scholarly journals The Correlation of Cycloplegic Refraction with Corneal Radius of Curvature-Adjusted Axial Length in Chinese Preschoolers

2021 ◽  
Author(s):  
Xiao-hong Zhou ◽  
Yian Li ◽  
Wei Wang ◽  
Chen-hao Yang
Keyword(s):  
Axial Length ◽  
Chinese Children ◽  
Radius Of Curvature ◽  
Refractive Errors ◽  
Spherical Equivalent ◽  
Spherical Equivalent Refraction ◽  
Curvature Coefficient ◽  
Corneal Radius ◽  
The Mean ◽  
And Gender

Abstract Background: In order to master the refractive status and detect severe refractive errors quickly and effectively, this study aimed to investigate the association of axial length after adjusting for corneal radius of curvature with refraction in a group of Chinese preschoolers. Methods: Retrospective review of 716 Chinese children aged from 3 to 6 years, who underwent cycloplegic optometry with 1% atropine eye gel in the ophthalmology department of Children’s Hospital of Fudan University, National Children’s Medical Center in Shanghai. Meanwhile axial length, corneal radius of curvature and cycloplegic autorefraction were obtained and axial length/corneal radius of curvature (AL/CR) ratio was calculated. The correlations of spherical equivalent refraction (SER) with axial length, corneal radius of curvature, AL/CR ratio and corneal radius of curvature-adjusted axial length were analyzed. Results: Only data from the right eye were included in this analysis. Among 716 eyes of 716 Chinese preschoolers, the mean (±SD) SER was 2.28±2.41 diopters (D), of which hyperopia, emmetropia, myopia were 84.64%, 8.54%, 6.84%, respectively. The mean(±SD) axial length, corneal radius of curvature and AL/CR ratio were 21.89±1.01mm, 7.76±0.27 mm, and 2.82±0.13, respectively. The SER was highly negative correlated with both axial length (coefficient –0.722) and AL/CR ratio (coefficient-0.814), and weakly correlated with corneal radius of curvature (coefficient 0.090) and gender(coefficient 0.093). Axial length was weakly correlated with age and gender(coefficient 0.232 and 0.268, respectively), but moderately correlated with corneal radius of curvature (coefficient 0.424). After adjusting for corneal radius of curvature, the correlation coefficient between SER and axial length significantly increased to-0.918. Conclusion: In the samples of 716 3-to 6-year-old Chinese children, axial length was moderately correlated with corneal radius of curvature. After adjusting for corneal radius of curvature, refraction was closely correlated with axial length than axial length alone and AL/CR ratio. Therefore, corneal radius of curvature-adjusted axial length might be a useful tool for pediatric ophthalmologists to detect refractive errors. Key Words: spherical equivalent refraction; corneal radius of curvature; adjusted; axial length; preschoolers.

scholarly journals The Role of Axial Length-Corneal Radius of Curvature Ratio in Refractive State Categorization in a Nigerian Population

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Eghosasere Iyamu ◽  
Joy Iyamu ◽  
Christian Izuchukwu Obiakor
Keyword(s):  
Axial Length ◽  
Inverse Correlation ◽  
Radius Of Curvature ◽  
Spherical Equivalent ◽  
Refractive State ◽  
Spherical Equivalent Refraction ◽  
Nigerian Population ◽  
Corneal Radius ◽  
The Mean

The aim of this study was to investigate the association of axial length (AL)/corneal radius of curvature (CRC) ratio (AL/CRC) with spherical equivalent refractive state (SER) in young adults. A total of seventy () subjects consisting of 31 males and 39 females participated in this study. Subjects were categorized into emmetropia, hyperopia and myopia using the spherical equivalent refraction. The axial length was measured with I-2100 A-Scan ultrasonography/Biometer (CIMA Technology, USA), the corneal radius of curvature with Bausch & Lomb H-135A (Bausch & Lomb Corp., USA), and the refractive state by static retinoscopy and subjective refraction. The mean AL, CRC and AL/CRC ratio of all subjects were 23.74 ± 0.70 mm, 7.84 ± 0.19 mm, and 3.03 ± 0.14, respectively. Myopes had significantly longer AL, steeper CRC and higher AL/CRC ratio than the emmetropes and hyperopes. There was statistically significant inverse correlation between AL and CRC (, ), SER (, ), and between SER and AL/CRC (, ). A significant positive correlation was found between CRC and SER (, ). The categorization of the refractive state of an individual is better done by using the AL/CRC ratio index.

scholarly journals Development of Refractive Parameters in 3- to 6-Year-Old Children and Its Application in Myopia Prediction and Intervention Guidance

