Effect of axial length and anterior chamber depth on the peripheral refraction profile

AIM: To evaluate the effect of axial length (AL) and anterior chamber depth (ACD) on peripheral refractive profile in myopic patients compared to emmetropic participants. METHODS: This cross-sectional study was conducted in right eyes of 58 participants of whom 38 were emmetropic and 20 were myopic. Central and peripheral refraction were measured at 10°, 20°, and 30° eccentricities in nasal and temporal fields using an open-field autorefractor. The Lenstar LS900 was used to measure ACD and AL. The participants were divided into three groups of short (<22.5 mm), normal (22.5-24.5 mm), and long eye (>24.5 mm) according to AL and three groups of low ACD (<3.00 mm), normal ACD (3.00-3.60 mm), and high ACD (>3.60 mm) according to ACD. RESULTS: The mean age of the participants was 22.26±3.09y (range 18-30y). The peripheral mean spherical refractive error showed a hypermetropic shift in myopic and emmetropic groups although this shift was more pronounced in the myopic group. The results showed significant changes in the spherical equivalent, J0, and J45 astigmatism in all gazes with an increase in eccentricity (P<0.001). The pattern of refractive error changes was more noticeable in long and short eyes versus normal AL eyes. Moreover, the pattern of peripheral refractive changes was much more prominent in the high ACD group versus the normal ACD group and in the normal ACD group versus the low ACD group. CONCLUSION: Peripheral refraction changes are greater in participants with AL values outside the normal range and deeper ACD values compared to participants with normal AL and ACD.

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Measurement of the anterior chamber depth and ocular axial length: transpalpebral B-mode ultrasound using an 18-MHz linear probe compared with the IOL Master 500

Medical Ultrasonography ◽

10.11152/mu-2676 ◽

2020 ◽

Author(s):

Julia Gutierrez-Vazquez ◽

Lorenzo Ismael Perez-Sanchez ◽

Maria Satrustegui-Lapetra ◽

Juan Jose Arevalo-Manso ◽

Juan Jesus Gomez-Herrera ◽

...

Keyword(s):

Anterior Chamber ◽

Axial Length ◽

Anterior Chamber Depth ◽

Cross Sectional Study ◽

Mean Difference ◽

Cross Sectional ◽

Bland Altman Method ◽

Wide Range ◽

Linear Probe ◽

The Mean

Aims: To determine the reliability of transpalpebral ultrasound in B-mode (B-TUS) with a high-resolution linear probe (18 MHz) in estimating both the ocular anterior chamber depth (ACD) and axial length (AL), as well as its agreement with the IOL Master 500 optical biometer. Material and methods: Cross-sectional study on 82 eyes of 41 volunteers with no history of eye disease. ACD and AL were determined using B-TUS and the IOL Master 500. The agreement between the two tech-niques and the variability of B-TUS (inter- and intra-observer) were analyzed with the Bland-Altman method. To this end, the mean difference between measures±1.96 SD was calculated to determine the limits of agreement (LoA). Results: The mean difference±1.96SD between B-TUS and the IOL Master 500 was -0.41±0.25mm for ACD (p<0.001) and -0.48±0.45 mm for AL (p<0.001). The maximum variability for B-TUS (average±1.96SD) was 0.00±0.35 mm at the inter-observer level for AL, and 0.00±0.18mm at the intra-observer level for AL. Conclusion: The determination of ACD and AL by B-TUS has a good re-liability and variability, in line with other sonographic techniques. However, it systematically provides smaller measurements than those obtained with the IOL Master 500, similar to the conventional ultrasound techniques. B-TUS could be useful in the assessment and follow-up of a wide range of ophthalmic diseases, in which a high accuracy in ACD and AL is not determinant.

