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Bisignano KK, Smith JD, Harrison WW. Variations in Retinal Oxygen Saturation in a Diverse Healthy Population. CLINICAL OPTOMETRY 2024; 16:147-155. [PMID: 39045010 PMCID: PMC11265219 DOI: 10.2147/opto.s468076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 06/05/2024] [Indexed: 07/25/2024]
Abstract
Purpose Local retinal oxygen saturation is a research technique, which has the potential as a biomarker for diabetes. However, normative data has not been established. This study examined differences in oxygen saturation around the macula and characterizes the relationship between age, race, refractive error (RE), sex, blood pressure (BP), prediabetic status and oxygen saturation. Methods Fifty-nine subjects aged 22-69 (38.8 ± 14.7 years) were included who were racially diverse and with equal gender distribution. None had eye disease. Oxygen saturation was taken with the Zilia Ocular in 4 locations around the macula 3.1 degrees from the fovea and they were also averaged. BP, RE, and HbA1c were noted. Regression analyses for oximetry and other factors were completed as were t-tests with multiple comparison corrections. Results There were significant variations in oximetry measures by race, with higher pigmentation levels associated with lower oximetry values (p < 0.01). There was no relationship between oximetry and sex (p = 0.34), RE (p = 0.67), BP (systolic p = 0.61, diastolic p = 0.71) nor prediabetic status (p = 0.87). Oximetry was associated with age when controlling for race (P < 0.002). Nasal-temporal variations showed nasal oximetry to higher than temporal measures (P < 0.01). Conclusion This study revealed race/pigmentation is an important influence on oximetry measures. Retinal location also caused variations, likely due to proximity to larger vessels nasally. No differences in sex, RE nor BP were observed to alter local oxygen saturation. However, age was correlated when considered with race. This study will inform our future work in different disease states and is an important first step in evaluating this technology.
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Affiliation(s)
- Kelly K Bisignano
- Department of Clinical Sciences College of Optometry, University of Houston, Houston, TX, USA
| | - Jennyffer D Smith
- Department of Clinical Sciences College of Optometry, University of Houston, Houston, TX, USA
| | - Wendy W Harrison
- Department of Clinical Sciences College of Optometry, University of Houston, Houston, TX, USA
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2
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Saeed A, Hadoux X, van Wijngaarden P. Hyperspectral retinal imaging biomarkers of ocular and systemic diseases. Eye (Lond) 2024:10.1038/s41433-024-03135-9. [PMID: 38778136 DOI: 10.1038/s41433-024-03135-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/20/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Hyperspectral imaging is a frontier in the field of medical imaging technology. It enables the simultaneous collection of spectroscopic and spatial data. Structural and physiological information encoded in these data can be used to identify and localise typically elusive biomarkers. Studies of retinal hyperspectral imaging have provided novel insights into disease pathophysiology and new ways of non-invasive diagnosis and monitoring of retinal and systemic diseases. This review provides a concise overview of recent advances in retinal hyperspectral imaging.
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Affiliation(s)
- Abera Saeed
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, 3002, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, 3002, VIC, Australia
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, 3002, VIC, Australia
| | - Peter van Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, 3002, VIC, Australia.
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, 3002, VIC, Australia.
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3
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Ramm L, Spoerl E, Terai N, Herber R, Pillunat LE. Association Between Corneal Changes and Retinal Oximetry in Diabetes Mellitus. Clin Ophthalmol 2024; 18:1235-1243. [PMID: 38737594 PMCID: PMC11088381 DOI: 10.2147/opth.s456020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/21/2024] [Indexed: 05/14/2024] Open
Abstract
Purpose Diabetes mellitus (DM) causes different corneal changes that are associated with the severity of diabetic retinopathy. To identify the pathophysiological reasons for this, corneal tomography and optical densitometry (COD) were combined with retinal oximetry. Methods Patients with DM and healthy subjects were included in this pilot study. Spatially resolved corneal thickness and COD were assessed using the Pentacam HR (Oculus). The pachymetry difference (PACDiff) was calculated as an indicator of an increase in the peripheral corneal thickness. Oxygen saturation (SO2) of the retinal vessels was measured using the Retinal Vessel Analyzer (Imedos Systems UG). Subsequently, the associations between corneal and retinal parameters were analyzed. Results Data from 30 patients with DM were compared with those from 30 age-matched healthy subjects. In DM, arterial (P = 0.048) and venous (P < 0.001) SO2 levels were increased, and arteriovenous SO2 difference was decreased (P < 0.001). In patients, PACDiff was higher than that in healthy subjects (P < 0.05), indicating a stronger increase in peripheral corneal thickness. The COD was reduced in DM (P = 0.004). The PACDiff of concentric rings with a diameter of 4 mm (r = -0.404; P = 0.033) to 8 mm (r = -0.522; P = 0.004) was inversely correlated with the arteriovenous SO2 difference. Furthermore, PACDiff 4 mm was negatively associated with arterial SO2 (r = -0.389; P = 0.041), and the COD of the peripheral corneal areas correlated positive with arterial SO2 (COD total 10-12 mm: r = 0.408; P = 0.025). Conclusion These associations might indicate a common pathogenesis of corneal and retinal changes in DM, which could be caused by reduced oxygen supply, mitochondrial dysfunction, oxidative stress, and cytokine effects.
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Affiliation(s)
- Lisa Ramm
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Eberhard Spoerl
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Naim Terai
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Robert Herber
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
| | - Lutz E Pillunat
- Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, 01307, Germany
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4
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Rahimi M, Hossain F, Leahy S, Blair NP, Jiang X, Shahidi M. Inner retinal oxygen delivery and metabolism in progressive stages of diabetic retinopathy. Sci Rep 2024; 14:4414. [PMID: 38388657 PMCID: PMC10883954 DOI: 10.1038/s41598-024-54701-w] [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: 07/27/2023] [Accepted: 02/15/2024] [Indexed: 02/24/2024] Open
Abstract
Previous studies have reported increased retinal venous oxygen saturation and decreased retinal blood flow and oxygen metabolism in non-proliferative diabetic retinopathy (NPDR). The current study aimed to determine alterations in both inner retinal oxygen delivery (DO2) and metabolism (MO2) in proliferative DR (PDR) as well as at stages of NPDR. A total of 123 subjects participated in the study and were categorized into five groups: non-diabetic control (N = 32), diabetic with no diabetic retinopathy (NDR, N = 34), mild NPDR (N = 31), moderate to severe NPDR (N = 17), or PDR (N = 9). Multi-modal imaging was performed to measure oxygen saturation and blood flow, which were used for derivation of DO2 and MO2. There were significant associations of groups with DO2 and MO2. DO2 was lower in PDR and not significantly different in NDR and NPDR stages as compared to the non-diabetic control group. MO2 was decreased in PDR and moderate to severe NPDR as compared to the control group, and not significantly reduced in NDR and mild NPDR. The findings demonstrate reductions in both DO2 and MO2 in PDR and MO2 in moderate to severe NPDR, suggesting their potential as biomarkers for monitoring progression and treatment of DR.
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Affiliation(s)
- Mansour Rahimi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Farzana Hossain
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Sophie Leahy
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Xuejuan Jiang
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA.
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5
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Tang S, An X, Sun W, Zhang Y, Yang C, Kang X, Sun Y, Jiang L, Zhao X, Gao Q, Ji H, Lian F. Parallelism and non-parallelism in diabetic nephropathy and diabetic retinopathy. Front Endocrinol (Lausanne) 2024; 15:1336123. [PMID: 38419958 PMCID: PMC10899692 DOI: 10.3389/fendo.2024.1336123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/23/2024] [Indexed: 03/02/2024] Open
Abstract
Diabetic nephropathy (DN) and diabetic retinopathy (DR), as microvascular complications of diabetes mellitus, are currently the leading causes of end-stage renal disease (ESRD) and blindness, respectively, in the adult working population, and they are major public health problems with social and economic burdens. The parallelism between the two in the process of occurrence and development manifests in the high overlap of disease-causing risk factors and pathogenesis, high rates of comorbidity, mutually predictive effects, and partial concordance in the clinical use of medications. However, since the two organs, the eye and the kidney, have their unique internal environment and physiological processes, each with specific influencing molecules, and the target organs have non-parallelism due to different pathological changes and responses to various influencing factors, this article provides an overview of the parallelism and non-parallelism between DN and DR to further recognize the commonalities and differences between the two diseases and provide references for early diagnosis, clinical guidance on the use of medication, and the development of new drugs.
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Affiliation(s)
- Shanshan Tang
- College of Traditional Chinese Medicine, Changchun University of Traditional Chinese Medicine, Changchun, China
| | - Xuedong An
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Wenjie Sun
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Yuehong Zhang
- Fangshan Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Cunqing Yang
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaomin Kang
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Yuting Sun
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Linlin Jiang
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Xuefei Zhao
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Qing Gao
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Hangyu Ji
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Fengmei Lian
- Guang’an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
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6
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Morin H, Havlík J, Chrapek O, Hrevuš M, Nemec P, Rejmont L, Tesar J, Kalousova M, Zima T, Šín M. Correlation Between Vitreous Level of Angiogenic Growth Factors and Oxygen Saturation in Retinal Vessels in Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2023; 64:4. [PMID: 38047739 DOI: 10.1167/iovs.64.15.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023] Open
Abstract
Purpose The aim of this study was to investigate whether there is any association between the levels of the angiogenic growth factors and the vascular oxygen saturation in eyes with diabetic retinopathy. Methods The study was designed as a prospective trial. The cohort consisted of 29 diabetic patients with scheduled vitreous procedures (intravitreal injection or pars plana vitrectomy). The control group included 30 patients scheduled for macular surgery (macular hole or epiretinal membrane). Nine patients (four from the diabetic maculopathy [DM] group and five from the control group) were excluded from the study because of unsuccessful vitreous samples. Retinal oximetry was performed several hours before the vitreous procedure was performed, and vitreous samples were obtained during the procedure. The concentrations of VEGF, Serpin F1/pigment epithelium-derived factor (PEDF), and placental growth factor (PlGF) were measured by ELISA. Results A negative correlation between level of VEGF and arteriovenous (AV) saturation difference was determined in the DM group (Pearson correlation coefficient r = -0.607; two-tailed test, P = 0.002). Also a negative correlation between level of PlGF and AV saturation difference was determined in the DM group (Pearson correlation coefficient r = -0.521; two-tailed test, P = 0.011) A positive correlation between PlGF level and the vein saturation was not statistically significant (Pearson correlation coefficient r = 0.325; two-tailed test, P = 0.130). We did not find any correlation between vitreous level of PEDF and vascular saturation within the DM group. Conclusions Our findings in diabetic patients suggests a correlation between the intravitreal level of proangiogenic factors and the AV difference measured by retinal oximetry.
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Affiliation(s)
- Hana Morin
- Department of Ophthalmology, Military University Hospital Prague, 1 st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Havlík
- Department of Ophthalmology, Military University Hospital Prague, 1 st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Oldrich Chrapek
- Department of Ophthalmology, Faculty of Medicine, Masaryk University Brno, Czech Republic
- Department of Ophthalmology, University Hospital, Brno, Czech Republic
| | - Michal Hrevuš
- Department of Ophthalmology, University Hospital Olomouc, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic
| | - Pavel Nemec
- Department of Ophthalmology, Military University Hospital Prague, 1 st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Leoš Rejmont
- Department of Ophthalmology, Military University Hospital Prague, 1 st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Tesar
- Department of Ophthalmology, Military University Hospital Prague, 1 st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Marta Kalousova
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, and General University Hospital in Prague, Prague, Czech Republic
| | - Tomaš Zima
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, and General University Hospital in Prague, Prague, Czech Republic
| | - Martin Šín
- Department of Ophthalmology, Military University Hospital Prague, 1 st Faculty of Medicine, Charles University, Prague, Czech Republic
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7
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Lapointe N, Akitegetse C, Poirier J, Picard M, Sauvageau P, Sauvageau D. Targeted spectroscopy in the eye fundus. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:126004. [PMID: 38111476 PMCID: PMC10725981 DOI: 10.1117/1.jbo.28.12.126004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/20/2023]
Abstract
Significance The assessment of biomarkers in the eye is rapidly gaining traction for the screening, diagnosis, and monitoring of ocular and neurological diseases. Targeted ocular spectroscopy is a technology that enables concurrent imaging of the eye fundus and analysis of high-quality spectra from a targeted region within the imaged area. This provides structural, compositional, and functional information of specific regions of the eye fundus from a non-invasive approach to ocular biomarker detection. Aim The aim of our study was to demonstrate the multimodal functionality and validation of targeted ocular spectroscopy. This was done in vitro, using a reference target and a model eye, and in vivo. Approach Images and spectra from different regions of a reference target and a model eye were acquired and analyzed to validate the system. Targeted ocular fluorescence spectroscopy was also demonstrated with the same model. Subsequently, in vivo imaging and diffuse reflectance spectra were acquired to assess blood oxygen saturation in the optic nerve head and the parafovea of healthy subjects. Results Tests conducted with the reference target showed accurate spectral analysis within specific areas of the imaging space. In the model eye, distinct spectral signatures were observed for the optic disc, blood vessels, the retina, and the macula, consistent with the variations in tissue composition and functions between these regions. An ocular oximetry algorithm was applied to in vivo spectra from the optic nerve head and parafovea of healthy patients, showing significant differences in blood oxygen saturation. Finally, targeted fluorescence spectral analysis was performed in vitro. Conclusions Diffuse reflectance and fluorescence spectroscopy in specific regions of the eye fundus open the door to a whole new range of monitoring and diagnostic capabilities, from assessment of oxygenation in glaucoma and diabetic retinopathy to photo-oxidation and photodegradation in age-related macular degeneration.
