Disc Area Research Articles

Ethnomahematics Exploration in the Traditional Game of Sipak Rago

Education and culture cannot be separated in daily life. Ethnomathematics exists to bridge the gap between culture and education, especially in mathematics. Humans are unaware of activities that use basic mathematical concepts and ideas like counting, measuring (length, area, volume, and weight), number construction, games, and buying-selling activities. This study examines and analyzes the Minangkabau traditional games in the scope of geometry. This research is exploratory research with an ethnographic approach. The subjects of this study were 6 players of the Sipak Rago game. The data was collected through observation, documentation, and interview to find mathematical concepts in the Sipak Rago game. Based on the research, there are mathematical concepts in the Sipak Rago game like the concept of circle elements, circle circumference formula, circle area formula, and angle on a circle.

Relationship of individual and mixed prenatal phthalate exposure with placental structure and efficiency in the prospective Ma'anshan Birth Cohort Study

BackgroundFew studies have investigated the associations between prenatal phthalate exposure and placental structure and function with inconsistent conclusions. MethodsNested on the Ma'anshan Birth Cohort study, 2723 women provided spot urine samples during the first, second and third trimesters of pregnancy to analyze six phthalate metabolites. The outcomes of interest were placental weight, efficiency (birth weight/placental weight), chorionic disc area and disc eccentricity. The relationships of prenatal exposure to a single phthalate with placental measures were analyzed. The associations between prenatal phthalate mixture exposure and placental measures were also evaluated. ResultsMost phthalate metabolites were significantly associated with placental weight, efficiency and chorionic disc area during the whole gestation and in each trimester of pregnancy, with different directions of relationships. Sensitivity analyses revealed similar findings, indicating the robustness of the statistical results. Furthermore, inverted U-shaped nonlinear relationships of prenatal exposure to some phthalate metabolites with placental weight, efficiency and chorionic plate area were observed. However, quantile g-computation mixture models did not reveal any association between maternal combined exposure to the total phthalate metabolites and placental measures. ConclusionsMaternal exposure to most phthalates and their metabolites was associated with placental weight, efficiency and chorionic plate area in both a linear manner and an inverted U-shaped nonlinear manner. However, the mixture of multiple phthalate metabolites was not observed to be associated with any placental measure.

Optic disc area frequency distribution in a large sample of retinographic images

ObjectiveTo describe a new method to estimate the frequency distribution of optic nerve disc area, using digital retinographic images.Methods and analysisWe analysed 492 023 fundus images obtained with seven fundus...

Ocular and Hemodynamic Factors Contributing to the Central Visual Function in Glaucoma Patients With Myopia.

PurposeThe purpose of this study was to investigate the ocular and hemodynamic factors contributing to the central visual function in glaucoma patients with myopia.MethodsThis study was a prospective observational study, which included 236 eyes of 140 patients with normal-tension glaucoma (NTG), which includes 114 eyes with mild myopia (axial length ≥24 and <26 mm) and 122 eyes with moderate-to-severe myopia (axial length ≥26 mm). Ocular characteristics were axial length and posterior pole profiles, including peripapillary atrophy (PPA) to disc area ratio, disc tilt ratio, disc torsion, and disc-foveal angle. Hemodynamic factors included standard deviation of the mean of qualified normal-to-normal intervals (SDNN) of a heart rate variability (HRV) test and vessel density (VD) parameters from optical coherence tomography angiography (OCTA). The root mean square error was estimated as a measure of the VD fluctuation. Association between ocular characteristics and VD parameters of the OCTA with the central sensitivity of the 10-degree visual field or the presence of central scotoma were analyzed.ResultsDeep layer VD of the peripapillary and macular areas showed significant differences between mild and moderate-to-severe myopia (P = 0.034 and P = 0.045, respectively). Structural parameters, especially PPA to disc area ratio, had significant correlation with peripapillary VD parameters in myopic eyes. Lower SDNN value (ß = 0.924, P = 0.011), lower deep VD of the macular area (ß = 0.845, P = 0.001), and greater fluctuation of deep VD in the peripapillary area (ß = 1.517, P = 0.005) were associated with the presence of central scotoma in patients with glaucoma with myopia in multivariate logistic regression analysis.ConclusionsThe structural changes by myopia, especially in the peripapillary region, affected VD parameters in myopic eyes. Lower deep VD and greater VD fluctuation in the peripapillary region showed association with central scotoma in patients with glaucoma with myopia, suggesting both structural and vascular changes by myopia may be related to central visual function in glaucoma patients with myopia.

