucoma, can be seen in the high number of publications on this subject in recent years, which obliges us to review its diagnosis and treatment.
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Affiliation(s)
- L C Gutiérrez Martín
- Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda, Madrid, Spain.
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5
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Kim JA, Lee EJ, Kim TW, Yang HK, Hwang JM. Comparison of Optic Nerve Head Microvasculature Between Normal-Tension Glaucoma and Nonarteritic Anterior Ischemic Optic Neuropathy. Invest Ophthalmol Vis Sci 2021; 62:15. [PMID: 34398197 PMCID: PMC8374994 DOI: 10.1167/iovs.62.10.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To compare the microvasculature of the optic nerve head (ONH) and peripapillary tissues in eyes with normal-tension glaucoma (NTG) and nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA). Methods Thirty-eight eyes with treatment-naïve NTG, 38 eyes with NAION matched for retinal nerve fiber layer (RNFL) thickness in each superior and inferior quadrant, and 38 healthy eyes matched by age were included. ONH and peripapillary retinal microvasculature was evaluated in en face images obtained using OCTA. Vessel density (VD) was calculated as the percent area occupied by vessels in the measured region in each layer segmented into the prelaminar tissue (PLT), lamina cribrosa (LC), and peripapillary retina (PR). Results VDs in the PLT and LC were lower in NTG eyes than in both NAION and healthy eyes (P ≤ 0.008), and did not differ between the NAION and healthy eyes. VDs in the PR did not differ between the NTG and NAION eyes. In intersectoral comparisons, VDs in the PLT (P = 0.030) and LC (P = 0.028) were lower in the affected than in the unaffected sector of eyes with NTG, but the differences did not occur in eyes with NAION. VD in the PR was lower in the affected than in the unaffected sector in both NTG and NAION eyes (both P < 0.001). Conclusions Despite similar degrees of RNFL loss and VD decreases in the PR, VDs in the ONH differed between eyes with NTG and NAION, indicating different mechanisms of vascular impairment and ONH damage in each condition.
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Affiliation(s)
- Ji-Ah Kim
- Department of Ophthalmology, Ewha Womans University College of Medicine, Ewha Womans University Seoul Hospital, Seoul, Korea
| | - Eun Ji Lee
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Tae-Woo Kim
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hee Kyung Yang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jeong-Min Hwang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
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Abstract
Early detection and monitoring are critical to the diagnosis and management of glaucoma, a progressive optic neuropathy that causes irreversible blindness. Optical coherence tomography (OCT) has become a commonly utilized imaging modality that aids in the detection and monitoring of structural glaucomatous damage. Since its inception in 1991, OCT has progressed through multiple iterations, from time-domain OCT, to spectral-domain OCT, to swept-source OCT, all of which have progressively improved the resolution and speed of scans. Even newer technological advancements and OCT applications, such as adaptive optics, visible-light OCT, and OCT-angiography, have enriched the use of OCT in the evaluation of glaucoma. This article reviews current commercial and state-of-the-art OCT technologies and analytic techniques in the context of their utility for glaucoma diagnosis and management, as well as promising future directions. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Alexi Geevarghese
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA;
| | - Gadi Wollstein
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA; .,Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA.,Center for Neural Science, NYU College of Arts and Sciences, New York, NY 10003, USA
| | - Hiroshi Ishikawa
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA; .,Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA
| | - Joel S Schuman
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA; .,Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA.,Center for Neural Science, NYU College of Arts and Sciences, New York, NY 10003, USA.,Department of Physiology and Neuroscience, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA
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Characterization of laser speckle flowgraphy pulse waveform parameters for the evaluation of the optic nerve head and retinal circulation. Sci Rep 2021; 11:6847. [PMID: 33767305 PMCID: PMC7994841 DOI: 10.1038/s41598-021-86280-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 03/12/2021] [Indexed: 01/14/2023] Open
Abstract
To characterize laser speckle flowgraphy (LSFG) pulse waveform parameters for ocular circulation evaluation, a multicenter, prospective, cross-sectional study was conducted in 111 eyes of 86 healthy Japanese individuals. Optic nerve head (ONH) tissue-area, vessel-area mean blur rate (MT and MV, respectively), and MT and MV pulse waveform parameters were obtained using LSFG and ONH structural parameters using planimetry. Multivariate linear mixed-effects modeled regression analysis identified factors contributing to MT- or MV-waveforms using age, gender, smoking history, body mass index, systolic and diastolic blood pressure, heart rate, intraocular pressure, axial length, disc, rim, and β-peripapillary atrophy areas, MT or MV, central retinal artery, and vein equivalents (CRAE and CRVE) as explanatory variables. MT- and MV-waveforms significantly correlated with one or more systemic factors, consistent with previous studies. Following confounding factor adjustment, MT-Skew significantly negatively correlated with β-PPA area (P = 0.026); MT- and MV-flow acceleration index positively correlated with CRAE, MT, and MV (P = 0.041–< 0.001), compatible with these parameters’ observed correlations to systemic factors. Significantly negative correlations of the blowout score and acceleration time index to CRAE partly conflicted with their correlations to systemic factors, and other waveform parameters showed little correlation to ocular factors. Thus, Skew and flow acceleration index assisted the in vivo ocular circulation characterization.
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Wang X, Chen J, Kong X, Sun X. Quantification of Retinal Microvascular Density Using Optic Coherence Tomography Angiography in Primary Angle Closure Disease. Curr Eye Res 2020; 46:1018-1024. [PMID: 33170750 DOI: 10.1080/02713683.2020.1849728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Purpose: To evaluate the microvascular density of the peripapillary and parafoveal areas of the eyes with primary angle closure disease (PACD) using optical coherence tomography angiography (OCTA).Materials and methods: An observational study was conducted with 76 PACD patients (29 eyes with primary angle closure suspect, 22 eyes with primary angle closure [PAC], and 25 eyes with primary angle closure glaucoma [PACG]) and 27 control eyes. OCTA was performed for all subjects to acquire a 4.5 × 4.5 mm scanning area centered on the optic discs and a 3 × 3 mm parafoveal cubes. Peripapillary and parafoveal vessel density (VD) were compared between these four groups, and the relationship between VD values and structural and functional changes was evaluated.Results: Among all four groups, the peripapillary VD of the PACG eyes was the lowest in all six sections (all P < .01), while the parafoveal VD was lower than that of the normal group only in the average, superior, and inferior areas (all P < .05). The PAC group had lower peripapillary VD than the normal group (62.6[55.2-67.4] vs. 66.7[54.7-69.3], P = .01), while their retinal nerve fiber layer (RNFL) and ganglion cell complex thickness were not significantly different than those of the control group (all P > .05). In addition, the stages of PACD, visual field mean deviation, and RNFL thickness were shown to be predictors of the peripapillary VD in the multiple linear regression analysis.Conclusions: The PAC eyes had lower peripapillary VD than normal eyes when their RNFL and GCC thickness did not differ. This suggests that a reduction in retinal VD may occur before structural loss in PAC eyes. Retinal VD measurement may be a useful tool for the assessment of PACD.
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Affiliation(s)
- Xiaolei Wang
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Ministry of Health (Fudan University), and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China
| | - Junyi Chen
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Ministry of Health (Fudan University), and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China
| | - Xiangmei Kong
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Ministry of Health (Fudan University), and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College of Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Ministry of Health (Fudan University), and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
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9
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Chen X, Wang X, Hu X, Sun X. The evaluation of juvenile ocular hypertension by optical coherence tomography angiography. BMC Ophthalmol 2020; 20:423. [PMID: 33087093 PMCID: PMC7576766 DOI: 10.1186/s12886-020-01641-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 09/09/2020] [Indexed: 11/29/2022] Open
Abstract
Background Vessel density (VD) of the elderly ocular hypertension patients measured by optical coherence tomography angiography (OCTA) have been reported. However, the studies of VD in juvenile ocular hypertension (JOHT) are limited. We wished to evaluate VD changes using OCTA in JOHT. We also investigated the potential risk parameters of intraocular pressure (IOP) and vertical cup/disc ratio (CDR) with OCTA for observing the development of JOHT. Methods We examined 86 eyes in 45 control (Ctrl) subjects and 65 eyes in 34 patients with JOHT using OCTA at the glaucoma clinic of the Eye, Ear, Nose, and Throat Hospital of Fudan University. The VD of radial peripapillary capillaries (RPC) and the perifoveal superficial vascular plexus (SVP) was compared between the Ctrl and JOHT groups. Other basic study factors such as age, sex, blood pressure, best-corrected visual acuity, central corneal thickness, IOP, CDR, the thickness of the retinal nerve fiber layer, ganglion cell complex, visual field mean deviation, and pattern standard deviation were also recorded. Results Bare difference was found in the nasal-inferior and temporal RPC-VD between the Ctrl and JOHT groups (P = 0.042 and P = 0.033, respectively) while SVP-VD was not (all P > 0.05). In the mixed linear regression model analysis, temporal RPC-VD was marginally negatively associated with high IOP (r = − 1.379, P = 0.043). Five additional sections of nasal, inferior-nasal, inferior-temporal, superior-temporal, and superior-nasal RPC-VD showed positive correlation with large CDR (all P < 0.05). SVP-VD in the superior and nasal regions was marginally negatively correlated with high IOP (r = − 1.877, P = 0.023; r = − 1.693, P = 0.049). No other regions were found statistical different of relationship between IOP, CDR and VD. Conclusions Nasal-inferior and temporal peripapillary VD was marginally lower in JOHT subjects. Regarding parameters of IOP and CDR, peripapillary temporal VD had a borderline level of negative correlation with IOP more than 21 mmHg while additional five regions were strongly positively correlated with large CDR. Some macular regions only found marginal positive correlation with parameter of high IOP. We conclude that OCTA can be used as a potential technique to evaluate the VD in JOHT and peripapillary scans should be analyzed individually based on different levels of CDR.