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Affiliation(s)
| | | | | | | | | | - Dominic Sauvageau
- Zilia Inc., Quebec City, Québec, Canada
- University of Alberta, Department of Chemical and Materials Engineering, Edmonton, Alberta, Canada
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8
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Akitegetse C, Poirier J, Sauvageau D. Sensitivity of visible range multi-wavelength algorithms for retinal tissue oximetry to acquisition parameters. BIOMEDICAL OPTICS EXPRESS 2023; 14:4296-4309. [PMID: 37799705 PMCID: PMC10549742 DOI: 10.1364/boe.495721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/16/2023] [Accepted: 07/18/2023] [Indexed: 10/07/2023]
Abstract
This study examined the sensitivity of broadband spectroscopy algorithms for retinal tissue oximetry to spectral acquisition parameters. Monte Carlo simulations were conducted on a 4-layer retinal model to assess the impact of various parameters. The optimal spectral range for accurate measurements was determined to be 530 nm to 585 nm. Decreased spectral resolution below 4 nm significantly reduced accuracy. Using an acquisition area larger than the blood vessel resulted in an underestimation of oxygen saturation, especially for high values. A threshold was observed where increased light intensity had no significant impact on measurement variability. The study highlights the importance of informed parameter selection for accurately assessing retinal microcapillary oxygenation and studying local hemodynamics.
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Affiliation(s)
| | | | - Dominic Sauvageau
- Zilia inc., Québec, QC, G1K 3G5, Canada
- Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
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9
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Hirsch K, Cubbidge RP, Heitmar R. Dual wavelength retinal vessel oximetry - influence of fundus pigmentation. Eye (Lond) 2023; 37:2246-2251. [PMID: 36460856 PMCID: PMC9716545 DOI: 10.1038/s41433-022-02325-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Clinical methods examining oxygenation parameters in humans have been used in many different care settings, but concerns have been raised regarding their clinical utility when assessing people with darker skin pigmentation. While saturation values can be crucial in emergency medicine, they are equally valuable in assessing disease mechanisms and monitoring change in disease progression. Retinal pigmentation varies across individuals and hence, can impact on retinal oxygen parameters. The objective of this study was to quantify and eliminate the impact of retinal pigmentation on retinal vessel oxygen saturation parameters measured in the superficial retinal arterioles and venules. METHODS 105 healthy individuals of varying skin colour, iris colour and heritage were included. Following a full eye exam to exclude any ocular abnormality, all participants underwent intraocular pressure, systemic blood pressure measurements and dilated dual wavelength retinal photography. Rotation matrices were employed to minimise the dependency of retinal pigmentation on arterial and venous oxygen saturation measurements determined in a concentric measurement annulus. RESULTS Retinal oxygen saturation in venules showed a linear correlation with retinal pigmentation (y = 0.34 × x + 38.598), whereas arterial saturation followed a polynomial pattern (y = 0.0089 × x2 + 0.7499 × x + 85.073). Both arterial and venous saturation values were corrected using local fundus pigmentation. Pre-correction retinal arterial and venous oxygen saturation were 89.0% (±13.1) and 43.7% (±11.5), respectively, and post- correction values were 94.8% (±8.7) for arteries and 56.3% (±7.0) veins. CONCLUSIONS When assessing multi-ethnic cohorts, it is important to consider the impact of pigmentation on imaging parameters and to account for it prior to clinical interpretation.
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Affiliation(s)
- Katrin Hirsch
- The University of the West of England, School of Health and Social Wellbeing, Glenside Campus, Bristol, BS16 1DD, UK.
| | - Robert P Cubbidge
- ABDO College, Godmersham Park, Canterbury, Kent, CT4 7DT, UK
- Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Rebekka Heitmar
- University of Huddersfield, School of Applied Sciences, Centre for Vision across the Life Span, Queensgate, HD1 3DH, UK.
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10
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Gullaksen S, Vernstrøm L, Sørensen SS, Funck KL, Petersen L, Bek T, Poulsen PL, Laugesen E. Effects of semaglutide and empagliflozin on oxygenation, vascular autoregulation, and central thickness of the retina in people with type 2 diabetes: A prespecified secondary analysis of a randomised clinical trial. J Diabetes Complications 2023; 37:108472. [PMID: 37062189 DOI: 10.1016/j.jdiacomp.2023.108472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/20/2023] [Accepted: 04/04/2023] [Indexed: 04/18/2023]
Abstract
AIMS Semaglutide and empagliflozin have shown cardiovascular protection. In SUSTAIN-6, semaglutide was associated with an increased risk of diabetic retinopathy. We investigated whether changes in retinal oxygenation, retinal vascular autoregulation, and central retinal thickness are altered by semaglutide, empagliflozin or the combination. METHODS This study was a prespecified, secondary outcome from a randomised, 32 weeks partly placebo-controlled, partly open-label, clinical trial on the effects of semaglutide and empagliflozin on arterial stiffness and kidney oxygenation. A total of 120 participants with type 2 diabetes, established or high risk of cardiovascular disease and age ≥50 years were randomised into four parallel groups (semaglutide, empagliflozin, the combination or tablet placebo, n = 30 for each group). We primarily hypothesized that semaglutide would increase venular oxygenation. RESULTS We found no changes in retinal arteriolar, venular or venular-arteriolar oxygenation nor in retinal vessel diameter regardless of treatment group. Semaglutide increased central retinal thickness compared to placebo with ~1 % (3.8 μm 95 % CI [0.9;6.7], p = 0.009) with no changes in the empagliflozin or combination group. CONCLUSION Neither semaglutide, empagliflozin nor the combination alters markers of retinal function. The effect of semaglutide on central retinal thickness was small, but the clinical significance is uncertain.
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Affiliation(s)
- Søren Gullaksen
- Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark; Steno Diabetes Center, Aarhus University Hospital, 8200 Aarhus N, Denmark.
| | - Liv Vernstrøm
- Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Steffen Skovgaard Sørensen
- Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | | | - Line Petersen
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Per Løgstrup Poulsen
- Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark; Steno Diabetes Center, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Esben Laugesen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark; Steno Diabetes Center, Aarhus University Hospital, 8200 Aarhus N, Denmark; Diagnostic Centre, Silkeborg Regional Hospital, 8600 Silkeborg, Denmark
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11
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Feng X, Jin Z, Zhou Z, Gao M, Jiang C, Hu Y, Lu Y, Li J, Ren Q, Zhou C. Retinal oxygen kinetics imaging and analysis (ROKIA) based on the integration and fusion of structural-functional imaging. BIOMEDICAL OPTICS EXPRESS 2022; 13:5400-5417. [PMID: 36425629 PMCID: PMC9664891 DOI: 10.1364/boe.465991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/27/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
The retina is one of the most metabolically active tissues in the body. The dysfunction of oxygen kinetics in the retina is closely related to the disease and has important clinical value. Dynamic imaging and comprehensive analyses of oxygen kinetics in the retina depend on the fusion of structural and functional imaging and high spatiotemporal resolution. But it's currently not clinically available, particularly via a single imaging device. Therefore, this work aims to develop a retinal oxygen kinetics imaging and analysis (ROKIA) technology by integrating dual-wavelength imaging with laser speckle contrast imaging modalities, which achieves structural and functional analysis with high spatial resolution and dynamic measurement, taking both external and lumen vessel diameters into account. The ROKIA systematically evaluated eight vascular metrics, four blood flow metrics, and fifteen oxygenation metrics. The single device scheme overcomes the incompatibility of optical design, harmonizes the field of view and resolution of different modalities, and reduces the difficulty of registration and image processing algorithms. More importantly, many of the metrics (such as oxygen delivery, oxygen metabolism, vessel wall thickness, etc.) derived from the fusion of structural and functional information, are unique to ROKIA. The oxygen kinetic analysis technology proposed in this paper, to our knowledge, is the first demonstration of the vascular metrics, blood flow metrics, and oxygenation metrics via a single system, which will potentially become a powerful tool for disease diagnosis and clinical research.
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Affiliation(s)
- Ximeng Feng
- Department of Biomedical Engineering,
College of Future Technology, Peking
University, Beijing 100871, China
- Institute of Biomedical
Engineering, Shenzhen Bay Laboratory, Shenzhen 5181071,
China
- Institute of Biomedical
Engineering, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
- Institute of Medical
Technology, Peking University Health Science Center, Peking
University, Beijing 100191, China
| | - Zi Jin
- Institute of Biomedical
Engineering, Shenzhen Bay Laboratory, Shenzhen 5181071,
China
- Institute of Biomedical
Engineering, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
| | - Zixia Zhou
- Department of Ophthalmology,
Peking University Shenzhen Hospital,
Shenzhen 518034, China
| | - Mengdi Gao
- Department of Biomedical Engineering,
College of Future Technology, Peking
University, Beijing 100871, China
- Institute of Biomedical
Engineering, Shenzhen Bay Laboratory, Shenzhen 5181071,
China
- Institute of Biomedical
Engineering, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
- Institute of Medical
Technology, Peking University Health Science Center, Peking
University, Beijing 100191, China
| | - Chunxia Jiang
- Department of Ophthalmology,
Peking University Shenzhen Hospital,
Shenzhen 518034, China
| | - Yicheng Hu
- Department of Biomedical Engineering,
College of Future Technology, Peking
University, Beijing 100871, China
- Institute of Biomedical
Engineering, Shenzhen Bay Laboratory, Shenzhen 5181071,
China
- Institute of Biomedical
Engineering, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
- Institute of Medical
Technology, Peking University Health Science Center, Peking
University, Beijing 100191, China
| | - Yanye Lu
- Institute of Biomedical
Engineering, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
- Institute of Medical
Technology, Peking University Health Science Center, Peking
University, Beijing 100191, China
| | - Jinying Li
- Department of Ophthalmology,
Peking University Shenzhen Hospital,
Shenzhen 518034, China
| | - Qiushi Ren
- Department of Biomedical Engineering,
College of Future Technology, Peking
University, Beijing 100871, China
- Institute of Biomedical
Engineering, Shenzhen Bay Laboratory, Shenzhen 5181071,
China
- Institute of Biomedical
Engineering, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
- Institute of Medical
Technology, Peking University Health Science Center, Peking
University, Beijing 100191, China
| | - Chuanqing Zhou
- College of Medical Instrument, Shanghai University of Medicine and Health Sciences, Shanghai 201318, China
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12
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Leahy S, Matei N, Blair NP, Shahidi M. Retinal Oxygen Delivery and Metabolism Response to Hyperoxia During Bilateral Common Carotid Artery Occlusion in Rats. Invest Ophthalmol Vis Sci 2022; 63:30. [PMID: 35767246 PMCID: PMC9251813 DOI: 10.1167/iovs.63.6.30] [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 The purpose of the current study was to test the hypothesis that responses of total retinal blood flow (TRBF), inner retinal oxygen delivery (DO2), metabolism (MO2), and extraction fraction (OEF) to hyperoxia are higher after minutes of bilateral common carotid artery occlusion (BCCAO) as compared to days of BCCAO. Methods Twenty-eight rats were subjected to BCCAO for 30 minutes (n = 12), 1 day (n = 8), or 3 days (n = 8). Eight of the 12 rats were also evaluated at baseline, prior to BCCAO. During room air breathing (RA) and 100% O2 inspiration (hyperoxia), blood flow and phosphorescence lifetime imaging were performed to measure TRBF and vascular O2 contents, respectively. DO2, MO2, and OEF were calculated from these measurements. Results After 30 minutes or 3 days of BCCAO, TRBF did not differ between RA and hyperoxia conditions (P ≥ 0.14) but decreased under hyperoxia after 1 day (P = 0.01). Compared to RA, DO2 and MO2 were increased under hyperoxia after 30 minutes of BCCAO (P ≤ 0.02). Additionally, MO2 was decreased under hyperoxia after 1 day of BCCAO (P = 0.04). OEF was decreased under hyperoxia compared to RA (P < 0.001). Under hyperoxia, TRBF and DO2 were reduced after all BCCAO durations compared to baseline (P ≤ 0.04), whereas MO2 did not differ from baseline after 30 minutes of BCCAO (P = 1.00). Conclusions The findings indicate that hyperoxia introduced minutes after ischemia can reduce DO2 impairments and potentially return MO2 to approximately normal values. This information contributes to the knowledge of the effect of supplemental oxygen intervention on TRBF, DO2, MO2, and OEF outcomes after variable durations of ischemia.
