scholarly journals Axial length, anterior chamber depth and lens thickness: Their intercorrelations in black South Africans

2017 ◽  
Vol 76 (1) ◽  
Author(s):  
Khathutshelo P. Mashige ◽  
Olalekan A. Oduntan
Keyword(s):  
Confidence Interval ◽  
Anterior Chamber ◽  
Negative Correlation ◽  
Axial Length ◽  
Repeated Measures ◽  
Pearson Correlation ◽  
Anterior Chamber Depth ◽  
P Values ◽  
Lens Thickness ◽  
Biometric Indices

Purpose: To determine means and ranges for axial length, anterior chamber depth, lens thickness values and their intercorrelations in an African population.Methods: Six hundred participants (N = 600) were selected through stratified random cluster sampling from geographically contiguous areas of Durban, South Africa. All participants underwent height measurements and standard vision testing. Repeated measures of axial length, anterior chamber depth and lens thickness were taken with the Nidek US-500 Echoscan.Results: Participants’ ages ranged from 10 to 66 years with a mean age of 28.15 ± 13.09 years (95% confidence interval, 27.09–29.19). Of all the subjects, 295 (49.17%) were females and 305 (50.83%) were males. Axial length ranged from 20.42 mm to 27.28 mm with a mean of 23.05 mm ± 0.98 mm (95% confidence interval, 22.97–23.14), anterior chamber depth ranged from 2.38 mm to 4.13 mm with a mean of 3.21 mm ± 0.37 mm (95% confidence interval, 3.18–3.24) and crystalline lens thicknesses ranged from 2.24 mm to 4.66 mm with a mean of 3.69 mm ± 0.25 mm (95% confidence interval, 3.66–3.71). All three biometric indices were significantly higher in men than in women (all p-values < 0.05). A multivariate linear regression model indicated that axial length and anterior chamber depth decreased with age, while lens thickness increased with age. All biometric indices directly correlated with the male gender and height (all p-values < 0.001). Pearson correlation coefficient tests showed that axial length was significantly positively correlated with anterior chamber (r = 0.66, p < 0.001) and negatively correlated with lens thickness (r = -0.52, p < 0.001). A significant negative correlation was found between lens thickness and anterior chamber depth values (r = -0.68, p < 0.001).Conclusion: Normative values for axial length, anterior chamber depth and lens thickness are determined for the first time in a black South African sample, aged 10–66 years. Age, gender and height were associated with biometric indices. While there was a positive correlation between axial length and anterior chamber depth, there was a negative correlation between lens thickness and both axial length and anterior chamber depth. These biometric data and their intercorrelations may provide some insights into the pathophysiological mechanisms of angle-closure glaucoma in this population.

scholarly journals Repeatability and reproducibility of axial length, anterior chamber depth and crystalline lens thickness measurements using the Nidek US-500 Echoscan

2015 ◽  
Vol 74 (1) ◽  
Author(s):  
Khathutshelo P. Mashige
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Repeated Measures ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Crystalline Lens ◽  
Angle Closure ◽  
Lens Thickness ◽  
Primary Angle Closure Glaucoma ◽  
The Right

Aim: The reliability of an instrument used to collect data for clinical and research purposes is greatly important, especially when it is used to determine changes in measured ocular parameters over time. The purpose of this study was to determine the intra-session repeatability and inter-session reproducibility of axial length (AL), anterior chamber depth (ACD) and crystalline lens thickness (LT) measurements using the Nidek US-500 Echoscan.Method: Fifty successive automatic measurements of the above parameters were taken on the right eyes only of 12 healthy subjects aged 23–44 years old, followed by similar repeated measures after 1 week. Sample standard deviations (s.d.), precision (P) and coefficient of repeatability (COR) were calculated to determine intra-session repeatability. Coefficient of reproducibility (CRP), Bland and Altman plots, concordance correlation coefficients (CCC) and paired t-tests that compared measurements obtained in the first and second sessions, were used to determine inter-session reproducibility.Results: Both the intra-session repeatability and inter-session reproducibility were within acceptable limits for the three variables assessed.Conclusion: The study showed that the Nidek US-500 Echoscan provides accurate, repeatable and reproducible measurements of AL, ACD and LT in healthy eyes. This finding will be of interest to optometrists and ophthalmologists who measure these parameters when diagnosing, managing and investigating conditions such as primary angle-closure glaucoma and keratoconus.

