Developing a Five-Minute Normative Database of Heart Rate Variability for Diagnosing Cardiac Autonomic Dysregulation for Patients with Major Depressive Disorder.

Heart rate variability (HRV) is related to cardiac vagal control and emotional regulation and an index for cardiac vagal control and cardiac autonomic activity. This study aimed to develop the Taiwan HRV normative database covering individuals aged 20 to 70 years and to assess its diagnosing validity in patients with major depressive disorder (MDD). A total of 311 healthy participants were in the HRV normative database and divided into five groups in 10-year age groups, and then the means and standard deviations of the HRV indices were calculated. We recruited 272 patients with MDD for cross-validation, compared their HRV indices with the normative database, and then converted them to Z-scores to explore the deviation of HRV in MDD patients from healthy groups. The results found a gradual decline in HRV indices with advancing age in the HC group, and females in the HC group exhibit higher cardiac vagal control and parasympathetic activity than males. Conversely, patients in the MDD group demonstrate lower HRV indices than those in the HC group, with their symptoms of depression and anxiety showing a negative correlation with HRV indices. The Taiwan HRV normative database has good psychometric characteristics of cross-validation.

Three-dimensional choroidal contour mapping in healthy population.

Purpose was to study 3-dimensional choroidal contour at choroidal inner boundary (CIB) and choroidal outer boundary (COB) in healthy eyes. Healthy eyes imaged on wide field swept-source optical coherence tomography were included. Delineation of CIB and COB was done based on our previously reported methods. Quantitative analysis of the surfaces of CIB and COB was based on analyzing best fit spherical radius (R) (overall and sectoral). One hundred and seven eyes of 74 subjects with a mean age of 46.4 ± 19.3 years were evaluated. Overall, R COB (mean ± SD: 22.5 ± 4.8 mm) < R CIB (32.4 ± 9.4 mm). Central sector had the least R at COB (7.2 ± 5.9 mm) as well as CIB (25.1 ± 14.3 mm) across all age groups. Regression analysis between R (CIB) and age (r = -0.31, r2 = 0.09) showed negative correlation (P < 0.001) and that between R (COB) and age was positive (r = 0.26, r2 = 0.07) (P = 0.01). To conclude, central sector is the steepest sector in comparison to all the other sectors. This is indicative of a prolate shape of choroidal contour at CIB and COB. Outer boundary of choroid is steeper than inner boundary across all age groups. However, with ageing, outer boundary becomes flatter and inner boundary becomes steeper.

Removing outliers from the normative database improves regional atrophy detection in single-subject voxel-based morphometry.

PURPOSE: Single-subject voxel-based morphometry (VBM) compares an individual T1-weighted MRI to a sample of normal MRI in a normative database (NDB) to detect regional atrophy. Outliers in the NDB might result in reduced sensitivity of VBM. The primary aim of the current study was to propose a method for outlier removal ("NDB cleaning") and to test its impact on the performance of VBM for detection of Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). METHODS: T1-weighted MRI of 81 patients with biomarker-confirmed AD (n = 51) or FTLD (n = 30) and 37 healthy subjects with simultaneous FDG-PET/MRI were included as test dataset. Two different NDBs were used: a scanner-specific NDB (37 healthy controls from the test dataset) and a non-scanner-specific NDB comprising 164 normal T1-weighted MRI from 164 different MRI scanners. Three different quality metrics based on leave-one-out testing of the scans in the NDB were implemented. A scan was removed if it was an outlier with respect to one or more quality metrics. VBM maps generated with and without NDB cleaning were assessed visually for the presence of AD or FTLD. RESULTS: Specificity of visual interpretation of the VBM maps for detection of AD or FTLD was 100% in all settings. Sensitivity was increased by NDB cleaning with both NDBs. The effect was statistically significant for the multiple-scanner NDB (from 0.47 [95%-CI 0.36-0.58] to 0.61 [0.49-0.71]). CONCLUSION: NDB cleaning has the potential to improve the sensitivity of VBM for the detection of AD or FTLD without increasing the risk of false positive findings.