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Affiliation(s)
- Xiaoxiao Chen
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Fenyang Road. 83, Shanghai, 200031, China
| | - Xiaolei Wang
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Fenyang Road. 83, Shanghai, 200031, China
| | - Xinxin Hu
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Fenyang Road. 83, Shanghai, 200031, China
| | - Xinghuai Sun
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Fenyang Road. 83, Shanghai, 200031, China. .,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China. .,NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China.
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Acosta E, Olvera-Angeles M, González-Amador E, Sasian J, Schwiegerling J, Arines J. Wavefront coding with Jacobi-Fourier phase masks for retinal imaging. APPLIED OPTICS 2020; 59:G234-G238. [PMID: 32749338 DOI: 10.1364/ao.391941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/20/2020] [Indexed: 06/11/2023]
Abstract
Wavefront coding is a technique that combines optical phase elements and digital signal processing in order to increase the effective depth of focus of optical systems. The success of wavefront coding lies in the design of a suitable phase mask placed at the system's aperture. This element allows for image formation invariant under the effects of different second-order optical aberrations. In optical systems limited by temporally or spatially varying high-order aberrations, the use of wavefront coding has not been fully demonstrated. Here we propose the choice of Jacobi-Fourier shaped phase masks to produce sharp and clear retinal images of living eyes. To demonstrate the potential use of the technique, we analyze the performance of the Jacobi-Fourier phase masks through experimental simulations to alleviate aberrations for different eye aberrations. We will show that the best mask choice is robust to noise while keeping acceptable resolution and reducing image artefacts.
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11
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Ocular Perfusion Pressure and the Risk of Open-Angle Glaucoma: Systematic Review and Meta-analysis. Sci Rep 2020; 10:10056. [PMID: 32572072 PMCID: PMC7308312 DOI: 10.1038/s41598-020-66914-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 05/28/2020] [Indexed: 02/03/2023] Open
Abstract
Low ocular perfusion pressure (OPP) has been proposed as an important risk factor for glaucoma development and progression, but controversy still exists between studies. Therefore, we conducted a systematic review and meta-analysis to analyze the association between OPP and open-angle glaucoma (OAG). Studies were identified by searching PubMed and EMBASE databases. The pooled absolute and standardised mean difference in OPP between OAG patients and controls were evaluated using the random-effects model. Meta-regression analysis was conducted to investigate the factors associated with OPP difference between OAG patients and controls. A total of 43 studies were identified including 3,009 OAG patients, 369 patients with ocular hypertension, and 29,502 controls. The pooled absolute mean difference in OPP between OAG patients and controls was −2.52 mmHg (95% CI −4.06 to −0.98), meaning significantly lower OPP in OAG patients (P = 0.001). Subgroup analyses showed that OAG patients with baseline IOP > 21 mmHg (P = 0.019) and ocular hypertension patients also had significantly lower OPP than controls (P < 0.001), but such difference in OPP was not significant between OAG patients with baseline IOP of ≤21 mmHg and controls (P = 0.996). In conclusion, although no causal relationship was proven in the present study, our findings suggest that in patients with high baseline IOP, who already have a higher risk of glaucoma, low OPP might be another risk factor.
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12
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Optical Coherence Tomography Angiography of Optic Disc in Eyes With Primary Open-angle Glaucoma and Normal-tension Glaucoma. J Glaucoma 2020; 28:243-251. [PMID: 30624391 DOI: 10.1097/ijg.0000000000001184] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE To examine vessel density (VD) properties of the optic nerve head in eyes with ocular hypertension (OHT), high-tension glaucoma (HTG), and normal-tension glaucoma (NTG) and to evaluate associations on structural parameters of retinal nerve fiber layer (RNFL). METHODS Three groups of patients with OHT (n=15), HTG (n=36), and NTG (n=22), and a healthy control group (n=23) were included in this study. Peripapillary VD and optic disc flow area were measured using optical coherence tomography angiography, and peripapillary RNFL (pRNFL) thickness was determined. Global and sectoral analysis of optic nerve head vasculature and pRNFL thickness were measured. RESULTS Glaucomatous eyes had lower global peripapillary VD (HTG: 54.04±5.11, NTG: 54.74±6.37) compared with nonglaucomatous eyes (OHT: 59.72±1.63, controls: 61.35±2.47). VD parameters of the optic disc were comparable between the control and OHT group and between the HTG and NTG group. In the HTG and NTG groups we found significant correlations between average peripapillary VD and global pRNFL thickness (HTG ρ=0.71, P<0.001; NTG ρ=0.65, P=0.001). This was true for all sectors except for the temporal position. CONCLUSIONS Overall, glaucomatous eyes had lower peripapillary VD compared with normal and OHT eyes. There is a strong relationship between the peripapillary structure of RNFL and its vasculature.
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13
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Gardiner SK, Cull G, Fortune B, Wang L. Increased Optic Nerve Head Capillary Blood Flow in Early Primary Open-Angle Glaucoma. Invest Ophthalmol Vis Sci 2019; 60:3110-3118. [PMID: 31323681 PMCID: PMC6645706 DOI: 10.1167/iovs.19-27389] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Blood flow in the optic nerve head (ONH) is known to be reduced in eyes with advanced glaucoma. However, experimental results from non-human primates suggest an initial increase in ONH blood flow at the earliest stages of damage. This study assesses flow and pulsatile hemodynamics across a range of severities to test the hypothesis that this also occurs in human glaucoma. Methods Laser speckle flowgraphy was used to measure average mean blur rate (MBRave) within ONH tissue (a correlate of capillary blood flow) and the pulsatile waveform in 93 eyes with functional loss and 74 glaucoma suspect/fellow eyes without functional loss. These were compared against results from 92 healthy control eyes. Parameters produced by the instrument's software were age-corrected, then compared between groups using generalized estimating equation models. Results The mean MBRave in the control eyes was 12.5 units. In glaucoma suspect/fellow eyes, the mean was 16.4 units, higher with P < 0.0001. In eyes with functional loss, the mean was 13.8 units, lower than eyes without functional loss with P < 0.0001, although still higher than control eyes with P = 0.0096. Analysis of the pulsatile waveform suggested that the deceleration in flow as it approaches its maximum across the cardiac cycle was delayed in glaucoma. Conclusions Blood flow within ONH capillaries was higher in glaucoma suspect eyes than in healthy controls. It was less elevated in eyes that had developed functional loss. The mechanisms causing these changes and their relation to concurrent changes in pulsatile hemodynamics remain under investigation.
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Affiliation(s)
- Stuart K Gardiner
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
| | - Grant Cull
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
| | - Brad Fortune
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
| | - Lin Wang
- Devers Eye Institute, Legacy Health, Portland, Oregon, United States
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14
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Blair NP, Tan MR, Felder AE, Shahidi M. Retinal Oxygen Delivery, Metabolism and Extraction Fraction and Retinal Thickness Immediately Following an Interval of Ophthalmic Vessel Occlusion in Rats. Sci Rep 2019; 9:8092. [PMID: 31147557 PMCID: PMC6542852 DOI: 10.1038/s41598-019-44250-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/09/2019] [Indexed: 11/30/2022] Open
Abstract
Limited knowledge is currently available about alterations of retinal blood flow (F), oxygen delivery (DO2), oxygen metabolism (MO2), oxygen extraction fraction (OEF), or thickness after the ophthalmic blood vessels have been closed for a substantial interval and then reopened. We ligated the ophthalmic vessels for 120 minutes in one eye of 17 rats, and measured these variables within 20 minutes after release of the ligature in the 10 rats which had immediate reflow. F, DO2 and MO2 were 5.2 ± 3.1 μL/min, 428 ± 271 nL O2/min, and 234 ± 133 nL O2/min, respectively, that is, to 58%, 46% and 60% of values obtained from normal fellow eyes (P < 0.004). OEF was 0.65 ± 0.23, 148% of normal (P = 0.03). Inner and total retinal thicknesses were 195 ± 24 and 293 ± 20 μm, respectively, 117% and 114% of normal, and inversely related to MO2 (P ≤ 0.02). These results reflect how much energy is available to the retina immediately after an interval of nonperfusion for 120 minutes. Thus, they elucidate aspects of the pathophysiology of nonperfusion retinal injury and may improve therapy in patients with retinal artery or ophthalmic artery obstructions.
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Affiliation(s)
- Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, USA
| | - Michael R Tan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, USA
| | - Anthony E Felder
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, USA.