scholarly journals Ocular Biometrics of Vietnamese Young Adults with Myopia

2019 ◽  
Vol 7 (24) ◽  
pp. 4283-4286
Author(s):  
Hien Thi Thu Nguyen ◽  
Dung Thi Thanh Nguyen ◽  
Dong Ngoc Pham ◽  
Anh Phuong Tran ◽  
Do Quyet ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Pearson Correlation ◽  
Anterior Chamber Depth ◽  
Spherical Equivalent ◽  
Central Cornea ◽  
Spherical Equivalent Refraction ◽  
Cornea Thickness ◽  
Central Cornea Thickness ◽  
Biometric Indices

BACKGROUND: Myopia is most prevalent type of refraction error. In some Asian countries, the prevalence of myopia can be 80 – 90% in the population aged 17 – 18. AIM: To analyze the correlation between ocular biometric indices and refraction status in Vietnamese young myopes. METHODS: A prospective cross – section study was conducted in young myopes. Data on axial length, central cornea thickness, corneal topography & anterior chamber depth and spherical equivalent were collected. Independent Sample T Test and ANOVA test were used to compare between groups. The correlations between ocular biometry and myopic spherical equivalent refraction were examined by Pearson Correlation with the level of significance p < 0.05. RESULTS: Totally, 418 eyes from 209 patients were recruited. The average axial length, central cornea thickness, cornea refraction & anterior chamber depth were 25.68 ± 1.09 mm, 539.78 ± 32.665 µm, 43.16 ± 1.369 D, 3.30 ± 0.243 mm, respectively. The correlation between axial length and spherical equivalent refraction (SER) was high (r = - 0.742, p < 0.0001) while those between central cornea thickness and cornea refraction were negligible (r = - 0.107, p = 0.029; r = -0.123, p = 0.012; respectively). There was no correlation between anterior chamber depth and spherical equivalent refraction (r = 0.019, p = 0.697). CONCLUSION: Among ocular biometric indices, axial length was significantly correlated with spherical equivalent of young adult patients.

scholarly journals Influence of measurement differences of anterior chamber depth and axial length on lens thickness evaluation in cataract patients: a comparison of two tests

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jiayi Xu ◽  
Chen Li ◽  
Lijun Wang ◽  
Caixin Li ◽  
Xin Li ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Pearson Correlation ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Lens Thickness ◽  
Cataract Patients ◽  
Good Agreement

Abstract Background The purpose of this study was to investigate the agreement of lens thickness (LT) measurements made by contact A-scan ultrasonography and Lenstar LS900 as well as the influence of anterior chamber depth (ACD) and axial length (AL) measurement differences on LT measurement in cataract patients in the two techniques. Methods 1247 cataract patients (1247 eyes) participated in this retrospective cross-sectional study. Ocular biometric measurements were performed with Lenstar LS900 and A-scan ultrasonography respectively, and the measured results of AL, ACD and LT were compared using Pearson correlation coefficients (r) and Bland-Altman analyses. Results Bland-Altman analyses showed poor agreement between the A-scan ultrasonography and Lenstar LS900 in measuring AL and ACD. The average difference of LT was 0.01 mm; the consistency limit was − 0.86 mm, 0.88 mm; and 95.27% of datapoints were within the 95% consistency limit. The consistency of LT measurements between the two techniques was poor for those subjects whose ACD or AL values were beyond the 95% consistency limit. Among the subjects whose AL or ACD values measured by A-scan ultrasonography were greater than those measured by Lenstar LS900, 93.33% of them were within the 95% consistency limit, suggesting that the consistency of LT measurement between the two techniques was poor. Of patients whose ACD or AL measured by A-scan ultrasonography were smaller than that of Lenstar LS900, 96.01% of them were within the 95% consistency limit. Conclusions There was good agreement of the LT measurements between A-scan ultrasonography and Lenstar LS900, except for the axis deviating from the apparent axis during A-scan ultrasonography. If this error can be avoided, A-scan ultrasonography can replace Lenstar LS900 in LT measurement in cataract patients.

