Disc Area Research Articles

Relationships between functional temporomandibular joint space and disc morphology, position, and condylar osseous condition in patients with temporomandibular disorder.

To investigate the correlations between joint space and temporomandibular joint (TMJ) components and the compressive states of the disc and condyle subsequent to joint space changes. A total of 240 TMJs were categorized according to disc morphology, disc position, and condylar osseous condition. The two-dimensional (2D) and three-dimensional (3D) measurements were compared. The functional joint space (FJS) and disc areas on closed- and open-mouth images (DA-C and DA-O) were also calculated, and the joint space was measured in five directions. Different groups of TMJ components were compared. A spring model was used to simulate the effect of condylar displacement on the disc and condyle. Disc morphology was strongly correlated with its position. The measurements were equivalent between 2D and 3D methods. DA-C and FJS differed significantly between groups. The DA-C to FJS ratio differed between the Class 2 and Class 3 groups and between disc displacement groups with and without reduction. Altered disc morphology and position were correlated with significant changes in joint space in the 60°, 90°, and 120° directions. Despite minor discrepancies among condylar osseous conditions, reduced joint space was correlated with bone destruction at the corresponding site. The spring model stimulation revealed that condylar displacement caused elevated stresses on the disc and condyle. Condylar displacement causes joint space alterations while exerting compressive pressure on both the disc and condyle. Proper condylar positioning within the fossa is recommended to ensure sufficient articular disc accommodation.

Peripapillary Atrophy Area as an Indicator of Glaucomatous Structural and Functional Progression.

To determine whether peripapillary atrophy (PPA) area is an indicator of glaucomatous structural and functional damage and progression. In this retrospective longitudinal analysis from ongoing prospective study we qualified 71 eyes (50 subjects) with glaucoma. All subjects had a comprehensive ophthalmic examination, visual field (VF), and spectral-domain optical coherence tomography (OCT) testing in at least three visits. PPA was manually delineated on en face OCT optic nerve head scans, while observing the corresponding cross-sectional images, as the hyper-reflective area contiguous with the optic disc. The mean follow-up duration was 4.4 ± 1.4years with an average of 6.8 ± 2.2 visits. At baseline, PPA area was significantly associated only with VF's mean deviation (MD; P = 0.041), visual field index (VFI; P = 0.041), superior ganglion cell inner plexiform layer (GCIPL; P = 0.011), and disc area (P = 0.011). Longitudinally, PPA area was negatively and significantly associated with MD (P = 0.015), VFI (P = 0.035), GCIPL (P = 0.009), superior GCIPL (P = 0.034), and disc area (P = 0.007, positive association). Longitudinal change in PPA area is an indicator of glaucomatous structural and functional progression but PPA area at baseline cannot predict future progression. Longitudinal changes in peripapillary atrophy area measured by OCT can be an indicator of structural and functional glaucoma progression.

ULTRA-WIDEFIELD IMAGING DETECTION RATE IN IDENTIFYING PERIPHERAL RETINAL TEARS IN SINGLE VERSUS MONTAGE OF PERIPHERAL STEERING.

To compare the detection rate of orthogonal, directed peripheral steering, and automontaged images with ultra-widefield imaging and the factors influencing the ability to identify retinal breaks. Retrospective cohort study. Three hundred and seventy-six treatment-naive eyes (349 patients) that underwent laser retinopexy for retinal breaks between 2015 and 2021 were included. Pretreatment ultra-widefield orthogonal, peripheral steering, and automontage were cross-referenced to scleral-depressed examination to determine whether images successfully visualized all retinal breaks. Total relative retinal area (RRA) visualized was divided by its optic disk area (pixels) to calculate relative retinal area. Potential associations were assessed by linear regression analysis. One hundred and sixty two eyes (154 patients) met inclusion criteria. Orthogonal, peripheral steering, and automontage images showed detection rates of 47.5%, 90.7%, and 80.0%, respectively. Relative retinal area increased from orthogonal versus montage by 34.7% ± 26.5% (mean ± SD), which increased the detection rate by 90.8% ( P = 0.006). In linear probability models, vertical meridian tears decreased probability of identification in orthogonal, peripheral steering, and automontage by -26.6%, -86.2%, and -68.7%, respectively ( P < 0.001), and horizontal meridian tears increased the probability by 62.2%, 92.9%, and 85.5%, respectively, ( P < 0.001). Tears posterior to the equator in orthogonal images increased the probability (91.4%, P < 0.001). Artifacts such as lids/lashes, reflection, and face guard decreased the probability in directed peripheral steering by -28.6%, -50.0%, and -66.7%, respectively, ( P = 0.020, P = 0.049, and P = 0.016). Using directed peripheral steering and automontage increases RRA and detection rate of identifying peripheral retinal breaks. Tears in horizontal meridians or posterior to the equator increase the probability of identification. Common ultra-widefield imaging artifacts can significantly limit the probability of identifying retinal tears.

