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Clinical relevance of protruded retinal layers in minimum rim width measurement of the optic nerve head
摘要： background/aims Optical coherence tomography (OCT) imaging of the optic nerve head minimum rim width (MRW) has recently been shown to sometimes contain components besides extended retinal nerve fibre layer (RNFL). This study was conducted to determine whether excluding these components, termed protruded retinal layers (PRLs), from MRW increases diagnostic accuracy for detecting glaucoma. Methods In this cross-sectional study, we included 123 patients with glaucoma and 123 normal age-similar controls with OCT imaging of the optic nerve head (24 radial scans) and RNFL (circle scan). When present, PRLs were manually segmented, and adjusted MRW measurements were computed. We compared diagnostic accuracy of adjusted versus unadjusted MRW measurement. We also determined whether adjusted MRW correlates better with RNFL thickness compared with unadjusted MRW. results The median (IQR) visual field mean deviation of patients and controls was ?4.4 (?10.3 to ?2.1) dB and 0.0 (?0.6 to 0.8) dB, respectively. In the 5904 individual B-scans, PRLs were identified less frequently in patients (448, 7.6%) compared with controls (728, 12.3%; p<0.01) and were present most frequently in the temporal sector of both groups. Areas under the receiver operating characteristic curves and sensitivity values at 95% specificity indicated that PRL adjustment did not improve diagnostic accuracy of MRW, globally or temporally. Furthermore, adjusting MRW for PRL did not improve its correlation with RNFL thickness in either group. Conclusion While layers besides the RNFL are sometimes included in OCT measurements of MRW, subtracting these layers does not impact clinical utility.
关键词： minimum rim width,OCT imaging,glaucoma,protruded retinal layers,optic nerve head
更新于2025-09-09 09:28:46
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Variation in the Three-Dimensional Histomorphometry of the Normal Human Optic Nerve Head With Age and Race: Lamina Cribrosa and Peripapillary Scleral Thickness and Position
摘要： This study quantified the thickness and depth of the lamina cribrosa (LC) and peripapillary scleral thickness in high-resolution three-dimensional (3D) fluorescent reconstructions of the optic nerve head (ONH) in eyes from donors of African (AD) and European descent (ED). A total of 64 eyes (45 ED, 19 AD) from 51 normal donors were obtained within 6 hours of death and fixed at 10 mm Hg of pressure. The optic nerve head was trephined from the globe and digitally reconstructed at 1.5 3 1.5 3 1.5 lm voxel resolution with an automated episcopic fluorescence technique. The load-bearing ONH connective tissue surfaces were manually delineated in 3D using custom software. The lamina cribrosa and peripapillary sclera were significantly thinner in AD eyes adjusting for age and sex (LC was 24 6 11 lm thinner; P ? 0.0350; scleral was 56 6 22 lm thinner; P ? 0.0097). The lamina cribrosa was significantly thinner in females (23 6 11 lm thinner; P ? 0.0425). Age was not significantly associated with any morphologic parameter in the ED group. However, increasing age was associated with an increase in scleral thickness (1.3 lm/year, P ? 0.0499) and an increase in LC depth (2.3 lm/year, P ? 0.0035) in the AD group. The sclera was thickest in the superior and temporal regions while the LC was thinnest superiorly. Substantial sectorial and racial differences in LC and scleral morphology were observed, as well as increasing LC depth and scleral thickness with age in the AD group. Results suggest greater age-related remodeling of the load-bearing ONH connective tissues in eyes from AD individuals that could explain, in part, the greater predilection to glaucomatous injury seen in aged AD populations.
关键词： race,lamina cribrosa,morphometry,optic nerve head
更新于2025-09-09 09:28:46
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Multi-scale LBP and SVM Classification to Identify Diabetic Retinopathy in Lesions
摘要： Diabetic Retinopathy (DR) is the most common disease induced by the complication of diabetes, causing blindness. In many rural areas, the contributions of ophthalmologists are predicatively less to treat the disease. Detection of lesions in the early stage is a progressive measure to diagnose DR. Initially, a preprocessing method is performed to detect the Optic Nerve Head (ONH) in the lesion. Based on the degree of reflectance in ONH, feature extraction is computed using multi-scale Local Binary Pattern (LBP) algorithm. Here, Gabor convolution is estimated and the structure of ONH is encoded. This extends to a statistical computation in terms of the moment and standard deviation. A Support Vector Machine (SVM) classification is formulated to locate the hemorrhages and exudates and an effective probabilistic multi-label lesion classification is performed to acquire five sets of results representing the diabetic retinopathy: 1) Grade-1 Exudates, 2) Grade-2 Exudates, 3) Micro aneurysms, 4) Hemorrhages, 5) Neovascularization. Finally, the affected area of lesions is used to diagnose the disease.