scholarly journals Influence of measurement differences of anterior chamber depth and axial length on lens thickness evaluation in cataract patients: a comparison of two tests

2020 ◽  
Author(s):  
Jiayi Xu ◽  
Chen Li ◽  
Lijun Wang ◽  
Caixin Li ◽  
Xin Li ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Pearson Correlation ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Lens Thickness ◽  
Cataract Patients ◽  
Good Agreement

Abstract Background: The purpose of this study was to investigate the agreement of lens thickness (LT) measurements made by contact A-scan ultrasonography and Lenstar LS900 as well as the influence of anterior chamber depth (ACD) and axial length (AL) measurement differences on LT measurement in cataract patients in the two techniques.Methods: 1247 cataract patients (1247 eyes) participated in this retrospective cross-sectional study. Ocular biometric measurements were performed with Lenstar LS900 and A-scan ultrasonography respectively, and the measured results of AL, ACD and LT were compared using Pearson correlation coefficients (r) and Bland-Altman analyses.Results: Bland-Altman analyses showed poor agreement between the A-scan ultrasonography and Lenstar LS900 in measuring AL and ACD. The average difference of LT was 0.01 mm; the consistency limit was -0.86 mm, 0.88 mm; and 95.27% of datapoints were within the 95% consistency limit. The consistency of LT measurements between the two techniques was poor for those subjects whose ACD or AL values were beyond the 95% consistency limit. Among the subjects whose AL or ACD values measured by A-scan ultrasonography were greater than those measured by Lenstar LS900, 93.33% of them were within the 95% consistency limit, suggesting that the consistency of LT measurement between the two techniques was poor. Of patients whose ACD or AL measured by A-scan ultrasonography were smaller than that of Lenstar LS900, 96.01% of them were within the 95% consistency limit.Conclusions: There was good agreement of the LT measurements between A-scan ultrasonography and Lenstar LS900, except for the axis deviating from the apparent axis during A-scan ultrasonography. If this error can be avoided, A-scan ultrasonography can replace Lenstar LS900 in LT measurement in cataract patients.

scholarly journals Influence of measurement differences of anterior chamber depth and axial length on lens thickness evaluation in cataract patients: a comparison of two tests

2020 ◽  
Author(s):  
Jiayi Xu ◽  
Chen Li ◽  
Lijun Wang ◽  
Caixin Li ◽  
Xin Li ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Pearson Correlation ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Lens Thickness ◽  
Cataract Patients ◽  
Good Agreement

Abstract Background: The purpose of this study was to investigate the agreement of lens thickness (LT) measurements made by contact A-scan ultrasonography and Lenstar LS900 as well as the influence of anterior chamber depth (ACD) and axial length (AL) measurement differences on LT measurement in cataract patients in the two techniques.Methods: 1247 cataract patients (1247 eyes) participated in this retrospective cross-sectional study. Ocular biometric measurements were performed with Lenstar LS900 and A-scan ultrasonography respectively, and the measured results of AL, ACD and LT were compared using Pearson correlation coefficients (r) and Bland-Altman analyses.Results: Bland-Altman analyses showed poor agreement between the A-scan ultrasonography and Lenstar LS900 in measuring AL and ACD. The average difference of LT was 0.01 mm; the consistency limit was -0.86 mm, 0.88 mm; and 95.27% of datapoints were within the 95% consistency limit. The consistency of LT measurements between the two techniques was poor for those subjects whose ACD or AL values were beyond the 95% consistency limit. Among the subjects whose AL or ACD values measured by A-scan ultrasonography were greater than those measured by Lenstar LS900, 93.33% of them were within the 95% consistency limit, suggesting that the consistency of LT measurement between the two techniques was poor. Of patients whose ACD or AL measured by A-scan ultrasonography were smaller than that of Lenstar LS900, 96.01% of them were within the 95% consistency limit.Conclusions: There was good agreement of the LT measurements between A-scan ultrasonography and Lenstar LS900, except for the axis deviating from the apparent axis during A-scan ultrasonography. If this error can be avoided, A-scan ultrasonography can replace Lenstar LS900 in LT measurement in cataract patients.