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ya Zhang ◽  
Ming Su ◽  
Hua Liu ◽  
Yanxia Song ◽  
Jing Liu ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Clinical Work ◽  
Hebei Province ◽  
Radius Of Curvature ◽  
Spherical Equivalent ◽  
Ocular Biometry ◽  
Refractive Development ◽  
Corneal Radius ◽  
The Mean ◽  
Vision Screener

Objective. To investigate refractive development and prevalence of myopia in children aged 3-6 years in Hebei Province, China, and to explore the developmental law of refraction, so as to clinically guide the prediction and intervention of myopia. Methods. In May 2019, a total of 6120 people were inspected in 68 kindergartens in 11 cities in Hebei Province. Child refractive refraction was checked under noncycloplegia using a handheld binocular vision screener (SW-800, SUOER, Tianjin, China). Axial length (AL) and corneal radius of curvature (CR) were measured using an ocular biometry (IOLMaster 500, Carl Zeiss, Germany). Myopia was defined as spherical equivalent SE ≤ − 0.75   D . Results. A total of 5506 children aged 3-6 years met the criteria and were included in the statistical analysis. The prevalence of myopia was 3.49% (1.93% at age 3, 2.90% at age 4, 3.78% at age 5, and 3.88% at age 6). Overall, the mean SE was + 0.67 ± 1.05   D ( + 0.81 ± 1.00   D at age 3, + 0.79 ± 1.05   D at age 4, + 0.67 ± 1.08   D at age 5, and + 0.13 ± 1.01   D at age 6); the mean CR was 7.76 ± 0.26   mm ( 7.78 ± 0.26   mm at age3, 7.75 ± 0.25   mm at age 4, 7.77 ± 0.26   mm at age 5, and 7.76 ± 0.25   mm at age 6); the mean AL was 22.31 ± 0.73   mm ( 21.98 ± 0.63   mm at age 3, 22.12 ± 0.69   mm at age 4, 22.34 ± 0.73   mm at age 5, and 22.49 ± 0.73   mm at age 6). Conclusions. Prevalence of myopia increases with age in children aged 3-6 years in Hebei, China. With the increase of age, CR is basically stable, and AL increases gradually. AL/CR, which is closely related to SE, can be used as an indicator to predict myopia and guide clinical work.

Topical atropine in retarding myopia progression and axial length growth in children with myopia

2020 ◽  
Vol 13 (4) ◽  
pp. 111-114
Author(s):  
Abdur Rahman Mohammad Alam ◽  
Md. Sanwar Hossain ◽  
Md. Shafiqul Islam
Keyword(s):  
Axial Length ◽  
Control Group ◽  
Refractive Errors ◽  
Spherical Equivalent ◽  
Myopia Progression ◽  
Length Growth ◽  
Significant Difference ◽  
The Mean ◽  
And Control

This study was conducted to observe the effect of atropine in retarding myopia progression and axial length growth in 36 myopic children (atropine group, 24; control, 12). The initial spherical equivalent of the atropine group and control group was -3.0 ± 1.6 dioptre and -3.5 ± 1.6 dioptre respectively. At the 12th month in atropine group, it was -2.9 ± 2.6 dioptre and -4.6 ± 1.9 dioptre in the control group. The power of the atropine group reduced but rose in the control group after 12 months. There was a statistically significant difference in final refractive errors between the two groups (p<0.05). The initial axial length of the atropine group and control group was 24.3± 1.0 mm and 24.6 ± 1.1 mm respectively. In 12th month, the changes in axial length in the two groups was insignificant. However, the mean axial length progression at 12 months of the atropine group was -0.1 ± 0.1 mm and it was lower than the control group which was -0.2 ± 0.2 mm, and this was statistically significant (p<0.05). In conclusion, topical atropine (0.01%) retarded myopia progre-ssion and axial length growth in myopic children.    

Astigmatism and its components in 12-year-old Chinese children: the Anyang Childhood Eye Study

2018 ◽  
Vol 103 (6) ◽  
pp. 768-774 ◽  
Author(s):  
He Li ◽  
Shi-Ming Li ◽  
Luo-Ru Liu ◽  
Ya-Zhou Ji ◽  
Meng-Tian Kang ◽  
...  
Keyword(s):  
Study Data ◽  
Chinese Children ◽  
Refractive Errors ◽  
Spherical Equivalent ◽  
Corneal Curvature ◽  
Old Chinese ◽  
Spherical Equivalent Refraction