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A calculator proposal for estimating refractive error after 3 years using the onset biometric values in primary school children: a cohort study

10.22541/au.161971139.95061043/v1 ◽

2021 ◽

Author(s):

Feride Tuncer Orhan ◽

Haluk Huseyin Gürsoy

Keyword(s):

Primary School ◽

Anterior Chamber ◽

Refractive Error ◽

Axial Length ◽

Anterior Chamber Depth ◽

Primary School Children ◽

Optical Parameters ◽

Spherical Equivalent ◽

Final Data ◽

The Mean

Aim To evaluate consecutive measurements of the biometric parameters, age, and refraction error in a Turkish population at primary school age. Materials and Methods A total of 197 children aged between 7-12 years were included. The data of three consecutive measurements of children, who were examined at least once a year for three years using both cycloplegic auto-refractometry and optical biometry, were used in this retrospective study. Spherical equivalent <-0.50D was considered to be myopic; >+0.75D was considered to be hypermetropic. Age, gender, body mass index, spherical equivalent, axial length, anterior chamber depth, central corneal thickness, keratometry, and lens thickness were analyzed. The onset data obtained in 2013 whereas, the final data were from 2015. Logistic and Cox regression analyses were performed (p<0.05). Results The mean of the onset and the final spherical equivalents were 0.19D (0.56), and 0.08D (0.80), respectively. The myopia prevalence was increased among refractive errors in observation periods (univariable analysis p=0.029; multivariable analysis p=0.017). The onset axial length (HR:4.55, 95%CI:2.87-7.24, p<0.001), keratometry (HR:2.04, 95%CI:1.55-2.67, p<0.001) and age (HR:0.73, 95%CI: 0.57-0.92, p=0.009) correlated myopia progression. To calculate the estimated spherical equivalent, the onset data were included in the logistic regression model. The onset data of spherical equivalent (β=0.916, p<0.001), axial length (β=-0.451, p<0.001), anterior chamber depth (β=0.430, p=0.005) and keratometry (β=-0.172, p<0.001) were found to be significantly associated with the mean SE at the final data. Conclusions To calculate the estimated spherical equivalent following three years, an equation was proposed. The estimated refractive error of children can be calculated by using the proposed equation with the associated onset optical parameters.

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Psychological Distress during COVID-19 Curfews and Social Distancing in Saudi Arabia: A Cross-Sectional Study

10.21203/rs.3.rs-40296/v1 ◽

2020 ◽

Author(s):

Badrah S Alghamdi ◽

Yasser AlAtawi ◽

Fahad S. AlShehri ◽

Haythum O. Tayeb ◽

Hanin Abo Abo Taleb ◽

...

Keyword(s):

Mental Health ◽

Saudi Arabia ◽

Psychological Distress ◽

Cross Sectional Study ◽

Depression And Anxiety ◽

Sectional Study ◽

Normal Range ◽

Cross Sectional ◽

The Mean ◽

Stress Score

Abstract Background Coronavirus disease 2019 (COVID-19) has spread to over 150 countries worldwide. Since the first case of COVID-19 was confirmed in Saudi Arabia, cases have continued to escalate exponentially. The COVID-19 outbreak has had a negative effect on mental health and well-being. The study aim was to investigate the effects of the strict national regulations associated with the COVID-19 pandemic on the population’s mental health. Methods This was a cross-sectional study of a convenience sample of Saudi residents. Participants completed an online questionnaire after 1 month of a nationwide 24-hour curfew. We measured psychological distress using the Depression, Anxiety and Stress Scale-21 (DASS-21). We ran binary logistic regression analyses to detect variables that significantly predicted DASS-21 scores. Results The sample comprised 2252 Saudi residents. The DASS-21 score means and standard deviations for depression and anxiety for the whole sample (10.73 ± 10.29 and 6.98 ± 8.30, respectively) were in the range of mild depression and anxiety. In contrast, the mean DASS-21 stress score was within the normal range (11.97 ± 10.80). The mean stress score for healthcare workers was within normal range (13.70 ± 10.68), but was significantly higher than the mean score for the public (11.56 ± 10.89; P = .0006). Several variables (e.g. age, gender and history of contact with confirmed COVID-19 cases) were significantly associated with higher DASS-21 scores. Conclusions The COVID-19 pandemic has created a psychological burden. Therefore, there is an urgent need to implement emergency psychological interventions to reduce the negative psychosocial effects of the pandemic on public mental health.