Normative Database of the Superior-Inferior Thickness Asymmetry for All Inner and Outer Macular Layers of Adults for the Posterior Pole Algorithm of the Spectralis SD-OCT.

BACKGROUND: This study aims to establish a reference for the superior-inferior hemisphere asymmetry in thickness values for all macular layers for the posterior pole algorithm (PPA) available for the Spectralis SD-OCT device. METHODS: We examined 300 eyes of 300 healthy Caucasian volunteers aged 18-84 years using the PPA, composed of a grid of 64 (8 × 8) cells, to analyze the thickness asymmetries of the following automatically segmented macular layers: 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); retinal pigment epithelium (RPE); inner retina; outer retina; complete retina. Mean ± standard deviation and the 2.5th and 97.5th percentiles of the thickness asymmetry values were obtained for all the corresponding cells. RESULTS: All the macular layers had significant superior-inferior thickness asymmetries. GCL, IPL, INL, ONL and RPE showed significantly greater thicknesses in the superior than the inferior hemisphere, whereas RNFL and OPL were thicker in the inferior hemisphere. The largest differences between hemispheres were for RNFL and ONL. CONCLUSIONS: This is the first normative database of macular thickness asymmetries for the PPA and should be considered to distinguish normal from pathological values when interpreting superior-inferior macular asymmetries.

High Myopia Normative Database of Peripapillary Retinal Nerve Fiber Layer Thickness to Detect Myopic Glaucoma in a Chinese Population.

PURPOSE: To develop and validate the performance of a high myopia (HM)-specific normative database of peripapillary retinal nerve fiber layer (pRNFL) thickness in differentiating HM from highly myopic glaucoma (HMG). DESIGN: Cross-sectional multicenter study. PARTICIPANTS: A total of 1367 Chinese participants (2325 eyes) with nonpathologic HM or HMG were included from 4 centers. After quality control, 1108 eyes from 694 participants with HM were included in the normative database; 459 eyes from 408 participants (323 eyes with HM and 136 eyes with HMG) and 322 eyes from 197 participants (131 eyes with HM and 191 eyes with HMG) were included in the internal and external validation sets, respectively. Only HMG eyes with an intraocular pressure > 21 mmHg were included. METHODS: The pRNFL thickness was measured with swept-source (SS) OCT. Four strategies of pRNFL-specified values were examined, including global and quadrantic pRNFL thickness below the lowest fifth or the lowest first percentile of the normative database. MAIN OUTCOMES MEASURES: The accuracy, sensitivity, and specificity of the HM-specific normative database for detecting HMG. RESULTS: Setting the fifth percentile of the global pRNFL thickness as the threshold, using the HM-specific normative database, we achieved an accuracy of 0.93 (95% confidence interval [CI], 0.90-0.95) and 0.85 (95% CI, 0.81-0.89), and, using the first percentile as the threshold, we acheived an accuracy of 0.85 (95% CI, 0.81-0.88) and 0.70 (95% CI, 0.65-0.75) in detecting HMG in the internal and external validation sets, respectively. The fifth percentile of the global pRNFL thickness achieved high sensitivities of 0.75 (95% CI, 0.67-0.82) and 0.75 (95% CI, 0.68-0.81) and specificities of 1.00 (95% CI, 0.99-1.00) and 1.00 (95% CI, 0.97-1.00) in the internal and external validation datasets, respectively. Compared with the built-in database of the OCT device, the HM-specific normative database showed a higher sensitivity and specificity than the corresponding pRNFL thickness below the fifth or first percentile (P < 0.001 for all). CONCLUSIONS: The HM-specific normative database is more capable of detecting HMG eyes than the SS OCT built-in database, which may be an effective tool for differential diagnosis between HMG and HM. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Surface Electromyography of Pharyngeal Swallowing in Healthy Chinese Individuals: Establishment of a Timing and Amplitude Database.