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Wei X, Balne PK, Meissner KE, Barathi VA, Schmetterer L, Agrawal R. Assessment of flow dynamics in retinal and choroidal microcirculation. Surv Ophthalmol 2018; 63:646-664. [DOI: 10.1016/j.survophthal.2018.03.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 03/19/2018] [Accepted: 03/19/2018] [Indexed: 01/08/2023]
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16
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Curtis TM, McLaughlin D, O'Hare M, Kur J, Barabas P, Revolta G, Scholfield CN, McGeown JG, McGahon MK. Isolation of Retinal Arterioles for Ex Vivo Cell Physiology Studies. J Vis Exp 2018. [PMID: 30059036 PMCID: PMC6126467 DOI: 10.3791/57944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The retina is a highly metabolically active tissue that requires a substantial blood supply. The retinal circulation supports the inner retina, while the choroidal vessels supply the photoreceptors. Alterations in retinal perfusion contribute to numerous sight-threatening disorders, including diabetic retinopathy, glaucoma and retinal branch vein occlusions. Understanding the molecular mechanisms involved in the control of blood flow through the retina and how these are altered during ocular disease could lead to the identification of new targets for the treatment of these conditions. Retinal arterioles are the main resistance vessels of the retina, and consequently, play a key role in regulating retinal hemodynamics through changes in luminal diameter. In recent years, we have developed methods for isolating arterioles from the rat retina which are suitable for a wide range of applications including cell physiology studies. This preparation has already begun to yield new insights into how blood flow is controlled in the retina and has allowed us to identify some of the key changes that occur during ocular disease. In this article, we describe methods for the isolation of rat retinal arterioles and include protocols for their use in patch-clamp electrophysiology, calcium imaging and pressure myography studies. These vessels are also amenable for use in PCR-, western blotting- and immunohistochemistry-based studies.
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Affiliation(s)
- Tim M Curtis
- Centre for Experimental Medicine, Queen's University of Belfast
| | - Declan McLaughlin
- Centre for Biomedical Sciences (Education), Queen's University of Belfast
| | - Michael O'Hare
- Centre for Experimental Medicine, Queen's University of Belfast
| | - Joanna Kur
- Centre for Experimental Medicine, Queen's University of Belfast
| | - Peter Barabas
- Centre for Experimental Medicine, Queen's University of Belfast
| | - Gordon Revolta
- Centre for Experimental Medicine, Queen's University of Belfast
| | - C Norman Scholfield
- Department of Pharmaceutical Chemistry and Pharmacognosy, Naresuan University
| | - J Graham McGeown
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University of Belfast
| | - Mary K McGahon
- Centre for Biomedical Sciences (Education), Queen's University of Belfast;
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Peripapillary Vessel Density Reversal after Trabeculectomy in Glaucoma. J Ophthalmol 2018; 2018:8909714. [PMID: 30046465 PMCID: PMC6038471 DOI: 10.1155/2018/8909714] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 05/23/2018] [Indexed: 11/17/2022] Open
Abstract
Purpose To evaluate the microvascular changes at the peripapillary area and optic disc in glaucomatous eyes after IOP lowering by trabeculectomy using OCT angiography. Methods 25 patients with primary open-angle glaucoma (POAG) who underwent trabeculectomy by a single surgeon were evaluated. Using optical coherence tomography angiography, vessel density was evaluated within the whole image, peripapillary, nasal region, and temporal region. Peripapillary vessel density was measured preoperative, 1 week, 1 month, and 3 months postoperatively in POAG patients. Reversal of vessel density was calculated for all analyzed areas. Results The intraocular pressure (IOP) decreased from 30.92 ± 6.32 mmHg (range, 18-44) to 12.64 ± 3.35 mmHg (range, 8-22) at 3-month postoperatively. Compared with the preoperative baseline value, whole vessel density, peripapillary vessel density (PvD), and PvD in nasal region and temporal region were significantly increased at 3-month postoperatively. The magnitude of the vessel density reversal was significantly associated with higher preoperative IOP and greater IOP reduction. Conclusions A significant increase in the peripapillary vessel density was demonstrated after trabeculectomy using OCT angiography. The reversal of peripapillary vessel density was associated with higher preoperative IOP and greater IOP reduction. Our postoperative results suggest that the ocular perfusion impairment by high intraocular pressure can be improved by IOP reduction, and the reversal of microvasculature may contribute to the rate of glaucoma progression.
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Correlation of flow density, as measured using optical coherence tomography angiography, with structural and functional parameters in glaucoma patients. Graefes Arch Clin Exp Ophthalmol 2018; 256:589-597. [DOI: 10.1007/s00417-017-3865-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/24/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022] Open
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Capillary Dropout at the Retinal Nerve Fiber Layer Defect in Glaucoma: An Optical Coherence Tomography Angiography Study. J Glaucoma 2017; 26:e142-e145. [PMID: 27599177 DOI: 10.1097/ijg.0000000000000540] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate the microvasculature changes of retinal nerve fiber layer (RNFL) defects in glaucoma. DESIGN The study design is a case report. PATIENTS AND METHODS Four glaucomatous eyes were included in this observational cross-sectional study. The microvasculature changes of RNFL defects were examined using optical coherence tomography (OCT) angiography. RESULTS Three eyes had apparent wedge-shaped capillary dropout on OCT angiography. In the fourth eye, detection of wedge-shaped capillary loss was difficult because of overall capillary drop out due to advanced glaucoma. Capillary dropout detection by OCT angiography was correlated with visual field loss and RNFL defect detection by regular OCT. Compared with regular OCT used to obtain retinal thickness maps, OCT angiography is often better at visualizing the borders of lesions in the RNFL. CONCLUSIONS OCT angiography can detect capillary dropout in RNFL defects in glaucomatous eyes, and therefore could be a useful glaucoma examination tool.
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OCT Angiography Changes in the 3 Parafoveal Retinal Plexuses in Response to Hyperoxia. Ophthalmol Retina 2017; 2:329-336. [PMID: 29888339 DOI: 10.1016/j.oret.2017.07.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Purpose Use projection-resolved OCT angiography to investigate the autoregulatory response in the 3 parafoveal retinal plexuses under hyperoxia. Design Prospective cohort study. Participants Nine eyes from 9 healthy participants. Methods One eye from each participant was scanned using a commercial spectral-domain OCT system. Two repeated macular scans (3 × 3 mm2) were acquired at baseline and during oxygen breathing. The split-spectrum amplitude-decorrelation algorithm was used to detect blood flow. The projection-resolved algorithm was used to suppress projection artifacts and resolve blood flow in 3 distinct parafoveal plexuses. The Wilcoxon signed-rank test was used to compare baseline and hyperoxic parameters. The coefficient of variation, intraclass correlation coefficient, and pooled standard deviation were used to assess the reliability of OCT angiography measurements. Main Outcome Measures Flow index and vessel density were calculated from the en face angiograms of each of the 3 plexuses, as well as from the all-plexus inner retinal slab. Results Hyperoxia induced significant reduction in the flow index (-11%) and vessel density (-7.8%) of only the deep capillary plexus (P < 0.001) and in the flow index of the all-plexus slab (P = 0.015). The flow index also decreased in the intermediate capillary plexus and the superficial vascular complex, but these changes were small and not statistically significant. The projection-resolved OCT angiography showed good within-session baseline repeatability (coefficient of variation, 0.8%-5.2%; intraclass correlation coefficient, 0.93-0.98) in all parameters. Relatively large between-day response reproducibility was observed (pooled standard deviation, 1.7%-9.4%). Conclusions Projection-resolved OCT angiography was able to show that the retinal autoregulatory response to hyperoxia affects only the deep capillary plexus, but not the intermediate capillary plexus or superficial vascular complex.
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Abstract
The choroid is part of the uveal tract and is a heavily vascularized bed that also contains connective tissue and melanin pigment. Given the role of the choroidal vasculature in the blood supply of the anterior laminar and prelaminar regions of the optic nerve head, the peripapillary choroid might be a relevant target for investigation in patients with glaucoma. The purpose of this paper is to critically review the current understanding of potential role of the choroid in the pathogenesis of glaucomatous damage.
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Pechauer AD, Tan O, Liu L, Jia Y, Hou V, Hills W, Huang D. Retinal Blood Flow Response to Hyperoxia Measured With En Face Doppler Optical Coherence Tomography. Invest Ophthalmol Vis Sci 2017; 57:OCT141-5. [PMID: 27409465 PMCID: PMC4968776 DOI: 10.1167/iovs.15-18917] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Purpose To use multiplane en face Doppler optical coherence tomography (OCT) to measure the change in total retinal blood flow (TRBF) in response to hyperoxia. Methods One eye of each healthy human participant (n = 8) was scanned with a commercial high-speed (70-kHz) spectral OCT system. Three repeated scans were captured at baseline and after 10 minutes of oxygen (hyperoxia) by open nasal mask. The procedure was performed twice on day 1 and once more on day 2. Blood flow of each vein was estimated using Doppler OCT at an optimized en face plane. The TRBF was summed from all veins at the optic disc. The TRBF hyperoxic response was calculated as the TRBF percent change from baseline. Results Participants experienced a 23.6% ± 10.7% (mean ± standard deviation [SD]) decrease (P < 0.001, paired t-test) in TRBF during hyperoxia. The within-day repeatability of baseline TRBF was 4.1% and the between-day reproducibility was 10.9% coefficient of variation (CV). Between-grader reproducibility was 3.9% CV. The repeatability and reproducibility (pooled SD) of hyperoxic response were 6.1% and 6.4%, respectively. Conclusions The multiplane en face Doppler OCT algorithm was able to detect, in all participants, a decreased TRBF in response to hyperoxia. The response magnitude for each participant varied among repeated trials, and the averaging of multiple trials was helpful in establishing the individual response. This technique shows good potential for the clinical investigation of vascular autoregulation.