Association between changes in the retina with major depressive disorder and sleep quality

BackgroundMajor depressive disorder (MDD) is linked to degenerative and inflammatory processes in the brain. The retina, as well as the brain, originates from the ectoderm. The changes in the retina that occur in concert with MDD and sleep quality are not very clear. This study aimed to detect changes in the retinal nerve fibre layer (RNFL) and macular thickness in Chinese patients in correlation with MDD and sleep quality. MethodsThirty-six MDD patients and 187 age- and sex-matched healthy controls were enrolled in this study. All subjects were scanned by spectral-domain optical coherence tomography (OCT) and completed the Stroop Colour–Word Test (SCWT), Pittsburgh Sleep Quality Index, and Patient Health Questionnaire–9. ResultsThe RNFL and macular thickness were significantly thinner and disc-area enlargement of the right eye and cup-volume enlargement of both eyes were present in MDD patients. Linear regression analysis revealed that the RNFL and macular thickness in patients with MDD were correlated with sleep quality and the severity of depression. SCWT scores were higher following expansion of the cup volume of the right eye (all p < 0.01) and in correlation with larger disc areas. ConclusionsSerious degrees of depression and insomnia in MDD patients may reflect obvious atrophy of the inner and outer rings of the right macula and enlargement of the optic disc in both eyes. These retinal structural changes might influence the visual cognition of patients with MDD.

Analysis of Microcirculation Changes in the Macular Area and Para-Optic Disk Region After Implantable Collamer Lens Implantation in Patients With High Myopia.

Myopia has become an important public health problem to be solved urgently. Posterior chamber phakic implantable Collamer lens (ICL) implantation is one of the latest and safest products for myopia correction worldwide. This prospective cross-sectional case series aimed to observe changes in the macular retinal thickness, retinal nerve fiber layer (RNFL) thickness of para-optic disk region, and blood flow density after posterior ICL implantation in patients with high myopia using optical coherence tomography angiography (OCTA). A total of 67 eyes of 67 patients with high myopia, who underwent ICL implantation at The Affiliated Eye Hospital of Nanjing Medical University from January 2020 and December 2020, were included. The spherical equivalent (SE) of the operative eyes was >−6.00 D. The changes in vision, intraocular pressure (IOP), SE, and vault were observed pre-operatively, and follow-up were performed 1 week, 1 month, and 3 months. OCTA was used to observe the changes in the CRT, retinal thickness of paracentral fovea, FAZ, superficial and deep retinal blood flow density in the macular area, RNFL thickness of para-optic disk region, and blood flow density before and after ICL implantation. The uncorrected distance visual acuity (UDVA) and best corrected distance visual acuity (CDVA) of the patients post-operation were significantly improved (P < 0.001). The IOP increased in comparison with other time points at 1 week post-operation (P < 0.05). There were no significant changes in CRT post-operation. The retinal thickness in the upper, lower, nasal, and temporal quadrants of the paracentral fovea increased significantly at 1 month and 3 months post-operation (P < 0.05). The FAZ area at all postoperative time points were decreased (P < 0.001). At 3 months post-operation, the blood flow density of the superficial and deep retinal layers in the upper, lower, and nasal macular area were significantly reduced (P < 0.05). At 1 month post-operation, the RNFL thickness in the temporal para-optic disk region and blood flow density were significantly reduced (P = 0.001 and P < 0.05, respectively). ICL implantation for highly myopic eyes led to an increase of the retinal thickness in the upper, lower, nasal, and temporal regions of the paracentral fovea; reduction of RNFL thickness in the temporal area of para-optic disk; decrease in FAZ area; and decrease in the blood flow density of some deep and superficial retinal layers as well as that of the temporal para-optic disk region.

