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 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 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.

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.

Axial length/corneal radius of curvature ratio and refractive status in an adult Nigerian population

2017 ◽  
Vol 20 (10) ◽  
pp. 1328 ◽  
Author(s):  
SA Badmus ◽  
AI Ajaiyeoba ◽  
BO Adegbehingbe ◽  
OH Onakpoya ◽  
AO Adeoye
Keyword(s):  
Axial Length ◽  
Radius Of Curvature ◽  
Curvature Ratio ◽  
Refractive Status ◽  
Nigerian Population ◽  
Corneal Radius

scholarly journals Anthropometry, Amplitude of Accommodation, and Spherical Equivalent Refractive Error in a Nigerian Population

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Eghosasere Iyamu ◽  
Joy Edoghogho Iyamu ◽  
Liticia Oghovwerha
Keyword(s):  
Body Mass Index ◽  
Body Weight ◽  
Body Mass ◽  
Refractive Error ◽  
Inverse Correlation ◽  
Spherical Equivalent ◽  
Free Standing ◽  
Spherical Equivalent Refraction ◽  
Nigerian Population ◽  
Push Up

Aim. The aim of this study was to investigate the association between anthropometry, amplitude of accommodation assessed by minus-lens to blur (AAPUB) and push-up to blur (AAMLB), and spherical equivalent refraction (SEQ). Method. A total of two hundred and one subjects aged between 17 and 70 years with mean age of years, consisting of 93 males and 108 females were recruited for this study. Anthropometric variables were measured with standard instruments like the free-standing rod for height, weighing balance for body weight, and body mass index (BMI) calculated. The refractive error was measured by static retinoscopy and subjective refraction. Result. An inverse correlation was found between age, AAMLB and AAPUB (, −0.81, both ). BMI increased with age (, ). There was an inverse correlation between BMI, AAPUB and AAMLB (, −0.25, both ), respectively. However, the association between SEQ and anthropometry was not significant . The AAPUB and AAMLB decreased with age while BMI increased. AAPUB and AAMLB decreased with BMI, but were not affected by the SEQ. Conclusion. BMI increased with age while AA measured by the two methods decreased with age, and BMI increased with decreasing AA.

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 Volume of the ligamentum capitis femoris in osteoarthritic hip joints of adult dogs

2003 ◽  
Vol 74 (1) ◽  
Author(s):  
J.D. Mande ◽  
P.M.F. Mbithi ◽  
S.W. Mbugua ◽  
I.B.J. Buoro ◽  
P.K. Gathumbi
Keyword(s):  
General Anaesthesia ◽  
Crucial Role ◽  
Hip Dysplasia ◽  
Inverse Correlation ◽  
Water Displacement ◽  
Hip Joints ◽  
Ligamentum Capitis Femoris ◽  
The Mean ◽  
Canine Hip Dysplasia

Ventrodorsal pelvic radiographs were made of 32 adult dogs under general anaesthesia. The hip joints were evaluated according to the severity of osteoarthritic changes graded as 0, 1, 2 or 3. The dogs were euthanased, the hip joints opened and the ligamentum capitis femoris dissected out in toto. The volume of each ligament was determined using a water displacement technique and the mean volume compared to the four radiographic grades of osteoarthritis. There was an inverse correlation (r = -0.75) between the mean volume of the ligamentum capitis femoris and the increasing severity of osteoarthritis as assessed by radiography. The results confirmed the crucial role of radiography in the clinical evaluation of hip dysplasia and osteoarthritis in the adult dog. Assessment of the volume of the ligamentum capitis femoris revealed that it is an important tool for research in canine hip dysplasia and osteoarthritis.

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.

Sign in / Sign up

Export Citation Format

Share Document