This study determined the surface electromyography (sEMG) characteristics of healthy Chinese adults during swallowing to provide a reference for the clinical differential diagnosis of swallowing and dysphagia. sEMG was performed on 187 healthy adults to obtain quantitative information on normal pharyngeal swallowing. The evaluated parameters included the timing and amplitude of sEMG activity in the submental and infrahyoid muscles. A normative database was constructed for the timing and amplitude of muscle activity during pharyngeal swallowing. Results indicated that the duration of sEMG activity was related to the age of the patient; the duration gradually increasing with age. Similarly, the duration of the sEMG activity was associated with the type of swallowing. The duration of the sEMG activity was similar for dry and wet swallowing but was significantly different for excessive swallowing. The mean amplitude of sEMG activity for the submental and infrahyoid muscles was not significantly associated with patient age. A significant correlation between the mean amplitude of sEMG activity and the types of normal swallowing was observed in infrahyoid, but not in submental muscle activity. This study is the first report on the establishment of a normative database for the duration and amplitude of muscle activity based on sEMG analysis of pharyngeal swallowing in healthy Chinese adults.

The Resting State of Taiwan EEG Normative Database: Z-Scores of Patients with Major Depressive Disorder as the Cross-Validation.

This study referred to the standard of electroencephalography (EEG) collection of normative databases and collected the Taiwan normative database to examine the reliability and validation of the Taiwan EEG normative database. We included 260 healthy participants and divided them into five groups in 10-year age-group segments and calculated the EEG means, standard deviation, and z-scores. Internal consistency reliability was verified at different frequencies between the three electrode locations in the Taiwan normative database. We recruited 221 major depressive disorder (MDD) patients for cross-validation between the Taiwan and NeuroGuide normative databases. There were high internal consistency reliabilities for delta, theta, alpha, beta, and high-beta at C3, Cz, and C4 in the HC group. There were high correlations between the two z-scores of the Taiwan and NeuroGuide normative databases in the frontal, central, parietal, temporal, and occipital lobes from MDD patients. The beta z-scores in the frontal lobe and central area, and the high-beta z-scores in the frontal, central, parietal, temporal, and occipital lobes were greater than one for MDD patients; in addition, the beta and high-beta absolute value z-scores in the whole brain were greater than the ones of MDD patients. The Taiwan EEG normative database has good psychometric characteristics of internal consistency reliability and cross-validation.

A normative database of wide-field swept-source optical coherence tomography angiography quantitative metrics in a large cohort of healthy adults.

PURPOSE: Data from healthy eyes is needed to interpret optical coherence tomography angiography (OCTA) findings. However, very little normative data is available for wide-field swept-source OCTA (WF SS-OCTA), particularly 12 × 12-mm and disc-centered angiograms. Therefore, we aim to report quantitative metrics in a large sample of control eyes. METHODS: In this cross-sectional observational study, 482 eyes of 375 healthy adults were imaged on the 100 kHz Zeiss PLEX® Elite 9000 using protocols centered on the fovea (3 × 3, 6 × 6, and 12 × 12-mm) and optic disc (6 × 6 and 12 × 12-mm) between December 2018 and January 2022. The ARI Network (Zeiss Portal v5.4) was used to calculate vessel density (VD) and vessel skeletonized density (VSD) in the superficial capillary plexus, deep capillary plexus, and whole retina, as well as foveal avascular zone (FAZ) parameters. Mixed-effect multiple linear regression models were used for statistical analysis. RESULTS: The subjects' median age was 55 (38-63) years, and 201 (53.6%) were female. Greater age and worse best-corrected visual acuity (BCVA) were associated with significantly lower VD and VSD (p < 0.05). VD and VSD differed based on race and cataract status, but not sex, on some scan protocols (p < 0.05). FAZ circularity decreased with age, and FAZ dimensions differed based on race and ethnicity in certain scan protocols. CONCLUSIONS: We report a large database of parafoveal and peripapillary vascular metrics in several angiogram sizes. In referencing these values, researchers must consider characteristics such as age, race, and BCVA, but will have a valuable point of comparison for OCTA measurements in pathologic settings.

A Normative Brain MRI Database of Neurotypical Participants from 5 to 90 Years of Age.