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Affiliation(s)
- Sophie Leahy
- Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
| | - Nathanael Matei
- Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
| | - Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, California, United States
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13
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Veiby NC, Simeunovic A, Heier M, Brunborg C, Saddique N, Moe MC, Dahl‐Jørgensen K, Petrovski G, Margeirsdottir HD. Retinal venular oxygen saturation is associated with non-proliferative diabetic retinopathy in young patients with type 1 diabetes. Acta Ophthalmol 2022; 100:388-394. [PMID: 34668632 DOI: 10.1111/aos.15018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/22/2021] [Accepted: 08/31/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To determine the contribution of retinal vessel density (VD), central retinal vessel diameter and retinal oxygen (O2 ) saturation independently of other known risk factors in the development of non-proliferative diabetic retinopathy (NPDR). METHODS Macular optical coherence tomography angiography (OCTA), central retinal artery/vein equivalent diameter (CRAE/CRVE) measurements and retinal oximetry were performed in a cross-sectional study of 166 eyes from 166 individuals with type 1 diabetes (T1D) aged 14-30 years. Multiple logistic regression analysis was used to investigate whether O2 saturation, retinal vessel diameters and vessel density in the deep capillary plexus (VD-DCP) were associated with NPDR, when adjusting for known risk factors. The individuals were allocated to one group without and one group with NPDR. RESULTS Multiple logistic regression analysis showed that age (OR = 1.25, 95% CI: 1.04-1.49) and AV-difference in O2 saturation (OR = 0.85, 95% CI 0.77-0.93) were significantly associated with NPDR. CONCLUSION Our findings suggest that age and lower AV-O2 saturation difference contribute to explaining the grade of NPDR independently of other well-known risk factors. Reduced delivery of O2 to the retinal tissue is associated with the development of NPDR in young patients with T1D and should be given appropriate weight in the risk stratification at early stages of the disease.
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Affiliation(s)
- Nina C.B.B. Veiby
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
| | - Aida Simeunovic
- Department of Paediatrics and adolescent Medicine Akershus University Hospital Lorenskog Norway
- Department of Paediatrics Oslo University Hospital Oslo Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
- Oslo Diabetes Research Centre Oslo Norway
| | - Martin Heier
- Department of Paediatrics Oslo University Hospital Oslo Norway
- Oslo Diabetes Research Centre Oslo Norway
| | - Cathrine Brunborg
- Oslo Centre of Biostatistics and Epidemiology Oslo University Hospital Oslo Norway
| | - Naila Saddique
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
| | - Morten C. Moe
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
| | - Knut Dahl‐Jørgensen
- Department of Paediatrics Oslo University Hospital Oslo Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
- Oslo Diabetes Research Centre Oslo Norway
| | - Goran Petrovski
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
| | - Hanna D. Margeirsdottir
- Department of Paediatrics Oslo University Hospital Oslo Norway
- Oslo Diabetes Research Centre Oslo Norway
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14
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Akitegetse C, Landry P, Robidoux J, Lapointe N, Brouard D, Sauvageau D. Monte-Carlo simulation and tissue-phantom model for validation of ocular oximetry. BIOMEDICAL OPTICS EXPRESS 2022; 13:2929-2946. [PMID: 35774309 PMCID: PMC9203094 DOI: 10.1364/boe.458079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 03/27/2022] [Accepted: 04/11/2022] [Indexed: 06/15/2023]
Abstract
Ocular oximetry, in which blood oxygen saturation is evaluated in retinal tissues, is a promising technique for the prevention, diagnosis and management of many diseases and conditions. However, the development of new tools for evaluating oxygen saturation in the eye fundus has often been limited by the lack of reference tools or techniques for such measurements. In this study, we describe a two-step validation method. The impact of scattering, blood volume fraction and lens yellowing on the oximetry model is investigated using a tissue phantom, while a Monte Carlo model of the light propagation in the eye fundus is used to study the effect of the fundus layered-structure. With this method, we were able to assess the performance of an ocular oximetry technique in the presence of confounding factors and to quantify the impact of the choroidal circulation on the accuracy of the measurements. The presented strategy will be useful to anyone involved in studies based on the eye fundus diffuse reflectance.
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Affiliation(s)
| | - Patricia Landry
- Affaires médicales et innovation, Héma-Québec, Québec, QC, G1V 5C3, Canada
| | - Jonathan Robidoux
- Affaires médicales et innovation, Héma-Québec, Québec, QC, G1V 5C3, Canada
| | | | - Danny Brouard
- Affaires médicales et innovation, Héma-Québec, Québec, QC, G1V 5C3, Canada
| | - Dominic Sauvageau
- Zilia inc., Québec, QC, G1K 3G5, Canada
- Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
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15
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Weigert G, Georgopoulos M, Buehl W, Maccora K, Aliyeva L, Steiner I, Schmidt‐Erfurth U, Sacu S. The influence of retinal oxygen saturation and choroidal volume on postoperative outcomes in patients with epiretinal membrane. Acta Ophthalmol 2022; 100:e743-e752. [PMID: 34396704 PMCID: PMC9291286 DOI: 10.1111/aos.14966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/17/2021] [Indexed: 11/28/2022]
Abstract
Purpose To investigate the effects of vitrectomy (Vy) with or without same time cataract surgery and membrane plus internal limiting membrane peeling (MP+ILMP) on retinal oxygenation and choroidal volume and their role on postoperative outcome. Methods Thirty‐two eyes were included in this prospective clinical study. All patients received 23 gauge Vy+MP+ILMP without endotamponade. Additional cataract surgery was performed in 14 patients. Follow‐up visits were scheduled at day 1, week 1, month 1 and month 3. At each visit, best corrected visual acuity (BCVA) using ETDRS charts (except at day 1), oxygenation of retinal vessels using the Oxymap T1, and optical coherence tomography (OCT, Heidelberg Spectralis) was performed. Results Mean BCVA increased significantly from 73 ± 11 letters to 77 ± 7 letters at month 3 (p = 0.02). Mean central retinal thickness (CRT) decreased from 456 ± 84 µm at baseline to 418±58µm (p = 0.01 baseline versus month 3). In the cataract surgery group, CRT was higher at month 3 than in the group without (400 ± 58 µm versus 441 ± 51 µm; p = 0.007). There was no statistically significant difference in choroidal volume or oxygenation of retinal vessels between groups (additional cataract surgery versus vitrectomy alone). Oxygenation of retinal arteries tended to decrease at day 1 followed by an increase, but the changes did not reach the level of significance (p = 0.29 baseline versus month 3). Oxygenation of retinal veins increased significantly (p = 0.02 baseline versus month 1; p = 0.04 baseline versus month 3, accordingly). There was a significant negative correlation (Spearman correlation coefficient rs = −0.35, p = 0.047) between visual acuity and oxygenation of retinal veins at month 3. No statistically significant correlation was found between CRT and oxygenation of neither retinal arteries nor veins. Choroidal volume (CV) of the central mm did not change significantly during the study period (baseline: 0.203 ± 0.04 mm3, median: 0.206, month 3: 0.205 ± 0.04 mm3, p = 0.54). There was no statistically significant effect of choroidal volume at baseline on postoperative clinical outcomes (change in BCVA estimate [95% CI]: 7 [−76; 90], p = 0.86; change in CRT: 147 [−577; 871], p = 0.68). Conclusion Oxygen saturation may affect the visual acuity outcome but not the CRT in patients after vitrectomy for epiretinal membrane. Choroidal thickness had no statistically significant influence on the study outcomes. Further studies are needed to evaluate if the measurement of retinal oxygenation may be helpful in the decision for surgery.
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Affiliation(s)
- Günther Weigert
- Department of Ophthalmology Medical University of Vienna Vienna Austria
| | | | - Wolf Buehl
- Department of Ophthalmology Medical University of Vienna Vienna Austria
- Vienna Clinical Trial Center Medical University of Vienna Vienna Austria
| | - Katia Maccora
- Department of Ophthalmology Medical University of Vienna Vienna Austria
- Vienna Clinical Trial Center Medical University of Vienna Vienna Austria
| | - Leyla Aliyeva
- Department of Ophthalmology Medical University of Vienna Vienna Austria
- Vienna Clinical Trial Center Medical University of Vienna Vienna Austria
| | - Irene Steiner
- CeMSIIS Center for Medical Statistics, Informatics and Intelligent Systems Section for Medical Statistics Medical University of Vienna Vienna Austria
| | | | - Stefan Sacu
- Department of Ophthalmology Medical University of Vienna Vienna Austria
- Vienna Clinical Trial Center Medical University of Vienna Vienna Austria
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16
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Zabek O, Calzetti G, Prétot D, Scholl HPN, Della Volpe Waizel M. Full-field sensitivity threshold and the relation to the oxygen metabolic retinal function in retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2022; 260:2517-2527. [PMID: 35355116 DOI: 10.1007/s00417-022-05638-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/17/2022] [Accepted: 03/19/2022] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The aim of our study was to evaluate retinal function with white light dark-adapted full-field sensitivity threshold (FST) and find possible correlations with metabolic function measured with retinal oximetry (RO) in patients with retinitis pigmentosa (RP). METHODS In this prospective observational study (BASEC 2020-00,122), FST and RO measurements were performed on 66 RP eyes (33 subjects, 12♀ 21♂) aged between 18 and 80 years (mean 43.2 years); all eyes were graded for disease severity. Main outcome parameters were white FST thresholds using the Diagnosys Espion system with the ColorDomeTM LED full-field stimulator (Diagnosys LLC, Lowell, MA) as well as the main RO parameters: the mean arterial (A-SO2; %), venular (V-SO2; %) oxygen saturation, their difference (A-V SO2; %), and the corresponding mean diameters of the peripapillary retinal arterioles (D-A; μm) and venules (D-V; μm) recorded with the oxygen saturation tool of the Retinal Vessel Analyser (RVA; IMEDOS Systems UG, Jena, Germany). In addition, semi-automated kinetic perimetry (V4e, III4e, I4e, III3e isopters, Octopus 900®, Haag-Streit AG Bern, Switzerland) was performed and included in the linear mixed-effects models analysis calculated with SPSS®. RESULTS Neither the oxygen saturation parameters (p > 0.21) nor the D-A and D-V (p > 0.13) showed significant correlations with the FST. However, when compared systematically with the visual field (VF) areas of the different isopters, RO parameters V-SO2 (p = 0.024) and A-V SO2 (p < 0.02) showed significant correlations. Furthermore, both V-SO2 and A-V SO2 showed gradual changes with more pronounced impairment in oxygen metabolic function in advanced stages of RP when analyzed in subgroups of disease severity grades. CONCLUSION In contrast to standardized VF parameters, white dark-adapted FST appears not to correlate with retinal oxygen metabolic function measured with RO in patients with RP, suggesting that the two examinations may capture unrelated aspects of the retinal pathological process. However, RO showed a significant association with standardized VF testing parameters and may, therefore, offer an alternative outcome measure for interventional trials.
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Affiliation(s)
- Olga Zabek
- Department of Ophthalmology, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Giacomo Calzetti
- Department of Ophthalmology, University Hospital Basel, University of Basel, Basel, Switzerland.,Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
| | | | - Hendrik P N Scholl
- Department of Ophthalmology, University Hospital Basel, University of Basel, Basel, Switzerland.,Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
| | - Maria Della Volpe Waizel
- Department of Ophthalmology, University Hospital Basel, University of Basel, Basel, Switzerland. .,Heuberger Eye Clinic, Olten, Switzerland.
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17
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Beach JM, Rizvi M, Lichtenfels CB, Vince R, More SS. Topical Review: Studies of Ocular Function and Disease Using Hyperspectral Imaging. Optom Vis Sci 2022; 99:101-113. [PMID: 34897230 DOI: 10.1097/opx.0000000000001853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Advances in imaging technology over the last two decades have produced significant innovations in medical imaging. Hyperspectral imaging (HSI) is one of these innovations, enabling powerful new imaging tools for clinical use and greater understanding of tissue optical properties and mechanisms underlying eye disease.Hyperspectral imaging is an important and rapidly growing area in medical imaging, making possible the concurrent collection of spectroscopic and spatial information that is usually obtained from separate optical recordings. In this review, we describe several mainstream techniques used in HSI, along with noteworthy advances in optical technology that enabled modern HSI techniques. Presented also are recent applications of HSI for basic and applied eye research, which include a novel method for assessing dry eye syndrome, clinical slit-lamp examination of corneal injury, measurement of blood oxygen saturation in retinal disease, molecular changes in macular degeneration, and detection of early stages of Alzheimer disease. The review also highlights work resulting from integration of HSI with other imaging tools such as optical coherence tomography and autofluorescence microscopy and discusses the adaptation of HSI for clinical work where eye motion is present. Here, we present the background and main findings from each of these reports along with specific references for additional details.
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Affiliation(s)
- James M Beach
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
| | - Madeeha Rizvi
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
| | - Caitlin B Lichtenfels
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
| | - Robert Vince
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota
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18
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Mlčák P, Chlup R, Kudlová P, Krystyník O, Král M, Kučerová V, Spurná J, Titzová S, Hübnerová P, Vláčil O, Šínová I, Karhanová M, Zapletalová J, Šín M. Retinal oxygen saturation is associated with HbA1c but not with short-term diabetes control, internal environment, smoking and mild retinopathy - ROXINEGLYD study. Acta Ophthalmol 2022; 100:e142-e149. [PMID: 33742561 DOI: 10.1111/aos.14853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 01/20/2021] [Accepted: 02/27/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE Purpose of this prospective uncontrolled single-centre pilot study was to find an association of retinal oxygen saturation (SatO2 ) with acid-base balance (ABB), carboxyhaemoglobin concentration, current plasma glucose concentration (PG), mean PG and PG variability over the last 72 hr, haemoglobin A1c (HbA1c), and other conditions. METHODS Forty-one adults (17 men) with type 1 (N = 14) or type 2 (N = 27) diabetes mellitus, age 48.6 ± 13.5 years, diabetes duration 9 (0.1-36) years, BMI 29.4 ± 6.3 kg/m2 , and HbA1c 52 ± 12.7 mmol/mol completed the study. The 4-day study comprised two visits (Day l, Day 4) including 72 hr of continuous glucose monitoring (CGM) by iPro® 2 Professional CGM (Medtronic, MiniMed, Inc., Northridge, CA, USA). Retinal oximeter Oxymap T1 (Oxymap ehf., Reykjavik, Iceland) was used to assess SatO2 . RESULTS Wilcoxon signed-rank test showed no SatO2 difference between eyes and visits. Spearman's correlation analysis revealed a significant correlation between arterial SatO2 and PG variability in type 2 diabetes mellitus, a positive correlation of venous SatO2 with HbA1c and with finger pulse oximetry. However, no correlation of SatO2 with ABB, carboxyhaemoglobin, current PG, mean PG over the 72 hr, age, diabetes duration, BMI, lipoproteinaemia, body temperature, systolic and diastolic blood pressure, heart rate, central retinal thickness and retinal nerve fibre layer thickness was found. CONCLUSION This study confirmed the association of venous SatO2 with long-term but not with short-term diabetes control, ABB and other conditions. The increased SatO2 and questionable impact of PG variability on retinal SatO2 is a research challenge.