Design of Concrete Block Paving in Home Zone Traffic Circle Areas

Contemporary street space upgrade or regeneration projects tend to include setting up home zones that are located in large city suburbs, smaller towns or spas. These home zones feature one-way streets, merging of a pavement and carriageway into one level surface and various traffic calming measures (TCM), including speed tables and traffic circles (TC). Concrete paving blocks are the preferred surfacing material. As part of this study, traffic surveys were carried out in a small seaside spa in Poland to determine the accelerations and decelerations of vehicles passing through four traffic circles that have different central island heights and different streetscape characteristics. A visual assessment of the pavement condition was also carried out. The pavement deformation changes were analysed using 3D models derived on the basis of the terrestrial laser scanning data obtained with the Trimble SX10 scanning total station. The existing pavement structure was analysed as part of this study. Next, the areas that require strengthening were identified based on subsidence and horizontal forces analyses, with the latter calculated from the observed decelerations and accelerations of the passing vehicles. Finally, design guidelines are given for concrete block surfacing in high traffic impact locations.

Correlation between Disc Imaging Observations and Clinical Efficacy after Percutaneous Endoscopic Lumbar Discectomy: A 1-Year Follow-up Study.

The connection between alterations in the disc structure following percutaneous endoscopic lumbar discectomy (PELD) and symptoms in patients postsurgery has not been reported yet. The purpose of the present study was to discuss the potential correlation between the changes in the morphological characteristics of various reference surfaces of the intervertebral disc after percutaneous endoscopic lumbar discectomy (PELD) and clinical outcomes, to identify the morphological parameters that affect efficacy and provide an evidence-based foundation for assessing postoperative efficacy. From October 2019 to October 2021, after percutaneous endoscopic lumbar discectomy (PELD), 98 individuals were enrolled. MRI DICOM data of the lumbar spine were obtained before and after surgery, specifically around 3 months. The morphological parameters of the operated and adjacent segments of the discs were measured using T2-weighted images from three reference planes. Outcomes were assessed using the Oswestry disability index (ODI), visual analogue pain scores for the back and leg (VAS-back/VAS-leg), Japanese Orthopaedic Association (JOA) scores, and recovery rates. Postoperative changes in disc parameters and outcomes were compared between patients with different severity and types of LDH based on the MSU staging. Patients completed the questionnaire during outpatient follow-up appointments 3, 6, and 12 months after the surgery. The follow-up period was 14.69 ± 4.21 months, ranging from 12 to 24 months. Parameters such as area and circumference of intervertebral discs in the cross-section were not associated with the change in the efficacy index. Postoperatively, a negative correlation between the variation of the disc height, disc height index, and protrusion distance and the difference in VAS scores for low back pain at 3 and 6 months was observed among the two sagittal change parameters. Differences between changes in disc imaging parameters and postoperative efficacy were not statistically significant between various types of lumbar disc herniation. For the patients after percutaneous endoscopic lumbar discectomy, the changes in parameters such as disc area and circumference in the cross-sectional plane are not associated with efficacy, and the changes in disc height and herniation distance in the sagittal plane provide a morphologic basis for the assessment of short-term postoperative efficacy. In addition, the changes in disc morphologic parameters and postoperative efficacy do not differ between various types of lumbar disc herniation.

