Normative Databases Research Articles

Advances in Biofeedback Instrumentation, Software, and Normative Values, II

This special issue continues the focus of the Spring 2019 issue on advances in instrumentation, software, and applications in biofeedback and neurofeedback. Here the articles will focus on the use of normative databases in neurofeedback assessment and treatment and the use of dynamic muscle assessment. In addition, Arnon Rolnick and Yossi Ehrenreich summarize issues in the infant's acquisition of self-knowledge through interactions with the mother.Thomas Collura provides a review of the basic principles of the QEEG, the mathematical tools utilized to analyze cortical activation patterns, and the clinical value of well-informed use of QEEG. He reviews the emergence of normative databases, which allow real-time comparison of EEG values with a reference database of normal EEGs. This enables the evaluation of whether specific measures are normal range, abnormal, and even how abnormal. He introduces the concept of a z-score, which establishes a statistical framework for the interpretation of all aspects of the QEEG. Collura also reminds the clinician of the importance of reviewing the raw EEG. A QEEG is a statistical transform of the raw EEG and therefore misses many qualitative features evident in the original. Collura also reviews the importance and the meaning of the various measures of connectivity in the QEEG. Coherence, phase, asymmetry, and burst metrics are common forms of connectivity analyzed in the QEEG. Finally, he reviews the importance of artifacting, that is, removing distortions or contaminations of the EEG.In the next article, Gabriel Sella provides a detailed guide for applying the Sella protocol for dynamic muscle assessment. The Sella protocol is a structured assessment protocol, including static muscle assessment and dynamic muscle assessment, that utilizes standardized electrode placements, conditions, and scripted specified movements during assessment. This protocol can serve as a basis for designing biofeedback-assisted rehabilitation of patients with chronic pain and other musculoskeletal problems.Finally, Arnon Rolnick and Yossi Ehrenreich provide a discussion of the role of the mother's facial expression in the child's emotional development. They emphasize the child's use of the mother's facial expressions in developing self-awareness and regulating moods through interactive dyadic processes with the mother. They propose a new type of biofeedback therapy that is based on facial expressions and facial recognition, as well as on physiological indicators.

The Analysis of Intra-retinal Layers with Automatic Optical Coherence Tomography Segmentation in Healthy Subjects

Aims: To give normative databases of each retinal layers on OCT images in the healthy Caucasian population in Turkey and investigate the relevance of the data with factors such as age, gender, axial length and refraction.
 Study Design: Prospective, cross sectional, descriptive study.
 Place and Duration of Study: Department of Ophthalmology, Faculty of Medicine, Kirsehir Ahi Evran University, Kirsehir/TURKEY. Between September 2017 and March 2018.
 Methodology: 133 participants underwent full ophthalmologic examination and spectral domain OCT imaging (Spectralis, Heidelberg Engineering, Germany). After the automatic segmentation, central 1 mm and 1-3 mm superior, inferior, nasal and temporal thicknesses of retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retina pigment epithelium (RPE), inner retinal layers (IRL), outer retinal layers (ORL) and total retina thickness (TRT) analyzed with respect to age, gender, axial length and refraction (spherical equivalent).
 Results: Central 1 mm INL, ONL, ORL, IRL and TRT and four quadrants of pericentral 1-3 mm thicknesses of RPE had positive correlation with the age. All the sections of total retina, RNFL, GCL, IPL, INL, ONL and IRL thicknesses were significantly thicker in males compared to females. The thicknesses of all RNFL sections and central 1 mm circle thicknesses of TRT, IPL, INL, OPL, RPE and IRL had positive correlation with the axial length.
 Conclusion: A normative database for thicknesses of intra-retinal layers in Turkish population was presented in the study and significant impacts of the age, gender and axial length were presented.