scholarly journals A cross sectional clinical study on correlation between myopia and intraocular pressure and ocular biometric values among adults in tertiary eye care in Palakkad, Kerala, India

2018 ◽  
Vol 6 (8) ◽  
pp. 2790
Author(s):  
Raja A. M. ◽  
Rajendraprasad A. ◽  
Seema G.
Keyword(s):  
Clinical Study ◽  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Corneal Curvature ◽  
College Hospital ◽  
Cross Sectional ◽  
Intra Ocular Pressure ◽  
Lens Thickness ◽  
Ocular Pressure

Background: To find out whether there is a correlation between intra ocular pressure and ocular biometric values like corneal curvature, anterior chamber depth, lens thickness and vitreous chamber depth in myopic eyes.Methods: A cross sectional clinical study was conducted in karuna medical college hospital Palakkad Kerala, India from September 2015 to August 2017. 1000 eyes of 500 myopic patients attending the ophthalmology OPD were included in this study. Goldman applanation tonometry was used to measure intra ocular pressure. Bausch and Lomb keratometer was used to measure corneal curvature and Biometer A scan machine was used to measure anterior chamber depth, lens thickness, vitreous chamber depth and axial length.Results: In this study majority of the patients age group was 16-20 years. The overall mean intra ocular pressure was 15mmhg and mean radius of corneal curvature was 44.12D. In this study average anterior chamber depth was 3.55mm and mean lens thickness was 3.56mm.Mean vitreous chamber depth was 18.40. In this study mean axial length was 24.60mm.Conclusions: Amount of myopia and variation in corneal curvature was not statistically significant. There was no correlation between intra ocular pressure and degree of myopia. But anterior chamber depth, lens thickness, vitreous chamber depth and axial length were statistically very significant with amount of myopia.

scholarly journals Biometric indicators of Eyes with Occult Lens Subluxation inducing Secondary Acute Angle Closure

2019 ◽  
Author(s):  
Xiaoli Xing ◽  
Liangyu Huang ◽  
Fang Tian ◽  
Yan Zhang ◽  
Yingjuan Lv ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Acute Angle ◽  
Angle Closure ◽  
Lens Subluxation ◽  
Lens Thickness ◽  
Primary Angle Closure ◽  
Lens Position ◽  
Acute Angle Closure

Abstract Background : To compare the anterior biometricsof eyes with secondary acute angle closure induced by occult lens subluxation (ASAC-LS), which were misdiagnosed at the first visit withacute primary angle closure (APAC), chronic primary angle closure glaucoma (CPACG), or cataracts. Methods: This retrospective case series ncluded 17 eyes with angle closure due to occult LS which were misdiagnosed with APAC at the first visit, 56 APACeyes, 54 CPACGeyes, and 56 cataracteyes. The axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AD), and lens thickness (LT) were recorded. The lens position (LP), relative lens position (RLP), and corrected lens position (CLP) were calculated. Quantitative data were subject to a one-way analysis of variance and correlation analysis. Categorical data were analysed using the chi-squared test. Receiver operating characteristic (ROC) curves were plotted to obtain a suitable cut-off value for ocular biometrics. Results: The ASAC-LSpatients had a longer ocular AL than the APACand CPACGpatients. The CCTinthe ASAC-LS patientsdid not significantly differ from that in the APAC patientsbut did significantly differ from that of the CPACG and cataract patients.The APAC patientshad the smallest ACD, while the ASAC-LS patientshad the smallest AD. The ASAC-LS patientshad the thickest lenses. According to the ROC curve analysis, the RLP, ACD, AD, CLP, and LP hada high power of discrimination. Conclusions: This study revealed that ASAC-LS patients had a shallower AD and thicker CCT compared to APAC, CPACG, and cataract patients. Biometric parameters ACD, ADwere characteristic of lens subluxation according to our data. The calculated parameters RLP,CLP, LP can be helpful in the differential diagnosis between ASAC-LSand APAC, CPACG, Cataract. Trial registration: NCT03752710, retrospectively registered. Keywords:Lens subluxation; Acute angle-closure; Biometry; Anterior chamber depth; Lens thickness; Axial length

scholarly journals Effects of diode laser photocoagulation treatment on ocular biometric parameters in premature infants with retinopathy of prematurity