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Quantification of Trabecular-Iris Contact and its Prevalence by Optical Coherence Tomography in a Healthy Caucasian Population

European Journal of Ophthalmology ◽

10.5301/ejo.5000919 ◽

2016 ◽

Vol 27 (4) ◽

pp. 417-422 ◽

Cited By ~ 4

Author(s):

José Ignacio Fernández-Vigo ◽

Lucía De-Pablo-Gómez-De-Liaño ◽

Cristina Fernández-Vigo ◽

Inés Sánchez-Guillén ◽

Enrique Santos-Bueso ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Anterior Chamber ◽

Refractive Error ◽

Axial Length ◽

Corneal Thickness ◽

Anterior Segment ◽

Anterior Chamber Depth ◽

Fourier Domain ◽

Optical Coherence ◽

Cross Sectional

Purpose To determine the prevalence of trabecular-iris contact (TIC) and quantify this contact in healthy Caucasian individuals using Fourier-domain optical coherence tomography (FD-OCT). Methods For this cross-sectional study, 2,012 eyes of 1,006 healthy subjects were recruited among individuals undergoing a routine ophthalmologic checkup. In each participant, age, sex, intraocular pressure, and spherical refractive error were first recorded along with anterior chamber depth and volume, central corneal thickness measured with the Pentacam, and axial length with the IOLMaster. Anterior chamber angle variables and the presence of TIC in the horizontal quadrants were determined by anterior segment FD-OCT (RTVue 100®). When TIC was observed, TIC length (TICL) and its percentage in relation to the length of the trabecular meshwork (TICL percentage) were also measured. Results Trabecular-iris contact in the horizontal quadrants was observed in 34 eyes of 25 patients, representing 1.6% of the total number of eyes examined. In this subgroup of individuals, mean age was 55.8 years, 84% were women, and spherical refractive error ranged from -0.25 to 8.25 D. Eyes with TIC showed an angle width of less than 23.2 degrees and axial length shorter than 23.7 mm. Mean TICL was 239 ± 79 μm (103-495 μm) and mean TICL percentage was 46.9% ± 13.9% (17.2%-76.3%). Conclusions The prevalence of TIC was low in this population. Fourier-domain optical coherence tomography emerged as useful to assess its prevalence and quantify the extent of TIC.

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

BMC Ophthalmology ◽

10.1186/s12886-020-01754-w ◽

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.

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Refraction in Preschool Children in Kazanlak, Bulgaria

Folia Medica ◽

10.3897/folmed.62.e47463 ◽

2020 ◽

Vol 62 (2) ◽

pp. 345-351

Author(s):

Kiril Slaveykov ◽

Kalina Trifonova

Keyword(s):

Preschool Children ◽

Refractive Error ◽

Axial Length ◽

Cross Sectional Study ◽

Spherical Equivalent ◽

Sectional Study ◽

Cross Sectional ◽

Refractive State ◽

Myopic Shift ◽

The City

Introduction: The refractive state of the eye changes as the eye’s axial length increases and the cornea and lens flatten. In general, eyes are hyperopic at birth, become slightly more hyperopic until the age of 7, which at this point we see a myopic shift toward plano until the eyes reach their adult dimensions, usually by about the age 16. Aim: To determine the prevalence of refractive error in preschool children aged 3 - 6 in the city of Kazanlak, Bulgaria. Materials and methods: A cross-sectional study was conducted in a kindergarten based school within the city of Kazanlak, Bulgaria. Out of 15 kindergarten schools, 10 chose to participate in the study. The children underwent non-mydriatic refraction screening using a Plus-Optix S12с mobile camera. Myopia, hyperopia and astigmatism were defined as being a spherical equivalent (SE) ≤ −0.50 D, SE ≥ +2.00 D and cylindrical diopters ≤ −1.00 D. Results: A total of 596 children were screened. Out of these 596 children; 526 were with ametropia (470 hypermetropia, 46 myopia) and 50 had astigmatism. Strabismus was found in 12 children, with a further 8 children suffering from amblyopia and finally 8 children were also found to be diagnosed with anisometropia. In 8 cases there were no results due to opacities or due to the small size of the pupil. Conclusion: The prevalence of refractive error in preschool children is similar to that found in other research in the field. While most cases fall into the category of emmetropia or mild hypermetropia, most of the children had never been to an ophthalmologist. A mandatory checkup should be issued for all children below the age of seven.

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

10.21203/rs.3.rs-62251/v2 ◽

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.

