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Optical Coherence Tomography Biomarkers of the Outer Blood-Retina Barrier in Patients with Diabetic Macular Oedema.
Damian, I, Nicoara, SD
Journal of diabetes research. 2020;:8880586
Abstract
BACKGROUND Numerous studies confirmed the main role of the inner blood-retinal barrier in the development of Diabetic Macular Oedema (DMO). Lately, the focus of research shifted towards the external retinal barrier with potential involvement in the pathogenesis of DMO. OBJECTIVE We aim to identify the OCT changes of the external blood-retinal barrier in patients with DMO and to define them as biomarkers with predictive value. Materials and method. We set up retrospectively 3 groups of patients diagnosed with nonproliferative diabetic retinopathy (NPDR) and DMO, proliferative diabetic retinopathy (PDR) and DMO, and controls. We compared the RPE thickness in every quadrant between groups and performed correlations between best-corrected visual acuity (BCVA) and the thickness of the retinal layers. The Social Science Statistics platform was used for statistical tests. RESULTS The NPDR-DMO group consisted of 18 eyes, the PDR-DMO group consisted of 19 eyes, and the control group included 36 eyes. In the PDR-DMO group, RPE thickness was decreased in almost all quadrants (p < 0.001); in the NPDR-DMO group, only the central minimum and central maximum values of the RPE thickness were significantly different from the control group. We did not find any strong correlation between BCVA and the thickness of the retinal layers. CONCLUSION The thickness of the RPE layer is an OCT biomarker able to predict the functioning of the outer BRB. Eyes with PDR-DMO exhibited decreased thickness of the RPE layer in almost all quadrants, highlighting the degenerative changes occurring in a hypoxic environment. The thickness of a specific layer could not be identified as a biomarker to correlate significantly with BCVA, most likely because we did not analyze specific morphologic features, such as continuity and reflectivity. The analysis of the RPE thickness could clarify the unexplained decrease of BCVA and predict early the evolution of DR.
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Automated Deformation-Based Analysis of 3D Optical Coherence Tomography in Diabetic Retinopathy.
Khansari, MM, Zhang, J, Qiao, Y, Gahm, JK, Sarabi, MS, Kashani, AH, Shi, Y
IEEE transactions on medical imaging. 2020;(1):236-245
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Abstract
Diabetic retinopathy (DR) is a significant microvascular complication of diabetes mellitus and a leading cause of vision impairment in working age adults. Optical coherence tomography (OCT) is a routinely used clinical tool to observe retinal structural and thickness alterations in DR. Pathological changes that alter the normal anatomy of the retina, such as intraretinal edema, pose great challenges for conventional layer-based analysis of OCT images. We present an alternative approach for the automated analysis of OCT volumes in DR research based on nonlinear registration. In this paper, we first obtain an anatomically consistent volume of interest (VOI) in different OCT images via carefully designed masking and affine registration. After that, efficient B-spline transformations are computed using stochastic gradient descent optimization. Using the OCT volumes of normal controls, for which layer-based segmentation works well, we demonstrate the accuracy of our registration-based analysis in aligning layer boundaries. By nonlinearly registering the OCT volumes of DR subjects to an atlas constructed from normal controls and measuring the Jacobian determinant of the deformation, we can simultaneously visualize tissue contraction and expansion due to DR pathology. Tensor-based morphometry (TBM) can also be performed for quantitative analysis of local structural changes. In our experimental results, we apply our method to a dataset of 105 subjects and demonstrate that volumetric OCT registration and TBM analysis can successfully detect local retinal structural alterations due to DR.
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Effects of Systemic Profiles on Choroidal Thickness in Treatment-Naïve Eyes With Diabetic Retinopathy.
Choi, MG, Chung, H, Yoon, YH, Kim, JT
Investigative ophthalmology & visual science. 2020;(11):12
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Abstract
PURPOSE The purpose of this study was to analyze the effects of systemic and ocular profiles on subfoveal choroidal thickness (SFChT) in treatment-naïve eyes with diabetic retinopathy (DR). METHODS This study included patients with treatment-naïve DR. They underwent routine laboratory evaluations, including complete blood cell count, liver function tests, kidney function tests, and urinalysis for macroalbuminuria. The systemic and ocular factors associated with the change in SFChT in DR were analyzed. RESULTS A total of 136 eyes from 136 patients with diabetes and 30 eyes from 30 age-matched healthy controls were recruited. Generalized linear model analyses showed that the SFChT in treatment-naïve eyes with DR was positively associated with the DR grade and estimated glomerular filtration rate (eGFR; P = 0.001) and negatively associated with age (P < 0.001) and serum phosphorus levels (P = 0.001). Treatment-naïve eyes with proliferative DR (PDR; 313.4 ± 9.0 µm) or severe nonproliferative DR (NPDR; 299.7 ± 9.7 µm) had thicker choroid than eyes with mild to moderate NPDR (251.7 ± 11.1 µm) or no DR (231.2 ± 14.5 µm) after adjusting for age, eGFR, and phosphorus levels. CONCLUSIONS Choroid is affected by renal function and the grade of DR in patients with diabetes. Advanced retinopathy is associated with choroidal thickening, and the severity of concomitant renal disease is associated with choroidal thinning.