Chapter 1 - Fetal neurology: Principles and practice with a life-course perspective

Clinical service, educational, and research components of a fetal/neonatal neurology program are anchored by the disciplines of developmental origins of health and disease and life-course science as programmatic principles. Prenatal participation provides perspectives on maternal, fetal, and placental contributions to health or disease for fetal and subsequent neonatal neurology consultations. This program also provides an early-life diagnostic perspective for neurologic specialties concerned with brain health and disease throughout childhood and adulthood. Animal models and birth cohort studies have demonstrated how the science of epigenetics helps to understand gene-environment interactions to better predict brain health or disease. Fetal neurology consultations provide important diagnostic contributions during critical or sensitive periods of brain development when future neurotherapeutic interventions will maximize adaptive neuroplasticity. Age-specific normative neuroinformatics databases that employ computer-based strategies to integrate clinical/demographic, neuroimaging, neurophysiologic, and genetic datasets will more accurately identify either symptomatic patients or those at risk for brain disorders who would benefit from preventive, rescue, or reparative treatment choices throughout the life span.

Comparison of methods to quantify macular and peripapillary vessel density in optical coherence tomography angiography

PurposeTo compare macular and peripapillary vessel density values calculated on optical coherence tomography angiography (OCT-A) images with different algorithms, elaborate conversion formula, and compare the ability to discriminate healthy from affected eyes.MethodsCross-sectional study of healthy subjects, patients with diabetic retinopathy, and glaucoma patients (44 eyes in each group). Vessel density in the macular superficial capillary plexus (SCP), deep capillary plexus (DCP), and the peripapillary radial capillary plexus (RCP) were calculated with seven previously published algorithms. Systemic differences, diagnostic properties, reliability, and agreement of the methods were investigated.ResultsHealthy eyes exhibited higher vessel density values in all plexuses compared to diseased eyes regardless of the algorithm used (p<0.01). The estimated vessel densities were significantly different at all the plexuses (p<0.0001) as a function of method used. Inter-method reliability and agreement was mostly poor to moderate. A conversion formula was available for every method, except for the conversion between multilevel and fixed at the DCP. Substantial systemic, non-constant biases were evident between many algorithms. No algorithm outperformed the others for discrimination of patients from healthy subjects in all the retinal plexuses, but the best performing algorithm varied with the selected plexus.ConclusionsAbsolute vessel density values calculated with different algorithms are not directly interchangeable. Differences between healthy and affected eyes could be appreciated with all methods with different discriminatory abilities as a function of the plexus analyzed. Longitudinal monitoring of vessel density should be performed with the same algorithm. Studies adopting vessel density as an outcome measure should not rely on external normative databases.

Cognitive Impairments and Dysexecutive Behavioral Disorders in Chronic Kidney Disease.

The purpose of this study was to characterize cognitive impairments and behavioral disorders in a sample of patients with chronic kidney disease (CKD). A total of 52 patients with CKD were prospectively recruited over a 344-day period. Cognitive functions (memory, action speed, executive function, and language) and behavioral characteristics were assessed with a standardized comprehensive battery. The patients' performances were interpreted with a validated method on the basis of normative data from 1,003 healthy control subjects. Brain MRI and biological data were collected. Multivariable linear regression models and bootstrap analyses were used to identify risk factors for cognitive impairment. Cognitive impairment was observed in 32.5% (95% confidence interval: 17%-48%) of the 40 included patients with full data sets. Action speed and executive functions were the most frequently impaired domains. Dysexecutive behavioral disorders were observed in 27% of patients, and depression was observed in 32.5%. Cognitive impairment was independently associated with stroke volume, high serum parathyroid hormone and uric acid levels, and low serum glucose levels (adjusted R2=0.54, p<0.001 One-third of patients with CKD had cognitive impairments (action speed and executive functions), behavioral dysexecutive disorders (hypoactivity with apathy, irritability, or anosognosia), or depression.

Comentario normativo sobre el uso del superlativo "valientísimo" y del indefinido singular en la expresión "cualquiera que sean" por parte de estudiantes de nivel avanzado de ELE

We will try to expose in this essay, mainly by means of normative works and data bases, the difficulty of striking out incorrect expressions used by students of Spanish as a Foreign Language in a C1 level. For this purpose we will analyze two examples which may illustrate this question well: the use of valientísimo (as opposed to valentísimo) as the superlative form of the adjective valiente, and the use of the singular indefinite pronoun cualquiera (as opposed to the plural form cualesquiera) in the expression cualquiera que sean. We intend to awaken a reflection in the reader, possible teacher of Spanish Language, and perhaps help him or her to rethink normative grammar explanations.