Clinical Significance of Optic Disc Hemorrhage Size in Visual Field Progression in Glaucoma

PurposeTo investigate the correlation between optic disc hemorrhage (DH) size and glaucoma progression. DesignA retrospective observational cohort study MethodsXXXX SettingA single tertiary hospital in South Korea Study PopulationTwo hundred and fifty (250) open-angle glaucoma (OAG) patients with DH. Participants were followed for 5 years or longer, with a minimum of 5 visual field (VF) tests. Observation ProcedureThe DH area was calculated by comparing the pixel numbers of the DH area with the disc area based on optical coherence tomography (OCT). For recurrent DH cases, we calculated the average DH area. DH size was classified as large or small based on the median value. Rates of mean deviation (MD) loss were determined using Guided Progression Analysis (GPA). Univariable and multivariable regression analyses were performed to identify significant predictors of MD loss. Main outcome measuresDH size and longitudinal VF progression ResultsThe mean follow-up period was 11.1 ± 3.6 years. The group with large DH showed faster global MD loss relative to the group with small DH (-0.51±0.48 dB/y vs. -0.36±0.42 dB/y, p = 0.01). In the multivariable model, mean DH size, maximum DH size, and initial MD were all significantly associated with the overall rate of MD loss (all p < 0.05). ConclusionsDH size was associated with the rate of VF deterioration. Eyes with larger DH showed more pronounced VF progression.

Independently tunable dual Fano resonances based on plasmonic MIM Sagnac loop coupling Taiji resonator

In this paper, we first propose and demonstrate independently tunable dual Fano resonances based on a plasmonic structure composed of MIM (metal-insulator-metal) Sagnac loop with embedded Taiji resonator. An S-shaped crossover branch inside the Taiji ring resonator can tailor the propagating modes into their counter-propagating directions, finally tuning the number of whispering-gallery modes (WGMs) in Taiji resonator. Both Fano resonances originate from the interference between the discrete state generated from WGMs in Taiji resonator and continuous state from modes propagating in the plasmonic Sagnac loop. By stuffing a silver circle area (SCA) inside S-shaped branch, dual Fano resonances can be tuned independently as SCA has different sizes or locates at different places. Fano resonance would be influenced and shifted strongly when SCA locates at the energy intensity valley of WGM, while without any influence as SCA situates at the energy intensity peak of WGM. Thanks to the strong sub-wavelength light confinement of dual Fano resonances based on MIM plasmonic system, an optical refractometric sensor with figure of merit (FOM) of 100/RIU and high sensitivity of 1899 nm/RIU is demonstrated. Furthermore, this hybrid structure is also used for temperature sensing of ethanol with the maximal sensitivity of −0.793 nm/°C. This compact plasmonic Sagnac loop coupling Taiji resonator demonstrates impressive practical prospects for high-sensitivity biochemical sensors, nonlinear optics, and optical modulation.

Fetal Growth Restriction Leads to an Enlarged Cup-to-Disc Ratio in Adults Born at Full Term

PurposeThis study explores associations between fetal growth restriction or excessive fetal growth, along with perinatal factors on the optic nerve head morphology in adulthood. DesignRetrospective cohort study. MethodsThis retrospective cohort study involved a prospective ophthalmological examination of individuals born at full term (with a gestational age of ≥37 weeks) from 1969 to 2002. Each participant underwent non-mydriatic fundus camera photography to capture images of the optic discs, followed by manual measurements. The vertical cup-to-disc ratio (VCDR) and optic disc area were examined and analyzed in relation to the baby's birth weight relative to the gestational age. These categories included those with former moderate (birth weight percentile between the 3rd and <10th), severe SGA (below the 3rd percentile), normal (AGA, 10th-90th percentile), and moderately (birth weight >90th to 97th percentile) and severely (birth weight >97th percentile) large for gestational age (LGA) adults within the age range of 18 to 52 years. ResultsOverall, 535 eyes of 280 individuals (age 29.74±9.23 years, 144 females) born at full term were included. Multivariable analysis showed a significant association between a larger VCDR and the severe SGA group (B = 0.05, 95% CI 0.01-0.10; p = 0.02). In the univariable model, placental insufficiency was associated with VCDR (B=0.10, 95% CI 0.01-0.19; p=0.03). Other perinatal factors did not demonstrate an association with VCDR. Furthermore, there was an indication of an association suggesting a smaller optic disc area in individuals born moderately SGA at full term (B = -0.17, 95% CI -0.33- -0.001; p = 0.05). ConclusionThis study provides evidence that individuals born at-term with severe SGA have an increased VCDR, suggesting that fetal growth restriction has a lasting impact on optic disc morphology independent of prematurity throughout adulthood.