关键词： statistical computation,Gabor convolution,local binary pattern,optic nerve head,support vector machine
更新于2025-09-09 09:28:46
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Changes in the Blood Flow of the Optic Nerve Head Induced by Different Concentrations of Epinephrine in Intravitreal Infusion During Vitreous Surgery
摘要： PURPOSE. We investigated whether intravitreal infusion solution containing epinephrine affects optic nerve head (ONH) blood ?ow during vitreous surgeries. METHODS. The subjects were 22 patients with epimacular membrane or idiopathic macular hole. During vitreous surgery, ONH blood ?ow was examined before and 10 minutes after intravitreal infusion of solution containing epinephrine, via a laser speckle ?owgraphy (LSFG) technique modi?ed for acquiring measurements in a supine position. Epinephrine concentration was set at 1.0 mg/500 mL (1:500,000) or 0.5 mg/500 mL (1:1,000,000), with each concentration assigned to 11 consecutive patients. Relative pupil diameter, IOP, blood pressure, and pulse rate also were measured. RESULTS. A signi?cant reduction in blood ?ow throughout the ONH was induced by intravitreal infusion of epinephrine at 1:500,000, but not at 1:1,000,000. Blood ?ow in ONH tissue was diminished at both concentrations, while that in vessels of the ONH was not altered signi?cantly by either concentration. Both epinephrine concentrations induced signi?cant pupillary dilatation, but no signi?cant changes in IOP, blood pressure, or pulse rate. CONCLUSIONS. This study suggests that epinephrine, used in combination with intravitreal infusion solution, may decrease ONH blood ?ow during vitreous surgeries, as indicated by measurements obtained via a modi?ed LSFG technique. Attention must be paid to the effects of intravitreal infusion of epinephrine on ocular circulation, particularly ONH blood ?ow.
关键词： laser speckle ?owgraphy,optic nerve head,epinephrine,supine position,blood ?ow,vitreous surgery
更新于2025-09-09 09:28:46
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Optic nerve head width and retinal nerve fiber layer changes are good indexes for validating the successful induction of experimental anterior ischemic optic neuropathy
摘要： Reproducible skills are essential for successful induction of a rat model of anterior ischemic optic neuropathy (rAION). We established an in vivo validation index by measuring the natural course of optic nerve head (ONH) width and retinal nerve fiber layer (RNFL) thickness in the rAION model using optical coherence tomography (OCT). The rAION model was induced by photodynamic operations. We measured the ONH width and RNFL thickness in the acute stage (<3 days), subacute stage (day 7 and day 14) and later stage (day 28) post-infarct by OCT. RNFL were measured by hematoxylin and eosin stain (HE) to confirm the OCT findings. The RGCs survival rate was determined by retrograde Fluoro-gold labeling, and the visual function was assessed with flash visual-evoked potentials (FVEPs) 4 weeks post-infarct. The ONH showed significant swelling in the acute stage, which also correlated with RNFL swelling. The swelling was reduced to normal within one-week post-infarct. The rAION group (0.51± 0.12 mm2) showed a significant RNFL thinning when compared with sham groups (0.92±0.15 mm2, p<0.05) on day-28 post-infarct. And HE-stained retina cross sections also showed RNFL thinning, which further confirmed our OCT Findings. The RGC density and P1-N2 amplitude were significantly reduced in rAION. Swelling, reduction of swelling, and atrophy of RNFL in acute, sub-acute, and later stage, respectively, are important events for confirming the successful induction of rAION. They suggest that the longitudinal OCT data provides a reliable index for validating the reproducibility and correct order of rAION.
关键词： optic nerve head (ONH),retinal ganglion cells (RGCs),optical coherence tomography (OCT),anterior ischemic optic neuropathy in rats (rAION),retina nerve fiber layer (RNFL)
更新于2025-09-04 15:30:14
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Evaluation of Ocular Perfusion in Alzheimer’s Disease Using Optical Coherence Tomography Angiography
摘要： Background: There is increasing evidence for the involvement of cerebrovascular factors in Alzheimer’s disease (AD). Objective: To evaluate retinal and optic nerve head perfusion in patients with AD using optical coherence tomography angiography (OCTA), and to analyze the correlations of quantitative OCTA metrics with AD pathology and vascular cerebral lesions in AD patients. Methods: 36 eyes of 36 patients with AD (study group) and 38 eyes of 38 healthy subjects (control group) were prospectively included in this study. OCTA was performed using RTVue XR Avanti with AngioVue. In addition, patients underwent a detailed ophthalmological and neurological examination including Mini-Mental State Examination, cerebral magnetic resonance imaging, and amyloid-β (Aβ) and tau levels in the cerebrospinal fluid (CSF). Results: The flow density in the superficial retinal OCT angiogram of the macula in the study group was significantly lower compared to the control group (p = 0.001). There was a significant correlation between the flow density in the superficial retinal OCT angiogram of the macula, as measured using OCTA, and the Fazekas scale (Spearman’s correlation coefficient = –0.520; p = 0.003). There was no significant correlation between the Aβ or tau levels in the CSF and the flow density data. Conclusion: Patients with AD showed a reduced flow density in the radial peripapillary capillaries layer and in the superficial retinal OCT angiogram when compared with healthy controls. The reduced retinal flow density measured using OCTA is not specifically associated with AD pathology but is associated with the vascular cerebral lesions in AD.
关键词： optical coherence tomography angiography,retinal and optic nerve head perfusion,Alzheimer’s disease,flow density
更新于2025-09-04 15:30:14