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23
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Maram J, Srinivas S, Sadda SR. Evaluating ocular blood flow. Indian J Ophthalmol 2017; 65:337-346. [PMID: 28573987 PMCID: PMC5565900 DOI: 10.4103/ijo.ijo_330_17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 05/04/2017] [Indexed: 02/01/2023] Open
Abstract
Studies have shown that vascular impairment plays an important role in the etiology and pathogenesis of various ocular diseases including glaucoma, age-related macular degeneration, diabetic retinopathy, and retinal venous occlusive disease. Thus, qualitative and quantitative assessment of ocular blood flow (BF) is a topic of interest for early disease detection, diagnosis, and management. Owing to the rapid improvement in technology, there are several invasive and noninvasive techniques available for evaluating ocular BF, with each of these techniques having their own limitations and advantages. This article reviews these important techniques, with a particular focus on Doppler Fourier domain optical coherence tomography (OCT) and OCT-angiography.
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Affiliation(s)
- Jyotsna Maram
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, California, USA
| | - Sowmya Srinivas
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, California, USA
| | - Srinivas R Sadda
- Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, California, USA
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Peripapillary retinal vessel density in eyes with acute primary angle closure: an optical coherence tomography angiography study. Graefes Arch Clin Exp Ophthalmol 2017; 255:1013-1018. [PMID: 28161831 DOI: 10.1007/s00417-017-3593-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 01/02/2017] [Accepted: 01/16/2017] [Indexed: 10/20/2022] Open
Abstract
PURPOSE The purpose was to investigate peripapillary retinal vessel density in resolved acute primary angle closure (APAC) eyes. METHODS This was a prospective, cross-sectional observational study. Thirty-four eyes of 34 patients with unilateral APAC were included, together with the fellow eyes with primary angle closure suspect (PACS) as controls. Peripapillary retinal vessel density was measured using optical coherence tomography (OCT) angiography. Peripapillary retinal vessel density was compared in both eyes and the potential relationship with visual field (VF) test results was evaluated. RESULTS After an acute attack, the peripapillary retinal vessel density was lower in the APAC than in the PACS eyes (79.3 ± 8.2 versus 85.6 ± 4.9, respectively; P = 0.001). The VF mean deviation (MD) (-7.7 ± 6.7 versus -3.3 ± 1.8 dB, P = 0.002), and the pattern standard deviation (PSD) (4.6 ± 3.3 versus 2.4 ± 0.9 dB, P = 0.001) were worse for the APAC than the PACS eyes, but both had similar thicknesses of the retinal nerve fiber layer (RNFL) (111.8 ± 9.6 versus 114.1 ± 29.1 μm, P = 0.880) and ganglion cell complex (GCC) (94.7 ± 7.5 versus 91.8 ± 9.3 μm, P = 0.328). The peripapillary retinal vessel density was significantly correlated with the VF MD (vessel density: r = 0.455, P = 0.008) and PSD (vessel density: r = -0.592, P < 0.001) in the APAC eyes. CONCLUSIONS Even when IOP was normalized after the acute attack, the APAC eyes had a lower peripapillary retinal vessel density, which was correlated with the VF values. OCT angiography is a reliable method for detecting vascular changes in glaucomatous eyes that show no thinning of the RNFL and GCC.
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25
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Lee KM, Lee EJ, Kim TW. Juxtapapillary choroid is thinner in normal-tension glaucoma than in healthy eyes. Acta Ophthalmol 2016; 94:e697-e708. [PMID: 27288014 DOI: 10.1111/aos.13086] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 03/07/2016] [Indexed: 12/15/2022]
Abstract
PURPOSE To measure the juxtapapillary choroidal thickness in eyes with normal-tension glaucoma (NTG) and to compare it with healthy eyes. METHODS Twelve radial B-scan images of the optic nerve head (ONH) were obtained from 96 patients with NTG and 48 healthy subjects matched by age using swept-source (SS) optical coherence tomography (OCT). The juxtapapillary choroidal thickness was defined as the average choroidal thickness within 500 μm from the border tissue of Elschnig. Choroidal thinning in patients with NTG was assessed by calculating the relative choroidal thickness, defined as the ratio of the measured juxtapapillary choroidal thickness in each meridian to the corresponding value in age-matched healthy controls. Retinal nerve fibre layer (RNFL) damage as reflected by circumpapillary RNFL thickness (measured using spectral-domain OCT) was also assessed. RESULTS The juxtapapillary choroid was significantly thinner in NTG eyes than in healthy control eyes in the inferotemporal and superotemporal sectors. The relative choroidal thinning was topographically associated with the hemispheric location of dominant RNFL damage. The average juxtapapillary choroidal thickness was not associated with either the global RNFL thickness or the visual field mean deviation. Age and untreated intraocular pressure were significantly associated with the juxtapapillary choroidal thickness in NTG eyes in both univariate and multivariate analyses (all p < 0.05). CONCLUSIONS Decreased microvascular circulation in the ONH as a result of juxtapapillary choroidal thinning could be an important part of the pathogenesis of optic nerve damage in NTG.
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Affiliation(s)
- Kyoung Min Lee
- Department of Ophthalmology; Seoul National University College of Medicine; Seoul National University Bundang Hospital; Seongnam Korea
| | - Eun Ji Lee
- Department of Ophthalmology; Seoul National University College of Medicine; Seoul National University Bundang Hospital; Seongnam Korea
| | - Tae-Woo Kim
- Department of Ophthalmology; Seoul National University College of Medicine; Seoul National University Bundang Hospital; Seongnam Korea
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Abstract
The early detection of glaucoma is imperative in order to preserve functional vision. Structural and functional methods are utilized to detect and monitor glaucomatous damage and the vision loss it causes. The relationship between these detection measures is complex and differs between individuals, especially in early glaucoma. Using both measures together is advised in order to ensure the highest probability of glaucoma detection, and new testing methods are continuously developed with the goals of earlier disease detection and improvement of disease monitoring. The purpose of this review is to explore the relationship between structural and functional glaucoma detection and discuss important technological advances for early glaucoma detection.
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Affiliation(s)
- Katie A. Lucy
- Department of Ophthalmology, New York University School of Medicine, New York, NY, USA
| | - Gadi Wollstein
- Department of Ophthalmology, New York University School of Medicine, New York, NY, USA
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27
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Differences in Ocular Blood Flow Between People of African and European Descent With Healthy Eyes. J Glaucoma 2016; 25:709-15. [DOI: 10.1097/ijg.0000000000000509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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28
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Xu H, Yu J, Kong X, Sun X, Jiang C. Macular microvasculature alterations in patients with primary open-angle glaucoma: A cross-sectional study. Medicine (Baltimore) 2016; 95:e4341. [PMID: 27537559 PMCID: PMC5370786 DOI: 10.1097/md.0000000000004341] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
To evaluate and compare macular microvasculature changes in eyes with primary open-angle glaucoma (POAG) to normal eyes, and to assess associations among the retinal microvasculature, neural structural damage, and visual field loss.Ninety-nine eyes (68 patients with POAG and 31 normal subjects) were enrolled in this study. Thirty-five eyes with early-stage glaucoma (EG), 33 eyes with advanced-stage glaucoma (AG), and 31 normal eyes were included. An optical coherence tomography system with a split-spectrum amplitude-decorrelation angiography algorithm was used to measure the macular capillary vessel area density and retinal thickness. Visual field testing (30-2 and 10-2 programs) was performed using a Humphrey field analyzer. Correlations between the capillary vessel area density, retinal thickness, and visual field parameters were analyzed.Compared to normal eyes, those with EG and AG had a lower macular capillary vessel area density and lesser retinal thickness (P < 0.001, all). Results of multivariate linear regression analyses showed that each standard deviation (SD) decrease in the vessel area density was associated with a 1.5% and 4.2% thinning of the full retinal thickness and inner retinal layer thickness, respectively. Each SD decrease in the vessel area density was also associated with a 12.9% decrease in the mean sensitivity and a 33.6% increase in the pattern standard deviation (P < 0.001, both). The Pearson partial regression analysis model showed that the vessel area density was most strongly associated with the inner retinal layer thickness and inferior hemimacular thickness. Furthermore, a lower vessel area density was strongly associated with a more severe hemimacular visual field defect and the corresponding hemimacular retinal thickness.The macular capillary vessel area density and retinal thickness were significantly lower in eyes with POAG than in normal eyes. A diminished macular microvasculature network is closely associated with visual field defects, which are dependent on structural damage due to POAG.