A non-linear approach to predicting the amplitude and timing of the sunspot area in cycle 25

ABSTRACT The sunspot cycle waxes and wanes over a period of about 11 years and modulates ‘space weather’. Therefore, predicting the maximum amplitude of the solar cycle is an important goal for both solar physics and space weather. It is clear nowadays that cyclic variations of the Sun are non-linear processes, and thus the above-mentioned goal is difficult to reach with accuracy, albeit several methods currently exist to forecast both long-term and short-term variations. Solar cycle 25 has recently started and knowing the strength and timing of maximum of this cycle in advance is essential. In this study, a non-linear prediction algorithm, non-linear empirical dynamical modelling (EDM), is used to forecast the maximum amplitude and timing of the sunspot area of this cycle. This technique was tested on the last solar cycle 24 (Sarp et al. 2018) and the results obtained are in good agreement with observed values. Our study unveils that the maximum amplitude of the sunspot area of the whole solar disc will be 1606.49 ± 412.78 millionths of the solar hemispheric area (m.s.h.) and is expected to occur around 2025 March. We found that the predicted maximum sunspot areas in the Northern and Southern hemispheres are 731.39 ± 192.7 and 764.89 ± 195.39 m.s.h., respectively, with probable times of maxima around 2023 September and 2024 August, respectively. These results indicate that the strength of the sunspot area in solar cycle 25 will be weaker than or comparable with that in solar cycle 24. Such results are discussed and compared with other recent forecasts.

Antenatal and neonatal factors and morphology of the optic nerve head in the Northern Finland birth cohort.

The optic nerve head (ONH) is a part of the brain that can be evaluated through the transparent medium of the eye. The purpose of this study was to explore the possible correlations among the properties of the optic nerve head, maternal factors during pregnancy and neonatal parameters in a randomized sample of a birth cohort. The Northern Finland 1966 Birth Cohort has been prospectively monitored since their antenatal period. Data on pregnancy and neonatal period were collected during gestation and right after birth in 1966. A randomized sample of 3070 subjects underwent an ophthalmic assessment at the age of 46-48 years. The examination protocol included scanning laser ophthalmoscopy with the Heidelberg Retina Tomograph. The ophthalmological parameters assessed were the disc area and the neuroretinal rim volume of the ONH. We found that chronic pulmonary disease of the mother (p = 0.007), the number of gestational weeks (p = 0.030) and the mother's highest measured systolic blood pressure (p = 0.035) during pregnancy had a statistically significant effect on the disc area. Smaller disc size was associated with pulmonary disease and early gestation. There was a significant difference in rim volume between genders (p < 0.001). Women had larger neuroretinal rim volumes compared to men. In this population-based study, the vast majority of antenatal and neonatal factors showed no correlation with optic disc area or rim volume. Furthermore, even the factors with statistically significant correlation with ONH morphology had limited predictive value.

An Exact Connection between π and the Golden Ratio φ

This article establishes a geometrical and mathematical bridge between the universal constant &amp;pi;&amp;nbsp; and the golden ratio &amp;phi;&amp;nbsp; by interrelating the construction of the area of a circle using two approaches: one formed using the rotation of a regular unit pentagon and the other one from the rotation of its inverse ― the pentagram of side reference &amp;phi; . The mathematical end result is a linear expression of &amp;pi;&amp;nbsp; as a function of &amp;phi; . As an interesting side result, an expression for the area of a circle is derived based on the golden ratio &amp;phi;&amp;nbsp; and a geometrically motivated coefficient. A scripted program for the verification of the derived expressions is provided.

Evaluation of the Effect of Uncomplicated Cataract Surgery on Retina and Optic Disc: Optical Coherence Tomography Angiography Study.