Model of stressed-strained state of multi-layered reinforced concrete structure with the use of composite reinforcement

The development in calculating reinforced concrete structure method covers a wide range of issues, including the expansion of fields such as application of new innovative materials which consist of concrete and reinforcement . In order to apply modern construction of multi-layer structure using concrete with different mechanical and physical characteristics, it is compulsory to conduct researches on the stressed-strained state of these structures under various types of load, which is determined not only by the stressed-strained state of the multi-layer reinforced concrete structure, but also by the properties of the reinforcement.The object of the study is multi-layer reinforced concrete structures of concrete with various physical and mechanical characteristics of materials - concrete and reinforcement under the influence of various types of loading. The subject of this study is the fluctuation in the stress-strain state under loadings of multi-layer reinforced concrete structures with the use of composite reinforcement. Studies related to the use of composite reinforcement in multi-layer structures have not been carried out, which significantly limits the scope of its application.The methods of investigation are based on numerical modeling of stresses and deformations of multi-layer reinforced concrete elements under the action of different combinations of loads. The use of modern software systems allows a number of studies, combining different combinations of loads and the variability of the strength and deformation characteristics of materials in structural concrete or in low strength concrete for the middle layer and various types of metal or composite reinforcement . In order to precisely calculate and measure these materials, the physical and mechanical properties of materials are used, which are determined on the basis of normative data or experimental studies. Numerical simulation makes it possible to compare the results obtained and construct theoretical dependencies in a wide range of specified parameters for constructing cross sections of multi-layer reinforced concrete elements. The range of this research is limited in the short-term load effect of reinforced concrete.The obtained scientific results allow determine rational parameters for modeling various design solutions of multi-layer reinforced concrete structures. The practical importance of the research will expand the areas of rational use of multi-layer reinforced concrete structures and ensure safe operation throughout the life cycle of buildings and structures using multi-layer structures.

Association of ocular, cardiovascular, morphometric and lifestyle parameters with retinal nerve fibre layer thickness.

BackgroundGlaucoma is a neurodegenerative disease, leading to thinning of the retinal nerve fibre layer (RNFL). The exact influence of ocular, cardiovascular, morphometric, lifestyle and cognitive factors on RNFL thickness (RNFLT) is unknown and was analysed in a subgroup of the Gutenberg Health Study (GHS).MethodsGlobal peripapillary RNFLT was measured in 3224 eyes of 1973 subjects (49% female) using spectral-domain optical coherence tomography (SD-OCT). The association of age, sex, ocular, cardiovascular, morphometric, lifestyle and cognitive factors on RNFLT was analysed using Pearson correlation coefficient and fitting a linear mixed model.ResultsIn the univariable analysis highest correlations were found for axial length (r = -0.27), spherical equivalent (r = 0.24), and glaucoma (r = -0.15) (p<0.0001, respectively). Other significant correlations with RNFLT were found for age, sex, intraocular pressure, systemic hypertension and systolic blood pressure, previous eye surgery, cholesterol, homocysteine, history of coronary artery disease, history of myocardial infarction, apnoea, diabetes and alcohol intake, p<0.05, respectively. Body length, body weight, BMI, diastolic blood pressure, blood glucose, HbA1c, history of apoplexy, cognitive function, peripheral artery disease, tinnitus, migraine, nicotine intake, central corneal thickness, and pseudophakia were not significantly correlated with RNFLT. The regression model revealed a significant relationship between RNFLT and age in decades (p<0.02), spherical equivalent (p<0.0001), axial length (p<0.0001), glaucoma (p<0.0001), tinnitus (p = 0.04), apnoea (p = 0.047), homocysteine (p = 0.05) and alcohol intake >10g/d for women and >20g/d for men (p = 0.02). Glaucoma, apnoea, higher homocysteine, higher alcohol intake and higher axial length as well as age were related to decreased RNFLT while higher spherical equivalent or history for tinnitus were related to thicker RNFL.ConclusionRNFLT is related to age, ocular parameters and lifestyle factors. Considering these parameters in normative databases could improve the evaluation of peripapillary RNFLT. It is necessary to evaluate if a reduction of alcohol intake as well as the therapy of apnea or high homocysteine levels could positively influence RNFLT.

