scholarly journals Signal Strength as an Important Factor in the Analysis of Peripapillary Microvascular Density Using Optical Coherence Tomography Angiography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hyung Bin Lim ◽  
Yong Woo Kim ◽  
Ki Yup Nam ◽  
Cheon Kuk Ryu ◽  
Young Joon Jo ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Structural Parameters ◽  
Signal Strength ◽  
Microvascular Density ◽  
Optical Coherence ◽  
Regression Analyses ◽  
Fiber Layer ◽  
Nerve Fiber Layer Thickness ◽  
Perfusion Density

Abstract The quality of the scan image is important in peripapillary circulation analysis using optical coherence tomography angiography (OCTA). We aimed to investigate the effects of signal strength (SS) on the peripapillary microvascular density acquired from OCTA. A total of 259 eyes from 259 young healthy subjects were included. Peripapillary OCTA images using 3 × 3 mm angiography scan were acquired from all participants. Subjects were divided into four groups according to the SS: SS 7, SS 8, SS 9, and SS 10. Vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated. VD and PD were compared among the four groups, and linear regression analyses were performed to identify and evaluate the clinical factors associated with average VD. As the SS increased from 7 to 10, the average VD and PD increased; these increases were statistically significant (all, p < 0.001). Regression analyses showed that four factors were significantly correlated with average VD: age (partial r = 0.133), average retinal nerve fiber layer thickness (partial r = 0.169), cup/disc ratio (partial r =−0.481), and SS (partial r = 0.413). SS is a significant factor affecting peripapillary microvascular density, and its influence is similar to well-known structural parameters associated with glaucoma.

scholarly journals Peripapillary microvasculature in patients with diabetes mellitus: An optical coherence tomography angiography study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yong-Il Shin ◽  
Ki Yup Nam ◽  
Seong Eun Lee ◽  
Min-Woo Lee ◽  
Hyung-Bin Lim ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Plexiform Layer ◽  
Control Group ◽  
Diabetic Patients ◽  
Inner Plexiform Layer ◽  
Optical Coherence ◽  
Regression Analyses ◽  
Fiber Layer

Abstract To evaluate changes in peripapillary microvascular parameters in diabetes mellitus (DM) patients using optical coherence tomography angiography (OCTA). Seventy-one diabetic patients (40 in the no diabetic retinopathy [DR] group and 31 in the non-proliferative DR [NPDR] group) and 50 control subjects. OCTA (Zeiss HD-OCT 5000 with AngioPlex) 6 × 6 mm scans centered on the optic disc were analyzed. Peripapillary vessel density (VD), perfusion density (PD) in superficial capillary plexus (SCP) were automatically calculated. The average macular ganglion cell-inner plexiform layer (mGC-IPL) and peripapillary retinal nerve fiber layer (pRNFL) thicknesses of the no DR and NPDR groups were significantly thinner than those of the control group. The no DR and NPDR groups showed lower peripapillary VD and PD in SCP compared with the control group. Using univariate regression analyses, the average mGC-IPL thickness, the pRNFL thickness, the no DR group and NPDR group were significant factors that affected the peripapillary VD and PD in SCP. Multivariate regression analyses showed that the grade of DR was a significant factor affecting the peripapillary VD and PD in SCP. OCTA revealed that peripapillary microvascular parameters in the no DR and NPDR groups were lower than those of normal controls. The peripapillary VD and PD in SCP were correlated with the mGC-IPL thickness, the pRNFL thickness, and the no DR and NPDR groups. Changes in peripapillary OCTA parameters may help with understanding the pathophysiology of DM and evaluating a potentially valuable biomarker for patients with subclinical DR.

scholarly journals Altered peripapillary vessel density and nerve fiber layer thickness in thyroid-associated ophthalmopathy using optical coherence tomography angiography

2021 ◽  
Author(s):  
Huan Jian ◽  
Yujiao Wang ◽  
Luyu Ou ◽  
Weimin He
Keyword(s):  
Optical Coherence Tomography ◽  
Linear Regression ◽  
Nerve Fiber ◽  
Layer Thickness ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Nerve Fiber Layer Thickness ◽  
Thyroid Associated Ophthalmopathy

Abstract Objective To measure the peripapillary vessel density (VD) and retinal nerve fiber layer thickness (RNFLT) in thyroid-associated ophthalmopathy (TAO) and dysthyroid optic neuropathy (DON) patients using optical coherence tomography angiography (OCTA), and determine their prognostic relevance. Methods Forty-three TAO patients with or without DON (82 eyes in total) and 26 healthy subjects (52 eyes) were enrolled. All participants underwent ophthalmology and endocrinology tests. The peripapillary VD in retinal peripapillary capillary layer and RNFLT were analyzed using OCTA images. Multiple linear regression analysis was used to assess the relationship between peripapillary VD /RNFLT and the relevant factors. Results The total peripapillary VD and RNFLT were significantly lower in the DON patients compared to the other groups (P < 0.001, 95% confidence intervals), and each quadrant of VD and RNFLT showed similar results except temporal RNFLT. No significant difference was seen between the RNFLT and VD of active non-DON (ANDON), inactive non-DON (NDON) patients and normal control (NC) group. Multivariable linear regression model showed that high IOP is an independent risk factor for lower peripapillary VD and RNFLT (β = −0.465, P < 0.001 and β = −0.343, P = 0.002 respectively). Conclusion OCTA parameters are suitable indicators for diagnosing DON. TAO patients with high IOP should be considered at high risk of retinal vessel and nerve fiber layer deterioration. In addition, patients with TAO should be advised to quit smoking since it could affect peripapillary VD and RNFLT.

scholarly journals Criteria for the reliability of optical coherence tomography measurements in patients with age-related cataract

2021 ◽  
pp. 6-11
Author(s):  
A.A. Shpak ◽  
◽  
A.A. Troshina ◽  
Keyword(s):  
Optical Coherence Tomography ◽  
Nerve Fiber ◽  
Signal Strength ◽  
Reliable Data ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Nerve Fiber Layer Thickness ◽  
Age Related ◽  
Central Subfield Thickness

Purpose. To determine optimal criteria for reliable optical coherence tomography (OCT) measurements in patients with age-related cataract. Material and methods. We examined 83 patients (83 eyes) with agerelated cataract before and after cataract surgery. The intensity of lens opacity was assessed by the Cirrus HD-OCT signal strength and Pentacambased Scheimpflug images analysis. Clinical cataract grading was performed according to the WHO classification. Preoperative measurement was considered reliable if its' difference with postoperative measurement did not exceed 5 ?m for the peripapillary retinal nerve fiber layer thickness (pRNFL) and 8 ?m for the central subfield thickness. Results. According to the ROC analysis, only the OCT signal strength allows to distinguish reliable OCT measurements: area under the ROC-curve (AUC) of the OCT signal strength was 0.815 (95% confidence interval 0.720–0.909) for the pRNFL and 0.756 (95% CI: 0.632–0.880) for the central subfield thickness. The best signal strength thresholds for reliable data were 5.5 for pRNFL and 4.5 for the central macular thickness (considering that the signal strength is measured in integers, these values should be rounded to 6 and 5 respectively). The rest of the studied parameters had AUC less than 0.6 so they cannot be used for evaluating OCT data. Conclusion. In patients with age-related cataract, only OCT signal strength can determine reliability of the OCT measurements. The lowest signal strength for reliable data on the Cirrus HD-OCT is 6 for pRNFL and 5 for centr al subfield thickness. Key words: optical coherence tomography, cataract, retina, nerve fiber layer, lens densitometry.

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