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Affiliation(s)
- Huan Xu
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College, Fudan University
- Key Laboratory of Myopia, Ministry of Health (Fudan University)
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University)
| | - Jian Yu
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College, Fudan University
- Key Laboratory of Myopia, Ministry of Health (Fudan University)
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University)
| | - Xiangmei Kong
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College, Fudan University
- Key Laboratory of Myopia, Ministry of Health (Fudan University)
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University)
- Correspondence: Xiangmei Kong, Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd, Shanghai 200031, China (e-mail: )
| | - Xinghuai Sun
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College, Fudan University
- Key Laboratory of Myopia, Ministry of Health (Fudan University)
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University)
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Chunhui Jiang
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital, Shanghai Medical College, Fudan University
- Key Laboratory of Myopia, Ministry of Health (Fudan University)
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University)
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Twenty-four-hour intraocular pressure and ocular perfusion pressure characteristics in newly diagnosed patients with normal tension glaucoma. Eye (Lond) 2016; 30:1481-1489. [PMID: 27472211 DOI: 10.1038/eye.2016.168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/23/2016] [Indexed: 01/09/2023] Open
Abstract
PurposeTo determine the mean 24-h intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) characteristics of newly diagnosed, previously untreated, Caucasian, normal tension glaucoma (NTG) patients and to identify relationships between these features and visual field (VF) loss at diagnosis.MethodsConsecutive newly diagnosed NTG patients underwent 24-h habitual IOP and blood pressure (BP) monitoring. Parameters from pooled measurements obtained in the sitting (0800-2200 hours) and supine (1200-0600 hours) positions were compared and associations were sought with VF mean deviation (MD) and pattern standard deviation (PSD).ResultsSixty-two Caucasian NTG patients (24 men and 38 women) successfully completed circadian IOP and BP monitoring. In habitual position, 8 subjects (12.9%) exhibited a diurnal acrophase, 42 subjects (67.7%) demonstrated a nocturnal acrophase, one subject (1.6%) showed a flat rhythm and 11 patients (17.7%) revealed a biphasic/polyphasic rhythm. Nighttime MOPP values (supine position) were significantly greater than diurnal values (sitting position); (P<0.001). No association could be demonstrated between glaucomatous damage, as indicated by VF parameters, and either mean habitual 24-h IOP (P=0.20 and P=0.12 for MD and PSD, respectively), or habitual 24-h MOPP (P=0.96 and 0.29, for MD and PSD, respectively).ConclusionsIn this cohort of Caucasian NTG patients, most patients exhibited a nocturnal IOP acrophase when evaluated in a habitual position. No association was found between 24-h IOP or MOPP and VF damage.
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Optic Disc Vascularization in Glaucoma: Value of Spectral-Domain Optical Coherence Tomography Angiography. J Ophthalmol 2016; 2016:6956717. [PMID: 26998352 PMCID: PMC4779818 DOI: 10.1155/2016/6956717] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/21/2016] [Accepted: 01/24/2016] [Indexed: 11/24/2022] Open
Abstract
Purpose. To detect changes in optic nerve head (ONH) vascularization in glaucoma patients using spectral-domain OCT angiography (OCT-A). Material and Method. Fifty glaucoma patients and 30 normal subjects were evaluated with OCT-A (AngioVue®, Optovue). The total ONH vessel density and temporal disc vessel density were measured. Clinical data, visual field (VF) parameters, and spectral-domain OCT evaluation (RNFL: retinal nerve fiber layer thickness, GCC: ganglion cell complex thickness, and rim area) were recorded for glaucoma patients. Correlations among total and temporal ONH vessel density and structural and VF parameters were analyzed. Results. In the glaucoma group, total and temporal ONH vessel density were reduced by 24.7% (0.412 versus 0.547; p < 0.0001) and 22.88% (0.364 versus 0.472; p = 0.001), respectively, as compared with the control group. Univariate analysis showed significant correlation between rim area (mm2) and temporal ONH vessel density (r = 0.623; p < 0.0001) and total ONH vessel density (r = 0.609; p < 0.0001). Significant correlations were found between temporal and total ONH vessel density and RNFL, GCC, VF mean deviation, and visual field index. Conclusion. In glaucoma patients OCT-A might detect reduced ONH blood vessel density that is associated with structural and functional glaucomatous damage. OCT-A might become a useful tool for the evaluation of ONH microcirculation changes in glaucoma.
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Mottet B, Aptel F, Geiser M, Romanet J, Chiquet C. Facteurs vasculaires du glaucome. J Fr Ophtalmol 2015; 38:983-95. [DOI: 10.1016/j.jfo.2015.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 08/27/2015] [Accepted: 08/27/2015] [Indexed: 11/25/2022]
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Burgansky-Eliash Z, Bartov E, Barak A, Grinvald A, Gaton D. Blood-Flow Velocity in Glaucoma Patients Measured with the Retinal Function Imager. Curr Eye Res 2015; 41:965-70. [PMID: 26513272 DOI: 10.3109/02713683.2015.1080278] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PURPOSE Circulatory abnormalities in the retina, optic nerve and choroid have been detected by various technologies in glaucoma patients. However, there is no clear understanding of the role of blood flow in glaucoma. The purpose of this study was to compare retinal blood-flow velocities using the retinal function imager (RFI) between glaucoma and healthy subjects. MATERIALS AND METHODS Fifty-nine eyes of 46 patients with primary open-angle glaucoma (POAG), 51 eyes of 31 healthy individuals and 28 eyes of 23 patients with glaucomatous optic neuropathy (GON) but normal perimetry were recruited for this study. Three eyes of 2 patients in the glaucoma group and 2 eyes of 1 patient in the GON group had normal pressure at the time of diagnosis. Eighty-three percent of the glaucoma patients and 73% of the patients in the GON group were treated with anti-glaucoma medications. All patients were scanned by the RFI. Differences among groups were assessed by mixed linear models. RESULTS The average venous velocity in the GON group (3.8 mm/s) was significantly faster than in the glaucoma (3.3 mm/s, p = 0.03) and healthy (3.0 mm/s, p = 0.005) groups. The arterial velocity in the GON group was not different from any of the other study groups (4.7 mm/s). The arterial and venous velocity in the POAG eyes was not different than in the healthy eyes (arterial: 4.3 versus 4.2 mm/s, p = 0.7; venous: 3.3 versus 3.0 mm/s, p = 0.3). A subgroup of 13 glaucoma patients who had perimetric glaucoma in 1 eye and normal visual field (VF) in the fellow eye showed a trend of lower velocity in the glaucoma eyes. CONCLUSIONS Changes in retinal blood-flow velocity were detected only in the pre-perimetric state, but not in perimetric glaucoma. These findings might represent early dysregulation in the retinal vasculature.
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Affiliation(s)
- Zvia Burgansky-Eliash
- a Department of Ophthalmology , The Edith Wolfson Medical Center , Holon , Israel.,b Sackler Faculty of Medicine , Tel Aviv University , Tel Aviv , Israel
| | - Elisha Bartov
- a Department of Ophthalmology , The Edith Wolfson Medical Center , Holon , Israel.,b Sackler Faculty of Medicine , Tel Aviv University , Tel Aviv , Israel
| | - Adiel Barak
- b Sackler Faculty of Medicine , Tel Aviv University , Tel Aviv , Israel.,c Department of Ophthalmology , Tel-Aviv Medical Center , Tel Aviv , Israel
| | - Amiram Grinvald
- d Department of Neurobiology , Weizmann Institute of Science , Rehovot , Israel
| | - Dan Gaton
- b Sackler Faculty of Medicine , Tel Aviv University , Tel Aviv , Israel.,e Department of Ophthalmology, Rabin Medical Center , Petah Tikva , Israel
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Detecting Blood Flow Response to Stimulation of the Human Eye. BIOMED RESEARCH INTERNATIONAL 2015; 2015:121973. [PMID: 26504775 PMCID: PMC4609341 DOI: 10.1155/2015/121973] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/10/2015] [Indexed: 12/14/2022]
Abstract
Retinal blood supply is tightly regulated under a variety of hemodynamic considerations in order to satisfy a high metabolic need and maintain both vessel structure and function. Simulation of the human eye can induce hemodynamics alterations, and attempt to assess the vascular reactivity response has been well documented in the scientific literature. Advancements in noninvasive imaging technologies have led to the characterization of magnitude and time course in retinal blood flow response to stimuli. This allowed for a better understanding of the mechanism in which blood flow is regulated, as well as identifying functional impairments in the diseased eye. Clinically, the ability to detect retinal blood flow reactivity during stimulation of the eye offers potential for the detection, differentiation, and diagnosis of diseases.
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Lee B, Choi W, Liu JJ, Lu CD, Schuman JS, Wollstein G, Duker JS, Waheed NK, Fujimoto JG. Cardiac-Gated En Face Doppler Measurement of Retinal Blood Flow Using Swept-Source Optical Coherence Tomography at 100,000 Axial Scans per Second. Invest Ophthalmol Vis Sci 2015; 56:2522-30. [PMID: 25744974 DOI: 10.1167/iovs.14-16119] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To develop and demonstrate a cardiac gating method for repeatable in vivo measurement of total retinal blood flow (TRBF) in humans using en face Doppler optical coherence tomography (OCT) at commercially available imaging speeds. METHODS A prototype swept-source OCT system operating at 100-kHz axial scan rate was developed and interfaced with a pulse oximeter. Using the plethysmogram measured from the earlobe, Doppler OCT imaging of a 1.5- × 2-mm area at the optic disc at 1.8 volumes/s was synchronized to cardiac cycle to improve sampling of pulsatile blood flow. Postprocessing algorithms were developed to achieve fully automatic calculation of TRBF. We evaluated the repeatability of en face Doppler OCT measurement of TRBF in 10 healthy young subjects using three methods: measurement at 100 kHz with asynchronous acquisition, measurement at 100 kHz with cardiac-gated acquisition, and a control measurement using a 400-kHz instrument with asynchronous acquisition. RESULTS The median intrasubject coefficients of variation (COV) of the three methods were 8.0%, 4.9%, and 6.1%, respectively. All three methods correlated well, without a significant bias. Mean TRBF measured at 100 kHz with cardiac-gated acquisition was 40.5 ± 8.2 μL/min, and the range was from 26.6 to 55.8 μL/min. CONCLUSIONS Cardiac-gated en face Doppler OCT can achieve smaller measurement variability than previously reported methods. Although further validation in older subjects and diseased subjects is required, precise measurement of TRBF using cardiac-gated en face Doppler OCT at commercially available imaging speeds should be feasible.