Gulf Arabic nouns and verbs: A standardized set of 319 object pictures and 141 action pictures, with predictors of naming latencies.

Standardized pictorial stimuli and predictors of successful picture naming are not readily available for Gulf Arabic. On the basis of data obtained from Qatari Arabic, a variety of Gulf Arabic, the present study provides norms for a set of 319 object pictures and a set of 141 action pictures. Norms were collected from healthy speakers, using a picture-naming paradigm and rating tasks. Norms for naming latencies, name agreement, visual complexity, image agreement, imageability, age of acquisition, and familiarity were established. Furthermore, the database includes other intrinsic factors, such as syllable length and phoneme length. It also includes orthographic frequency values (extracted from Aralex; Boudelaa & Marslen-Wilson, 2010). These factors were then examined for their impact on picture-naming latencies in object- and action-naming tasks. The analysis showed that the primary determinants of naming latencies in both nouns and verbs are (in descending order) image agreement, name agreement, familiarity, age of acquisition, and imageability. These results indicate no evidence that noun- and verb-naming processes in Gulf Arabic are influenced in different ways by these variables. This is the first database for Gulf Arabic, and therefore the norms collected from the present study will be of paramount importance for researchers and clinicians working with speakers of this variety of Arabic. Due to the similarity of the Arabic varieties spoken in the Gulf, these different varieties are grouped together under the label "Gulf Arabic" in the literature. The normative databases and the standardized pictures from this study can be downloaded from http://qufaculty.qu.edu.qa/tariq-khwaileh/download-center/ .

EmoFinder: The meeting point for Spanish emotional words

We present here emoFinder ( http://usc.es/pcc/emofinder ), a Web-based search engine for Spanish word properties taken from different normative databases. The tool incorporates several subjective word properties for 16,375 distinct words. Although it focuses particularly on normative ratings for emotional dimensions (e.g., valence and arousal) and discrete emotional categories (fear, disgust, anger, happiness, and sadness), it also makes available ratings for other word properties that are known to affect word processing (e.g., concreteness, familiarity, contextual availability, and age of acquisition). The tool provides two main functionalities: Users can search for words matched on specific criteria with regard to the selected properties, or users can obtain the properties for a set of words. The output from emoFinder is highly customizable and can be accessed online or exported to a computer. The tool architecture is easily scalable, so that it can be updated to include word properties from new Spanish normative databases as they become available.

Thai Norms for Name, Image, and Category Agreement, Object Familiarity, Visual Complexity, Manipulability, and Age of Acquisition for 480 Color Photographic Objects.

Normative databases containing psycholinguistic variables are commonly used to aid stimulus selection for investigations into language and other cognitive processes. Norms exist for many languages, but not for Thai. The aim of the present research, therefore, was to obtain Thai normative data for the BOSS, a set of 480 high resolution color photographic images of real objects (Brodeur et al. in PLoS ONE 5(5),2010. https://doi.org/10.1371/journal.pone.0010773 ). Norms were provided by 584 Thai university students on eight dimensions: name agreement, object familiarity, visual complexity, category agreement, image agreement, two types of manipulability (graspability and mimeability), and age of acquisition. The results revealed comparatively similar levels of name agreement to Brodeur et al. especially when unfamiliar items were factored out. The pattern of intercorrelations among the Thai psycholinguistic norms was comparable to previous studies and our cross-linguistic correlations were robust for the same set of pictures in English and French. Conjointly, the findings extend the relevancy of the BOSS to Thailand, supporting this photographic resource for investigations of language and other cognitive processes in monolingual, multilingual, and brain-impaired populations.

