301 research outputs found
Thirteen-Year Follow-up of Optic Disc Hemorrhages in the Ocular Hypertension Treatment Study
To determine the cumulative incidence of optic disc hemorrhage (ODH) before and after development of primary open angle glaucoma (POAG); determine the prognostic significance of ODH for the development of POAG; identify predictive factors for ODH
Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma
Purpose:To independently validate the performance of the University of North Carolina Optical Coherence Tomography (UNC OCT) Index in diagnosing and predicting early glaucoma. Methods:Data of 118 normal subjects (118 eyes) and 96 subjects (96 eyes) with early glaucoma defined as visual field mean deviation (MD) greater than -4 decibels (dB), aged 40 to 80 years, and who were enrolled in the Full-Threshold Testing Size III, V, VI comparison study were used in this study. CIRRUS OCT average and quadrants' retinal nerve fiber layer (RNFL); optic disc vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio, and rim area; and average, minimum, and six sectoral ganglion cell-inner plexiform layer (GCIPL) measurements were run through the UNC OCT Index algorithm. Area under the receiver operating characteristic curve (AUC) and sensitivities at 95% and 99% specificity were calculated and compared between single parameters and the UNC OCT Index. Results:Mean age was 60.1 ± 11.0 years for normal subjects and 66.5 ± 8.1 years for glaucoma patients (P < 0.001). MD was 0.29 ± 1.04 dB and -1.30 ± 1.35 dB in normal and glaucomatous eyes (P < 0.001), respectively. The AUC of the UNC OCT Index was 0.96. The best single metrics when compared to the UNC OCT Index were VCDR (0.93, P = 0.054), average RNFL (0.92, P = 0.014), and minimum GCIPL (0.91, P = 0.009). The sensitivities at 95% and 99% specificity were 85.4% and 76.0% (UNC OCT Index), 71.9% and 62.5% (VCDR, all P < 0.001), 64.6% and 53.1% (average RNFL, all P < 0.001), and 66.7% and 58.3% (minimum GCIPL, all P < 0.001), respectively. Conclusions:The findings confirm that the UNC OCT Index may provide improved diagnostic perforce over that of single OCT parameters and may be a good tool for detection of early glaucoma. Translational Relevance:The UNC OCT Index algorithm may be incorporated easily into routine clinical practice and be useful for detecting early glaucoma
Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma
Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo–electron volts), which is ascribed to an accretion disk corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems
Effects of Age on Optical Coherence Tomography Measurements of Healthy Retinal Nerve Fiber Layer, Macula, and Optic Nerve Head
Purpose—To determine the effects of age on global and sectoral peripapillary retinal nerve fiber
layer (RNFL), macular thicknesses and optic nerve head (ONH) parameters in healthy subjects using
optical coherence tomography (OCT).
Design—Retrospective, cross-sectional observational study.
Participants—226 eyes from 124 healthy subjects were included.
Methods—Healthy subjects were scanned using the Fast RNFL, Fast Macula, and Fast ONH scan
patterns on a Stratus OCT. All global and sectoral RNFL and macular parameters and global ONH
parameters were modeled in terms of age using linear mixed effects models. Normalized slopes were
also calculated by dividing the slopes by the mean value of the OCT parameter for inter-parameter
comparison.
Main Outcome Measures—Slope of each OCT parameter across age.
Results—All global and sectoral RNFL thickness parameters statistically significantly decreased
with increasing age, except for the temporal quadrant and clock hours 8-10, which were not statistically different from a slope of zero. Highest absolute slopes were in the inferior and superior
quadrant RNFL and clock hour 1 (superior nasal). Normalized slopes showed similar rate in all sectors
except for the temporal clock hours (8-10). All macular thickness parameters statistically
significantly decreased with increasing age, except for the central fovea sector, which had a slight
positive slope that was not statistically significant. The nasal outer sector had the greatest absolute
slope. Normalized macular slope in the outer ring was similar to the normalized slopes in the RNFL.
Normalized inner ring had shallower slope than the outer ring with similar rate in all quadrants. Disc
area remained nearly constant across the ages, but cup area increased and rim area decreased with
age, both of which were statistically significant.
Conclusions—Global and regional changes due to the effects of age on RNFL, macula and ONH
OCT measurements should be considered when assessing eyes over time.National Institutes of Health (U.S.) (R01-EY13178-09)National Institutes of Health (U.S.) (R01-EY11289-23)National Institutes of Health (U.S.) (P30-EY008098
Postoperative Complications in the Ahmed Baerveldt Comparison Study During Five Years of Follow-up
To compare the late complications in the Ahmed Baerveldt Comparison Study during 5 years of follow-up
Comparison of vertical cup-to-disc ratio estimates using stereoscopic and monoscopic cameras
Background: The use of monoscopic cameras for glaucoma screening is increasing due to their portability, lower cost, and non-mydriatic capabilities. However, it is important to compare the accuracy of such devices with stereoscopic cameras that are used clinically and are considered the gold standard in optic disc assessment. The aim of this study is to compare vertical cup-to-disc ratio (VCDR) estimates obtained using images taken with a monoscopic and stereoscopic camera. Methods: Participants were selected from the Tema Eye Survey. Eligible subjects had images of at least one eye taken with two cameras. They were classified as meeting the glaucoma threshold if an eye had a VCDR estimate >97.5th percentile, corresponding to >0.725 for this population. Hence, we used 0.725 as the cutoff to group eyes into two categories: positive and negative. We calculated sensitivity, specificity, and predictive values of VCDR assessed by expert readers at a reading center for monoscopic photos using stereoscopic photos as the gold standard. Results: Three hundred and seventy-nine eyes of 206 participants were included in the study. Most participants were female (60.2%) and the most common age group was 50–59 years (36.4%). Sixteen eyes met the glaucoma threshold (VCDR > 0.725). Of these, the VCDR estimates of 14 eyes (87.5%) disagreed on the glaucoma threshold from the two cameras. The sensitivity to detect glaucoma with the monoscopic camera was 14.3% (95% CI: 4.0, 40.3). Conclusions: The low sensitivity of monoscopic photos suggests that stereoscopic photos are more useful in the diagnosis of glaucoma
Longitudinal changes in peripapillary atrophy in the ocular hypertension treatment study: A case-control assessment
To explore the association between peripapillary atrophy (PPA) area and conversion from ocular hypertension (OHT) to glaucoma
Five-Year Treatment Outcomes in the Ahmed Baerveldt Comparison Study
To compare the five year outcomes of the Ahmed FP7 Glaucoma Valve (AGV) and the Baerveldt 101-350 Glaucoma Implant (BGI) for the treatment of refractory glaucoma
Three-year Treatment Outcomes in the Ahmed Baerveldt Comparison Study
To compare three year outcomes and complications of the Ahmed FP7 Glaucoma Valve (AGV) and Baerveldt 101–350 Glaucoma Implant (BGI) for the treatment of refractory glaucoma
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