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Affiliation(s)
- ByungKun Lee
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - WooJhon Choi
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Jonathan J Liu
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Chen D Lu
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Joel S Schuman
- UPMC Eye Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Gadi Wollstein
- UPMC Eye Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Jay S Duker
- New England Eye Center, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - Nadia K Waheed
- New England Eye Center, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
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Li Y, Li D, Ying X, Khaw PT, Raisman G. An energy theory of glaucoma. Glia 2015; 63:1537-52. [PMID: 25808326 DOI: 10.1002/glia.22825] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 02/26/2015] [Accepted: 03/02/2015] [Indexed: 11/11/2022]
Abstract
A radial array of fortified astrocytes (FASTs) is the load bearing structure of the rat optic nerve head (ONH). At the retinal end the ONH is suspended on a fluid filled extracellular space occupied by modified pigment cells which generate a glomerular-like formation of villi. We propose that regulation of fluid in and out of this space may contribute to buffering the normal fluctuations of intraocular pressure. The energy requirement for the fluid transfer process is provided by the dense vascularity of the ONH and is reflected in the giant mitochondria of the FASTs. We propose that glaucoma occurs when a maintained rise in pressure overwhelms the capacity of this regulatory system. Under these circumstances the FAST array becomes detached from its anchorage in the surrounding ONH sheath. Progressively driven backwards by the pressure, the FASTs degenerate. We propose that the degeneration of the FASTs is associated with ischemic damage caused by the backward stretching of their blood supply. Retraction of the FAST processes deprives the retinal ganglion cell axons of their energy support, resulting in axotomy. We consider that our previously observed rescue of axons and FASTs by transplantation of olfactory ensheathing cells is due to replacement of this lost energy source.
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Affiliation(s)
- Ying Li
- Department of Brain Repair and Rehabilitation, Spinal Research Unit, UCL Institute of Neurology, London, United Kingdom
| | - Daqing Li
- Department of Brain Repair and Rehabilitation, Spinal Research Unit, UCL Institute of Neurology, London, United Kingdom
| | - Xi Ying
- Department of Ophthalmology, Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China
| | - Peng T Khaw
- NIHR Biomedical Research Centre Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - Geoffrey Raisman
- Department of Brain Repair and Rehabilitation, Spinal Research Unit, UCL Institute of Neurology, London, United Kingdom
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Correlation of optic nerve microcirculation with papillomacular bundle structure in treatment naive normal tension glaucoma. J Ophthalmol 2014; 2014:468908. [PMID: 25574382 PMCID: PMC4276121 DOI: 10.1155/2014/468908] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 11/21/2014] [Indexed: 11/13/2022] Open
Abstract
Purpose. To assess the association between optic nerve head (ONH) microcirculation, central papillomacular bundle (CPB) structure, and visual function in eyes with treatment naive normal tension glaucoma (NTG). Methods. This study included 40 eyes of 40 patients with NTG and 20 eyes of 20 normal patients. We used laser speckle flowgraphy (LSFG) to measure mean blur rate (MBR) in all eyes and calculated the ratio of MBR in the horizontal quadrants of tissue area ONH (temporal/nasal ratio of MBR in the tissue area: T/N MT). Clinical findings also included retinal nerve fiber layer thickness (RNFLT) and ganglion cell complex thickness (GCCT) in the CPB and macular areas, best-corrected visual acuity (BCVA), mean deviation (MD), and refractive error. Results. T/N MT was correlated with both BCVA and MD. The OCT parameters most highly correlated with T/N MT were macular RNFLT and mid-CPB RNFLT. Furthermore, T/N MT, mid-CPB RNFLT, and macular RNFLT were higher in NTG than in normal eyes. A discrimination analysis revealed that T/N MT and refractive error were independent factors indicating NTG. Conclusions. Our results suggest that T/N MT is a candidate biomarker of NTG. Furthermore, T/N MT reflects visual function, including acuity and sensitivity, and CPB structure.
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Aizawa N, Kunikata H, Shiga Y, Yokoyama Y, Omodaka K, Nakazawa T. Correlation between structure/function and optic disc microcirculation in myopic glaucoma, measured with laser speckle flowgraphy. BMC Ophthalmol 2014; 14:113. [PMID: 25252729 PMCID: PMC4194365 DOI: 10.1186/1471-2415-14-113] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 09/10/2014] [Indexed: 11/23/2022] Open
Abstract
Background It is difficult to identify glaucoma in myopic eyes because the configuration of the optic disc varies; yet it is important clinically. Here, we used laser speckle flowgraphy (LSFG) to measure mean blur rate (MBR), representing optic disc microcirculation, and assessed its ability to identify glaucoma in eyes with myopic optic discs. Methods 129 eyes (normal disc: 21 eyes; myopic disc: 108 eyes) were enrolled. The eyes were classified as normal or mildly, moderately, or severely glaucomatous with standard automated perimetry (SAP). We determined the relationship between optic nerve head (ONH) MBR, measured with LSFG, mean deviation (MD), measured with SAP, and circumpapillary retinal nerve fiber layer thickness (cpRNFLT), measured with optical coherence tomography (OCT). Results ONH MBR and cpRNFLT decreased significantly with the severity of glaucoma. MBR was significantly correlated with cpRNFLT and MD (r =0.65 and r =0.63, respectively). A multiple regression analysis revealed that MBR and cpRNFLT were independent factors indicating glaucoma severity. A logistic regression analysis revealed that MBR and cpRNFLT were also independent factors indicating the presence of glaucoma. In a receiver operating characteristic (ROC) analysis, MBR and cpRNFLT could both differentiate between normal and glaucomatous eyes (MBR area under the ROC curve: 0.86, with a cut-off score of 24.0 AU). Conclusion These results suggest that in addition to cpRNFLT, non-invasive and objective LSFG measurements of MBR may enable the identification of glaucoma and the classification of its severity in eyes with myopic optic discs.
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Affiliation(s)
| | | | | | | | | | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
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Finzi A, Strobbe E, Tassi F, Fresina M, Cellini M. Hemifield pattern electroretinogram in ocular hypertension: comparison with frequency doubling technology and optical coherence tomography to detect early optic neuropathy. Clin Ophthalmol 2014; 8:1929-36. [PMID: 25284979 PMCID: PMC4181626 DOI: 10.2147/opth.s67193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To assess the sensitivity and specificity of hemifield pattern electroretinogram (HF-PERG) for detecting early retinal ganglion cell (RGC) damage in ocular hypertensive (OH) patients. METHODS Fifty-two OH patients (mean age 56±9.6 years) with an intraocular pressure (IOP) .21 mmHg were assessed. All subjects underwent HF-PERG, optical coherence tomography (OCT), and frequency doubling technology (FDT) visual field. RESULTS OH patients showed a significant increase of peak-time of the N95 (P=0.027) compared to controls. The amplitude of the N95 of the lower and upper HF-PERG showed significant differences (P=0.037 and P=0.023, respectively) between the two groups. A significant intraocular (P=0.006) and interocular (P=0.018) asymmetry of N95 amplitude was found. Receiver operating characteristic (ROC) curve analysis revealed a sensitivity of 93% for the N95 of the lower HF-PERG, whereas full-field pattern electroretinogram (PERG) N95 peak-time had a sensitivity of 88%. In OH patients, we found a thinning of OCT - retinal nerve fiber layer (RNFL), especially in the superior and inferior quadrant, although not statistically significant, and a significantly higher FDT pattern standard deviation (FDT-PSD; P=0.001). In the OCT-RNFL inferior quadrant, a sensitivity of 82% was recorded. Finally, the sensitivity of the FDT-PSD was 92%. CONCLUSION Our study shows that HF-PERG is a very sensitive test for detecting early damage of the RGC.