Optic Nerve Head and Retinal Nerve Fiber Layer Analysis in Emmetropic Malay Children.

The study aims to investigate the normal reference values for optic nerve head (ONH) and retinal nerve fiber layer (RNFL) parameters in emmetropic Malay children, utilizing measurements obtained through Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA). A cross-sectional study was conducted on 95 Malay children, aged between seven and 17 years, with no ocular abnormalities. It was held at Hospital Universiti Sains Malaysia, Malaysia, from January 2014 to December 2015. All children underwent a full ocular examination, including refraction and calculation of axial length. ONH and retinal nerve fiber layer thickness (RNFLT) parameters were measured using the Cirrus SD-OCT machine. One eye of each subject was selected randomly for study. The associations between the parameters and the effect of age, gender,axial length, and spherical equivalent (SE) on the measurements were statistically validated. Ninety-five children were involved in the study, with 65 females (68.4%) and 30 males (31.6%). The mean age was 10.6 (2.82) years, the mean intraocular pressure (IOP) was 14.8 (2.81) mmHg, the mean SE-refraction was 0.12 (0.28) diopters, and the mean axial length was 23.03 (0.76) mm. The mean disc area, rim area, and cup volume were 2.32 (0.40) mm2, 1.53 (0.33) mm2, and 0.204 (0.16) mm3, respectively. The average cup-to-disc ratio (SD) (CDR) and the vertical CDR were 0.55 (0.13) and 0.50(0.14). Mean (SD) RNFLT was 102.08 (11.08) μm for all patients. There was a strong positive correlation between the average, superior, and inferior RNFLT with the optical disc area. The rim area and the average, superior, inferior, and nasal RNFLT alsoshowed a significant correlation. The inferiorRNFLT was negatively correlated with the average CDR. There was also a major influence of gender on the disc area. There were no major age, axial length, and SE influences on the measurements. This study provided normative information for ONH and RNFLT parameters in emmetropic Malay children. It was observed that emmetropic Malay males exhibited a significantly larger optical disc area. The increase in RNFLT is correlated with a significant increase in disc and rim areas.

Rotating disc method to study the dissolution kinetics of copper metal in citric acid and hydrogen peroxide

This study reports the kinetics of copper metal dissolution in citric acid-hydrogen peroxide solution using the rotating disc method. The effect of the concentration of citric acid as well as hydrogen peroxide, stirring speed, disc surface area, and temperature was investigated. The concentration of hydrogen peroxide (0.25–1.5 mol/L) has a strong effect on the dissolution rate (mg/min) of copper with a reaction order of 0.92, compared to a reaction order of 0.42 with respect to the concentration of citric acid (0.125–1.5 mol/L). The reaction rate is directly proportional to the disc area (A) and square root of the disc rotation speed (ω1/2), as expected from the Levich equation. The activation energy of 33 kJ/mol, in the temperature range 30-60 °C is also comparable with the values reported in previous studies.

Potensi Konsep Matematika dalam Penggunaan Aperture di Fotografi

This study aims to help understand how the use of aperture works with mathematical concepts so that the use of this method is applied to photography activities and as a medium for learning mathematics in schools. The method used in this study is descriptive with the form of action research, because this study describes the mathematical concepts contained in the use of aperture in photography. From the interview, researchers collected information on mathematical concepts contained in the sequence located behind the F-stop number and explored the relationship between the F-stop number and the diameter of the circular aperture opening area in the lens, there are several mathematical concepts such as fractional numbers, geometric series, scales, comparisons, magnitudes &amp; units, space builds, to the area of a circle. In this case, it proves that in the use of Aperture in photography, there are mathematical concepts related to school mathematics learning

Soft X-Ray Energy Spectra in the Wide-field Galactic Disk Area Revealed with HaloSat