2021 ◽  
Vol 14 (2) ◽  
pp. 277-282
Author(s):  
Damla Erginturk Acar ◽  
◽  
Zuhal Ozen Tunay ◽  
Aysegul Arman ◽  
Anil Barak ◽  
...  
Keyword(s):  
Treatment Group ◽  
Anterior Chamber ◽  
Laser Treatment ◽  
Diode Laser ◽  
Premature Infants ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Biometric Parameters ◽  
Lens Thickness ◽  
Photocoagulation Treatment

AIM: To investigate the effects of diode laser treatment on ocular biometric parameters in premature infants with retinopathy of prematurity (ROP). METHODS: Premature infants who received diode laser treatment for ROP (n=68) and premature infants with spontaneous regressed ROP without treatment (n=50) were performed longitudinal ocular biometric measurements including anterior chamber depth, lens thickness and axial length as follows: 1d prior to laser treatment, and 3, 6, 9, and 12mo after the laser treatment. RESULTS: The mean birth weight, gestational age and initial examination time values were 936.53±302.07 g, 26.66±2.42wk, 36.26±2.73wk in the treatment group and 959.78±260.08 g, 27.28±2.10wk, 36.56±2.54wk in the control group. There was no statistically significant difference in these demographic characteristics of the groups. Anterior chamber depth, lens thickness and axial length demonstrated statistically significant linear increases during the study period in the two groups (P<0.001 for each). There were no statistically significant differences between the two groups in terms of anterior chamber depth after laser treatment. Measurements of the lens thickness at 9th and 12th months (9th month 3.70±0.22 vs 3.60±0.21 mm, P=0.017; 12th month 3.81±0.21 vs 3.69±0.22 mm, P=0.002) and the axial length at 12th month (19.35±0.79 vs 19.13±0.54 mm, P=0.031) after laser treatment were statistically higher in the treatment group. CONCLUSION: Diode laser retinal photocoagulation treatment in premature infants seems to increase the lens thickness and axial length.

scholarly journals Presbyopia and its anatomical and physiological variants

1970 ◽  
Vol 3 (2) ◽  
pp. 155-158
Author(s):  
M Gupta ◽  
RR Sukul ◽  
Y Gupta ◽  
M Dey ◽  
A Phougat ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Physiological Parameters ◽  
Corneal Curvature ◽  
Lens Thickness ◽  
Significant Difference ◽  
The Mean

Aim: To study the various ocular anatomical and physiological parameters in presbyopia. Materials and methods: We studied the various ocular anatomical and physiological parameters like corneal curvature (keratometry readings: K1 and K2), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) in 100 presbyopic patients between 35 - 55 years of age. The patients were divided into two age groups: I (35 – 44 years) and II (45-55 yrs). ACD, AL and LT were measured using an Ascan. CCT was measured with ultrasonic pachymetry. Results: The CCT decreased (BE), LT increased and ACD decreased (RE) significantly with increasing age (p < 0.05). There was no significant difference in males and females. Nearly 3/4th of the total increase in lens thickness was responsible for the decrease in the anterior chamber depth and the rest, 1/4th , goes posteriorly. Corneal curvature and AL showed no significant change with age. Conclusions: The mean of CCT decreased significantly with advancing age. As age increased, the mean value of lens thickness increased and anterior chamber depth decreased. Nearly 3/ 4th of total increase in LT was anteriorly, decreasing the ACD. Corneal curvature and AL has no relation with age. Key words: Presbyopia, central corneal thickness, anterior chamber depth, lens thickness, axial length DOI: http://dx.doi.org/10.3126/nepjoph.v3i2.5269 Nepal J Ophthalmol 2011; 3(2): 155-158

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