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Affiliation(s)
- Alessandro Finzi
- Department of Specialized, Diagnostic and Experimental Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| | - Ernesto Strobbe
- Department of Specialized, Diagnostic and Experimental Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| | - Filippo Tassi
- Department of Specialized, Diagnostic and Experimental Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| | - Michela Fresina
- Department of Specialized, Diagnostic and Experimental Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| | - Mauro Cellini
- Department of Specialized, Diagnostic and Experimental Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
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Tan C, Hu T, Peng MC, Liu SL, Tong JB, Ouyang W, Le Y. Age of Rats Seriously Affects the Degree of Retinal Damage Induced by Acute High Intraocular Pressure. Curr Eye Res 2014; 40:300-6. [DOI: 10.3109/02713683.2014.922194] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wang L, Cull G, Burgoyne CF, Thompson S, Fortune B. Longitudinal alterations in the dynamic autoregulation of optic nerve head blood flow revealed in experimental glaucoma. Invest Ophthalmol Vis Sci 2014; 55:3509-16. [PMID: 24812551 DOI: 10.1167/iovs.14-14020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To use a novel dynamic autoregulation analysis (dAR) to test the hypothesis that the optic nerve head (ONH) blood flow (BF) autoregulation is disrupted during early stages of experimental glaucoma (EG) in nonhuman primates. METHODS Retinal nerve fiber layer thickness (RNFLT, assessed by optical coherence tomography) and ONH BF (assessed by laser speckle imaging technique) were measured biweekly before and after unilateral laser treatment to the trabecular meshwork. Each nonhuman primate was followed until reaching either an early stage of damage (RNFLT loss < 20%, n = 6) or moderate to advanced stages of damage (RNFLT loss > 20%, n = 9). At each test, dAR was assessed by characterizing ONH BF changes during the first minute of rapid manometrical intraocular pressure (IOP) elevation from 10 to 40 mm Hg. The dAR analysis extracted the following parameters: baseline BF, average BF 10 seconds before IOP elevation; BFΔmax, maximum BF change from baseline BF; Tr, time from baseline BF to the BFΔmax; Kr, average descending BF rate. RESULTS Mean postlaser IOP was 20.2 ± 5.9 and 12.3 ± 2.6 mm Hg in EG and control eyes, respectively (P < 0.0001). Compared with prelaser values, baseline BF was higher in early EG, but lower in moderate to advanced EG (P = 0.01). Tr was increased and Kr was reduced in both stages (P < 0.01). BFΔmax was smaller in the early EG (P = 0.05) and remained low in the moderate to advanced EG (P = 0.15). No changes in the parameters were observed in control eyes. CONCLUSIONS Chronic IOP elevation causes ONH autoregulation dysfunction in the early stage of EG, characterized by a disrupted BF response and delayed Tr, revealed by dAR analysis.
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Affiliation(s)
- Lin Wang
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, United States
| | - Grant Cull
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, United States
| | - Claude F Burgoyne
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, United States
| | - Simon Thompson
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, United States
| | - Brad Fortune
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, United States
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Jia Y, Wei E, Wang X, Zhang X, Morrison JC, Parikh M, Lombardi LH, Gattey DM, Armour RL, Edmunds B, Kraus MF, Fujimoto JG, Huang D. Optical coherence tomography angiography of optic disc perfusion in glaucoma. Ophthalmology 2014; 121:1322-32. [PMID: 24629312 DOI: 10.1016/j.ophtha.2014.01.021] [Citation(s) in RCA: 526] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 01/14/2014] [Accepted: 01/16/2014] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To compare optic disc perfusion between normal subjects and subjects with glaucoma using optical coherence tomography (OCT) angiography and to detect optic disc perfusion changes in glaucoma. DESIGN Observational, cross-sectional study. PARTICIPANTS Twenty-four normal subjects and 11 patients with glaucoma were included. METHODS One eye of each subject was scanned by a high-speed 1050-nm-wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to compute 3-dimensional optic disc angiography. A disc flow index was computed from 4 registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc (C/D) ratios. Wide-field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. MAIN OUTCOME MEASURES Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations among disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. RESULTS In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in subjects with glaucoma. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV, respectively. The disc flow index was reduced by 25% in the glaucoma group (P = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R(2) = 0.752, P = 0.001). These correlations were significant even after accounting for age, C/D area ratio, NFL, and rim area. CONCLUSIONS Optical coherence tomography angiography, generated by the new SSADA, repeatably measures optic disc perfusion and may be useful in the evaluation of glaucoma and glaucoma progression.
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Affiliation(s)
- Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Eric Wei
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Xiaogang Wang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Xinbo Zhang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - John C Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Mansi Parikh
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Lori H Lombardi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Devin M Gattey
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Rebecca L Armour
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Beth Edmunds
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Martin F Kraus
- Pattern Recognition Lab and School of Advanced Optical Technologies, University Erlangen-Nuremberg, Erlangen, Germany; Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
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Wang L, Burgoyne CF, Cull G, Thompson S, Fortune B. Static blood flow autoregulation in the optic nerve head in normal and experimental glaucoma. Invest Ophthalmol Vis Sci 2014; 55:873-80. [PMID: 24436190 DOI: 10.1167/iovs.13-13716] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE To characterize the static blood flow autoregulation in the optic nerve head (ONH), and to investigate its role in hemodynamic changes in experimental glaucoma (EG). METHODS Unilateral elevation of intraocular pressure (IOP) was induced in 15 adult rhesus macaques by laser treatment to the trabecular meshwork. Prior to and after laser treatment, retinal nerve fiber layer thickness (RNFLT) was assessed, biweekly, by spectral-domain optical coherence tomography. Optic nerve head static autoregulation was assessed by determining the percentage blood flow (BF) change after the IOP was acutely increased from 10 to 30, 40, or 50 mm Hg manometrically, utilizing a laser speckle flowgraphy device. RESULTS Postlaser IOP (measured during average 7.7 ± 2.6 months) was 20.2 ± 5.9 mm Hg in EG eyes and 12.3 ± 2.6 mm Hg in control eyes (P < 0.0001). Retinal nerve fiber layer thickness was reduced by 33 ± 22% of the baseline values (P < 0.001) on average in EG eyes and by 0.4 ± 2.3% in control eyes (P > 0.05). The ONH BF remained at a constant level within a range of ocular perfusion pressure (OPP), 41 mm Hg and above. The autoregulation curves, created by all 723 tests in control and 352 tests in EG, were not significantly different (P = 0.71). CONCLUSIONS Optic nerve head BF in normal nonhuman primate (NHP) eyes is effectively regulated within a range of OPP approximately 41 mm Hg and above. Chronic IOP elevation causes no remarkable change to the static autoregulation within the ONH of EG eyes.
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Affiliation(s)
- Lin Wang
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon
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Siesky BA, Harris A, Amireskandari A, Marek B. Glaucoma and ocular blood flow: an anatomical perspective. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.12.41] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Role of nitric oxide in optic nerve head blood flow regulation during an experimental increase in intraocular pressure in healthy humans. Exp Eye Res 2013; 116:247-53. [PMID: 24060346 DOI: 10.1016/j.exer.2013.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 08/27/2013] [Accepted: 09/11/2013] [Indexed: 12/31/2022]
Abstract
The present study set out to investigate whether nitric oxide, a potent vasodilator, is involved in the regulatory processes in optic nerve head blood flow during an experimental increase in intraocular pressure (IOP). The study was conducted in a randomized, double-masked, placebo-controlled, three way cross-over design. 12 healthy subjects were scheduled to receive either L-NMMA (an unspecific nitric oxide synthase inhibitor), phenylephrine (an α-adrenoceptor agonist) or placebo on three different study days. Optic nerve head blood flow was measured using laser Doppler flowmetry and IOP was increased stepwise with a suction cup. Mean arterial pressure (MAP) and IOP were measured non-invasively and ocular perfusion pressure (OPP) was calculated as OPP = 2/3 MAP-IOP. Administration of L-NMMA and phenylephrine significantly increased MAP and therefore OPP at rest (p < 0.01). L-NMMA significantly reduced baseline blood flow in the optic nerve head (p < 0.01). Application of the suction cup induced a significant increase in IOP and a decrease in OPP (p < 0.01). During the stepwise increase in IOP, some autoregulatory potential was observed until OPP decreased approximately -30% below baseline. None of the administered substances had an effect on this autoregulatory behavior (p = 0.49). The results of the present study confirm that the human optic nerve head shows some regulatory capacity during a decrease in OPP. Nitric oxide is involved in the regulation of basal vascular tone in the optic nerve head but does not seem to be involved in the regulatory mechanisms during an acute increase in IOP in young healthy subjects.
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Cull G, Burgoyne CF, Fortune B, Wang L. Longitudinal hemodynamic changes within the optic nerve head in experimental glaucoma. Invest Ophthalmol Vis Sci 2013; 54:4271-7. [PMID: 23737471 DOI: 10.1167/iovs.13-12013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize longitudinal changes in basal blood flow (BF) of the optic nerve head (ONH) during progression of structural damage in experimental glaucoma (EG). METHODS Unilateral elevation of IOP was induced in 15 adult rhesus macaques by laser treatment to the trabecular meshwork. Prior to and after laser, retinal nerve fiber layer thickness (RNFLT) and ONH BF were measured biweekly by spectral-domain optical coherence tomography and a laser speckle flowgraphy device (LSFG), respectively. RESULTS Average postlaser IOP was 20.2 ± 5.9 mm Hg in EG eyes and 12.3 ± 2.6 mm Hg in control eyes (P < 0.0001). Longitudinal changes in basal ONH BF were strongly associated with changes in RNFLT as EG progressed from early through moderately advanced stages of damage, with Pearson correlation coefficients ranging from 0.64 to 0.97 (average = 0.81) and an average slope of 1.0. During early stage (RNFLT loss < 10%), basal ONH BF was mildly increased (9% ± 10%, P = 0.004) relative to baseline and compared with fellow controls (P = 0.02). Basal ONH BF declined continuously throughout subsequent stages in EG eyes reaching 25.0% ± 9.6% (P < 0.0001) below baseline at the final stage studied (RNFLT loss > 40%). In fellow control eyes, there was no significant change in basal ONH BF over time (P = 0.27). CONCLUSIONS In EG based on chronic mild-to-moderate IOP elevation, a two-phase pattern of ONH BF alteration was observed. ONH BF increased during the earliest stage (while RNFLT was within 10% of baseline) followed by a linear decline that was strongly correlated with loss of RNFLT.