We analyzed data from HaloSat observations for five fields in the Galactic disk located far away from the Galactic center (135° < l < 254°) to understand the nature of soft X-ray energy emission in the Galactic disk. The fields have 14° diameter and were selected to contain no significant high-flux X-ray sources. All five HaloSat soft X-ray energy spectra (0.4–7 keV with energy resolution of < 100 eV below 1 keV) show a possibility of the presence of unresolved high-temperature plasma in the Galactic disk (UHTPGD) with a temperature of 0.8–1.0 keV and an emission measure of (8–11) × 10−4 cm−6 pc in addition to the soft X-ray diffuse background components mainly studied at higher Galactic latitudes (solar wind charge exchange emission, Local Hot Bubble, Milky Way halo emission, and the cosmic X-ray background). This suggests that the UHTPGD is present across the whole Galactic disk. We also observed UHTPGD emission in a region with no bright sources in an XMM-Newton field contained within one of the HaloSat fields. The temperature and emission measure are consistent with those measured with HaloSat. Moreover, the stacked spectra of the X-ray pointlike sources and near-infrared-identified point sources such as stars in the XMM-Newton field also show a spectral feature similar to the UHTPGD emission. This suggests that the UHTPGD may partly originate from pointlike sources such as stars.

Reliability of Manual Measurements Versus Semiautomated Software for Glenoid Bone Loss Quantification in Patients With Anterior Shoulder Instability.

The presence of glenoid bone defects is indicative in the choice of treatment for patients with anterior shoulder instability. In contrast to traditional linear- and area-based measurements, techniques such as the consideration of glenoid concavity have been proposed and validated. To compare the reliability of linear (1-dimensional [1D]), area (2-dimensional [2D]), and concavity (3-dimensional [3D]) measurements to quantify glenoid bone loss performed manually and to analyze how automated measurements affect reliability. Cohort study (diagnosis); Level of evidence, 3. Computed tomography images of 100 patients treated for anterior shoulder instability with differently sized glenoid defects were evaluated independently by 2 orthopaedic surgeons manually using conventional software (OsiriX; Pixmeo) as well as automatically with a dedicated prototype software program (ImFusion Suite; ImFusion). Parameters obtained included 1D (defect diameter, best-fit circle diameter), 2D (defect area, best-fit circle area), and 3D (bony shoulder stability ratio) measurements. Mean values and reliability as expressed by the intraclass correlation coefficient [ICC]) were compared between the manual and automated measurements. When manually obtained, the measurements showed almost perfect agreement for 1D parameters (ICC = 0.83), substantial agreement for 2D parameters (ICC = 0.79), and moderate agreement for the 3D parameter (ICC = 0.48). When measurements were aided by automated software, the agreement between raters was almost perfect for all parameters (ICC = 0.90 for 1D, 2D, and 3D). There was a significant difference in mean values between manually versus automatically obtained measurements for 1D, 2D, and 3D parameters (P < .001 for all). While more advanced measurement techniques that take glenoid concavity into account are more accurate in determining the biomechanical relevance of glenoid bone loss, our study showed that the reliability of manually performed, more complex measurements was moderate.

Learning to measure the area of circles

ABSTRACT The study of the area of circles is an important component of mathematics education for students of all ages; however, evidence suggests that many middle school students struggle to interpret and apply the area formula of a circle. In this article, I report the findings of a classroom design study conducted to investigate the collective establishment and justification for the area formula of a circle. An instructional sequence comprising paper-based decomposition and recomposition measurement tasks situated on a grid was implemented in a Year 8 classroom (n = 18) and the collective mathematical practices that emerged from an analysis of the argumentation of students during whole-class discussion were documented. The findings extend the existing literature by illustrating how decomposition/recomposition tasks can be leveraged in a classroom context by grounding students’ reasoning in measurement strategies and opportunities to examine alternative strategies and justifications through whole-class discussions.