PurposeThe aim of the present study is to evaluate the effects of uncomplicated cataract surgery on microvascular structure of fovea, parafovea, optic disc, and peripapillary area with optical coherence tomography angiography (OCTA).MethodsThe study included 53 eyes of 53 patients, who undergone uncomplicated cataract surgery. The day before cataract surgery and at the 1st week, 1st month, 3rd month after surgery, best-corrected visual acuity, foveal avascular zone, acircularity index, superficial and deep foveal density, superficial and deep parafoveal density, central macular thickness, peripapillary retinal nerve fiber layer thickness value, and peripapillary vascular density were measured with OCTA.ResultsThe mean age of the patients was 62.1 ± 7.2 years (range, 42–69 years) and the sex of the patients was 25 male and 28 female. The foveal avascular zone value was decreased compared to the preoperative value (p < 0.05). There was no significant change in acircularity index postoperatively (p > 0.05). There was a significant increase in superficial and deep foveal density and superficial and deep parafoveal density (p < 0.05). According to preoperative period, peripapillary retinal nerve fiber layer and inside disc capillary density of optic disc increased significantly (p < 0.05). There was no significant change in peripapillary vascular density postoperatively (p > 0.05).ConclusionsChanges in the vascular density of the retina were detected with OCTA in eyes without ocular or systemic disease, which underwent uncomplicated cataract surgery. In the postsurgical period, OCTA provides important information in the evaluation and follow-up of these changes.

Thinner peripapillary retinal nerve fibre layer and macular retinal thickness in adolescents with surgically treated hydrocephalus in infancy.

To map the morphology of the retina and optic disc in adolescents with surgically treated hydrocephalus (HC) in infancy and to compare the results with healthy controls. The study comprised 26 adolescents (16 male, mean age 15 years) with HC and 31 sex- and aged-matched controls. The following optical coherence tomography (OCT) parameters were obtained: macular retinal thickness (MRT) and volume (MRV), thickness of the macular and peripapillary retinal nerve fibre layer (ppRNFL), and area of the optic disc, cup and rim. The MRT was thinner amongst those with HC compared with controls (right eye (RE) 262.2 ± 15.3 and 275.8 ± 15.1 μm; p = 0.0051), and the MRV was smaller (RE 7.37 ± 0.36 and 7.83 ± 0.35 mm3 ; p = 0.0002). The HC group showed a thinner ppRNFL (RE 88.3 ± 14.9 and 103.5 ± 8.1 μm; p = 0.0002) but a thicker central macular RNFL (RE 11.6 ± 10.4 and 2.07 ± 3.00 μm; p = <0.0001) and foveal minimum (RE 211.1 ± 32.0 and 186.3 ± 15.9 μm; p = 0.0013). Optic disc variables showed no difference between groups. Correlations were found in the HC group between best corrected visual acuity (expressed in logMAR) and ppRNFL (RE r = -0.56, p = 0.018), and disc area (RE r = -0.52, p = 0.033). Thinner ppRNFL and MRT and smaller MRV were found in adolescents with surgically treated HC in infancy compared with controls. In contrast, the central macular RNFL and foveal minimum were thicker. Further studies are required to evaluate the diagnostic value of OCT to indicate increased intracranial pressure timely and follow-up in individuals with surgically treated HC.

Diagnostic Accuracy of Macular Thickness Map and Texture En Face Images for Detecting Glaucoma in Eyes With Axial High Myopia

To evaluate the diagnostic accuracy of a novel optical coherence tomography texture-based en face image analysis (SALSA-Texture) that requires segmentation of only 1 retinal layer for glaucoma detection in eyes with axial high myopia, and to compare SALSA-Texture with standard macular ganglion cell-inner plexiform layer (GCIPL) thickness, macular retinal nerve fiber layer (mRNFL) thickness, and ganglion cell complex (GCC) thickness maps. Comparison of diagnostic approaches. Cross-sectional data were collected from 92 eyes with primary open-angle glaucoma (POAG) and 44 healthy control eyes with axial high myopia (axial length >26mm). Optical coherence tomography texture en face images, developed using SALSA-Texture to model the spatial arrangement patterns of the pixel intensities in a region, were generated from 70-μm slabs just below the vitreal border of the inner limiting membrane. Areas under the receiver operating characteristic curves (AUROCs) and areas under the precision recall curves (AUPRCs) adjusted for both eyes, axial length, age, disc area, and image quality were used to compare different approaches. The best parameter-adjusted AUROCs (95% confidence intervals) for differentiating between healthy and glaucoma high myopic eyes were 0.92 (0.88-0.94) for texture en face images, 0.88 (0.86-0.91) for macular RNFL thickness, 0.87 (0.83-0.89) for macula GCIPL thickness, and 0.87 (0.84-0.89) for GCC thickness. A subset analysis of highly advanced myopic eyes (axial length ≥27mm; 38 glaucomatous eyes and 22 healthy eyes) showed the best AUROC was 0.92 (0.89-0.94) for texture en face images compared with 0.86 (0.84-0.88) for macular GCIPL, 0.86 (0.84-0.88) for GCC, and 0.84 (0.81-0.87) for RNFL thickness (P ≤ .02 compared with texture for all comparisons). The current results suggest that our novel en face texture-based analysis method can improve on most investigated macular tissue thickness measurements for discriminating between highly myopic glaucomatous and highly myopic healthy eyes. While further investigation is needed, texture en face images show promise for improving the detection of glaucoma in eyes with high myopia where traditional retinal layer segmentation often is challenging.