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Affiliation(s)
- Petr Mlčák
- Department of Ophthalmology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
- Department of Physiology Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Rudolf Chlup
- Department of Physiology Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
- Department of Internal Medicine II – Gastroenterology and Hepatology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Pavla Kudlová
- Department of Health Sciences Faculty of Humanities Tomáš Baťa University Zlín Zlín Czech Republic
| | - Ondřej Krystyník
- Department of Internal Medicine III – Nephrology, Rheumatology and Endocrinology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Michal Král
- Department of Neurology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Veronika Kučerová
- Department of Clinical Biochemistry University Hospital Olomouc Olomouc Czech Republic
| | - Jaromíra Spurná
- Department of Internal Medicine III – Nephrology, Rheumatology and Endocrinology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Simona Titzová
- Department of Physiology Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Petra Hübnerová
- Department of Ophthalmology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
- Department of Physiology Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Ondřej Vláčil
- Department of Ophthalmology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Irena Šínová
- Department of Ophthalmology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Marta Karhanová
- Department of Ophthalmology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Jana Zapletalová
- Department of Medical Biophysics Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
| | - Martin Šín
- Department of Ophthalmology University Hospital Olomouc Faculty of Medicine and Dentistry Palacký University Olomouc Olomouc Czech Republic
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19
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Kallab M, Hommer N, Schlatter A, Bsteh G, Altmann P, Popa-Cherecheanu A, Pfister M, Werkmeister RM, Schmidl D, Schmetterer L, Garhöfer G. Retinal Oxygen Metabolism and Haemodynamics in Patients With Multiple Sclerosis and History of Optic Neuritis. Front Neurosci 2021; 15:761654. [PMID: 34712117 PMCID: PMC8546107 DOI: 10.3389/fnins.2021.761654] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 09/22/2021] [Indexed: 12/20/2022] Open
Abstract
Vascular changes and alterations of oxygen metabolism are suggested to be implicated in multiple sclerosis (MS) pathogenesis and progression. Recently developed in vivo retinal fundus imaging technologies provide now an opportunity to non-invasively assess metabolic changes in the neural retina. This study was performed to assess retinal oxygen metabolism, peripapillary capillary density (CD), large vessel density (LVD), retinal nerve fiber layer thickness (RNFLT) and ganglion cell inner plexiform layer thickness (GCIPLT) in patients with diagnosed relapsing multiple sclerosis (RMS) and history of unilateral optic neuritis (ON). 16 RMS patients and 18 healthy controls (HC) were included in this study. Retinal oxygen extraction was modeled using O2 saturations and Doppler optical coherence tomography (DOCT) derived retinal blood flow (RBF) data. CD and LVD were assessed using optical coherence tomography (OCT) angiography. RNFLT and GCIPLT were measured using structural OCT. Measurements were performed in eyes with (MS+ON) and without (MS-ON) history for ON in RMS patients and in one eye in HC. Total oxygen extraction was lowest in MS+ON (1.8 ± 0.2 μl O2/min), higher in MS-ON (2.1 ± 0.5 μl O2/min, p = 0.019 vs. MS+ON) and highest in HC eyes (2.3 ± 0.6 μl O2/min, p = 0.002 vs. MS, ANOVA p = 0.031). RBF was lower in MS+ON (33.2 ± 6.0 μl/min) compared to MS-ON (38.3 ± 4.6 μl/min, p = 0.005 vs. MS+ON) and HC eyes (37.2 ± 4.7 μl/min, p = 0.014 vs. MS+ON, ANOVA p = 0.010). CD, LVD, RNFLT and GCIPL were significantly lower in MS+ON eyes. The present data suggest that structural alterations in the retina of RMS patients are accompanied by changes in oxygen metabolism, which are more pronounced in MS+ON than in MS-ON eyes. Whether these alterations promote MS onset and progression or occur as consequence of disease warrants further investigation. Clinical Trial Registration: ClinicalTrials.gov registry, NCT03401879.
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Affiliation(s)
- Martin Kallab
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Nikolaus Hommer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Andreas Schlatter
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Vienna Institute for Research in Ocular Surgery (VIROS), Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria
| | - Gabriel Bsteh
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Patrick Altmann
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Alina Popa-Cherecheanu
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.,Department of Ophthalmology, University Emergency Hospital, Bucharest, Romania
| | - Martin Pfister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.,Institute of Applied Physics, Vienna University of Technology, Vienna, Austria
| | - René M Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.,Singapore Eye Research Institute, Singapore, Singapore.,Nanyang Technological University, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore.,Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
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20
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Changes of retinal oxygen saturation during treatment of diabetic macular edema with a pre-defined regimen of aflibercept: a prospective study. Graefes Arch Clin Exp Ophthalmol 2021; 260:451-457. [PMID: 34468834 PMCID: PMC8786788 DOI: 10.1007/s00417-021-05319-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/22/2021] [Accepted: 07/07/2021] [Indexed: 11/08/2022] Open
Abstract
Purpose To study the effect of anti-VEGF therapy for diabetic macular edema (DME) on retinal oxygen saturation (O2S) and its correlation with functional and anatomical changes of retinal tissue. Methods An interventional prospective single group study. Included were 10 eyes of 10 patients with visually significant DME which received a fixed regimen of intravitreal aflibercept every 4 weeks for 5 months, followed by 3 injections every 8 weeks, and were controlled monthly. Visual acuity (VA), central retinal thickness (CRT), arterial (aO2S), venous (vO2S) and arterio-venous difference (AVdO2S) retinal oxygen saturation were noted monthly. Changes after 5th (V6) injection and on last follow-up (V12) were studied. Correlations of different parameters were analyzed. Results The aO2S did not change whereas vO2S decreased (62.2 ± 9.4 pre-op to 57.2 ± 10.5 on V6, p = 0.03). This remained unchanged at 59.4 ± 13.2 on V12 (p = 0.2) and was accompanied by an increase of AVdO2S (40.8 ± 8.3 pre-op to 44.8 ± 10.6, p = 0.03 on V6) which was followed by a non-significant decrease to 41.8 ± 11.3 on V12 (p = 0.06). We found no correlation between BCVA and aO2S. However, mild correlation between BCVA and both vO2S and AVdO2S (r = −0.2 p = 0.035 and r = 0.185 p = 0.05 respectively) was found. No correlation was found between CRT and aO2S, vO2S, or AVdO2S. Conclusions During DME treatment with fixed regimen of intravitreal aflibercept over 11 months, we observed a reduction of vO2S and increase of AVdO2S which correlated with BCVA but not CRT. This could be explained by increasing consumption of O2S in the central retina and, possibly, by re-perfusion process.
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Auvazian SL, Cano J, Leahy S, Karamian P, Kashani A, Moshfeghi A, Ameri H, Blair NP, Shahidi M. Relating Retinal Vascular Oxygen Saturation and Microvasculature Morphology at Progressive Stages of Diabetic Retinopathy. Transl Vis Sci Technol 2021; 10:4. [PMID: 34111249 PMCID: PMC8107511 DOI: 10.1167/tvst.10.6.4] [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: 11/26/2022] Open
Abstract
Purpose Diabetic retinopathy (DR) is a common cause of vision loss in working age adults and presents changes in retinal vessel oxygenation and morphology. The purpose of this study was to test the hypothesis that there is an association of retinal vessel oxygen saturation with vessel density (VD) and tortuosity in DR. Methods Ninety-five subjects were classified in the following groups: nondiabetic control (N = 25), no DR (N = 28), mild nonproliferative DR (NPDR; N = 21), moderate to severe NPDR (N = 14), or treated proliferative DR (PDR; N = 7). Retinal oximetry was performed to measure arterial and venous oxygen saturation (SO2A and SO2V) and calculate oxygen extraction fraction (OEF). Optical coherence tomography angiography (OCTA) was performed for measurements of VD and vessel tortuosity index (VTI). Results There were statistically significant differences in SO2A and SO2V among groups (P< 0.004). SO2A and SO2V were higher in the PDR group compared to the control group and SO2V was also higher in the moderate to severe NPDR group. VD differed significantly among groups (P = 0.003), whereas VTI was not significantly different (P = 0.22). Compared to the control group, VD was lower in moderate to severe NPDR and PDR groups. VD was also lower in the PDR group than that in the no DR group (P = 0.03). There was a significant correlation of VTI with SO2V (r = 0.32, P = 0.002) and OEF (r = −0.35, P = 0.001). Conclusions Retinal vessel morphology, oxygenation, and tissue oxygen extraction were associated with each other in a cohort of subjects with and without DR. Translational Relevance The findings of this study have the potential to improve clinical management of DR by providing better understanding of human disease pathophysiology and propelling future studies to identify multiple image-based biomarkers for improved disease diagnosis and monitoring.
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Affiliation(s)
- Selin L Auvazian
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Jennifer Cano
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Sophie Leahy
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Preny Karamian
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Amir Kashani
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Andrew Moshfeghi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Hossein Ameri
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
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Abstract
Similar to other organs, the retina relies on tightly regulated perfusion and oxygenation. Previous studies have demonstrated that retinal blood flow is affected in a variety of eye and systemic diseases, including diabetic retinopathy, age-related macular degeneration, and glaucoma. Although measurement of peripheral oxygen saturation has become a standard clinical measurement through the development of pulse oximetry, developing a noninvasive technique to measure retinal oxygen saturation has proven challenging, and retinal oximetry technology currently remains inadequate for reliable clinical use. Here, we review current strategies and approaches, as well as several newer technologies in development, and discuss the future of retinal oximetry.
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Affiliation(s)
- Anupam K Garg
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA.,School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Darren Knight
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Leonardo Lando
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Daniel L Chao
- Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA.,School of Medicine, University of California San Diego, La Jolla, CA, USA.,Janssen Research and Development, Raritan, NJ, USA
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23
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Hosseinaee Z, Nima Abbasi, Pellegrino N, Khalili L, Mukhangaliyeva L, Haji Reza P. Functional and structural ophthalmic imaging using noncontact multimodal photoacoustic remote sensing microscopy and optical coherence tomography. Sci Rep 2021; 11:11466. [PMID: 34075105 PMCID: PMC8169886 DOI: 10.1038/s41598-021-90776-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/17/2021] [Indexed: 11/09/2022] Open
Abstract
Early diagnosis of ocular diseases improves the understanding of pathophysiology and aids in accurate monitoring and effective treatment. Advanced, multimodal ocular imaging platforms play a crucial role in visualization of ocular components and provide clinicians with a valuable tool for evaluating various eye diseases. Here, for the first time we present a non-contact, multiwavelength photoacoustic remote sensing (PARS) microscopy and swept-source optical coherence tomography (SS-OCT) for in-vivo functional and structural imaging of the eye. The system provides complementary imaging contrasts of optical absorption and optical scattering, and is used for simultaneous, non-contact, in-vivo imaging of murine eye. Results of vasculature and structural imaging as well as melanin content in the retinal pigment epithelium layer are presented. Multiwavelength PARS microscopy using Stimulated Raman scattering is applied to enable in-vivo, non-contact oxygen saturation estimation in the ocular tissue. The reported work may be a major step towards clinical translation of ophthalmic technologies and has the potential to advance the diagnosis and treatment of ocular diseases.
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Affiliation(s)
- Zohreh Hosseinaee
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Nima Abbasi
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Nicholas Pellegrino
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Layla Khalili
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Lyazzat Mukhangaliyeva
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Parsin Haji Reza
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada.