PurposeTo determine prevalence of refractive (RA), corneal (CA) and internal astigmatism (IA), including variation with gender and spherical equivalent refraction (SE), in a population of 12-year-old Chinese children.MethodsA total of 1783 students with a mean age of 12.7 years (range 10.0–15.6 years) completed comprehensive eye examinations in the Anyang Childhood Eye Study. Data of cycloplegic refraction and corneal curvature were analysed.ResultsPrevalences of RA, CA and IA ≥1.0 D were 17.4% (95%CI 15.6% to 19.2%), 52.8% (50.5% to 55.1%)%) and 20.9% (19.0% to 22.8%), respectively. With different limits of astigmatism axes classification, including ±15°, ±20° and ±30°, RA and CA axes were mainly ‘with-the-rule’ (WTR) (ie, correcting axis of negative cylinders at or near 180°), while those for IA axes were mainly ‘against-the-rule’ (ATR) (ie, correcting axis of negative cylinders at or near 90°). RA was not different between the genders, but girls had higher prevalence and greater means of CA and IA. RA and CA increased in students with higher ametropia (more myopia and more hyperopia) and were the highest in a high myopic group (SE≤−6 D), while IA was stable across refraction groups. Children with RA higher than 0.50 D were more likely to have lens corrections (51%, 57%, 61% and 69% for magnitudes of ≥0.50 D, ≥0.75 D, ≥1.0 D and ≥1.5 D, respectively).ConclusionsPrevalence of RA in the Chinese 12-year-old children was relatively high compared with other studies. RA and CA had mainly ‘WTR’ astigmatism, while IA was mainly ATR and partially compensated for CA. Girls had greater means and prevalences of CA and IA than did boys. Both RA and CA, but not IA, increased with refractive errors away from emmetropia.

scholarly journals Simultaneous Changes in Astigmatism with Noncycloplegia Refraction and Ocular Biometry in Chinese Primary Schoolchildren

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yaoyao Lin ◽  
Dandan Jiang ◽  
Chunchun Li ◽  
Xiao Chang ◽  
Balamurali Vasudevan ◽  
...  
Keyword(s):  
Odds Ratio ◽  
Radius Of Curvature ◽  
Spherical Equivalent ◽  
Ocular Biometry ◽  
Spherical Equivalent Refraction ◽  
Primary Schoolchildren ◽  
Corneal Radius ◽  
Independent Risk Factors ◽  
Clinically Significant

Purpose. To assess the changing profile of astigmatism in Chinese schoolchildren and the association between astigmatism changes and ocular biometry. Methods. We examined and followed up 1,463 children aged 6–9 years from Wenzhou, China. We measured noncycloplegic refraction twice each year and tested axial length (AL) and corneal radius of curvature (CRC) annually for two years. We defined clinically significant astigmatism (CSA) as ≤−0.75 diopter (D) and non-CSA astigmatism as ≤0 to >−0.75 D. Results. Prevalence of CSA at baseline was 22.4% (n = 327) and decreased to 20.3% (n = 297) at the two-year follow-up (P=0.046). Ninety-two (8.1%) non-CSA children developed CSA. In multiple regression, after adjusting for age, gender, baseline cylinder refraction, and axis, children who had longer baseline ALs (>23.58 mm; odds ratio (OR) = 5.19, 95% confidence interval (CI): 2.72–9.90) and longer baseline AL/CRC ratio (>2.99, OR = 4.99, 95% CI: 2.37–10.51) were more likely to develop CSA after two years. Four-hundred and two (27.5%) children had increased astigmatism, 783 (53.5%) had decreased, and 278 (19.0%) had no change during the two-year follow-up. Children with increased astigmatism had longer baseline ALs (23.33 mm, P<0.001), higher AL/CRC ratios (2.99 mm, P<0.001), and more negative spherical equivalent refraction (SER) (−0.63 D, P<0.001) compared with the decreased and no astigmatism change subgroups. Also, children in the increased astigmatism subgroup had more AL growth (0.68 mm, P<0.001), higher increases in AL/CRC ratio (0.08, P<0.001), and more negative SER change (−0.86 D, P<0.001) compared with the decreased and no astigmatism change subgroups. Conclusions. The prevalence of astigmatism decreased slightly over the two-year study period. Longer ALs and higher AL/CRC ratios were independent risk factors for developing CSA. Increased astigmatism was associated with AL growth, AL/CRC ratio increases, and the development of myopia. This trial is registered with ChiCTR1800019915.

scholarly journals Normative data and percentile curves for axial length and axial length/corneal curvature in Chinese children and adolescents aged 4–18 years

