scholarly journals Advancing Digital Workflows for Refractive Error Measurements

2020 ◽  
Vol 9 (7) ◽  
pp. 2205
Author(s):  
Arne Ohlendorf ◽  
Alexander Leube ◽  
Siegfried Wahl
Keyword(s):  
Refractive Error ◽  
T Test ◽  
Refractive Errors ◽  
Altman Analysis ◽  
Limits Of Agreement ◽  
Clinical Measurement ◽  
Different Types ◽  
Method Of Measurement ◽  
Mean Differences ◽  
The Right

Advancements in clinical measurement of refractive errors should lead to faster and more reliable measurements of such errors. The study investigated different aspects of advancements and the agreement of the spherocylindrical prescriptions obtained with an objective method of measurement (“Aberrometry” (AR)) and two methods of subjective refinements (“Wavefront Refraction” (WR) and “Standard Refraction” (StdR)). One hundred adults aged 20–78 years participated in the course of the study. Bland–Altman analysis of the right eye measurement of the spherocylindrical refractive error (M) identified mean differences (±95% limits of agreement) between the different types of measurements of +0.36 D (±0.76 D) for WR vs. AR (t-test: p < 0.001), +0.35 D (± 0.84 D) for StdR vs. AR (t-test: p < 0.001), and 0.0 D (± 0.65 D) for StdR vs. WR (t-test: p < 0.001). Monocular visual acuity was 0.0 logMAR in 96% of the tested eyes, when refractive errors were corrected with measurements from AR, indicating that only small differences between the different types of prescriptions are present.

Visual function and visual ability in adolescents with oculocutaneous albinism

2020 ◽  
pp. 026461962097369
Author(s):  
Shivani Naipal ◽  
Nishanee Rampersad
Keyword(s):  
Refractive Error ◽  
Visual Function ◽  
Colour Vision ◽  
Oculocutaneous Albinism ◽  
Refractive Errors ◽  
Visual Ability ◽  
Refractive Correction ◽  
The Mean ◽  
The Right

Individuals with ocular and oculocutaneous albinism (OCA) have significantly reduced visual acuity (VA) resulting in visual impairment (VI). The aim is to report on the visual function of adolescents with OCA and their quality of life (QoL) in terms of their visual ability. A total of 28 adolescents with OCA participated in this study. Tests of visual function included distance VA, refractive error, contrast sensitivity (CS), and colour vision. The Cardiff Visual Ability Questionnaire for Children (CVAQC) was used to assess visual ability. All participants presented with cutaneous hypopigmentation and nystagmus, while only two had strabismus. A mean myopic refractive error was found, and with-the-rule (WTR) astigmatism was most common. The mean best-corrected VA was 0.81 ± 0.17 logMAR and 0.81 ± 0.18 logMAR in the right and left eyes, respectively. The mean CS with the best refractive correction was 1.23 ± 0.33 log CS in the right eye and 1.29 ± 0.33 log CS in the left eye. The mean Cardiff visual ability score was −0.37 ± 0.79 log units. The variation of refractive errors and the magnitude thereof underscores the need for regular eye examinations in individuals with OCA. The majority of participants had moderate VI, and these participants had a better mean Cardiff visual ability score than those with severe VI. Similarly, participants with normal binocular CS had a better Cardiff visual ability score than those with a loss of CS.

scholarly journals The effect of initial lens diopter on myopia control by orthokeratology in Teenagers A retrospective Beijing Study

2019 ◽  
Author(s):  
Jifeng Yu ◽  
Wei Shi ◽  
Xue Liu ◽  
Si-Yuan Li ◽  
Li Li
Keyword(s):  
Refractive Error ◽  
Axial Length ◽  
Study Data ◽  
Refractive Errors ◽  
Mixed Effect Model ◽  
Mixed Effect ◽  
Effect Model ◽  
Significant Difference ◽  
The Right ◽  
Myopia Control