Controlled growth mechanism of ring-like In(Ga)As quantum Dot pairs on GaAs ring-ring-disk nanostructures templates

The ring-like In(Ga)As quantum dot pairs (QDPs) is prepared on GaAs ring-ring-disk (R-R-D) nanostructures template by droplet epitaxy (DE) method. The surface morphology of GaAs samples are characterized with Scanning Tunneling Microscope (STM), and studying local controlled growth mechanism of quantum dots (QDs) on GaAs R-R-D nanostructures. STM images show that In(Ga)As QDPs self-assembled a kind of complicated structure with one quantum dot (QD) pair in the center of nanostructures, other QDPs appearing both double rings and disk areas of original GaAs R-R-D nanostructures distributed like a exquisite ring. These In(Ga)As QDPs are uniformly arranged along the [10] direction of GaAs(001) surface. Combining Stranski-Krastanov (S-K) growth mode and the tensile effect of strain field in the [10] direction on sample surface, the nucleation position and distribution shape of ring-like In(Ga)As QDPs is locally controllable. It is found that high uniformly QDPs can be locally controlled by the original GaAs R-R-D nanostructures templates. These results can provide certain guiding significance for the controllable growth of QD by DE method.

The Method of Determining Layer in Bottom Drainage Roadway Taking Account of the Influence of Drilling Angle on Gas Extraction Effect

The pre-drainage of coalbed methane through boreholes in the bottom drainage roadway (BDR) is the key measure to prevent and control coal and gas outburst. Different arrangement layers in the BDR will make a difference in the range of drilling angle and affect the gas extraction effect. In this paper, the mathematical model of the rock loose circle area around elliptical drilling was constructed. Meanwhile, the fluid–solid coupling model is constructed by using COMSOL software, the dynamic response of coal permeability and volumetric strain with gas pressure and the Klinkenberg effect of gas are considered, and the effect of the change of the elliptical drilling angle on the pressure relief effect of the coal seam is studied. The results showed that the distance between the layer in the BDR and the pre-drainage coal seam would decrease, and the effective extraction length at the same point of gas extraction in the coal seam increases. The area of the rock loose circle and permeability around the drilling decayed negatively and exponentially with the increase in drilling angle. As the drilling angle decreased, the stress in the major axis of the ellipse at the drilling cross-section increased, so the drilling was prone to collapse, and the gas extraction was hindered. Finally, an optimal method of determining the layer in the BDR under the coupling effect of multiple factors was established by combining the measured ground stress. Through field measurement, the drilling extraction rate of the optimized scheme is 60% higher than that of the original scheme.

Identifying Those at Risk of Glaucoma: A Deep Learning Approach for Optic Disc and Cup Segmentation and Their Boundary Analysis.

Glaucoma is a leading cause of irreversible vision loss that gradually damages the optic nerve. In ophthalmic fundus images, measurements of the cup to optic disc (CD) ratio, CD area ratio, neuroretinal rim to optic disc (RD) area ratio, and rim thickness are key measures to screen for potential glaucomatous damage. We propose an automatic method using deep learning algorithms to segment the optic disc and cup and to estimate the key measures. The proposed method comprises three steps: The Region of Interest (ROI) (location of the optic disc) detection from a fundus image using Mask R-CNN, the optic disc and cup segmentation from the ROI using the proposed Multiscale Average Pooling Net (MAPNet), and the estimation of the key measures. Our segmentation results using 1099 fundus images show 0.9381 Jaccard Index (JI) and 0.9679 Dice Coefficient (DC) for the optic disc and 0.8222 JI and 0.8996 DC for the cup. The average CD, CD area, and RD ratio errors are 0.0451, 0.0376, and 0.0376, respectively. The average disc, cup, and rim radius ratio errors are 0.0500, 0.2257, and 0.2166, respectively. Our method performs well in estimating the key measures and shows potential to work within clinical pathways once fully implemented.