Features of the Optic Disc Anatomy in Elderly Men

Among the anomalies of the optic disc development, which change its anatomical characteristics, are the druses of the optic disc. Diagnostically, the druses of the optic disc are manifested by protrusion into the vitreous body, and changing in the area of the optic disc and its excavation. The aim of the study is to obtain new data on the optic disc anatomy in elderly men. Material and methods. The study was conducted in a group of men from 61 to 75 years old. The study included 53 eyes of patients treated with a disease of the visual organ unrelated to the pathology of the optic disc and macula. The study was carried out on the Optovue RTVue XR Avanti Sistem device using standard 3D Disc, GCC, ONH programs. Using optical coherence tomography the following morphometric parameters of the optic disc were evaluated: the volume of excavation, the thickness of the retinal nerve fiber layer, the area of the optic disc, the depth, the width and the area of the excavation of the optic disc in the horizontal plane. Conclusion. In the group of men from 61 to 75 years old, with increasing age, there is a decrease in the thickness of the retinal nerve fiber layer, the width of the excavation of the optic disc and the area of the optic disc. The shapes of optic disc excavation in elderly men are different, the triangular shape prevails – 47,8%, the remaining shapes occur with the same frequency.

Automated evaluation of parapapillary choroidal microvasculature in crowded optic discs: a controlled, optical coherence tomography angiography study.

To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography (OCT-A). Thirty patients with crowded discs, and 47 control subjects were enrolled in the study. One eye of each individual was included and OCT-A scans of optic discs were obtained in a 4.5×4.5 mm2 rectangular area. Radial peripapillary capillary (RPC) density, peripapillary retinal nerve fiber layer (pRNFL) thickness, cup volume, rim area, disc area, cup-to-disc (c/d) area ratio, and vertical c/d ratio were obtained automatically using device software. Automated parapapillary choroidal microvasculature (PPCMv) density was calculated using MATLAB software. When the vertical c/d ratio of the optic disc was absent or small cup, it was considered as a crowded disc. The mean signal strength index of OCT-A images was similar between the crowded discs and control eyes (P=0.740). There was no difference in pRNFL between the two groups (P=0.102). There were no differences in RPC density in whole image (P=0.826) and peripapillary region (P=0.923), but inside disc RPC density was higher in crowded optic discs (P=0.003). The PPCMv density in the inner-hemisuperior region was also lower in crowded discs (P=0.026). The pRNFL thickness was positively correlated with peripapillary RPC density (r=0.498, P<0.001). The inside disc RPC density was negatively correlated with c/d area ratio (r=-0.341, P=0.002). The higher inside disc RPC density and lower inner-hemisuperior PPCMv density are found in eyes with crowded optic discs.

Analysis of Signature Patterns: Consistency and Distinctiveness in Handwritten Signatures for Forensic Authentication

Handwritten signatures are unique behavioural attributes that serve as a distinct form of identification forindividuals. This study focuses on the analysis of signature patterns using various parameters, including aspect ratio, angle of the first letter with respect to the baseline, and the ratio of the area of a circle to its radius within the signature. A dataset consisting of 1200 genuine and 1200 simulated (English) signature samples from 12 individuals were examined using an image analysis tool to record measurements for these parameters. The primary objectives were to investigate the consistency of signatures within the same person and to compare genuine signatures with simulated ones. This study contributes to the field of forensic investigations by offering insights into the authentication of signatures and the measurement of dissimilarities between signatures of the same and different individuals based on their patterns. The findings aid in identifying most influential parameter in distinguishing genuine signatures from counterfeits and enhance the evidential value of handwritten signature samples. Additionally, the simplified approach employed in this study allows for universal applicability across languages. Future research endeavours could expand the dataset and explore additional parameters to further improve the accuracy and reliability of signature verification methods in forensic analysis.

Morphological and vascular evidence of glaucomatous damage in myopic guinea pigs with scleral crosslinking

Guinea pigs are often used as models for myopia studies. However, the imaging structure and vasculature of the optic nerve head (ONH) in guinea pigs are tentative. This study investigated morphological parameters and vascular characteristics of the ONH in guinea pigs with form deprivation (FD) myopia before and after scleral crosslinking (CXL), using optical coherence tomography (OCT) and OCT angiography (OCTA). Refractive error, axial length (AL), intraocular pressure (IOP), and OCT-based structural parameters of the ONH were measured at baseline and 3 weeks after the FD + CXL procedure in guinea pigs. The 88 guinea pigs analysed in this study were aged 3 (n = 29), 4 (n = 51), and 5 (n = 8) weeks. The IOP, AL, average and vertical cup-to-disc ratio (C/D), circumpapillary retinal nerve fibre layer, disc area, and cup volume increased at 3 weeks compared to baseline values (all p < 0.001). The refractive error and rim area decreased at 3 weeks compared to baseline values (all p < 0.001). After adjustment for age, IOP was correlated positively with average C/D (p = 0.039) and negatively with rim area (p = 0.009). The severity of blood signal defects was positively associated with the average C/D at 3 weeks (p = 0.027). These findings may facilitate further research on myopia using guinea pigs.