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ACUTE MACULAR AND PERIPAPILLARY ANGIOGRAPHIC CHANGES WITH INTRAVITREAL INJECTIONS.
Barash, A, Chui, TYP, Garcia, P, Rosen, RB
Retina (Philadelphia, Pa.). 2020;(4):648-656
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PURPOSE Intravitreal injections acutely and temporarily increase intraocular pressure (IOP), and this may have cumulative long-term effects including an increased risk for glaucoma surgery. This study was designed to measure retinal perfusion density changes on optical coherence tomography (OCT) angiography and OCT thickness alterations associated with acutely increased IOP after intravitreal injections. METHODS Retrospective observational clinical study of 40 eyes (39 patients) with various retinopathies from October 2016 to June 2017 at a tertiary care retina clinic in NYC. Patients were older than 18 years, with vision >20/100, able to fixate and without media opacities precluding OCT angiography, receiving intravitreal bevacizumab or aflibercept for diabetic retinopathy, retinal vein occlusion, macular degeneration, retinal neovascularization, or radiation retinopathy. The 3-mm × 3-mm macular and 4.5-mm × 4.5-mm peripapillary OCT angiography perfusion density, macular OCT thickness, and IOP were measured before and immediately after intravitreal injections. Paired t-test was used to compare preinjection and postinjection values for perfusion density and OCT thickness. Regression analysis was performed for potential effects of baseline IOP, IOP change, and age. RESULTS Statistically significant decreases in angiographic perfusion density (P < 0.05) were found in most areas of the superficial and deep layer macular OCT angiography, and the overall optic nerve head and the radial peripapillary capillary layer, preferentially temporal. Macular OCT thickness was significantly decreased in the temporal region and increased in the nasal region. Regression analysis showed relationships between age and decreased superficial macular perfusion. Preinjection IOP was only related to OCT thickness in the fovea. Intraocular pressure change was related only to decreased superficial macular perfusion density. CONCLUSION Intravitreal injections produce acute IOP changes that are associated with reduced macular and peripapillary perfusion density. Therefore, it is possible that patients receiving regular intravitreal injections may be sustaining perfusion-related injury to ocular structures that may produce glaucomatous damage to the macula and optic nerve.
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The relationship of central corneal thickness with the status of diabetic retinopathy.
Canan, H, Sahinoglu-Keskek, N, Altan-Yaycioglu, R
BMC ophthalmology. 2020;(1):220
Abstract
BACKGROUND To compare central corneal thickness (CCT) values measured by three different devices: slit-scanning topography (SST), ultrasonic pachymetry (UP), and optical coherence tomography (OCT) in diabetic eyes and compare the CCT values in patients with and without diabetic retinopathy. METHODS Ninety-six patients with diabetes mellitus were included in this prospective study and divided into two groups according to the presence of diabetic retinopathy, as Group I with retinopathy and Group II without. The CCT of 96 eyes was measured by three different devices; SST (Orbscan II), UP and OCT. The results of CCT measurements with three different devices were compared. Also, the intergroup differences in CCT measurements were evaluated. RESULTS The CCT was statistically insignificantly different between the two groups. Although the three methods of CCT measurements correlated well with each other, SST showed significantly (p < 0,0001) higher CCT results compared to both UP and OCT. CONCLUSIONS According to our results, neither the duration of DM nor the presence of diabetic retinopathy did have a significant effect on the CCT. The CCT values obtained with three devices were all in correlation. However, the results of SST were significantly higher compared to the other two. Our findings emphasize the value anterior segment OCT in CCT measurements, since it is a non-contact method and correlate very well with UP.
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Vessel Density around Foveal Avascular Zone as a Potential Imaging Biomarker for Detecting Preclinical Diabetic Retinopathy: An Optical Coherence Tomography Angiography Study.