Detecting Structural Progression in Glaucoma with Optical Coherence Tomography

Optical coherence tomography (OCT) is increasingly used to obtain objective measurements of the retinal nerve fiber layer (RNFL), optic nerve head, and macula for assessing glaucoma progression. Although OCT has been adopted widely in clinical practice, uncertainty remains concerning its optimal role. Questions include: What is the best structure to measure? What quantity of change is significant? Are structural changes relevant to the patient? How are longitudinal measurements affected by aging? How can changes resulting from aging be differentiated from true progression? How best should OCT be used alongside visual fields, and how often should OCT be performed? Recent studies have addressed some of these questions. Important developments include appreciation of the need to use a consistent point of reference for structural measurements, leading to the introduction of Bruch's membrane opening (BMO)-based measurements, including BMO-minimum rim width and BMO-minimum rim area. Commercially available OCT devices also permit analysis of macular changes over time, for example, changes in the ganglion cell and inner plexiform layers, the sites of the retinal ganglion cell bodies and dendrites, respectively. Several longitudinal studies have compared rates of change in RNFL and macular measurements, with some suggesting that the relative value of each parameter may differ at different stages of disease. In early disease, looking for change over time also may be useful for glaucoma diagnosis, with advantages over classifying eyes using cross-sectional normative databases. Optimal glaucoma management requires information from imaging and visual fields, and efforts have been made to combine information, reducing the noise inherent in both tests to benefit from their different performances according to the stage of disease. Combining information from different structural measurements may also be useful. There is now substantial evidence that progressive structural changes are of direct clinical relevance, with progressive changes on OCT often preceding functional loss and patients with faster change on OCT at increased risk of worsening visual losses. Identification of such patients offers the possibility of commencing or escalating treatment at an earlier stage. This review appraises recent developments in the use of OCT for assessing glaucoma progression.

A manifesto for cardiovascular imaging: addressing the human factor.

Our use of modern cardiovascular imaging tools has not kept pace with their technological development. Diagnostic errors are common but seldom investigated systematically. Rather than more impressive pictures, our main goal should be more precise tests of function which we select because their appropriate use has therapeutic implications which in turn have a beneficial impact on morbidity or mortality. We should practise analytical thinking, use checklists to avoid diagnostic pitfalls, and apply strategies that will reduce biases and avoid overdiagnosis. We should develop normative databases, so that we can apply diagnostic algorithms that take account of variations with age and risk factors and that allow us to calculate pre-test probability and report the post-test probability of disease. We should report the imprecision of a test, or its confidence limits, so that reference change values can be considered in daily clinical practice. We should develop decision support tools to improve the quality and interpretation of diagnostic imaging, so that we choose the single best test irrespective of modality. New imaging tools should be evaluated rigorously, so that their diagnostic performance is established before they are widely disseminated; this should be a shared responsibility of manufacturers with clinicians, leading to cost-effective implementation. Trials should evaluate diagnostic strategies against independent reference criteria. We should exploit advances in machine learning to analyse digital data sets and identify those features that best predict prognosis or responses to treatment. Addressing these human factors will reap benefit for patients, while technological advances continue unpredictably.

Assessment of Optical Coherence Tomography Color Probability Codes in Myopic Glaucoma Eyes After Applying a Myopic Normative Database

To evaluate the optical coherence tomography (OCT) color probability codes based on a myopic normative database and to investigate whether the implementation of the myopic normative database can improve the OCT diagnostic ability in myopic glaucoma. Comparative validity study. In this study, 305 eyes (154 myopic healthy eyes and 151 myopic glaucoma eyes) were included. A myopic normative database was obtained based on myopic healthy eyes. We evaluated the agreement between OCT color probability codes after applying the built-in and myopic normative databases, respectively. Another 120 eyes (60 myopic healthy eyes and 60 myopic glaucoma eyes) were included and the diagnostic performance of OCT color codes using a myopic normative database was investigated. The mean weighted kappa (Kw) coefficients for quadrant retinal nerve fiber layer (RNFL) thickness, clock-hour RNFL thickness, and ganglion cell-inner plexiform layer (GCIPL) thickness were 0.636, 0.627, and 0.564, respectively. The myopic normative database showed a higher specificity than did the built-in normative database in quadrant RNFL thickness, clock-hour RNFL thickness, and GCIPL thickness (P < .001, P< .001, and P < .001, respectively). The receiver operating characteristic curve values increased when using the myopic normative database in quadrant RNFL thickness, clock-hour RNFL thickness, and GCIPL thickness (P= .011, P= .004, P < .001, respectively). The diagnostic ability of OCT color codes for detection of myopic glaucoma significantly improved after application of the myopic normative database. The implementation of a myopic normative database is needed to allow more precise interpretation of OCT color probability codes when used in myopic eyes.