Brain magnetic resonance imaging (MRI) studies of clinical populations often require comparison to a normative 'control' cohort, usually of similar age/sex, scanned with the same protocol. The goal here was to create a normative brain MRI database of common quantitative methods to be used in comparisons with a variety of neurological disorders across the lifespan. 378 neurotypical controls (aged 5-90 years; median 31 years; 216 females, 162 males) completed brain MRI, cognitive testing, clinical assessment, and a demographics questionnaire. In addition, this large normative sample will yield novel insight into healthy brain development and aging.

Topography and Choroidal Thickness Measurement in Healthy Asian Indian Subjects using RTVue XR 100 Optical Coherence Tomography.

PURPOSE: The purpose was to study the choroidal thickness and its profile, derived from different point locations in healthy Asian Indian subjects using RTVue XR 100 optical coherence tomography (OCT) and to determine its correlation with age, refractive error, and axial length. METHODS: In this cross-sectional study, 300 eyes of 150 healthy subjects, with no ocular pathology, were scanned in a single session, using a line scan protocol of RTVue XR 100 OCT. Choroidal thickness was measured at the subfoveal region, and six measurements were obtained on either side of the fovea (temporal and nasal) at 500 µm interval apart, up to 3000 µm. The correlation between subfoveal choroidal thickness and age, refractive error, and axial length was assessed. RESULTS: Three hundred eyes of 150 healthy subjects were included in the analysis. Median age of the study participants was 55 years (interquartile range [IQR]: 44-61). The median subfoveal choroidal thickness was 235 µm (IQR: 210-263). The choroidal thickness was minimum at nasal 3000 µm from the fovea, while it was maximum in the subfoveal region. The point zones which were near the fovea showed thicker choroidal thickness than the outer zones, both nasally and temporally (P < 0.00001 at all locations), and at all point locations the choroid were thicker temporally than nasally (All P < 0.00001). Subfoveal choroidal thickness showed negative correlation with age (coefficient = -0.62, P = 0.03) and axial length (correlation = -8.52, P = 0.02). A decrease in subfoveal choroidal thickness of 0.62 µm/year was found by regression analysis. CONCLUSION: Our study provides normative database and topographic profile of choroidal thickness in the normal Asian Indian eyes using RTVue XR 100 OCT.

Normative database for Spaeth Richman contrast sensitivity test for Indian eyes.

Purpose: To ascertain normative database of contrast sensitivity (CS) using Spaeth/Richman CS test (SPARCS) in the Indian population. Methods: This cross-sectional study enrolled 200 healthy individuals, and CS was tested in both eyes of each participant using SPARCS. A detailed ocular examination was done before enrollment to rule out pathologies that may affect CS. A practice test was performed in the right eye (OD), followed by uniocular testing in each eye and a final binocular test. Results: Data of 400 eyes of 200 subjects who fulfilled the inclusion criteria was evaluated. The average age of subjects was 46.57 ± 16.77 years (range 21-79 years), with a slight female preponderance (53%, n = 106). A statistically significant decline in average SPARCS scores was noted with increasing age (P < 0.05), ranging from 86.68 (20-29 years age group) to 67.44 (70-79 years age group). Higher scores were noted in binocular testing than uniocular testing (Interclass correlation coefficient [ICC] = 0.83; P < 0.001). Females achieved statistically significant higher total scores in uniocular SPARCS testing (both OD and OS), but there was no significant difference noted between the two genders in binocular testing. Correlation between practice and main tests was statistically Significant with an interclass correlation coefficient of 0.54 (P < 0.001). Conclusion: Normative database for SPARCS was established for Indian eyes, with a decreasing trend noted in peripheral as well as central CS scores with increasing age.

Eccentric and Isometric Shoulder Rotation Strength and Range of Motion: Normative Values for Adolescent Competitive Tennis Players.