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24
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Stodtmeister R, Mielke V, Sandner D. The Oxygen Saturation in the Retinal Vessels of Patients with Diabetes Mellitus - The Search for Determinants. Klin Monbl Augenheilkd 2021; 239:1016-1024. [PMID: 34000750 DOI: 10.1055/a-1384-0737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Oxygen saturation in retinal vessels can be non-invasively measured by a new method. It is known that oxygen extraction is lowered in diabetic retinopathy. In the cross-sectional study presented here, it has been investigated whether diabetes-specific changes and typical accompanying diseases could influence the measurements in oximetry. METHODS During a time span of seven months, 237 diabetics were included who came to our clinic for an intravitreal injection, who met the inclusion criteria, who showed no exclusion criteria and gave written consent. 203 eyes of 203 patients were evaluated. The oxygen saturation (SO2) was measured in digitally stored fundus images taken with a fundus camera (Zeiss 450 FF). In its illumination beam, a filter was inserted with two transmission maxima at 584 nm and 610 nm (bandwidth 10 nm). With the program "Oximetry" (Imedos Systems, Jena, Germany), the venous and the arterial SO2 were measured. The values were stored in a spreadsheet. Diabetes related data, clinical parameters and accompanying diseases were documented in the predefined scheme. RESULTS In the whole patient sample, the venous oxygen saturation (vSO2) was 69 ± 12%, the arterial saturation (aSO2) 99 ± 5% and the arteriovenous difference 31 ± 9%. A statistically significant association could not be found between the measurement values of oximetry and age, duration of diabetes and HbA1c (Kruskal-Wallis ANOVA: p > 0.05). The differences in oximetry values between units of analysis (UOA) e.g. hypertension and non units of analysis (NOA) were analysed. Descriptive testing showed significant differences in vSO2% in the following units of analysis: allergies n = 47: UOA vs. NUOA: 64 vs. 69 (t test: p < 0.02); sartan therapy n = 46: UOA vs. NUOA: 64 vs. 70 (p = 0.003); state after intravitreal injections n = 144: 68 vs. 71 (p = 0.02). Oxygen extraction from the retinal capillaries was improved in patients who had injections with VEGF inhibitors. An improvement in oxygen extraction is also seen in patients with allergies and hypertension in comparison to those without these units of analysis. CONCLUSION The clinically observed improvement in the retinal state situation after intravitreal injections with VEGF inhibitors may be seen in association with the improved oxygen extraction. It seems reasonable to study whether a switch to sartans in the therapy of hypertension may improve retinal function.
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Affiliation(s)
- Richard Stodtmeister
- Augenklinik, Technische Universität Dresden, Deutschland.,Poliklinik, Augenspezialisten Saar, Völklingen, Deutschland
| | - Vivien Mielke
- Augenklinik, Technische Universität Dresden, Deutschland
| | - Dirk Sandner
- Augenklinik, Technische Universität Dresden, Deutschland
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25
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Hardarson SH, Stefánsson E, Bek T. Retinal oxygen saturation changes progressively over time in diabetic retinopathy. PLoS One 2021; 16:e0251607. [PMID: 33979414 PMCID: PMC8115819 DOI: 10.1371/journal.pone.0251607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/28/2021] [Indexed: 11/19/2022] Open
Abstract
PURPOSE According to cross-sectional studies, oxygen saturation is elevated in retinal vessels in diabetic patients. We evaluated how retinal oxygenation (metabolic marker), vessel diameters and retinopathy grade (structural markers) change over time in diabetic patients. DESIGN Prospective cohort study following screening in a hospital setting. METHODS Retinal oximetry images were acquired in 214 patients with the Oxymap T1 oximeter. Imaging was repeated after a median of 3.0 years (range 0.76-6.8 years). Oxygen saturation and vessel diameters were measured in the right eye. Semiquantitative grading of retinopathy according to international guidelines and red lesion count were performed on fundus photographs. RESULTS Retinopathy grade according to the international semiquantitative grading system was unchanged. Arteriolar saturation increased by 0.75±0.15 percentage points per year of follow-up (p<0.0001). Venular saturation increased by 1.74±0.26 percentage points per year (p<0.0001) and arteriovenous difference decreased by 0.99±0.20 percentage points per year (p<0.0001). Arteriolar diameters decreased by 2.7±8.5μm (p<0.0001) between visits and venular diameters decreased by 2.4±9.1μm (p = 0.0002). Median increase in red lesion count between visits was 2 lesions (range -128 to 212 lesions, p<0.0001). The change in red lesion count and change in diameters did not correlate with the length of follow-up (p>0.44). CONCLUSIONS Oxygen saturation in larger retinal vessels can increase and arteriovenous difference can decrease over time in diabetic patients without any observable changes in retinopathy grade. The results suggest that changes in retinal oxygen saturation may precede progression of diabetic retinopathy or that oxygen saturation is more sensitive to disease progression than retinopathy grade.
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Affiliation(s)
- Sveinn Hakon Hardarson
- Institute of Physiology, Department of Medicine, University of Iceland, Reykjavik, Iceland
- * E-mail:
| | - Einar Stefánsson
- Institute of Physiology, Department of Medicine, University of Iceland, Reykjavik, Iceland
- Department of Ophthalmology, Landspitali University Hospital, Reykjavik, Iceland
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, Aarhus N, Denmark
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26
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della Volpe Waizel M, Scholl HPN, Valmaggia C, Todorova MG. Retinal vessel oximetry in children with inherited retinal diseases. Acta Ophthalmol 2021; 99:52-60. [PMID: 32573052 DOI: 10.1111/aos.14466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/21/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Retinal vessel oximetry (RO) has been used to show altered metabolic function in patients with inherited retinal diseases (IRDs). The aim of this study was to investigate RO parameters of children with IRDs and presumed IRD carriers (pIRDc) and to compare them to controls. METHODS In this cross-sectional cohort study, 142 eyes from 71 Caucasian subjects were included: 40 eyes with IRDs, 26 eyes with pIRDc and 76 control eyes. The oxygen saturation was measured with the Retinal Vessel Analyser (IMEDOS Systems UG, Jena, Germany). Mean oxygen saturations in the peripapillary retinal arterioles (A-SO2 ; %) and venules (V-SO2 ; %) were estimated, and their difference (A-V SO2 ; %) was calculated. In addition, we evaluated the mean diameter in all major retinal arterioles (D-A; μm) and venules (D-V; μm). anova-based linear mixed-effects models were calculated with SPSS® . RESULTS In general, children suffering from IRDs differed from controls when the A-SO2 and A-V SO2 were taken into account: both the A-SO2 and the A-V SO2 were significantly increased (p = 0.012). In subgroup analyses, children suffering from rod-cone dystrophy (RCD) presented an A-SO2 increase (99.12 ± 8.24%) when compared to controls (91.33 ± 10.34%, p = 0.014) and pIRDc (92.37 ± 6.57%, p = 0.065). For V-SO2 significant changes in RCD (67.42 ± 9.19%) were found in comparison with controls (58.24 ± 11.74%, p < 0.041), pIRDc (56.67 ± 7.16%, p = 0.007), cone-rod dystrophies (CRD, 52.17 ± 5.32%, p < 0.001) and inherited macular dystrophies (IMD, 55.74 ± 6.96%, p = 0.004), In addition, A-V SO2 was decreased in RCD (31.69 ± 3.92%) when measured against CRD (41.9 ± 8.87%, p = 0.017) or IMD (39.52 ± 8.95%, p = 0.059). CONCLUSION In general, we found that children with IRDs presented early metabolic changes. Within IRDs, children with RCD showed more affected metabolic changes. Thus, RO may support early screening to rule out IRDs in children, and more precisely may help to differentiate those suffering from RCD.
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Affiliation(s)
- Maria della Volpe Waizel
- Department of Ophthalmology University of Basel Basel Switzerland
- Institute of Molecular and Clinical Ophthalmology Basel (IOB) Basel Switzerland
| | - Hendrik P. N. Scholl
- Department of Ophthalmology University of Basel Basel Switzerland
- Institute of Molecular and Clinical Ophthalmology Basel (IOB) Basel Switzerland
| | - Christophe Valmaggia
- Department of Ophthalmology University of Basel Basel Switzerland
- Department of Ophthalmology Cantonal Hospital St. Gallen St. Gallen Switzerland
| | - Margarita G. Todorova
- Department of Ophthalmology University of Basel Basel Switzerland
- Department of Ophthalmology Cantonal Hospital St. Gallen St. Gallen Switzerland
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27
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Kim K, Kim ES, Yu SY. Longitudinal changes in retinal microvasculature after panretinal photocoagulation in diabetic retinopathy using swept-source OCT angiography. Sci Rep 2021; 11:216. [PMID: 33420291 PMCID: PMC7794251 DOI: 10.1038/s41598-020-80697-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 12/22/2020] [Indexed: 12/23/2022] Open
Abstract
This study evaluated quantitative changes in microvascular parameters after panretinal photocoagulation (PRP) in diabetic retinopathy (DR), using swept-source OCT Angiography (SS-OCTA). A total of 27 treatment-naïve eyes were subjected to PRP and followed-up for > 12 months after the procedure. Foveal avascular zone (FAZ) area, macular perfusion density (PD), and vessel length density (VLD) were calculated on a 3 × 3 mm en face OCTA image and nonperfusion area (NPA) was obtained on a 12 × 12 mm en face OCTA image. One month after PRP, PD and VLD of superficial and deep capillary plexus decreased and subsequently, increased progressively across the next 12 months, with statistically significant differences (P = 0.015 and 0.02). Continuous decreasing trends in total NPA values was observed across 12 months after PRP (P = 0.125). A difference in PD of the superficial capillary plexus between baseline and 6 months post PRP, was significantly associated with the progression of DR, 12 months after PRP (OR 0.528; P = 0.025). We found significant longitudinal retinal microvascular changes after PRP in DR. Overall macular perfusion status was impaired and progressively recovered across the next 12 months, compared to the baseline. Additionally, the early treatment responses in PD can predict the long-term outcomes of PDR after PRP.
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Affiliation(s)
- Kiyoung Kim
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University Hospital, 23, Kyungheedae-ro, Dongdaemun-gu, Seoul, Republic of Korea
| | - Eung Suk Kim
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University Hospital, 23, Kyungheedae-ro, Dongdaemun-gu, Seoul, Republic of Korea
| | - Seung-Young Yu
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University Hospital, 23, Kyungheedae-ro, Dongdaemun-gu, Seoul, Republic of Korea.
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28
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C.B.B. Veiby N, Simeunovic A, Heier M, Brunborg C, Saddique N, Moe MC, Dahl‐Jørgensen K, Margeirsdottir HD, Petrovski G. Venular oxygen saturation is increased in young patients with type 1 diabetes and mild nonproliferative diabetic retinopathy. Acta Ophthalmol 2020; 98:800-807. [PMID: 32410388 DOI: 10.1111/aos.14462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/08/2020] [Accepted: 04/18/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE To clarify how early in the development of diabetic retinopathy (DR) can oxygen (O2 ) saturation changes be detected. METHODS Retinal oximetry was performed in a cross-sectional study, involving 14- to 30-year-old individuals: 185 with type 1 diabetes (T1D) and 94 controls. The subjects were divided into four groups according to the grade of DR. One-way ANOVA and post hoc tests were used to test for differences in the mean O2 saturations between the groups. RESULTS Fifty-eight (31 %) of the T1D patients had nonproliferative DR. There was no significant difference in O2 saturations between controls and T1D patients with no DR. Arteriolar and venular O2 saturations in T1D patients were significantly higher in moderate/severe DR than in no DR (p = 0.009 and p > 0.001), while venular O2 saturation was significantly higher in mild DR than in no DR (p = 0.013). CONCLUSION Increase in venular O2 saturation could not be detected before mild retinopathy had developed, and the retinal O2 saturation increase was measurable on the venular side first. Our results suggest that the increase in O2 saturation is likely a consequence of DR.
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Affiliation(s)
- Nina C.B.B. Veiby
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
| | - Aida Simeunovic
- Department of Paediatrics and adolescent Medicine Akershus University Hospital Lorenskog Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
- Oslo Diabetes Research Centre Oslo Norway
| | - Martin Heier
- Oslo Diabetes Research Centre Oslo Norway
- Department of Paediatrics Oslo University Hospital Oslo Norway
| | - Cathrine Brunborg
- Oslo Centre of Biostatistics and Epidemiology Oslo University Hospital Oslo Norway
| | - Naila Saddique
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
| | - Morten C. Moe
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
| | - Knut Dahl‐Jørgensen
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
- Oslo Diabetes Research Centre Oslo Norway
- Department of Paediatrics Oslo University Hospital Oslo Norway
| | - Hanna D. Margeirsdottir
- Oslo Diabetes Research Centre Oslo Norway
- Department of Paediatrics Oslo University Hospital Oslo Norway
| | - Goran Petrovski
- Center for Eye Research Department of Ophthalmology Oslo University Hospital Oslo Norway
- Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
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29
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Dinesen S, Jensen PS, Bloksgaard M, Mey JD, S.Lindholt J, Rasmusssen LM, Grauslund J. Coronary artery bypass surgery independently associates with retinal vascular oxygen saturation. Acta Ophthalmol 2020; 98:709-715. [PMID: 32301563 DOI: 10.1111/aos.14444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 02/20/2020] [Accepted: 03/24/2020] [Indexed: 01/09/2023]
Abstract
PURPOSE The retinal vasculature is the only part of the microcirculation that can be directly studied by non-invasive imaging. Based on the hypothesis that the systemic circulation is reflected in retinal vessels, we investigated if coronary artery bypass grafting (CABG) is related to changes in retinal vascular oxygen saturation (rSatO2 ). METHODS Retinal metabolism was evaluated by Oxymap T1, which simultaneously captures two retinal images at different wavelengths measuring the retinal arteriolar (raSatO2 ) and venular (rvSatO2 ) oxygen saturation. Three to 4 days after surgery, we measured the median rSatO2 after CABG in 38 patients and in 39 healthy controls (operated for cataract). RESULTS Coronary artery bypass grafting patients had higher raSatO2 (median ± standard deviation 93.1 ± 6.7% versus 90.5 ± 11.2%, p = 0.001) and rvSatO2 (57.4 ± 8.3% versus 53.5 ± 15.4%, p = 0.048) compared to healthy controls. In multivariable linear regression models, raSatO2 independently associated with CABG (coefficient + 3.6% in CABG patients, p = 0.007), and rvSatO2 correlated with gender (coefficient + 9.4% for females, p = 0.001) and CABG (coefficient + 8.2% in patients with CABG, p = 0.001). CONCLUSIONS Comparing patients with and without cardiovascular disease, raSatO2 and rvSatO2 positively and independently associated with CABG, suggesting their potential as non-invasive markers for coronary large artery disease.