Photoreceptor-Based Biomarkers in AOSLO Retinal Imaging.

Improved understanding of the mechanisms underlying inherited retinal degenerations has created the possibility of developing much needed treatments for these relentless, blinding diseases. However, standard clinical indicators of retinal health (such as visual acuity and visual field sensitivity) are insensitive measures of photoreceptor survival. In many retinal degenerations, significant photoreceptor loss must occur before measurable differences in visual function are observed. Thus, there is a recognized need for more sensitive outcome measures to assess therapeutic efficacy as numerous clinical trials are getting underway. Adaptive optics (AO) retinal imaging techniques correct for the monochromatic aberrations of the eye and can be used to provide nearly diffraction-limited images of the retina. Many groups routinely are using AO imaging tools to obtain in vivo images of the rod and cone photoreceptor mosaic, and it now is possible to monitor photoreceptor structure over time with single cell resolution. Highlighting recent work using AO scanning light ophthalmoscopy (AOSLO) across a range of patient populations, we review the development of photoreceptor-based metrics (e.g., density/geometry, reflectivity, and size) as candidate biomarkers. Going forward, there is a need for further development of automated tools and normative databases, with the latter facilitating the comparison of data sets across research groups and devices. Ongoing and future clinical trials for inherited retinal diseases will benefit from the improved resolution and sensitivity that multimodal AO retinal imaging affords to evaluate safety and efficacy of emerging therapies.

Impact of posture choice on one-handed pull strength variations at low, waist, and overhead pulling heights

Manual exertions with one hand are commonly performed; however, current one-handed normative strength databases note large strength variations not explained by participant demographics, e.g., age and gender. This study models how the postures that participants choose impact their one-handed pull strength. Lower-extremity posture, defined as distance from handle, were measured for 31 participants performing two maximum one-handed frontal pull exertions at three handle heights, resulting in a strength-posture dataset of 186 maximal exertions. Regression models with anthropometric and lower extremity positions were created for each handle height. Smaller distances between the front-foot and handle were associated with higher strength. Larger back-foot distance to handle was positively associated with strength for low and waist-level handle heights. Larger hip distances from the handle increased pull strengths and interacted with feet positions. This study quantifies the relationship between one-handed pull strength with anthropometry and postures and provides practitioners posture-based equations that can be used to estimate safe pull strengths given workplace posture constraints. Relevance to industryMaximum one-handed pull strength models are presented that can assist practitioners in: 1) assessing whether strength demands are within worker's capability in the workplace, 2) designing workplaces that better accommodate the range of postures chosen during maximum exertion, and 3) identify workplace layout constraints that adversely impact strength capabilities.

GDF15 is elevated in mice following retinal ganglion cell death and in glaucoma patients.

Glaucoma is the second leading cause of blindness worldwide. Physicians often use surrogate endpoints to monitor the progression of glaucomatous neurodegeneration. These approaches are limited in their ability to quantify disease severity and progression due to inherent subjectivity, unreliability, and limitations of normative databases. Therefore, there is a critical need to identify specific molecular markers that predict or measure glaucomatous neurodegeneration. Here, we demonstrate that growth differentiation factor 15 (GDF15) is associated with retinal ganglion cell death. Gdf15 expression in the retina is specifically increased after acute injury to retinal ganglion cell axons and in a murine chronic glaucoma model. We also demonstrate that the ganglion cell layer may be one of the sources of secreted GDF15 and that GDF15 diffuses to and can be detected in aqueous humor (AH). In validating these findings in human patients with glaucoma, we find not only that GDF15 is increased in AH of patients with primary open angle glaucoma (POAG), but also that elevated GDF15 levels are significantly associated with worse functional outcomes in glaucoma patients, as measured by visual field testing. Thus, GDF15 maybe a reliable metric of glaucomatous neurodegeneration, although further prospective validation studies will be necessary to determine if GDF15 can be used in clinical practice.