Locking effects in plowing-induced nanorippling of polystyrene surfaces

We have investigated the influence of the geometric shape bounding the scan pattern on the orientation of the nanoripples evolved from a polystyrene surface scraped by a silicon tip. Atomic force microscopy measurements at ambient conditions are compared with numeric simulations based on a continuum model describing the time evolution of a generic compliant surface, which is indented viscoplastically and sheared elastically at the location occupied by the scanning tip. The tendency of the ripples to align at a steady angle defined by the scan pattern can be significantly modified by the geometric confinement. The analysis of surface ripples resulting from square, circle, star, pentagon, hexagon, and heart-shaped areas allows us to recognize the distinct influence of straight and curved edges, and of sharp corners, on the nanostructuring process. Straight edges inclined in the direction defined by the locking angle result in a uniform ripple pattern covering the entire scanned region originated from them. These results pave the way to predict plowing-induced surface structures by computer simulations and define the most suitable scan path required to obtain a desired ripple pattern. Potential applications include the controlled fabrication of nanostructures for optical devices, antibacterial surfaces, microfluidic channeling, and flexible electronics.

Effects of intensive insulin therapy on the retinal microvasculature in patients with type 2 diabetes mellitus: a prospective observational study

BackgroundWe examined the retinal microvascular changes and associated factors in type 2 diabetes mellitus (T2DM) before and after intensive insulin therapy.MethodsThis prospective observational study recruited patients with T2DM and divided them into intensive insulin therapy and oral hypoglycemic agent groups. All patients enrolled in this study had diabetes without retinopathy or non-proliferative diabetic retinopathy. Optical coherence tomography angiography (OCTA) was used in all patients before treatment and at 1, 3, and 6 months after treatment. Vessel density (VD) and thickness changes in the macular and optic disc areas were assessed.ResultsThe study included 36 eyes in the intensive insulin therapy group and 36 in the oral hypoglycemic agent group. One month after treatment, VD in the deep capillary plexus (DCP) and peripapillary capillary VD (ppVD) were significantly decreased by intensification (P = 0.009, 0.000). At three months after treatment, decreases in VD induced by intensification were found in the superficial capillary plexus (SCP), DCP, foveal density in a 300-μm-wide region around the foveal avascular area (FD-300), and ppVD (P = 0.032, 0.000, 0.039, 0.000). Six months after treatment, decreases in VD by intensification were observed in the DCP and ppVD groups (P = 0.000, 0.000). Vessel density showed no significant change in the oral hypoglycemic agent group after treatment. The amount of DCP-VD reduction was correlated with macular thickening (r = 0.348, P = 0.038; r = 0.693, P = 0.000 and r = 0.417, P = 0.011, respectively) after intensive insulin therapy.ConclusionsInsulin-intensive treatment caused a transient reduction in vessel density in the macular and optic disc areas. DCP-VD and ppVD were more susceptible at an earlier stage. Retinal microvasculature monitoring using OCTA is vital for patients with type 2 diabetes receiving intensive insulin therapy.

Structural Abnormalities in the Papillary and Peripapillary Areas and Corresponding Visual Field Defects in Eyes With Pathologic Myopia.