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Affiliation(s)
- Sebastian Dinesen
- Department of Ophthalmology Odense University Hospital Odense Denmark
| | - Pia S. Jensen
- Department of Clinical Biochemistry and Pharmacology Odense University Hospital Odense Denmark
| | - Maria Bloksgaard
- Department of Molecular Medicine University of Southern Denmark Odense Denmark
| | - Jo De Mey
- Department of Molecular Medicine University of Southern Denmark Odense Denmark
- Department of Cardiac Thoracic and Vascular Surgery Odense University Hospital Odense Denmark
- Department of Pharmacology and Personalized Medicine Maastricht University Maastricht The Netherlands
| | - Jes S.Lindholt
- Department of Cardiac Thoracic and Vascular Surgery Odense University Hospital Odense Denmark
- Centre of Individualized Medicine in Arterial Diseases (CIMA) Odense University Hospital Odense Denmark
- Department of Clinical Research University of Southern Denmark Odense Denmark
| | - Lars M. Rasmusssen
- Department of Clinical Biochemistry and Pharmacology Odense University Hospital Odense Denmark
- Centre of Individualized Medicine in Arterial Diseases (CIMA) Odense University Hospital Odense Denmark
- Department of Clinical Research University of Southern Denmark Odense Denmark
| | - Jakob Grauslund
- Department of Ophthalmology Odense University Hospital Odense Denmark
- Department of Clinical Research University of Southern Denmark Odense Denmark
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30
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Hübnerová P, Mlčák P, Šínová I, Karhanová M, Šín M. Current use of the automatic retinal oximetry. Review. CESKÁ A SLOVENSKÁ OFTALMOLOGIE : CASOPIS CESKÉ OFTALMOLOGICKÉ SPOLECNOSTI A SLOVENSKÉ OFTALMOLOGICKÉ SPOLECNOSTI 2020; 76:3-11. [PMID: 32917089 DOI: 10.31348/2020/1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE To inform about possible use of the automatic retinal oximetry for the retinal oxygen saturation measurement in the eye and systemic diseases. METHODS We performed a literature review dealing with issues of retinal oxygen saturation monitoring by dual non-invasive retinal oximetry Oxymap T1 (Oxymap ehf. Reykjavík, Iceland). RESULTS We have found two main strains writing our paper on retinal oxygen saturation eye diseases. The first section concerns diseases created by having hypoxia as its main pathological factor - for example diabetes mellitus and retinal vein occlusion. The second group deals with atrophy as the main pathological mechanism which is typical for decreasing retinal oxygen consumption - for example glaucoma or retinitis pigmentosa (the second one named is not included in our work). Oximetry in systemic diseases creates a relatively new chapter of this branch with a very big potential of interdisciplinary cooperation for the future. It is possible the cooperation will not only include diabetologists but also neurologists (for example, in diseases like sclerosis multiplex or Devics, Alzheimers and Parkinsons disease) and haematologists (retinal oxygen saturation changes in patients with different rheological attributes of blood). CONCLUSION Retinal oxygen saturation measuring by automatic retinal oximetry is a relatively new method with scientifically confirmed high reproducibility of results. Currently it is the only experimental method with vast potentials not only in the realm of the possibility of observing eye diseases (diabetic retinopathy, retinal vein occlusion or glaucoma) but also in developing interdisciplinary cooperation with diabetologists, neurologists and haematologists.
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31
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The impact of macular edema on microvascular and metabolic alterations in retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2020; 259:643-652. [DOI: 10.1007/s00417-020-04913-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/15/2020] [Accepted: 08/25/2020] [Indexed: 10/23/2022] Open
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Garvey SL, Khansari MM, Jiang X, Varma R, Shahidi M. Assessment of retinal vascular oxygenation and morphology at stages of diabetic retinopathy in African Americans. BMC Ophthalmol 2020; 20:295. [PMID: 32682412 PMCID: PMC7368779 DOI: 10.1186/s12886-020-01566-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 07/10/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of blindness in working-age adults. The likelihood of visual impairment associated with DR is two-fold higher in the African-American (AA) compared to non-Hispanic white. Although alterations in retinal vessel oxygenation and morphology have been reported in DR, there is limited knowledge about these vascular changes in AA subjects. The purpose of the current study was to investigate alterations in retinal vascular oxygen saturation (SO2), vessel diameter (D) and tortuosity at severity stages of DR in AA subjects. METHODS A nested case-control study of 56 AA subjects was conducted. Right eyes were grouped as non-diabetic (ND) (N = 26), no clinical DR (NDR) (N = 19), or moderate/severe non-proliferative DR (NPDR) (N = 11). Imaging was performed using a commercially available scanning laser ophthalmoscope. Images were analyzed to determine retinal arterial and venous SO2 (SO2A and SO2V), diameter (DA and DV), and vessel tortuosity index (VTI) (VTIA and VTIV). RESULTS SO2V and DV were higher in NPDR compared to ND and NDR groups (P < 0.05). There were no significant differences in SO2A and DA among ND, NDR, and NPDR groups (P > 0.8). Maximum VTIA was higher in diabetics (NDR and NPDR) compared to non-diabetics (P < 0.03). There was no significant difference in maximum VTIV among the 3 groups (P = 0.5). CONCLUSIONS The findings advance our understanding of DR pathophysiology in the AA population and may propel identification of race-specific retinal vascular biomarkers for improved diagnosis and monitoring of DR.
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Affiliation(s)
- Sarah L Garvey
- College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Maziyar M Khansari
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, California, 90033, USA
- Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Xuejuan Jiang
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, California, 90033, USA
| | - Rohit Varma
- Southern California Eye Institute, CHA Hollywood Presbyterian Medical Center, Los Angeles, CA, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, California, 90033, USA.
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Wright WS, Eshaq RS, Lee M, Kaur G, Harris NR. Retinal Physiology and Circulation: Effect of Diabetes. Compr Physiol 2020; 10:933-974. [PMID: 32941691 PMCID: PMC10088460 DOI: 10.1002/cphy.c190021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In this article, we present a discussion of diabetes and its complications, including the macrovascular and microvascular effects, with the latter of consequence to the retina. We will discuss the anatomy and physiology of the retina, including aspects of metabolism and mechanisms of oxygenation, with the latter accomplished via a combination of the retinal and choroidal blood circulations. Both of these vasculatures are altered in diabetes, with the retinal circulation intimately involved in the pathology of diabetic retinopathy. The later stages of diabetic retinopathy involve poorly controlled angiogenesis that is of great concern, but in our discussion, we will focus more on several alterations in the retinal circulation occurring earlier in the progression of disease, including reductions in blood flow and a possible redistribution of perfusion that may leave some areas of the retina ischemic and hypoxic. Finally, we include in this article a more recent area of investigation regarding the diabetic retinal vasculature, that is, the alterations to the endothelial surface layer that normally plays a vital role in maintaining physiological functions. © 2020 American Physiological Society. Compr Physiol 10:933-974, 2020.
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Affiliation(s)
- William S Wright
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, South Carolina, USA
| | - Randa S Eshaq
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
| | - Minsup Lee
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
| | - Gaganpreet Kaur
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
| | - Norman R Harris
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
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Qiu X, Wang X, Hong P, Liu M, Wen Q, Chen Q. Retinal blood oxygen saturation and vascular endothelial growth factor-A in early diabetic retinopathy: A protocol for systematic review and meta-analysis. Medicine (Baltimore) 2020; 99:e20562. [PMID: 32541481 PMCID: PMC7302675 DOI: 10.1097/md.0000000000020562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) remains the most common microvascular complication of diabetes; both its high prevalence and associated high risk of vision loss lead it to the major global health burden. Despite significant research efforts, there still remains much of the underlying pathology not fully understand. In the past studies, inner retinal blood flow disturbances are widely assessed as a potential biomarker of DR. However, the results have been variable and even contradictory. Improved methods to figure out the metabolic disturbances associated with DR are essential. Some research showed that both vascular endothelial growth factor-A and blood oxygen saturation are higher in DR patients and correlated with disease severity. Therefore, we decided to conduct a systematic review and meta-analysis to find out the connection of them and provide robust evidence on the mechanism underlying this connection to help us better understand the pathophysiology behind the hypoxic retina and find better ways to treat DR. METHODS This study will be conducted according to Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. We will do electronic searches from PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang database, CNKI, and VIP database. Two reviewers will screen all the references independently and any disagreement will be solved by the third involvement. All data will be extracted by 2 independent reviewers according to a standardized data extraction sheet. Based on the type of studies, 2 reviewers will independently use different scales to assess the risk of bias. Any disagreements and conflicts will be resolved by discussing it with a third reviewer. We will conduct a random-effects meta-analysis. Individual and pooled odds ratios/relative risks and associated 95% confidence intervals will be calculated as well as between-study heterogeneity. The potential for publication bias will also be evaluated. If possible, we will explore reasons for potential between-study heterogeneity. RESULTS This study is a protocol for systematic review and meta-analysis without results. Associated data analysis will be carried out after the protocol. CONCLUSION The protocol aims to guide a meta-analysis whose purpose is investigating the association between retinal blood oxygen saturation and vascular endothelial growth factors in patients with early DR and trying to find out the mechanism that the changing of retinal oxygen saturation in patients with DR. INPLASY REGISTRATION NUMBER INPLASY202040161.
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Affiliation(s)
- Xianliang Qiu
- School of Clinical Medicine, Hospital of Chengdu University of Traditional Chinese Medicine
| | - Xian Wang
- School of Clinical Medicine, Hospital of Chengdu University of Traditional Chinese Medicine
| | - Peipei Hong
- School of Clinical Medicine, Hospital of Chengdu University of Traditional Chinese Medicine
| | - Min Liu
- School of Clinical Medicine, Hospital of Chengdu University of Traditional Chinese Medicine
| | - Qing Wen
- School of Clinical Medicine, Hospital of Chengdu University of Traditional Chinese Medicine
| | - Qiu Chen
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
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Blindbæk SL, Peto T, Grauslund J. Retinal arteriolar oxygen saturation predicts the need for intravitreal aflibercept in patients with diabetic macular oedema. BMJ Open Ophthalmol 2020; 5:e000382. [PMID: 32524033 PMCID: PMC7259848 DOI: 10.1136/bmjophth-2019-000382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/07/2019] [Accepted: 12/09/2019] [Indexed: 11/25/2022] Open
Abstract
Objective Given the increasing burden of repetitive intravitreal injections in diabetic macular oedema (DMO) treatment, non-invasive markers of treatment outcome are needed. Hence, we aimed to examine retinal oximetry parameters as markers of need for intravitreal aflibercept in patients with DMO. Methods This study was based on data from a 12-month clinical trial including 35 eyes of 25 patients with centre involving DMO. Retinal oximetry, visual acuity (VA) and central retinal thickness (CRT) were performed at baseline (BL). Patients then received 3 monthly injections of aflibercept followed by focal/grid laser photocoagulation. From month 4 (M4) through 12 (M12), patients were followed monthly and additional injections were given pro re nata if criteria of retreatment were met. We evaluated the difference in need for intravitreal aflibercept in groups of eyes with the highest and lowest retinal arteriolar and venular oxygen saturations, respectively. Results From BL-M12, overall VA letter score improved by 8.7 (7.2–10.2). Likewise CRT reduced by 100.7 (68.2–133.3) µm and the mean number of injections was 4.3 (3.8–4.8). Overall retinal arteriolar and venular oxygen saturations were 95.7 (93.0–98.4)% and 62.7 (59.4–65.9)% at BL. Eyes with the highest retinal arteriolar oxygen saturations had significantly more injections between BL and M12 compared with eyes with the lowest retinal arteriolar oxygen saturations (5.0 (4.2–5.8) vs 3.6 (3.1–4.0), p=0.002). Conclusion Higher retinal arteriolar oxygen saturation independently predicted the need for more intravitreal aflibercept during the first year of DMO treatment and may serve as a valuable adjunctive to established procedures for retinal imaging in terms of individualised treatment plans. Trial registration number NCT02554747
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Affiliation(s)
- Søren Leer Blindbæk
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,OPEN, Open Patient data Explorative Network, Odense University Hospital, Odense, Denmark
| | - Tunde Peto
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom
| | - Jakob Grauslund
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Steno Diabetes Center Odense, Odense, Denmark
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Yao HY, Tseng KW, Nguyen HT, Kuo CT, Wang HC. Hyperspectral Ophthalmoscope Images for the Diagnosis of Diabetic Retinopathy Stage. J Clin Med 2020; 9:jcm9061613. [PMID: 32466524 PMCID: PMC7356238 DOI: 10.3390/jcm9061613] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/18/2020] [Accepted: 05/25/2020] [Indexed: 12/17/2022] Open
Abstract
A methodology that applies hyperspectral imaging (HSI) on ophthalmoscope images to identify diabetic retinopathy (DR) stage is demonstrated. First, an algorithm for HSI image analysis is applied to the average reflectance spectra of simulated arteries and veins in ophthalmoscope images. Second, the average simulated spectra are categorized by using a principal component analysis (PCA) score plot. Third, Beer-Lambert law is applied to calculate vessel oxygen saturation in the ophthalmoscope images, and oxygenation maps are obtained. The average reflectance spectra and PCA results indicate that average reflectance changes with the deterioration of DR. The G-channel gradually decreases because of vascular disease, whereas the R-channel gradually increases with oxygen saturation in the vessels. As DR deteriorates, the oxygen utilization of retinal tissues gradually decreases, and thus oxygen saturation in the veins gradually increases. The sensitivity of diagnosis is based on the severity of retinopathy due to diabetes. Normal, background DR (BDR), pre-proliferative DR (PPDR), and proliferative DR (PDR) are arranged in order of 90.00%, 81.13%, 87.75%, and 93.75%, respectively; the accuracy is 90%, 86%, 86%, 90%, respectively. The F1-scores are 90% (Normal), 83.49% (BDR), 86.86% (PPDR), and 91.83% (PDR), and the accuracy rates are 95%, 91.5%, 93.5%, and 96%, respectively.