2021 ◽  
pp. bjophthalmol-2021-319431
Author(s):  
Xiangui He ◽  
Padmaja Sankaridurg ◽  
Thomas Naduvilath ◽  
Jingjing Wang ◽  
Shuyu Xiong ◽  
...  
Keyword(s):  
Axial Length ◽  
Intraclass Correlation ◽  
Radius Of Curvature ◽  
Specific Reference ◽  
Model Risk ◽  
Percentile Curves ◽  
Corneal Radius ◽  
And Gender ◽  
Gender Specific ◽  
Chinese Children And Adolescents

PurposeTo develop age-specific and gender-specific reference percentile charts for axial length (AL) and AL/corneal radius of curvature (AL/CR) and, to use percentiles to determine probability of myopia and estimate refractive error (RE).MethodsAnalysis of AL, cycloplegic RE and CR of 14 127 Chinese participants aged 4–18 years from 3 studies. AL and AL/CR percentiles estimated using Lambda-Mu-Sigma method and compared for agreement using intraclass correlation (ICC). Logistic regression was used to model risk of myopia based on age, gender, AL and AL/CR percentiles. Accuracy of AL progression and RE estimated using percentiles was validated using an independent sample of 5742 eyes of children aged 7–10 years.ResultsAge-specific and gender-specific AL and AL/CR (3rd, 5th, 10th, 25th, 50th, 75th, 90th and 95th) percentiles are presented. Concordance between AL and AL/CR percentiles improved with age (0.13 at 4 years to >0.75 from 13 years) and a year-to-year change was observed for all except <10th percentile from 15 years. Increasing age, AL and AL/CR was associated with a more myopic RE (r2=0.45,0.70 and 0.83, respectively). The sensitivity and specificity of the model to estimate probability of myopia was 86.0% and 84.5%, respectively. Estimation of 1-year change in AL using percentiles correlated highly with actual AL (ICC=0.98). Concordance of estimated to actual RE was high (ICC=0.80) and within ±0.50D and ±1.0D of actual RE for 47.4% and 78.9% of eyes, respectively.ConclusionAge-specific and gender-specific AL and AL/CR percentiles provide reference data, aid in identifying and monitoring individuals at risk of myopia and have utility in screening for myopia. AL/CR percentiles were more accurate in estimating probability of myopia in younger children.

scholarly journals “Yokoyama procedure” efficacy on non-highly myopic patients with acquired esotropia and hypotropia

2019 ◽  
Vol 30 (4) ◽  
pp. 676-679
Author(s):  
Massimiliano Serafino ◽  
Matteo Scaramuzzi ◽  
Edoardo Villani ◽  
Paolo Nucci
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Axial Length ◽  
Lateral Rectus ◽  
Inclusion Criteria ◽  
Resonance Imaging ◽  
Spherical Equivalent Refraction ◽  
Before And After ◽  
Weighted Magnetic Resonance Imaging ◽  
The Mean

Objective: To assess the efficacy of “Yokoyama Procedure,” on non-highly myopic patients with acquired esotropia and hypotropia. Methods: The study involved 10 eyes of 5 patients with eso-hypotropia. Inclusion criteria were acquired esotropic-hypotropic strabismus with lateral rectus inferior displacement and superior rectus nasal displacement confirmed by magnetic resonance imaging, refractive errors between ±6 D, and axial length < 27 mm. Range of full duction movements and maximum angles of abduction-sursumduction was measured in each eye before and after surgery. All patients underwent T1- and T2-weighted magnetic resonance imaging. The surgery was aimed at creating a junction between the muscle bellies of the superior and lateral rectus muscles. This junction was made approximately 14 mm behind the insertions using a non-absorbable mersilene 5/0 suture (Yokoyama procedure). Results: Mean patient age was 64.8 ± 4.8 years. The mean globe axial length was 25.4 ± 0.76 mm and a mean corresponding spherical equivalent refraction of −3.7 ± 1.7 D was observed. Eight eyes on 10 had mild limitation in abduction, while the remaining 2 had no limitation. Three out of 10 eyes showed a moderate limited sursumduction, 5 eyes were categorized as mild, and the remaining 2 had no limitation. No evident post-operative limitation was present in any eye, in both abduction and sursumduction (p < 0.01). Pre-operative esotropia and hypotropia were, respectively, 32 ± 11 prismatic diopters and 25 ± 5 prismatic diopters, and they were significantly reduced after surgery as 9 ± 1.7 prismatic diopters and 6 ±1 prismatic diopters (p = 0.043), respectively. Conclusion: Yokoyama procedure is an effective, fast, reversible procedure to face eso-hypotropic acquired strabismus, even in patients with a clear magnetic resonance imaging displacement of superior and lateral rectus muscles, and absence of globe dislocation and of elevated myopia.

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

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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