The aim of this cross-sectional study was to investigate isometric internal rotation (IR), external rotation (ER), abduction (ABD), and eccentric external rotation (eccER) shoulder strength and rotational range of motion (ROM) in adolescent male and female competitive tennis players. Additional aims of the study were to provide a tennis-specific normative database based on a large sample of players to deepen the knowledge regarding shoulder strength and ROM for adolescent competitive tennis players, and to discuss differences based on sex, age, and level of play. Shoulder strength and ROM was assessed in 301 adolescent competitive tennis players, 176 boys and 125 girls with a mean age of 14.6 and 14.4 years, respectively. Outcome variables of interest were isometric IR and ER strength, ABD strength, eccER shoulder strength, intermuscular strength ratios ER/IR and eccER/IR, IR ROM, ER ROM, and total range of motion (TROM). A General Linear Model two-way ANOVA was used to analyze differences in sex, age, and level of play. The findings of this study demonstrated age, side, and sex differences in the shoulder isometric strength, the eccER strength and ROM in adolescent competitive tennis players. Furthermore, when strength was expressed as ratios ER/IR and eccER/IR both sexes showed a lower ratio for eccER/IR in national players (0.95 ± 0.22 and 0.95 ± 0.23) compared to regional players (1.01 ± 0.32 and 1.07 ± 0.29) for male and female players, respectively. In conclusion, this paper presents a tennis-specific normative database for shoulder rotation strength and ROM in adolescent male and female competitive players. The key points in this evaluation are strength values normalized to body mass, intermuscular ratios, and TROM.

Evaluation of the Cirrus High-Definition OCT Normative Database Probability Codes in a Black American Population.

PURPOSE: Race-adjusted interpretation of data from Cirrus high-definition OCT (HD-OCT) devices is not standard practice. The aim of this study is to evaluate differences in peripapillary retinal nerve fiber layer (RNFL) thickness between healthy Black Americans and the Cirrus HD-OCT normative database. DESIGN: This is a cross-sectional observational study using control patients recruited from the greater Philadelphia, Pennsylvania, area. PARTICIPANTS: A total of 466 eyes were included in this study. Subjects were retrospectively identified from the control cohort of the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. METHODS: Using an age-stratified or linear regression method, we reclassified white-green-yellow-red color probability codes for RNFL thicknesses by quadrant. MAIN OUTCOME MEASURES: The distribution of reclassified color codes was compared with the expected 5%-90%-4%-1% percentiles and to the original color codes by the Cirrus machine. RESULTS: Average RNFL thickness in the POAAGG control cohort was thinner than in the Cirrus normative database in all except the nasal quadrant. The original color codes of the POAAGG cohort did not fall into the expected distributions, with more RNFL measurements assigned as white and red codes than expected (9.5% and 1.7%) and fewer measurements assigned as green and yellow codes than expected (85.3% and 3.5%) (P < 0.001). Compared with the original Cirrus machine, reclassification using linear regression produced color codes closest to the expected distributions (P = 0.09). The proportion of abnormal results shifted closer to the expected 5% in the nasal (1.3%, P < 0.001 vs. 3.0%, P = 0.048) and temporal (8.2%, P = 0.002 vs. 3.6%, P = 0.18) quadrants. CONCLUSIONS: Results further establish the presence of structural differences in the RNFL of Black American patients. Color code reclassification suggests that the existing Cirrus database may not be accurately evaluating glaucomatous nerves in patients of African descent. This study addresses an unmet need to assess Cirrus HD-OCT color probability codes in a Black American population.

Corneal Hysteresis in Thais and Variation of Corneal Hysteresis in Glaucoma.