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Affiliation(s)
- Hsin-Yu Yao
- Department of Ophthalmology, Kaohsiung Armed Forced General Hospital, Kaohsiung City 80284, Taiwan;
| | - Kuang-Wen Tseng
- Department of Medicine, Mackay Medical College, 46, Sec. 3, Zhongzheng Rd., Sanzhi Dist., New Taipei 25245, Taiwan;
| | - Hong-Thai Nguyen
- Department of Mechanical Engineering and Center for Innovative Research on Aging Society (CIRAS), National Chung Cheng University, 168, University Rd., Min Hsiung, Chia Yi 62102, Taiwan;
| | - Chie-Tong Kuo
- Department of Optometry and Innovation Incubation Center, Shu-Zen Junior College of Medicine and Management, Kaohsiung 821, Taiwan;
| | - Hsiang-Chen Wang
- Department of Mechanical Engineering and Center for Innovative Research on Aging Society (CIRAS), National Chung Cheng University, 168, University Rd., Min Hsiung, Chia Yi 62102, Taiwan;
- Correspondence:
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Kumar JRH, Seelamantula CS, Mohan A, Shetty R, Berendschot TJM, Webers CAB. Automatic analysis of normative retinal oximetry images. PLoS One 2020; 15:e0231677. [PMID: 32421691 PMCID: PMC7233590 DOI: 10.1371/journal.pone.0231677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/29/2020] [Indexed: 11/18/2022] Open
Abstract
Retinal oximetry is an important screening tool for early detection of retinal pathologies due to changes in the vasculature and also serves as a useful indicator of human-body-wide vascular abnormalities. We present an automatic technique for the measurement of oxygen saturation in retinal arterioles and venules using dual-wavelength retinal oximetry images. The technique is based on segmenting an optic-disc-centered ring-shaped region of interest and subsequent analysis of the oxygen saturation levels. We show that the two dominant peaks in the histogram of the oxygen saturation levels correspond to arteriolar and venular oxygen saturations from which the arterio-venous saturation difference (AVSD) can be calculated. For evaluation, we use a normative database of Asian Indian eyes containing 44 dual-wavelength retinal oximetry images. Validations against expert manual annotations of arterioles and venules show that the proposed technique results in an average arteriolar oxygen saturation (SatO2) of 87.48%, venular SatO2 of 57.41%, and AVSD of 30.07% in comparison with the expert ground-truth average arteriolar SatO2 of 89.41%, venular SatO2 of 56.32%, and AVSD of 33.09%, respectively. The results exhibit high consistency across the dataset indicating that the automated technique is an accurate alternative to the manual procedure.
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Affiliation(s)
- J. R. Harish Kumar
- Department of Electrical Engineering, Indian Institute of Science, Bangalore, India
- Department of Electrical and Electronics Engineering, Manipal Institute of Technology, MAHE, Manipal, India
- * E-mail: (JRHK); (CSS); (AM)
| | - Chandra Sekhar Seelamantula
- Department of Electrical Engineering, Indian Institute of Science, Bangalore, India
- * E-mail: (JRHK); (CSS); (AM)
| | - Ashwin Mohan
- Postgraduate Institute of Ophthalmology, Narayana Nethralaya, Bangalore, India
- * E-mail: (JRHK); (CSS); (AM)
| | - Rohit Shetty
- Postgraduate Institute of Ophthalmology, Narayana Nethralaya, Bangalore, India
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Retinal capillary oximetry with visible light optical coherence tomography. Proc Natl Acad Sci U S A 2020; 117:11658-11666. [PMID: 32398376 DOI: 10.1073/pnas.1918546117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Assessing oxygen saturation (sO2) remains challenging but is nonetheless necessary for understanding retinal metabolism. We and others previously achieved oximetry on major retinal vessels and measured the total retinal oxygen metabolic rate in rats using visible-light optical coherence tomography. Here we extend oximetry measurements to capillaries and investigate all three retinal vascular plexuses by amplifying and extracting the spectroscopic signal from each capillary segment under the guidance of optical coherence tomography (OCT) angiography. Using this approach, we measured capillary sO2 in the retinal circulation in rats, demonstrated reproducibility of the results, validated the measurements in superficial capillaries with known perfusion pathways, and determined sO2 responses to hypoxia and hyperoxia in the different retinal capillary beds. OCT capillary oximetry has the potential to provide new insights into the retinal circulation in the normal eye as well as in retinal vascular diseases.
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Mitsch C, Pemp B, Pollreisz A, Gleiss A, Karst S, Scholda C, Sacu S, Schmidt‐Erfurth U. Short-time effect of intravitreal injections on retinal vascular oxygenation and vessel diameter in patients with diabetic macular oedema or neovascular age-related macular degeneration. Acta Ophthalmol 2020; 98:e301-e308. [PMID: 31654481 PMCID: PMC7216886 DOI: 10.1111/aos.14276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 09/23/2019] [Indexed: 01/14/2023]
Abstract
PURPOSE To investigate the short-time effect of intravitreal injections (IVI) of the vascular endothelial growth factor inhibitors ranibizumab and aflibercept on retinal arterial and venous oxygen saturation (SO2a and SO2v), arteriovenous oxygen saturation difference (AVD) and vessel diameter (VDa and VDv) in patients with diabetic macular oedema (DME) and patients with choroidal neovascularization (CNV) due to age-related macular degeneration. METHODS Uncontrolled prospective observational study in 100 eyes. Retinal vessel oxygen saturation and diameters were assessed using a retinal oximeter before and minutes after IVI of ranibizumab or aflibercept. RESULTS 40 eyes with CNV and 34 eyes with DME were included in the analysis. At baseline, SO2a and SO2v were significantly higher in DME (p = 0.043 and p = 0.009, respectively). After IVI, SO2a significantly decreased in CNV and DME eyes by 2.6% (p = 0.016) and 4.6% (p = 0.002) and SO2v decreased by 14.0% (p = 0.004) and 12.4% (p = 0.017), respectively. However, a significant increase in AVD was only found in CNV (15.7%, p = 0.001). VDa decreased significantly only in DME by 5.7% (p = 0.010). No medication-specific disease effect was found and vice versa. CONCLUSIONS The observed changes can be interpreted as signs of increased metabolic demand during the physiological stress after an IVI. The abnormal arterial constriction and the abolished increase in AVD seen only in eyes with DME indicate an impairment of vascular autoregulation and oxygen distribution and a reduced neuroretinal metabolism in the diabetic retina with a significant impact on inner retinal oxygen consumption shortly after IVI.
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Affiliation(s)
- Christoph Mitsch
- Department of Ophthalmology and OptometryMedical University of ViennaViennaAustria
| | - Berthold Pemp
- Department of Ophthalmology and OptometryMedical University of ViennaViennaAustria
| | - Andreas Pollreisz
- Department of Ophthalmology and OptometryMedical University of ViennaViennaAustria
| | - Andreas Gleiss
- Center for Medical StatisticsInformatics and Intelligent SystemsMedical University of ViennaViennaAustria
| | - Sonja Karst
- Department of Ophthalmology and OptometryMedical University of ViennaViennaAustria
| | - Christoph Scholda
- Department of Ophthalmology and OptometryMedical University of ViennaViennaAustria
| | - Stefan Sacu
- Department of Ophthalmology and OptometryMedical University of ViennaViennaAustria
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della Volpe Waizel M, Türksever C, Todorova MG. Influence of cataract light scatters on retinal vessel oxygen saturation. Acta Ophthalmol 2020; 98:e56-e62. [PMID: 31654499 DOI: 10.1111/aos.14200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 07/03/2019] [Indexed: 12/23/2022]
Abstract
BACKGROUND The aim of our study was to compare metabolic (oxygen saturation; %) and anatomical parameters (retinal vessel diameter; μm) of retinal vessel oximetry (RO) in patients with cataract formation against those of healthy controls with clear lenses. METHODS A total of 96 eyes of 62 subjects were examined: 51 eyes from 33 cataract patients (mean age: 64.8y) were compared to 45 eyes from 29 controls with clear lenses (mean age: 61.5y). RO was performed with the oxygen saturation measurement tool from the RVA (IMEDOS Systems UG). The oxygen saturation in all major peripapillary retinal arterioles (A-SO2 ) and venules (V-SO2 ) was measured, and their difference (A-V SO2 ) was calculated. In addition, the corresponding diameter in retinal arterioles (D-A) and venules (D-V) was evaluated. Cataract formation was graded according to the Lens Opacities Classification System III (LOCS III). Oximetry data were compared with the grade of cataract formation within both groups. For statistical evaluation, anova-based linear mixed-effects models were calculated (spss® , pairwise comparisons: Bonferroni-corrected; p < 0.05). RESULTS Cataract eyes showed significantly lower A-SO2 and A-V SO2 values (mean ± SD 92.52 ± 9.80% and 28.56 ± 9.80%), when compared to healthy controls (95.47 ± 4.48% and 34.8 ± 7.08%; p = 0.046 and p = 0.001). Within the cataract group, cortical opacities showed significant interactions with the A-SO2 , V-SO2 and the A-V SO2 parameters (p = 0.027; p = 0.002; and p = 0.026, respectively). CONCLUSIONS These data indicate that the cataract-induced light scatter influences optical retinal oxygen measurements. Cortical opacities showed the highest influence on RO measurement when compared to nuclear opacification, nuclear colour and posterior cataract formation.
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Affiliation(s)
- Maria della Volpe Waizel
- Department of Ophthalmology University Hospital Basel Basel Switzerland
- University of Basel Basel Switzerland
| | - Cengiz Türksever
- University of Basel Basel Switzerland
- VISTA Klinik Binningen Switzerland
| | - Margarita G. Todorova
- Department of Ophthalmology University Hospital Basel Basel Switzerland
- University of Basel Basel Switzerland
- Department of Ophthalmology Cantonal Hospital St. Gallen St. Gallen Switzerland
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Harris A, Guidoboni G, Siesky B, Mathew S, Verticchio Vercellin AC, Rowe L, Arciero J. Ocular blood flow as a clinical observation: Value, limitations and data analysis. Prog Retin Eye Res 2020; 78:100841. [PMID: 31987983 PMCID: PMC8908549 DOI: 10.1016/j.preteyeres.2020.100841] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/24/2022]
Abstract
Alterations in ocular blood flow have been identified as important risk factors for the onset and progression of numerous diseases of the eye. In particular, several population-based and longitudinal-based studies have provided compelling evidence of hemodynamic biomarkers as independent risk factors for ocular disease throughout several different geographic regions. Despite this evidence, the relative contribution of blood flow to ocular physiology and pathology in synergy with other risk factors and comorbidities (e.g., age, gender, race, diabetes and hypertension) remains uncertain. There is currently no gold standard for assessing all relevant vascular beds in the eye, and the heterogeneous vascular biomarkers derived from multiple ocular imaging technologies are non-interchangeable and difficult to interpret as a whole. As a result of these disease complexities and imaging limitations, standard statistical methods often yield inconsistent results across studies and are unable to quantify or explain a patient's overall risk for ocular disease. Combining mathematical modeling with artificial intelligence holds great promise for advancing data analysis in ophthalmology and enabling individualized risk assessment from diverse, multi-input clinical and demographic biomarkers. Mechanism-driven mathematical modeling makes virtual laboratories available to investigate pathogenic mechanisms, advance diagnostic ability and improve disease management. Artificial intelligence provides a novel method for utilizing a vast amount of data from a wide range of patient types to diagnose and monitor ocular disease. This article reviews the state of the art and major unanswered questions related to ocular vascular anatomy and physiology, ocular imaging techniques, clinical findings in glaucoma and other eye diseases, and mechanistic modeling predictions, while laying a path for integrating clinical observations with mathematical models and artificial intelligence. Viable alternatives for integrated data analysis are proposed that aim to overcome the limitations of standard statistical approaches and enable individually tailored precision medicine in ophthalmology.