Abstract Background To investigate the effect of initial refractive error on the control of myopia by orthokeratology. Methods Retrospective study. Data were analyzed from 78 patients (156 eyes) who underwent orthokeratology in Beijing Children's Hospital from January 2014 to April 2018. The changes of axial length and diopter after wearing the lenses were measured. Patients were divided into six groups according to refractive error: <-1.00D, -1.00~ -2.00D, -2.00D~ -3.00D, -3.00D~ -4.00D, -4.00D~ -5.00D and -5.00~ -6.00D. A mixed-effect model was used to analyze the relevant data. At the same time, the interaction item between diopter and wearing time was analyzed, and the influence of gender was corrected. Results Patients averaged 12.9±2.161 years old. Two years after wearing orthokeratology lenses, there was a statistically significant difference with the interaction item between refractive error and wearing time in each group. The estimated values ​​were 0.0631 for the right eye and 0.053 for the left eye. Orthokeratology lenses controlled the progression of myopia well, but the reduction depended on the initial diopters. Binocular axial length examination didn’t show statistically significant difference with the interaction item. Axial length increased with time, and the magnitude of increase did not differ among groups. However, the increase in the axial length of the male more than that of the female.Conclusion Initial refractive errors have a significant impact on the control of myopia by orthokeratology. The less severe myopia patient demonstrated a more pronounced benefits after wearing orthokeratology lenses. Key words: refractive error; myopia; orthokeratology

Development and Validation of a Mobile Visual Acuity Examination App for Universal Use, Including Remote and Rural Region

2021 ◽  
Author(s):  
Soham V Govande
Keyword(s):  
Visual Acuity ◽  
Low Cost ◽  
Measurement Methods ◽  
T Test ◽  
Refractive Errors ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Snellen Chart ◽  
Wide Availability ◽  
R Project

Background: Visual refractive errors are projected to rise in the coming decades worldwide, especially in remote and rural regions. To combat this, smartphone visual acuity testing apps may allow for the early detection of refractive errors thanks to their low cost and wide availability. Hence, we developed the OcularCheck app as a free mobile vision screening tool for public health use. Objective: We sought to determine whether OcularCheck accurately measures distance visual acuity (DVA) in comparison to a standard Snellen chart (Space Saving Chart SSC-350). Methods and Results: In January 2021, we measured DVA in n=56 eyes using the OcularCheck app and a standard Snellen chart. To minimize bias, we used two separate examiners who were blinded to each other’s measurements. To assess the similarity of measurement methods, we performed a two-tailed, paired t-test and Bland-Altman analysis using the R-Project software. The t-test showed that differences in DVA between testing methods were not significant (P=0.698). Bland-Altman analysis showed that the mean difference between measurement methods was 0.01 LogMAR (95% CI -0.03 to 0.04), and the standard deviation of differences (0.139 LogMAR) was below the test-retest variability of the Snellen chart. The main limitation of the study was that we were not able to measure DVA with non-English optotypes. Conclusion: OcularCheck provides accurate DVA measurements, and it harbors the potential to expand the accessibility of DVA screening to resource-scarce regions.

scholarly journals Comparing the Use of Three Dendrometers for Measuring Diameters at Breast Height

2011 ◽  
Vol 35 (3) ◽  
pp. 136-141 ◽  
Author(s):  
Shangbin Liu ◽  
Walter Bitterlich ◽  
Chris J. Cieszewski ◽  
Michal J. Zasada
Keyword(s):  
Repeated Measures ◽  
Diameter Class ◽  
Limits Of Agreement ◽  
Clinical Measurement ◽  
The Third ◽  
Breast Height ◽  
Repeated Measures Analysis ◽  
Large Trees ◽  
Mean Differences ◽  
Diameter Classes

Abstract Three dendrometers are used to measure dbh. Two of the devices are the well-known and widely used d-tape and caliper. The third device is the lesser-known sector fork. In this study, measurements of dbh were collected from each dendrometer for each tree in nine plots, with each of the three plots nested in one of the diameter classes (small, medium, and large). The results from repeated-measures analysis of variance show that different dendrometers, the interaction between the dendrometer and diameter class, and the interaction between the dendrometer and plot significantly affected the dbh measurements. Statistically significant differences were detected in most of the comparisons of dbh measured by the three dendrometers. However, the actual mean differences and limits of agreement (Bland, J.M., and D.G. Altman. 1986. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:307–310) were small enough to support the claim that the dbh measurements made by the three dendrometers agree well in measurements of the small and medium trees (in this study, dbh of <16 in.). Thus, these statistically significant differences are not biologically and/or practically important. For the large trees (dbh 16 in. or more), the dbh measured by d-tape and caliper still agreed well. The sector fork should be used cautiously in measuring large trees.