Lateral thinking - Interocular symmetry and asymmetry in neurovascular patterning, in health and disease.

No biological system or structure is likely to be perfectly symmetrical, or have identical right and left forms. This review explores the evidence for eye and visual pathway asymmetry, in health and in disease, and attempts to provide guidance for those studying the structure and function of the visual system, where recognition of symmetry or asymmetry may be essential. The principal question with regards to asymmetry is not 'are the eyes the same?', for some degree of asymmetry is pervasive, but 'when are they importantly different?'. Knowing if right and left eyes are 'importantly different' could have significant consequences for deciding whether right or left eyes are included in an analysis or for examining the association between a phenotype and ocular parameter. The presence of significant asymmetry would also have important implications for the design of normative databases of retinal and optic nerve metrics. In this review, we highlight not only the universal presence of asymmetry, but provide evidence that some elements of the visual system are inherently more asymmetric than others, pointing to the need for improved normative data to explain sources of asymmetry and their impact on determining associations with genetic, environmental or health-related factors and ultimately in clinical practice.

Emerging Applications of Optical Coherence Tomography in Pediatric Optic Neuropathies

Limited cooperation and attention span often lead to poorly reliable assessments of visual acuity and visual fields in children, making diagnosis and monitoring of pediatric optic neuropathies challenging. As a noninvasive imaging modality, optical coherence tomography (OCT) could offer particular utility in this patient population. OCT provides high-resolution characterization of the optic nerve head, peripapillary retinal nerve fiber layer, and cellular layers of the macula, all of which can be used to assess the severity of optic nerve disease qualitatively and quantitatively. Application of OCT to pediatric patients has been limited by technical factors and lack of pediatric normative databases, but with recent technological improvements and rapidly expanding research efforts OCT is poised to revolutionize the management of optic neuropathies in children. We review current and emerging applications of OCT to important pediatric optic neuropathies such as glaucoma, papilledema, optic neuritis, optic pathway gliomas, and congenital optic disc anomalies.

Comparison of Ethnic-specific Databases in Heidelberg Retina Tomography-3 to Discriminate Between Early Glaucoma and Normal Chinese Eyes.

Purpose:To compare the diagnostic accuracy of the 3 race-specific normative databases in Heidelberg Retina Tomography (HRT)-3, in differentiating between early glaucomatous and healthy normal Chinese eyes.Method:52 healthy volunteers and 25 glaucoma patients were recruited for this prospective cross-sectional study. All underwent standardized interviews, ophthalmic examination, perimetry and HRT optic disc imaging. Area under the curve (AUC) receiver operating characteristics, sensitivity and specificity were derived to assess the discriminating abilities of the 3 normative databases, for both Moorfields Regression Analysis (MRA) and Glaucoma Probability Score (GPS).Results:A significantly higher percentage (65%) of patients were classified as “within normal limits” using the MRA-Indian database, as compared to the MRA-Caucasian and MRA-African-American databases. However, for GPS, this was observed using the African-American database. For MRA, the highest sensitivity was obtained with both Caucasian and African-American databases (68%), while the highest specificity was from the Indian database (94%). The AUC for discrimination between glaucomatous and normal eyes by MRA-Caucasian, MRA-African-American and MRA-Indian databases were 0.77 (95% CI, 0.67-0.88), 0.79 (0.69-0.89) and 0.73 (0.63-0.84) respectively. For GPS, the highest sensitivity was obtained using either Caucasian or Indian databases (68%). The highest specificity was seen with the African-American database (98%). The AUC for GPS-Caucasian, GPS-African-American and GPS-Indian databases were 0.76 (95% CI, 0.66-0.87), 0.77 (0.67-0.87) and 0.76 (0.66-0.87) respectively.Conclusion:Comparison of the 3 ethnic databases did not reveal significant differences to differentiate early glaucomatous from normal Chinese eyes.