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

10.21203/rs.3.rs-62251/v3 ◽

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

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Refractive error and biometrics of anterior segment of eyes of healthy young university students in Japan

Scientific Reports ◽

10.1038/s41598-019-51920-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Kumiko Kato ◽

Mineo Kondo ◽

Maki Takeuchi ◽

Koji Hirano

Keyword(s):

University Students ◽

Anterior Chamber ◽

Refractive Error ◽

Axial Length ◽

Corneal Thickness ◽

Anterior Segment ◽

Anterior Chamber Depth ◽

Japanese University ◽

The Mean ◽

Corneal Diameter

Abstract To determine the parameters of the anterior segment of eyes that are significantly associated with the refractive error in healthy young Japanese university students. This was a cross-sectional observational study of 229 healthy Japanese university students (men: women,147:82) whose age ranged between 20 to 29 years. Univariate and multivariate linear regression analyses were performed to identify the factors that were significantly correlated with the refractive error. The independent variables included age, sex, axial length, anterior chamber depth, corneal diameter, curvature of anterior surface of cornea, and central corneal thickness. The mean refractive error (spherical equivalent) was −4.1 ± 2.7 diopters (D) with a range of −12.5 to +0.5 D, and the mean axial length was 25.4 ± 1.3 mm with a range of 22.4 to 29.0 mm. Pearson univariate correlation analysis found that the refractive error was significantly and negatively correlated with the axial length (R = −0.82, P < 0.001), deeper anterior chamber (R = −0.30, P < 0.001), and larger corneal diameter (R = −0.21, P = 0.001). Multiple regression analysis showed that the refractive error was significantly associated with a longer axial length (P < 0.001), a deeper anterior chamber (P < 0.001), and a flatter corneal curvature (P < 0.001).The biometric values of the anterior segment of the eyes should make the eye more hyperopic which would reduce the myopia-inducing lengthening of the axial length.

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ADULT MYOPES

The Professional Medical Journal ◽

10.29309/tpmj/18.4855 ◽

2018 ◽

Vol 25 (11) ◽

pp. 1660-1666

Author(s):

NuhaMohamed Fath Elrahman ◽

AbdElaziz Mohamed Elmadina ◽

Manzoor Ahmad Qureshi ◽

Adil Mousa Younis ◽

Muhammad Ijaz Ahmad ◽

...

Keyword(s):

Axial Length ◽

Corneal Thickness ◽

Cross Sectional Study ◽

Age Group ◽

Spherical Equivalent ◽

Corneal Curvature ◽

Sectional Study ◽

Cross Sectional ◽

Gender And Age ◽

The Mean

Objectives: This study aimed to explore the correlation of central cornealthicknesses (CCT), mean keratometry (KM) and axial length (AL) to myopia degree in sphericalequivalent (SE) among Sudanese adults. Study Design: Cross sectional study. Setting:University Eye complex clinic and Makka Eye complex Omdurman. Period: April to October2015. Methods: Central Corneal Thickness (CCT), k-reading (KM), axial length and thedegree of refraction (SE) 0f 200 myopic eyes and 60 emmetropic eyes as a control groupwere measured. Results: Adult Sudanese females (57%) were found greater than males (43%)population; (χ 2 = 109.5, p = 0.000 ), most of the participants’ age was less than 25 years(χ 2 = 109.5, p = 0.000 ), and the mean myopic spherical equivalent (SE) was – 4.79 ± 2.55 D,ranging from -1.00 to -11.00 D. The mean CCT of the myopic group was 542.8 ±11.9 μm,while for the emmetropic group was 538.7 ±12.4 μm. The cornea were steeper in eyes withlonger axial length (r = 0.24, p =0.001). Eyes with higher myopic spherical equivalent hadlonger axial length (r =0.30, p <0.001). Mean keratometrys were steeper with increasing age(r= 0.24, p= 0.001). This study has shown that CCT has no correlation with degree of myopia(p= 0.46), gender (p= 0.99), and age (p= 0.07). The CCT, KM, and AL means for myopicparticipants were found significantly greater than emmetropic participants (p=0.000, 0.000,and 0.044 respectively. Conclusion: The females participants of myopia were higher rate thanmales, early adults’ age group were of higher rate myopic incident; there was no correlationbetween CCT and the degree of myopia, gender, and age. CCT, KM, and AL means for myopicwere found higher than emmetropic participant. Eyes with more myopic spherical equivalenthad longer axial length; corneal curvature mean becomes steeper with increasing age.

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