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Affiliation(s)
- Alon Harris
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA.
| | | | - Brent Siesky
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | - Sunu Mathew
- Indiana University School of Medicine, Indianapolis, IN, USA
| | - Alice C Verticchio Vercellin
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA; University of Pavia, Pavia, Italy; IRCCS - Fondazione Bietti, Rome, Italy
| | - Lucas Rowe
- Indiana University School of Medicine, Indianapolis, IN, USA
| | - Julia Arciero
- Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
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The flicker response of venous oxygen saturation is significantly reduced in the early and late stages of age-related macular degeneration. Graefes Arch Clin Exp Ophthalmol 2020; 258:31-37. [DOI: 10.1007/s00417-019-04533-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/13/2019] [Accepted: 11/01/2019] [Indexed: 10/25/2022] Open
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Takasago Y, Fujita T, Nakano Y, Osaka R, Miyake M, Muraoka Y, Tsujikawa A. Ranibizumab treatment improves diabetic macular oedema without influencing retinal oximetry parameters. Acta Ophthalmol 2019; 97:e1048-e1053. [PMID: 31127694 DOI: 10.1111/aos.14145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/28/2019] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate the effect of ranibizumab on retinal oximetry in eyes with diabetic macular oedema (DME). METHODS In this prospective interventional study, 30 eyes (30 patients) with DME were treated with three-monthly intravitreal ranibizumab injections, followed by pro re nata administration for 12 months. Retinal oximetry was performed using an Oxymap T1. RESULTS The mean number of injections was 6.6 ± 2.5. No adverse event was observed throughout the study period. Ranibizumab treatments for 12 months improved the macular oedema (p = 0.002) and achieved a recovery of visual acuity (VA; p = 0.011). However, oxygen saturation levels in the major retinal blood vessels, either the arteries or the veins, remained unchanged during the observational period. Arterial oxygen saturation was 100.3 ± 9.4% before treatment and 100.9 ± 10.7% (p = 0.698) at 6 months. Venous oxygen saturation was 56.4 ± 8.9% before treatment and 55.6 ± 8.6% (p = 0.529) at 6 months. In addition, there were no significant changes in diameters of the major retinal arteries and veins. Greater improvement of VA at 12 months was correlated with a smaller number of ranibizumab injections (r = 0.459, p = 0.011). The number of ranibizumab injections during these 12 months correlated with an increased baseline central retinal thickness (r = 0.385, p = 0.035). CONCLUSION Ranibizumab treatments for DME improved the macular oedema and achieved VA recovery, but no changes were noted in the retinal oxygen saturation.
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Affiliation(s)
- Yukari Takasago
- Department of Ophthalmology Kagawa University Faculty of Medicine Kagawa Japan
| | - Tomoyoshi Fujita
- Department of Ophthalmology Kagawa University Faculty of Medicine Kagawa Japan
| | - Yuki Nakano
- Department of Ophthalmology Kagawa University Faculty of Medicine Kagawa Japan
| | - Rie Osaka
- Department of Ophthalmology Kagawa University Faculty of Medicine Kagawa Japan
| | - Masahiro Miyake
- Department of Ophthalmology and Visual Sciences Kyoto University Graduate School of Medicine Kyoto Japan
| | - Yuki Muraoka
- Department of Ophthalmology and Visual Sciences Kyoto University Graduate School of Medicine Kyoto Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences Kyoto University Graduate School of Medicine Kyoto Japan
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della Volpe-Waizel M, Zuche HC, Müller U, Rickmann A, Scholl HPN, Todorova MG. Metabolic monitoring of transcorneal electrical stimulation in retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2019; 258:79-87. [DOI: 10.1007/s00417-019-04522-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/15/2019] [Accepted: 10/22/2019] [Indexed: 10/25/2022] Open
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Arthur E, Elsner AE, Sapoznik KA, Papay JA, Muller MS, Burns SA. Distances From Capillaries to Arterioles or Venules Measured Using OCTA and AOSLO. Invest Ophthalmol Vis Sci 2019; 60:1833-1844. [PMID: 31042789 PMCID: PMC6892442 DOI: 10.1167/iovs.18-25294] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Purpose To investigate distances from retinal capillaries to arterioles or venules noninvasively. Methods An adaptive optics scanning laser ophthalmoscope (AOSLO) and optical coherence tomography angiography (OCTA) imager acquired detailed maps of retinal vasculature. Using OCTA, we quantified the distance from the edge of an arteriole or venule to the middle of the nearest capillaries (periarteriole or perivenule capillary-free zones, respectively) within the superficial vascular plexus of 20 young healthy subjects with normal axial lengths. These distances were compared to AOSLO images for three subjects. We tested the relation between the peripheral capillary-free zones and FAZ horizontal, vertical, effective diameters, and asymmetry indices in the deep vascular plexus. We examined enlargement with OCTA of capillary-free zones in a type 2 diabetic patient. Results The periarteriole capillary-free zone (67.2 ± 25.3 μm) was readily visible and larger than the perivenule capillary-free zone (42.7 ± 14.4 μm), F(1, 998) = 771, P < 0.0001. The distance from foveal center (P = 0.003) and diameter (P = 0.048) were predictive of perivenule capillary-free zone values. OCTA and AOSLO corresponded for arterioles. FAZ effective diameter was positively associated with asymmetry indices, r = 0.49, P = 0.028, but not peripheral capillary-free zones, although focal enlargements were found in a diabetic patient. Conclusions For normal retinas, periarteriole and perivenule capillary-free zones are readily visible with OCTA and AOSLO. Periarteriole capillary-free zones were larger, consistent with arterioles carrying oxygen rich blood that diffuses to support the retina.
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Affiliation(s)
- Edmund Arthur
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | - Ann E Elsner
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | - Kaitlyn A Sapoznik
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | - Joel A Papay
- Indiana University School of Optometry, Bloomington, Indiana, United States
| | | | - Stephen A Burns
- Indiana University School of Optometry, Bloomington, Indiana, United States
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Petersen L, Bek T. The Oxygen Saturation in Vascular Abnormalities Depends on the Extent of Arteriovenous Shunting in Diabetic Retinopathy. ACTA ACUST UNITED AC 2019; 60:3762-3767. [DOI: 10.1167/iovs.19-27472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Line Petersen
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
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Lim LS, Lim XH, Tan L. Retinal Vascular Oxygen Saturation and Its Variation With Refractive Error and Axial Length. Transl Vis Sci Technol 2019; 8:22. [PMID: 31403000 PMCID: PMC6685695 DOI: 10.1167/tvst.8.4.22] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 06/18/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the relationships between refractive error, axial length (AL), and retinal vascular oxygen saturation in an adult population. Methods This was a hospital-based, prospective observational study. The left eyes of phakic adult subjects without media opacity were analyzed. Subjective undilated manifest refraction was performed, and refractive errors were defined as myopia (spherical equivalent [SE], <−1 D), emmetropia (SE between −1 D and +1 D) and hyperopia (SE >+1 D). Retinal oximetry was performed using the Oxymap system (Oxymap Inc., Reykjavik, Iceland). Multivariate linear regression models were constructed to assess the relationship between retinal vascular oxygen saturation, SE, and AL obtained with optical biometry, with adjustments for age, sex, race, blood pressure, hyperlipidemia, and diabetes mellitus. Results There were 85 subjects, with mean age of 66.1 ± 11.3 years. The majority were female (60%) and Chinese (84%). A total of 60% were myopic, 28% emmetropic, and 12% hyperopic. Mean SE was −5.29 ± 6.51 D and mean AL was 25.30 ± 2.99 mm. In multivariate analyses, more myopic SE and longer AL were associated with lower retinal arteriolar oxygen saturation (regression coefficient B = 0.61 [95% confidence interval, 0.28, 0.95], P = 0.001; and B = −1.13 [95% confidence interval, −1.71, −0.56], P < 0.001, respectively). Subjects with myopic SE and AL also had lower retinal arteriolar oxygen saturation than emmetropes and hyperopes (P = 0.03 and P = 0.02, respectively). Conclusions Eyes with more myopic SE and longer AL have lower retinal arteriolar oxygen saturation. Translational Relevance This study provides direct evidence of a link between retinal oxygenation and hypoxia and myopia by using a novel device that quantifies retinal vascular oxygenation in vivo.
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Affiliation(s)
- Laurence Shen Lim
- Singapore National Eye Centre, 11 Third Hospital Ave, Singapore 168751, Singapore.,Singapore Eye Research Institute, 11 Third Hospital Ave, Singapore 168751, Singapore
| | - Xian Hui Lim
- Singapore National Eye Centre, 11 Third Hospital Ave, Singapore 168751, Singapore
| | - Licia Tan
- Singapore National Eye Centre, 11 Third Hospital Ave, Singapore 168751, Singapore
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Convolutional Neural Networks for Spectroscopic Analysis in Retinal Oximetry. Sci Rep 2019; 9:11387. [PMID: 31388136 PMCID: PMC6684811 DOI: 10.1038/s41598-019-47621-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 06/20/2019] [Indexed: 01/06/2023] Open
Abstract
Retinal oximetry is a non-invasive technique to investigate the hemodynamics, vasculature and health of the eye. Current techniques for retinal oximetry have been plagued by quantitatively inconsistent measurements and this has greatly limited their adoption in clinical environments. To become clinically relevant oximetry measurements must become reliable and reproducible across studies and locations. To this end, we have developed a convolutional neural network algorithm for multi-wavelength oximetry, showing a greatly improved calculation performance in comparison to previously reported techniques. The algorithm is calibration free, performs sensing of the four main hemoglobin conformations with no prior knowledge of their characteristic absorption spectra and, due to the convolution-based calculation, is invariable to spectral shifting. We show, herein, the dramatic performance improvements in using this algorithm to deduce effective oxygenation (SO2), as well as the added functionality to accurately measure fractional oxygenation (\documentclass[12pt]{minimal}
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\begin{document}$${{\bf{SO}}}_{{\bf{2}}}^{{\boldsymbol{f}}{\boldsymbol{r}}}$$\end{document}SO2fr). Furthermore, this report compares, for the first time, the relative performance of several previously reported multi-wavelength oximetry algorithms in the face of controlled spectral variations. The improved ability of the algorithm to accurately and independently measure hemoglobin concentrations offers a high potential tool for disease diagnosis and monitoring when applied to retinal spectroscopy.
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49
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Bek T. Translational research in retinal vascular disease. An approach. Acta Ophthalmol 2019; 97:441-450. [PMID: 30801973 DOI: 10.1111/aos.14045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 01/12/2019] [Indexed: 12/24/2022]
Abstract
The clinical presentation of the most frequent vision threatening retinal diseases is dominated by lesions indicating that disturbances in retinal blood flow are involved in the pathogenesis of these diseases. The present review describes the experience from a translational strategy pursued to investigate retinal vascular diseases with diabetic retinopathy as the main object. The normal regulation of retinal blood flow is investigated in porcine retinal vessels in vitro and ex vivo. Subsequently, the in vitro findings are translated to clinical studies in normal persons in vivo, and it is investigated whether the mechanisms are disturbed in retinal vascular disease. This is followed by clinical intervention studies on these diseases. The approach has been used to investigate pressure autoregulation, metabolic autoregulation and vasomotion in retinal vessels. The investigations have shown that retinal vascular tone can be regulated by receptor-specific agonists and antagonists to vasoactive compounds such as purines, prostaglandins and nitric oxide synthesis and that the vasoactive effects can be modulated by the concentration and the mode of administration of these compounds. Additionally, it has been shown that retinal precapillary arterioles and capillaries not visible by ophthalmoscopy may play an important role for the pathophysiology of retinal vascular disease and its treatment. Future studies should focus on investigating normal and pathological regulation of retinal blood flow in these smaller vessels.
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Affiliation(s)
- Toke Bek
- Department of Ophthalmology Aarhus University Hospital Aarhus C DK‐8000 Denmark
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50
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Della Volpe-Waizel M, Traber GL, Maloca P, Zinkernagel M, Schmidt-Erfurth U, Rubin G, Roska B, Otto T, Weleber RG, Scholl HPN. New Technologies for Outcome Measures in Retinal Disease: Review from the European Vision Institute Special Interest Focus Group. Ophthalmic Res 2019; 63:77-87. [PMID: 31352462 DOI: 10.1159/000501887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/03/2019] [Indexed: 01/03/2023]
Abstract
Novel diagnostic tools to measure retinal function and structure are rapidly being developed and introduced into clinical use. Opportunities exist to use these informative and robust measures as endpoints for clinical trials to determine efficacy and to monitor safety of therapeutic interventions. In order to inform researchers and clinician-scientists about these new diagnostic tools, a workshop was organized by the European Vision Institute. Invited speakers highlighted the recent advances in state-of-the-art technologies for outcome measures in the field of retina. This review highlights the workshop's presentations in the context of published literature.
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Affiliation(s)
- Maria Della Volpe-Waizel
- Department of Ophthalmology, University of Basel, Basel, Switzerland.,Institute of Molecular and Clinical Ophthalmology (IOB), Basel, Switzerland
| | - Ghislaine L Traber
- Department of Ophthalmology, University of Basel, Basel, Switzerland.,Institute of Molecular and Clinical Ophthalmology (IOB), Basel, Switzerland
| | - Peter Maloca
- Institute of Molecular and Clinical Ophthalmology (IOB), Basel, Switzerland
| | - Martin Zinkernagel
- Department of Ophthalmology and Department of Clinical Research, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | | | - Gary Rubin
- UCL University College London, Institute of Ophthalmology, London, United Kingdom
| | - Botond Roska
- Institute of Molecular and Clinical Ophthalmology (IOB), Basel, Switzerland
| | - Tilman Otto
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | - Richard G Weleber
- Casey Eye Institute, Departments of Ophthalmology and Molecular and Medical Genetics, University of Oregon Health and Science University, Portland, Oregon, USA
| | - Hendrik P N Scholl
- Department of Ophthalmology, University of Basel, Basel, Switzerland, .,Institute of Molecular and Clinical Ophthalmology (IOB), Basel, Switzerland,
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