scholarly journals WRIST-WORN TRI-AXIAL ACCELEROMETER VALIDATION IN YOUNG, MIDDLE-AGED, AND OLDER ADULTS

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S332-S333
Author(s):  
Todd M Manini ◽  
Santiago Saldana ◽  
Duane Corbett ◽  
Amal A Wanigatunga ◽  
Eduardo Navarro ◽  
...  
Keyword(s):  
Daily Activities ◽  
Laboratory Setting ◽  
Activity Type ◽  
Limits Of Agreement ◽  
Metabolic Equivalents ◽  
Metabolic Intensity ◽  
Activity Types ◽  
Mean Differences ◽  
Measure Oxygen Consumption ◽  
The Right

Abstract Purpose: This study evaluated wrist-worn accelerometers for estimating metabolic intensity and classifying activity types across a wide age spectrum. Methods: Participants (n=141, 67% women, aged 20-89 yrs) performed a battery of 31 common daily activities (e.g. washing dishes, walking) in a standardized laboratory setting. A tri-axial accelerometer was worn on the right wrist during each activity whiel a portable metabolic unit was used to measure oxygen consumption (ml/kg/min), which was converted into metabolic equivalents (METs). Random forest analyses estimated metabolic intensity and classified activity type based on seven data features. Resulting estimates were cross-evaluated on a separate sample of 16 participants who performed a sub-set of activities in their home. Results: In the laboratory setting, mean differences between measured and predicted MET value for sedentary (0.36), lifestyle (0.02) and locomotor (0.30) activities were low, but the 95% limits of agreement ranges were relatively large (+/-1.0, +/-1.8, +/-3.1, respectively). Data features were 85%, 88%, and 71% accurate for identifying sedentary, lifestyle and locomotor activities. Prediction equations had an overall mean difference of 0.19 METs (95% limits of agreement = -1.3 to 1.7) when activities were performed at home. Conclusion: Data features extracted from a wrist worn tri-axial accelerometer provide a moderate-to-high group estimate of metabolic intensity and had modest accuracy in identifying activity types across a variety of daily activities. However, significant between person variations were evident. Additional work is needed to refine wrist-worn accelerometers for estimating physical activity type, intensity, duration and frequency across the age spectrum.

scholarly journals Comparison of pulmonary vein sizing by transesophageal echocardiogram and by direct angiogram

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
N Bachani ◽  
R Vadivelu ◽  
A Bagchi ◽  
JP Jadwani ◽  
GK Panicker ◽  
...  
Keyword(s):  
Left Atrium ◽  
Pulmonary Vein ◽  
Interatrial Septum ◽  
T Test ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Funding Sources ◽  
Chamber View ◽  
The Right ◽  
Paired T Test

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein (PV) anatomy and sizing is important to know before performing PV isolation. This information is conventionally obtained by angiography or by CT scan. Aim We undertook this study to identify and measure the PVs during TEE studies and validate these against angiography. Method 17 consecutive patients due to undergo PV isolation for paroxysmal atrial fibrillation were analysed. Using TEE, the PVs were visualised (Upper panel) as follows:  i) From the mid-esophageal four chamber view, the chamber probe was turned to the right at 110-130º for the bicaval view, where the RSPV was seen entering the left atrium adjacent to the SVC. ii) At 0º the SVC was imaged in its short axis, and the probe advanced till the interatrial septum was seen. The angle was changed to 30º to visualise the right inferior PV (RIPV). iii) From the two chamber view (70-90º), the probe was turned to the left and withdrawn to display the left superior PV (LSPV) entering the left atrium parallel to the appendage.iv) Keeping the LSPV in focus, the angle was changed to 135º and the probe advanced till the AV groove, where the left inferior PV (LIPV) was visualised. After transseptal puncture, each PV was cannulated. The PV angiograms were performed in several projections to obtain the best PV profile (lower panel). Using electronic callipers, each PV was measured within 1 cm of its entry into the left atrium, after having received all tributaries. Those PVs were considered for analysis which were measured by both TEE and angiography. The paired ‘T’ test was used to compare the PV diameters by TEE and angiography and the Bland Altman analysis was done to see the level of agreement. Results Of a total of 68 PVs, 62 could be adequately visualised by TEE and 50 by angiography. These 50 PVs were measured using both methods. The diameters of the PVs measured by TEE and angiography were not statistically different by the paired t test; LSPV14 ± 1.8 mm v/s 14.4 ± 2.1 mm; RSPV 13 ± 1.8 mm v/s 14.6 ± 3.5 mm; LIPV 11.9 ± 2.1 vs 13.2 ± 2.8 mm and RIPV 10.5 ± 2.7 vs 12.1 ± 2.9 mm. Bland Altman analysis showed most PV sizes estimated by TEE and angiography lay within limits of agreement. Conclusions A majority of PVs can be visualised by TEE using a defined protocol. TEE is a good technique to visualise and assess the size of PVs, avoiding the need for contrast medium and radiation. Abstract Figure. TEE and angiographic images of PVs