An Analysis of Optic Disc Parameters in Patients with Peripheral Retinal Tears Following Acute Posterior Vitreous Detachment: A Cross-Sectional Study.

To investigate association between optic disc parameters analyzed by optical coherence tomography (OCT) and occurrence of peripheral retinal tears in patients with symptomatic posterior vitreous detachment (PVD). This cross-sectional study enrolled 75 patients with symptoms of acute PVD, who were allocated into two groups based on whether a peripheral retinal tear occurred or not. When comparing the average retinal nerve fiber layer (RNFL) thickness (μm) between retinal tear and control groups, it was shown that patients with a retinal tear have a significantly higher (87.18 [95% confidence interval (CI), 84.47 to 89.9] vs 81.14 [95% CI, 77.81 to 84.46], P = 0.005) average RNFL thickness. Furthermore, we observed a significant difference (0.13, 0.06 to 0.22 vs 0.07, 0.04 to 0.1, P = 0.036, Mann-Whitney U-test) in the size of cup volume (mm3) between the tear and control groups, respectively. Linear regression showed a significant decrease (P = 0.029) in average RNFL thickness with increasing age, but without a significant difference between the two groups. There was no statistically significant difference between the tear and control groups in terms of rim area, disc area, and average cup-to-disc ratio. Patients with a higher average RNFL thickness and larger cup volume measured by OCT were more prone to develop a peripheral retinal tear. Increased peripapillary average RNFL thickness due to trauma and subsequent inflammation, possibly related to the more adherent posterior hyaloid membrane to the retina, may also indicate strengthened adhesions in the areas of the peripheral retina where retinal tears occur. OCT analysis of the optic nerve head may be used in everyday clinical practice as a predictor of the development of peripheral retinal tears in patients with symptomatic PVD.

Association between functional parameter and structural, and vascular parameters in advanced glaucoma

Aims/Purpose: We aimed to evaluate the function‐vasculature, and function–structure relationships in advanced glaucoma patients.Methods: This cross‐sectional study included 29 eyes of 24 advanced glaucoma patients. Advanced glaucoma was classified as visual fields (VFs) with a mean deviation (MD) below ‐12 dB according to Hodapp‐Parrish‐Anderson classification system. The structural parameters, cup/disc area ratio, cup/disc vertical ratio, cup/disc horizontal ratio, rim area, disc area, cup volume, retinal nerve fibre layer thickness, macular ganglion cell complex (GCC) thickness, were measured using optical coherence tomography (OCT, Optovue, Fremont, CA). The vessel density of superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), outer retina (OR), and choriocapillaris (CC) were analysed by optical coherence tomography angiography (OCTA, DRI OCT Triton Plus, Topcon, Tokyo, Japan). For all layers, the average vessel density of the area between 1 mm and 3 mm diameter circles was calculated, assuming the 1 mm diameter area centered on the fovea as the central region. Relationships between 10–2 VF MD values, and structural and vascular parameters were assessed by Pearson's correlation coefficients. p &lt; 0.05 was considered statistically significant.Results: The mean ± SD age of all patients was 61.9 ± 15.8 years and 75% were male. For structural parameters, there was a positive correlation between the MD and GCC thickness values (p = 0.001, r = 0.617), while none of the parameters of the optic disc were related to the MD value. There were significant positive correlations with the vessel densities of the SRCP and CC layers (p = 0.001, r = 0.593 and p = 0.002, r = 0.541, respectively).Conclusions: Decreased vessel densities of the SRCP and CC were significantly associated with severity of visual field damage. This study showed that OCTA can be a promising method in daily use for monitoring advanced glaucoma.