PURPOSE: To collect the normal value data of corneal hysteresis in Thais and study the variation of corneal hysteresis in glaucomatous eyes. METHODS: Retrospective cross-sectional study of corneal hysteresis (CH) in healthy non-glaucomatous and glaucomatous eyes. Demographic data, type and staging of glaucoma, Goldmann applanation tonometry (GAT) and ocular response analyzer parameters; CH, corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg) were collected. RESULTS: Data from one eye of 465 normal participants were included for the normal value data of CH. Mean CH, IOPcc and IOPg were 10.18 ± 1.48, 15.01 ± 3.04 and 14.16 ± 3.06 mmHg, respectively. Average age was 57.21 ± 14.4 years. CH at the fifth percentile was 8.0 mmHg. Women had significantly higher CH than men (10.29 ± 1.46 vs 9.90 ± 1.49 mmHg, p=0.009). Moderate negative correlation was found between age and CH, r = -0.338, p<0.001. There were 695 glaucomatous eyes from 429 patients including primary-open angle glaucoma (POAG), primary close-angle glaucoma (PACG), normal tension glaucoma (NTG) and ocular hypertension (OHT). CH in each glaucoma type and severity stage (early, moderate and severe) were as follows: POAG: 8.74 ± 1.52 mmHg (9.22 ± 1.47, 8.74 ± 1.23 and 7.92 ± 1.40 mmHg, p<0.001), PACG: 9.09 ± 1.72 mmHg (9.85 ± 1.45, 9.04 ± 1.68 and 8.45 ± 1.74 mmHg, p= 0.004), NTG: 9.55 ± 1.67 mmHg (9.47 ± 1.38, 9.75 ± 2.42 and 9.77 ± 1.34 mmHg, p 0.525) and OHT: 10.10 ± 1.40 mmHg. CONCLUSION: Compared with normal value data of corneal hysteresis, CH in glaucomatous eyes was lower. The more advanced glaucoma stage was associated with lower CH. Arising from normal value data, a low percentile of CH could be applied as the deviation value from normal and this dynamic property of CH could represent a glaucoma predictor in an effort to improve glaucoma care.

Normal Baseline Values for Isometric Shoulder Strength in Scaption for Healthy Filipino Individuals in the 20-30 year Age Group.

INTRODUCTION: Isometric shoulder strength is vital in the management of individuals suffering from shoulder diseases such as rotator cuff tears. Normal values for the working Filipino population who are at risk of developing shoulder problems are lacking. The objective of this study was to determine the isometric baseline isometric shoulder strengths in scaption of healthy Filipino individuals aged 20-30 years old without a history of a shoulder injury. MATERIAL AND METHODS: This is a cross-sectional descriptive study measuring the isometric strength values using the handheld IDO isometer of dominant and non-dominant shoulder of healthy Filipino individuals aged 20 to 30 years old. RESULTS: There is no significant difference in the mean isometric shoulder strength between the dominant and non-dominant arm for both sexes. The male gender scored higher values compared to the female gender and is statistically significant. CONCLUSION: There is no difference in isometric shoulder strength between the dominant and non-dominant shoulder. Strength differences favour the male gender.

Isometric Strength Database for Muscle Maximal Voluntary Endurance Field Tests: Normative Data.

BACKGROUND: Different field tests are used to evaluate muscle capacity, in particular maximal voluntary isometric endurance. However, although there are some normative values for a few muscle endurance tests, these do not consider the weight, height, gender, or age of individuals, which are well-known factors that influence muscle performance. HYPOTHESIS/PURPOSE: The purpose of this study was to investigate the test-retest reproducibility of eight field tests and establish muscle endurance norms, in a healthy population, based on their anthropometric characteristics, which could allow the optimal evaluation of the entire muscle function in a quick manner. DESIGN: Case series. METHODS: This study was conducted in two phases. The first phase was to check the reproducibility inter- and intra-assessor for eight isometric muscle field tests on 20 volunteer subjects aged 40.9 ± 11.6 years old (age range, 21-58 years). The second part was to establish muscle maximal voluntary isometric endurance norms according to these tests on a total of 400 healthy participants grouped by age (50 males and females in each of the age brackets, 20-29; 30-39; 40-49; 50-59 years old, for a total of 200 males and 200 females). RESULTS: The intra- and inter-assessor reproducibility tests are good for all muscle measurements (the intraclass correlation coefficients varied between 0.915 and 0.996 and the coefficient of variation between 3.6 and 11.8%). The area under the receiver operating characteristic curves demonstrates a good sensibility with values greater than 0.7 for each test. Each muscle belt presents same ratio regardless of the age and gender group. The simultaneous multiple regression analyses highlight that the anthropometric characteristics of subjects influence significantly the performance of isometric tests. CONCLUSION: This study has permitted establishing prediction equations in a healthy population according to their anthropometric characteristics as well as agonist/antagonist ratios for eight muscle isometric field tests after demonstrating a good reproducibility of all tests.