scholarly journals Repeatability and comparability of simulated K values between a grid projection-based device and a Placido/dual Scheimpflug device

2020 ◽  
Vol 2 (4) ◽  
pp. 270-280
Author(s):  
Julian Matius Tagal
Keyword(s):  
Coefficient Of Variation ◽  
Ocular Trauma ◽  
Mean Difference ◽  
Absolute Difference ◽  
Limits Of Agreement ◽  
The Mean ◽  
Mean Differences ◽  
The Right

Purpose: To evaluate the repeatability and comparability of simulated K values obtained by the Galilei G4 Corneal Tomographer and the iDesign Wavefront Abberometer. Methods: The right eyes of 100 consecutive pre-laser-assisted in situ keratomileusis (LASIK) patients were included in this study. Patients with a history or signs of previous corneal or ocular trauma and infection were excluded. Paired corneal measurements for flat (K1) and steep (K2) meridians were obtained with both the Galilei and the iDesign. Repeatability was evaluated by calculating the coefficient of variation (CV) of the paired measurements. The comparability between platforms was evaluated by calculation of the mean differences followed by the construction of Bland-Altman plots and calculation of limits of agreement (LOA). Results: While the mean CV for both devices was low (0.17% versus 0.57% for the Galilei and iDesign, respectively), a large proportion of eyes measured by the iDesign (22%) showed an absolute difference of > 0.5 D between paired readings, compared to 1% as measured by the Galilei. The Galilei consistently measured higher than the iDesign. Although the mean difference did not exceed 0.17 D, the LOAs were unacceptablywide at -0.52 D to 0.85 D and -0.69 D to 0.89 D for K1 and K2, respectively. Conclusion: As regards keratometry, the iDesign demonstrated clinically unacceptable repeatability. Both platforms demonstrated sufficiently wide LOA that we could not recommend that they are used interchangeably.

scholarly journals Evaluation of Refractive Errors in Children

2020 ◽  
Vol 11 (SPL4) ◽  
pp. 2249-2253
Author(s):  
Krithiga M ◽  
Xavier Jayaseelan C
Keyword(s):  
Refractive Error ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Common Type ◽  
Refractive Errors ◽  
Sectional Study ◽  
Cross Sectional ◽  
Medical College ◽  
Different Types ◽  
Eye Examination

The purpose of this study is to estimate the prevalence of refractive errors in children. Children of selected ages will be identified for visual acuity measurement, and primary eye examination will be performed. A cross-sectional study was conducted to evaluate the refractive errors in children in Saveetha medical college. A comprehensive eye examination was performed, and children with different types of refractive errors were found out. A total of 100 children were taken for the study. The sample size of the study is 100. Eye examination was performed, and refractive error was evaluated. The refractive errors that are most common in the affected age groups can be found out. The most common refractive error was found to be myopia, followed by hypermetropia and then astigmatism. This study helps to identify the most common type of error, and the causes can be found out. This is also helpful in the prevention of these errors. Early diagnosis will lead to proper and effective treatment. When these errors are left untreated, it can cause other severe effects in the eye. Awareness should be created among both the children and the parents about this problem, and the importance of regular eye examination can be stressed through this study.

scholarly journals Within- and Between-Body-Site Agreement of Skin Autofluorescence Measurements in People With and Without Diabetes-Related Foot Disease