Ragkousis, A, Kozobolis, V, Kabanarou, S, Bontzos, G, Mangouritsas, G, Heliopoulos, I, Chatziralli, I
Seminars in ophthalmology. 2020;(5-6):316-323
Abstract
Purpose: The purpose of this study was to investigate the changes of optical coherence tomography angiography (OCTA) parameters in diabetic retinopathy (DR) using an updated software with 3D projection artifact removal. Methods: In this cross-sectional observational study, 192 eyes of 111 patients with diabetes mellitus (DM) and 55 eyes of 34 age-matched healthy subjects were included. Diabetic patients were divided into three subgroups: without DR, with mild non-proliferative DR, and with moderate-to-severe non-proliferative DR. All eyes underwent dilated fundoscopy along with 3x3mm and 6x6mm OCTA image acquisition. Vessel density (VD), retinal thickness and foveal avascular zone (FAZ) parameters were analyzed. Correlation analyses between OCTA parameters and DR severity were also performed. Results: There was a statistically significant difference in all OCTA parameters among groups, except for superficial foveal VD in 6x6mm scan and whole image retinal thickness in both 3x3mm and 6x6mm scans, while 3x3mm scan parameters were found to be diagnostically superior to the corresponding ones of 6x6mm scan. As the DR stage progressed, the mean VD values decreased. FD-300, which is the VD of a 300-μm width annulus surrounding FAZ, demonstrated the strongest inverse correlation with DR severity (r = -0.590/rs = -0.562, p < .001) and showed the highest area under the ROC curve (AUROC = 0.833 ± 0.030, p < .001) in scan 3 × 3. Conclusion: OCTA shows progressive decrease of VD parameters with increasing DR severity. Foveal VD, FAZ area, and perimeter are not very useful indexes due to the high interindividual variability of FAZ size. OCTA and specifically FD-300 may serve as a promising DR screening tool for detecting preclinical microvascular alterations.
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PHOTORECEPTOR DAMAGE IN DIABETIC CHOROIDOPATHY.
Borrelli, E, Palmieri, M, Viggiano, P, Ferro, G, Mastropasqua, R
Retina (Philadelphia, Pa.). 2020;(6):1062-1069
Abstract
PURPOSE To investigate the relationship between choriocapillaris (CC) hypoperfusion and photoreceptor alterations in eyes with nonproliferative diabetic retinopathy (NPDR). METHODS In this prospective, observational, case-control study, 30 eyes (30 patients) with NPDR and 30 healthy eyes from 30 controls were enrolled at the University G. d'Annunzio, Chieti-Pescara, Italy. This study cohort underwent an ophthalmologic examination, including optical coherence tomography and optical coherence tomography angiography. The main outcome measures were as follows: 1) "normalized" reflectivity of en face image segmented at the ellipsoid zone level, which was calculated to quantify the photoreceptor damage, and 2) CC perfusion density. Secondary outcome measures were as follows: 1) superficial retinal capillary plexus (SCP), intermediate retinal capillary plexus (ICP), and deep retinal capillary plexus (DCP) perfusion density (based on the area of vessels); 2) SCP, ICP, and DCP vessel length density (based on a map with vessels of 1-pixel width); and 3) SCP, ICP, and DCP vessel diameter. RESULTS Mean ± SD age was 58.9 ± 11.1 years (range 38-79 years) in the NPDR group and 61.7 ± 11.3 years (range 39-87 years) in the control group (P > 0.05 for all the comparisons). Compared with controls, NPDR eyes displayed a lower "normalized" reflectivity (0.96 ± 0.25 in controls and 0.73 ± 0.19 in the NPDR group, P < 0.0001). Moreover, the NPDR group was characterized by an impaired perfusion in both the retinal and choroidal vasculature. In multiple regression analysis, ellipsoid zone "normalized" reflectivity displayed a significant direct association with CC perfusion density in patients with NPDR (P = 0.025 and P = 0.476, in NPDR and controls, respectively). CONCLUSION Eyes with NPDR are affected by macular hypoperfusion and photoreceptor damage, the latter investigated as ellipsoid zone "normalized" reflectivity. The diabetic choroidopathy seems to be strongly associated with photoreceptor damage.
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Changes in choroidal vascular parameters following pan-retinal photocoagulation using swept-source optical coherence tomography.
Kim, JT, Park, N
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie. 2020;(1):39-47
Abstract
BACKGROUND To assess the effect of pan-retinal photocoagulation (PRP) on choroidal vascular parameters in eyes with advanced diabetic retinopathy (DR). METHODS Forty patients (65 eyes) with severe nonproliferative DR or proliferative DR who underwent PRP were included. Changes in choroidal vascular parameters were assessed at 3, 6, and 12 months after PRP by using swept-source optical coherence tomography (OCT) and OCT angiography and were compared with baseline values. RESULTS Choroidal vascularity index (CVI) significantly decreased from 66.27% ± 1.55% at baseline to 65.85% ± 1.61%, 65.77% ± 1.29%, and 65.74% ± 1.60% at 3, 6, and 12 months after PRP, respectively. The ratio of luminal area to stromal area (L/S ratio) also significantly decreased from 1.98 ± 0.15 at baseline to 1.94 ± 0.14, 1.95 ± 0.13, and 1.93 ± 0.14 at 3, 6, and 12 months after PRP, respectively. The subfoveal choroidal thickness (SFCT) similarly showed a significant decrease from 319.50 ± 56.64 μm at baseline to 299. 07 ± 51.14 μm, 294.70 ± 58.96 μm, and 280.93 ± 53.57 μm at 3, 6, and 12 months after PRP, respectively. However, the choriocapillaris vessel density in both the fovea and parafovea showed no significant differences following PRP. CONCLUSION Eyes with advanced DR showed a significant reduction in CVI, L/S ratio, and SFCT over 12 months after PRP treatment.