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Affiliation(s)
- Grant Cull
- Devers Eye Institute, Legacy Research Institute, Portland, Oregon, USA
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Yoshida K, Ohguro I, Ohguro H. Black currant anthocyanins normalized abnormal levels of serum concentrations of endothelin-1 in patients with glaucoma. J Ocul Pharmacol Ther 2012; 29:480-7. [PMID: 23259919 DOI: 10.1089/jop.2012.0198] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE Our recent study, which involved a randomized, placebo-controlled, double-masked 24-month trial (Ophthalmologica 2012;228:26-35), revealed that oral administration of black currant anthocyanins (BCACs) slowed down the visual field deterioration and elevation of ocular blood flow of open-angle glaucoma (OAG). To elucidate the underlying mechanisms of these BCAC-induced effects, as possible factors affecting glaucomatous optic neuropathy, changes of serum endothelin-1 (ET-1), nitric oxide (NO), and antioxidative activities were examined in the present study. METHODS From among patients with OAG who participated in the randomized, placebo-controlled, double-masked trial, serum specimens were obtained from BCAC-treated (n=19) or placebo-treated (n=19) patients at baseline and every 6 months. Healthy volunteers (n=20) with age and gender matching the patients were used as a control. Serum ET-1 concentration, [NO2(-)] and [NO2(-) + NO3(-)] levels, advanced oxidation protein products (AOPP), and antioxidant activities were measured by using commercially available kits. RESULTS At the trial baseline, serum ET-1 concentrations were significantly lower in patients with OAG (BCACs, 3.18±1.06 pg/mL; placebo, 3.44±0.84 pg/mL) than those in healthy volunteers (4.38±1.03 pg/mL) (one-way analysis of variance and a Tukey's multiple comparison post hoc test, P<0.05). Upon administration of BCACs, serum ET-1 concentrations increased to the levels of those in healthy volunteers during the 24-month period. In contrast, those of placebo-treated patients remained at lower levels (3.82±1.14 pg/mL). While [NO2(-)] and [NO2(-)+NO3(-)] levels, AOPP, and antioxidative activities of patients from both the BCACs and placebo groups showed comparable levels to those of healthy subjects at baseline, no significant changes were observed during the observational period in either the BCAC or placebo groups. CONCLUSIONS Among the possible beneficial effects of BCACs toward visual field progression in patients with OAG, our present results suggest that BCACs caused normalization of serum ET-1 levels, and this may modulate ET-1-dependent regulation of the ocular blood hemodynamics.
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Affiliation(s)
- Kaori Yoshida
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
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Jia Y, Morrison JC, Tokayer J, Tan O, Lombardi L, Baumann B, Lu CD, Choi W, Fujimoto JG, Huang D. Quantitative OCT angiography of optic nerve head blood flow. BIOMEDICAL OPTICS EXPRESS 2012; 3:3127-37. [PMID: 23243564 PMCID: PMC3521313 DOI: 10.1364/boe.3.003127] [Citation(s) in RCA: 327] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/11/2012] [Accepted: 10/15/2012] [Indexed: 05/17/2023]
Abstract
Optic nerve head (ONH) blood flow may be associated with glaucoma development. A reliable method to quantify ONH blood flow could provide insight into the vascular component of glaucoma pathophysiology. Using ultrahigh-speed optical coherence tomography (OCT), we developed a new 3D angiography algorithm called split-spectrum amplitude-decorrelation angiography (SSADA) for imaging ONH microcirculation. In this study, a method to quantify SSADA results was developed and used to detect ONH perfusion changes in early glaucoma. En face maximum projection was used to obtain 2D disc angiograms, from which the average decorrelation values (flow index) and the percentage area occupied by vessels (vessel density) were computed from the optic disc and a selected region within it. Preperimetric glaucoma patients had significant reductions of ONH perfusion compared to normals. This pilot study indicates OCT angiography can detect the abnormalities of ONH perfusion and has the potential to reveal the ONH blood flow mechanism related to glaucoma.
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Affiliation(s)
- Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - John C. Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jason Tokayer
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Lorinna Lombardi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Bernhard Baumann
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chen D. Lu
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - WooJhon Choi
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - James G. Fujimoto
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
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Tan O, Wang Y, Konduru RK, Zhang X, Sadda SR, Huang D. Doppler optical coherence tomography of retinal circulation. J Vis Exp 2012:e3524. [PMID: 23022957 DOI: 10.3791/3524] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Noncontact retinal blood flow measurements are performed with a Fourier domain optical coherence tomography (OCT) system using a circumpapillary double circular scan (CDCS) that scans around the optic nerve head at 3.40 mm and 3.75 mm diameters. The double concentric circles are performed 6 times consecutively over 2 sec. The CDCS scan is saved with Doppler shift information from which flow can be calculated. The standard clinical protocol calls for 3 CDCS scans made with the OCT beam passing through the superonasal edge of the pupil and 3 CDCS scan through the inferonal pupil. This double-angle protocol ensures that acceptable Doppler angle is obtained on each retinal branch vessel in at least 1 scan. The CDCS scan data, a 3-dimensional volumetric OCT scan of the optic disc scan, and a color photograph of the optic disc are used together to obtain retinal blood flow measurement on an eye. We have developed a blood flow measurement software called "Doppler optical coherence tomography of retinal circulation" (DOCTORC). This semi-automated software is used to measure total retinal blood flow, vessel cross section area, and average blood velocity. The flow of each vessel is calculated from the Doppler shift in the vessel cross-sectional area and the Doppler angle between the vessel and the OCT beam. Total retinal blood flow measurement is summed from the veins around the optic disc. The results obtained at our Doppler OCT reading center showed good reproducibility between graders and methods (<10%). Total retinal blood flow could be useful in the management of glaucoma, other retinal diseases, and retinal diseases. In glaucoma patients, OCT retinal blood flow measurement was highly correlated with visual field loss (R(2)>0.57 with visual field pattern deviation). Doppler OCT is a new method to perform rapid, noncontact, and repeatable measurement of total retinal blood flow using widely available Fourier-domain OCT instrumentation. This new technology may improve the practicality of making these measurements in clinical studies and routine clinical practice.
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Affiliation(s)
- Ou Tan
- Department of Ophthalmology, Oregon Health and Science University, OR, USA
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Samarawickrama C, Hong T, Jonas JB, Mitchell P. Measurement of Normal Optic Nerve Head Parameters. Surv Ophthalmol 2012; 57:317-36. [PMID: 22726588 DOI: 10.1016/j.survophthal.2011.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 12/02/2011] [Accepted: 12/06/2011] [Indexed: 01/31/2023]
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Konduru RK, Tan O, Nittala MG, Huang D, Sadda SR. Reproducibility of retinal blood flow measurements derived from semi-automated Doppler OCT analysis. Ophthalmic Surg Lasers Imaging Retina 2012; 43:25-31. [PMID: 22251842 DOI: 10.3928/15428877-20111129-04] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/24/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE To evaluate reproducibility and intergrader agreement of total retinal blood flow (TRBF) measurements obtained by semi-automated grading of Doppler Fourier-domain optical coherence tomography (FD-OCT) scans. PATIENTS AND METHODS Doppler FD-OCT scans were obtained from 20 eyes of 18 subjects (10 glaucomatous, 10 normal). Scans were obtained using a circumpapillary scan protocol and analyzed using the Doppler OCT of Retinal Circulation software (version 2). Two masked, independent human graders manually refined the scans, adding or deleting vessels, changing vessel boundaries, and classifying vessels as veins or arteries. TRBF was calculated automatically by software summing flow in all veins. Agreement between various vessel parameters and TRBF values generated by the graders was analyzed. RESULTS Mean difference and mean absolute difference (± standard deviation, range) for TRBF were -0.55 (± 5.37, -8.53 to 13.6) and 3.84 (± 3.70, 0 to 13.6) μL/min, respectively, with an intraclass correlation (ICC) of 0.933 and limits of agreement (95% confidence interval [CI]) of -11.1 to +10.0. Venous area measurements showed similar levels of agreement with mean difference and mean absolute difference (± standard deviation, range) of -2.91 (± 4.29, -10.95 to 6.43) and 3.59 (± 3.70, 0 to 10.9) mm(2) with an ICC of 0.933 and limits of agreement (95% CI) were -11.3 and +05.5. The agreement for vessel identification between graders was almost perfect with a weighted kappa of 0.86. CONCLUSION Reproducible measurements of TRBF can be obtained from Doppler OCT data using semi-automated software with manual refinement. These findings should be of value in future studies evaluating retinal blood flow in various diseases.
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Affiliation(s)
- Ranjith K Konduru
- Doheny Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California 90033, USA
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