A commentary on establishing norms for error-related brain activity during the arrow flanker task among young adults.

We suggest that a large data set for the error-related negativity (ERN) and error positivity (Pe) components of the scalp-recorded event-related brain potential (ERP) recently published as normative is not ready for such use in research and, especially, clinical application. Such efforts are challenged by an incomplete understanding of the functional significance of between-person differences in amplitudes and of nuisance factors that contribute to amplitude differences, a lack of standardization of methods, and the use of a convenience sample for the potentially normative database. To move ERPs toward standardization and useful norms, we encourage more research on the meaning of differences in ERN scores, including factors that influence between- and within-person variation, and the dissemination of protocols for data collection and processing.

Normative Database for All Retinal Layer Thicknesses Using SD-OCT Posterior Pole Algorithm and the Effects of Age, Gender and Axial Lenght.

Our aim was to provide, for the first time, reference thickness values for the SD-OCT posterior pole algorithm (PPA) available for Spectralis OCT device (Heidelberg Engineering, Heidelberg, Germany) and to analyze the correlations with age, gender and axial length. We recruited 300 eyes of 300 healthy Caucasian subjects between 18 and 84 years. By PPA, composed of 64 (8 × 8) cells, we analyzed the thickness of the following macular layers: 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), retinal pigment epithelium (RPE), inner retina, outer retina and full retina. Mean ± SD, 1st, 5th, 95th percentiles were obtained for each cell at all macular layers. Significant negative correlations were found between age and thickness for most macular layers. The mean thickness of most macular layers was thicker for men than women, except for RNFL, OPL and RPE, with no gender differences. GCL, IPL and INL thicknesses positively correlated with axial length in central cells, and negatively in the cells near the optic disk. The mean RNFL thickness was positively associated with axial length. This is the first normative database for PPA. Age, gender and axial length should be taken into account when interpreting PPA results.

Diversity in optical coherence tomography normative databases: moving beyond race.

Normative databases of optical coherence tomography (OCT) metrics, such as retinal nerve fiber layer (RNFL) and macular thickness, are critical to clinical use of OCT imaging. In order to accurately represent the range of normal variation in patient populations, these normative databases must themselves be adequately diverse. Thus far, diversity in OCT normative databases has largely been defined as racial diversity. However, this has largely been based on self-reported "race," which is inconsistent and generally not scientifically rigorous as a form of categorization. Moreover, there is a great deal of variation even within any single racial group, suggesting that other drivers of variation, such as geography or socioeconomic status, may be more important metrics for diversity. Finally, race itself is a proxy for the biological variation that must be represented in such samples, and as such racial diversity does not itself inherently equate to adequate biologic diversity. As clinical use of OCT continues to grow, including to international settings, it is increasingly important that normative databases built into OCT systems accurately represent the populations to which they are applied. Race is not an ideal sole or even primary means of assessing sample diversity in this context. In future normative OCT database construction, other forms of diversity should be considered.

Relationships between gray matter volume and reading ability in typically developing children, adolescents, and young adults.

Reading is explicitly taught and foreshadows academic and vocational success. Studies comparing typical readers to those with developmental dyslexia have identified anatomical brain differences in bilateral temporo-parietal cortex, left temporo-occipital cortex, and bilateral cerebellum. Yet, it is unclear whether linear relationships exist between these brain structures and single real word reading ability in the general population. If dyslexia represents the lower end of the normal continuum, then relationships between gray matter volume (GMV) and reading ability would exist for all reading levels. Our study examined this question using voxel-based morphometry in a large sample (n = 404) of typically developing participants aged 6-22 derived from the NIH normative database. We tested correlations between individual GMV and single word reading and found none. After dividing this sample into groups based on age and on sex, we only found results in the group aged 15-22: positive correlations between GMV in left fusiform gyrus and reading, driven by females; and in right superior temporal gyrus in males. Multiple regressions also yielded no results, demonstrating that there is no general linear relationship between GMV and single real word reading ability. This provides an important context by which to interpret findings of GMV differences in dyslexia.