2019 ◽  
Vol 13 (5) ◽  
pp. 836-846 ◽  
Author(s):  
Malindu E. Fernando ◽  
Robert G. Crowther ◽  
Peter A. Lazzarini ◽  
Kunwarjit S. Sangla ◽  
Scott Wearing ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Foot Ulcers ◽  
Skin Autofluorescence ◽  
Concordance Correlation ◽  
Advanced Glycation ◽  
Limits Of Agreement ◽  
Large Maximum ◽  
Foot Disease ◽  
Mean Differences ◽  
The Right

Background: Skin autofluorescence has been used to assess longer term glycemic control and risk of complications. There is however no agreed site at which autofluorescence should be measured. This study evaluated the within- and between-site agreement in measurement of skin autofluorescence using a noninvasive advanced glycation end product (AGE) reader. Methods: Overall, 132 participants were included: 16 with diabetes-related foot ulcers (DFU), 63 with diabetes but without foot ulcers (DMC), 53 without diabetes or foot ulcers (HC). Skin autofluorescence was measured using the AGE Reader (DiagnOptics technologies BV, the Netherlands). Three consecutive skin autofluorescence measurements were each performed at six different body sites: the volar surfaces of both forearms (arms), dorsal surfaces of both calves (legs), and plantar surfaces of both feet (feet). Within- and between-site agreements were analyzed with concordance correlation coefficients (CCC) and 95% confidence intervals (95% CI), absolute mean differences (±standard deviation), and Bland-Altman limits of agreement. Results: The agreement between repeat assessments at the same site was almost perfect (CCC [95% CI] ranging from 0.94 [0.91-0.96] for assessments in the right foot to 0.99 [0.99-0.99] for assessments in the left arm). The limits of agreement were narrow within ±0.5 arbitrary units for all sites. The between-site agreement in measurements was poor (CCC < 0.65) with large maximum absolute mean differences (±SD) in arbitrary units (DFU = 3.40 [±2.04]; DMC = 3.15 [±2.45]; HC = 2.72 [±1.83]) and wide limits of agreement. Conclusions: Skin autofluorescence measurements can be repeated at the same site with adequate repeatability but measurements at different sites in the same patient have marked differences. The reason for this variation across sites and whether this has any role in diabetes-related complications needs further investigation.

scholarly journals Inter-observer reliability of clinical measurement of suprasternal notch-nipple distance and breast ptosis

2014 ◽  
Vol 47 (01) ◽  
pp. 61-64 ◽  
Author(s):  
Emma Hansson ◽  
Jonas Manjer ◽  
Anita Ringberg
Keyword(s):  
Clinical Practice ◽  
Exact Science ◽  
Suprasternal Notch ◽  
Breast Ptosis ◽  
Good Reliability ◽  
Clinical Measurement ◽  
Observer Reliability ◽  
Mean Differences ◽  
Set Up ◽  
The Right

ABSTRACT Context: Suprasternal notch-nipple distance and breast ptosis are two measurements that are often used in everyday plastic surgical clinical practice. Nonetheless, the reliability of standard breast measurements has never been tested. Aim: The aim of the present study was to test the inter-observer reliability of clinical measurement of ptosis and suprasternal notch-nipple distance. Settings and Design: Six raters measured ptosis and suprasternal notch-nipple distance in 12 breasts on the same day. Statistical Analysis Used: Intra-class correlation (ICC) coefficients, the coefficient of variation (CV) and Bland-Altman plots. Results and Conclusions: The results show that there is certain variation between different raters. The ICC of average measures between raters is 0.92 for the ptosis and 0.94 for the suprasternal notch-nipple distance, that is, the agreement between different raters is high. According to the Bland—Altman plots, the overall assessment of the comparisons of measurements between the different raters shows that the direction of the mean differences is close to zero. This study shows that there is a good reliability for measurements of suprasternal notch-nipple distance and ptosis. Nonetheless, there is a slight inter-rater variability in the measurements. Even though standardised, measurement of breasts is not an exact science and care has to be taken when the measurements are performed. The surgeon should have this in mind when measurements are used in clinical practice to evaluate breasts and to choose the right surgical method, as well as when guidelines for indications for surgery are set up.

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