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Objective Evaluation of Proliferative Diabetic Retinopathy Using OCT.
Schwartz, R, Khalid, H, Sivaprasad, S, Nicholson, L, Anikina, E, Sullivan, P, Patel, PJ, Balaskas, K, Keane, PA
Ophthalmology. Retina. 2020;(2):164-174
Abstract
PURPOSE To present the routine use of OCT and OCT angiography (OCTA) for the objective diagnosis and monitoring of proliferative diabetic retinopathy (PDR). DESIGN Retrospective, observational case series. PARTICIPANTS Patients with diabetic retinopathy imaged using a standardized PDR protocol. METHODS Patients routinely imaged with a standardized PDR protocol between March 2017 and January 2019 were included. This included a 12×9-mm structural OCT volume centered on the macula and a 6×6-mm OCTA scan centered on the optic nerve head obtained using a Topcon swept-source system (DRI OCT-1 Triton, Topcon, Tokyo, Japan). Ultra-widefield fluorescein angiography (FA) was also performed when clinically indicated. The ground truth for each case was determined by merging the findings from biomicroscopy and imaging modalities to generate the maximum level of detection for each finding. MAIN OUTCOME MEASURES Detection rates of new-onset, regression, and reactivation of neovascularization of the disc (NVD) and neovascularization elsewhere (NVE) using different modalities (biomicroscopy/color photography, structural OCT, B-scan OCTA, en face OCTA). Detection of progression of tractional retinal detachment (TRD). RESULTS A total of 383 eyes of 204 patients were evaluated. After excluding patients without PDR or with insufficient image quality, 47 eyes of 35 patients were included. For the detection of new-onset NVD and NVE, structural OCT had the highest detection rate (100%) of all modalities. However, for the detection of regression or reactivation of neovascularization (NV), B-scan OCTA had the highest detection rate (100%). Structural OCT detected regression only in 45.5% of cases, resulting in a low detection rate of reactivation (12.5%). Among 10 eyes with TRD, OCT detected fovea-threatening TRD during follow-up in 7 eyes, resulting in vitrectomy. CONCLUSIONS This study demonstrates the utility of novel multimodal imaging in the daily management of patients with PDR. Posterior pole structural OCT had the best detection rate for NV, and B-scan OCTA showed the most potential for objective monitoring of disease after treatment.
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Cut-off value of strut-vessel distance for the resolution of acute incomplete stent apposition in the early phase using serial optical coherence tomography after cobalt-chromium everolimus-eluting stent implantation.
Oda, H, Itoh, T, Sasaki, W, Uchimura, Y, Taguchi, Y, Kaneko, K, Sakamoto, T, Goto, I, Sakuma, M, Ishida, M, et al
Journal of cardiology. 2020;(6):641-647
Abstract
OBJECTIVE The purpose of this study was to identify a cut-off value to predict the resolution of incomplete-stent-apposition (ISA) after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation at early follow-up. BACKGROUND To date, appropriate stent apposition at the acute period using intracoronary imaging has been recommended because persistent ISA is considered to be a risk factor for stent thrombosis. We examined the indices for resolving acute ISA. In particular, we determined the cut-off value for strut vessel distance (SV-distance) as visualized by optical coherence tomography (OCT) at 8 months after CoCr-EES implantation. However, the cut-off value of SV-distance for the earlier resolution of ISA is unclear. METHODS A total of 95 cases and 103 stents were registered in the MECHANISM Elective substudy. The SV-distance was measured at the deepest site of the target malapposition and every 1 mm from the proximal edge to the distal edge of the mal-apposed area using OCT. Cut-off values for ISA resolution at 1 and 3 months were estimated by SV-distance using receiver operating characteristic analysis. RESULTS The total number of analyzed struts was 14,418 at the 1-month follow-up and 11,986 at the 3-month follow-up. The optimal SV-distance cut-off values just after stent implantation to predict ISA resolution were 185 µm at the 1-month follow-up and 195 μm at the 3-month follow-up. CONCLUSION For resolution of ISA, SV-distance cut-off values of 185 µm at 1 month postimplantation and 195 μm at 3 months postimplantation can be used as the index of endpoint of the percutaneous coronary intervention.