PurposeTo identify structural abnormalities in the papillary and peripapillary area in eyes with pathologic myopia (PM) and normal IOP and to determine their relationship to visual field (VF) defects.MethodsOne hundred eight eyes of 70 patients with PM were retrospectively studied. The disc-centered swept source optical coherence tomographic images and the Goldmann VF recorded within 1 year of the optical coherence tomographic examination were analyzed. Four structural abnormalities were identified: lamina cribrosa (LC) defects, ridge protrusions, intrachoroidal cavitations (ICC), and prelaminar schisis. The correspondence of the VF defects with the structural abnormalities was assessed.ResultsThe mean age, axial length, and optic disc area of the 108 eyes were 58.7 ± 10.0 years, 31.1 ± 2.4 mm, and 4.7 ± 2.2 mm2, respectively. Eighty-five of the 108 eyes (78.7%) had at least one abnormality and 49.4% (42/85) had two or more abnormalities. LC defects, ridge protrusions, ICC, and prelaminar schisis were detected in 47.2%, 33.3%, 21.3%, and 30.6% of the eyes, respectively. VF defects at the corresponding areas of these structural abnormalities were seen in 63% of the eyes with LC defects, 39% of the eyes with ridge protrusions, and 21% of the eyes with ICC.ConclusionsFour kinds of structural abnormalities with corresponding VF defects are commonly observed in the papillary and peripapillary region of eyes with PM. The presence of these abnormalities suggests a possibility of functional damage.

3D Microstructure of the Healthy Non-Human Primate Lamina Cribrosa by Optical Coherence Tomography Imaging.

PurposeThe lamina cribrosa (LC) has an important role in the pathophysiology of ocular diseases. The purpose of this study is to characterize in vivo, noninvasively, and in 3D the structure of the LC in healthy non-human primates (NHPs).MethodsSpectral-domain optical coherence tomography (OCT; Leica, Chicago, IL) scans of the optic nerve head (ONH) were obtained from healthy adult rhesus macaques monkeys. Using a previously reported semi-automated segmentation algorithm, microstructure measurements were assessed in central and peripheral regions of an equal area, in quadrants and depth-wise. Linear mixed-effects models were used to compare parameters among regions, adjusting for visibility, age, analyzable depth, graded scan quality, disc area, and the correlation between eyes. Spearmen's rank correlation coefficients were calculated for assessing the association between the lamina's parameters.ResultsSixteen eyes of 10 animals (7 males and 3 females; 9 OD, 7 OS) were analyzed with a mean age of 10.5 ± 2.1 years. The mean analyzable depth was 175 ± 37 µm, with average LC visibility of 25.4 ± 13.0% and average disc area of 2.67 ± 0.45mm2. Within this volume, an average of 74.9 ± 39.0 pores per eye were analyzed. The central region showed statistically significantly thicker beams than the periphery. The quadrant-based analysis showed significant differences between the superior and inferior quadrants. The anterior LC had smaller beams and pores than both middle and posterior lamina.ConclusionsOur study provides in vivo microstructure details of NHP's LC to be used as the foundation for future studies. We demonstrated mostly small but statistically significant regional variations in LC microstructure that should be considered when comparing LC measurements.

Asymmetry of Optic Nerve Head Parameters Measured by Confocal Scanning Laser Ophthalmoscopy in Myopic Anisometropic Eyes

Background: This study aimed to evaluate the asymmetry of optic nerve head parameters measured by confocal scanning laser ophthalmoscopy (CSLO) in myopic anisometropic eyes. Methods: A total of 36 eyes of 18 healthy myopic anisometropic subjects, defined as cases in which the difference in spherical equivalent (SE) between both eyes is ≥1.5D, were recruited. The optic nerve heads were measured using the Heidelberg retina tomograph II (Heidelberg Engineering, GmBH, Heidelberg, Germany). Differences in optic nerve head parameters between more myopic eyes and fellow eyes were evaluated using the paired-sample t-test. Pearson correlation and multiple linear regression analysis were used to evaluate factors associated with cup/disc ratio (CDR). Results: The cup/disc area ratio (mean difference 0.07 ± 0.11, P = 0.027), horizontal (mean difference 0.10 ± 0.17, P = 0.033), and vertical CDR (mean difference 0.13 ± 0.18, P = 0.008) were significantly smaller in more myopic eye. Larger disc area was independently and significantly associated with larger cup/disc area ratio (β = 0.561, P = 0.001) and vertical CDR (β = 0.499, P = 0.03). Conclusion: The CDR, horizontal, and vertical CDR were significantly smaller in the more myopic eyes in myopic anisometropic subjects. Further studies with larger samples are needed to confirm the asymmetry of the optic nerve head in myopic anisometropic eyes.