The Effect of Relative Corneal Refractive Power Shift Distribution on Axial Length Growth in Myopic Children Undergoing Orthokeratology Treatment

PurposeTo determine if the spatial distribution of the relative corneal refractive power shift (RCRPS) explains the retardation of axial length (AL) elongation after treatment by either orthokeratology (OK) or multifocal soft contact lenses (MFCLs).MethodsChildren (8–14 years) were enrolled in the OK (n = 35) or MFCL (n = 36) groups. RCRPS maps were derived by computing the difference between baseline and 12-month corneal topography maps and then subtracting the apex values. Values at the same radius were averaged to obtain the RCRPS profile, from which four parameters were extracted: (1) Half_x and (2) Half_y, i.e., the x- and y-coordinates where each profile first reached the half peak; (3) Sum4 and (4) Sum7, i.e., the summation of powers within a corneal area of 4- and 7-mm diameters. Correlations between AL elongation and these parameters were analyzed by multiple linear regression.ResultsAL elongation in the OK group was significantly smaller than that in the MFCL group (p = 0.040). Half_x and Half_y were also smaller in the OK group than the MFCL group (p < 0.001 each). Half_x was correlated with AL elongation in the OK group (p = 0.005), but not in the MFCL group (p = 0.600). In an analysis that combined eyes of both groups, Half_x was correlated with AL elongation (β = 0.161, p < 0.001).ConclusionsThe OK-induced AL elongation and associated RCRPS Half_x were smaller than for the MFCL. Contact lenses that induce RCRPS closer to the corneal center may exert better myopia control.

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Evaluation of axial length/total corneal refractive power ratio as a potential marker for ocular diagnosis of Marfan’s syndrome in children

International Journal of Ophthalmology ◽

10.18240/ijo.2021.08.13 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1218-1224

Author(s):

Tian-Hui Chen ◽

◽

Yu-Liang Wang ◽

Min Zhang ◽

Jia-Hui Chen ◽

...

Keyword(s):

Roc Curve ◽

Axial Length ◽

Curve Analysis ◽

Youden Index ◽

Control Group ◽

Marfan’S Syndrome ◽

Roc Curve Analysis ◽

Marfan's Syndrome ◽

Refractive Power ◽

Corneal Refractive Power

AIM: To investigate whether the axial length (AL)/total corneal refractive power (TCRP) ratio is a sensitive and simple factor that can be used for the early diagnosis of Marfan’s syndrome (MFS) in children. METHODS: The relationship between the AL/TCRP ratio and the diagnosis of MFS for 192 eyes in 97 children were evaluate. The biological characteristics, including age, sex, AL, and TCRP, were collected from medical records. Receiver operating characteristic (ROC) curve analysis was performed to investigate whether the AL/TCRP ratio effectively distinguishes MFS from other subjects. The Youden index was used to re-divide the whole population into two groups according to an AL/TCRP ratio of 0.59. RESULTS: Of 96 subjects (mean age 7.46±3.28y) evaluated, 56 (110 eyes) had a definite diagnosis of MFS in childhood based on the revised Ghent criteria, 41 (82 eyes) with diagnosis of congenital ectopia lentis (EL) were included as a control group. AL was negatively correlated with TCRP, with a linear regression coefficient of -0.36 (R2=0.08). A significant correlation was found between age and the AL/TCRP ratio (P=0.023). ROC curve analysis showed that the AL/TCRP ratio distinguished MFS from the other patients at a threshold of 0.59. MFS patients were present in 24/58 (41.38%) patients with an AL/TCRP ratio of ≤0.59 and in 34/39 (87.18%) patients with an AL/TCRP ratio of >0.59. CONCLUSION: An AL/TCRP ratio of >0.59 is significantly associated with the risk of MFS. The AL/TCRP ratio should be measured as a promising marker for the prognosis of children MFS. Changes in the AL/TCRP ratio should be monitored over time.

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Axial length and its associations in the Ural Very Old Study

Scientific Reports ◽

10.1038/s41598-021-98039-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mukharram M. Bikbov ◽

Gyulli M. Kazakbaeva ◽

Ellina M. Rakhimova ◽

Iuliia A. Rusakova ◽

Albina A. Fakhretdinova ◽

...

Keyword(s):

Axial Length ◽

Educational Level ◽

High Myopia ◽

Regression Coefficient ◽

Multivariable Analysis ◽

Very Old ◽

Refractive Power ◽

Higher Educational ◽

Corneal Refractive Power ◽

Axial Myopia

AbstractTo assess the distribution of axial length as surrogate for myopia and its determinants in an old population, we performed the Ural Very Old Study as a population-based cohort study. Out of 1882 eligible individuals aged 85 + years, the Ural Very Old Study performed in an urban and rural region in Bashkortostan/Russia included 1526 (81.1%) individuals undergoing ophthalmological and medical examinations with sonographic axial length measurement. Biometric data were available for 717 (47.0%) individuals with a mean age of 88.0 ± 2.6 years (range 85–98 years; 25%). Mean axial length was 23.1 ± 1.1 mm (range 19.37–28.89 mm). Prevalences of moderate myopia (axial length 24.5–< 26.5 mm) and high myopia (axial length ≥ 26.5 mm) were 47/717 (6.6%; 95% CI 4.7, 8.4) and 10/717 (1.4%; 95% CI 0.5, 2.3), respectively. In multivariable analysis, longer axial length was associated (coefficient of determination r2 0.25) with taller body height (standardized regression coefficient beta:0.16;non-standardized regression coefficient B: 0.02; 95% confidence interval (CI) 0.01, 0.03; P < 0.001), higher level of education (beta: 0.12; B: 0.07; 95% CI 0.02, 0.11; P = 0.002), and lower corneal refractive power (beta: − 0.35; B: − 0.23; 95% CI − 0.28, − 0.18; P < 0.001). Higher prevalence of moderate myopia, however not of high myopia, was associated with higher educational level (OR 1.39; 95% CI 1.09, 1.68; P = 0.007) and lower corneal refractive power (OR 0.77; 95% CI 0.63, 0.94; P = 0.01). In this old study population, prevalence of moderate axial myopia (6.6% versus 9.7%) was lower than, and prevalence of high axial myopia (1.4% versus 1.4%) was similar as, in a corresponding study on a younger population from the same Russian region. Both myopia prevalence rates were higher than in rural Central India (1.5% and 0.4%, respectively). As in other, younger, populations, axial length and moderate myopia prevalence increased with higher educational level, while high myopia prevalence was independent of the educational level.

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Corneal refractive power after myopic LASIK

Ophthalmology ◽

10.1016/s0161-6420(03)00839-x ◽

2003 ◽

Vol 110 (9) ◽

pp. 1857 ◽

Cited By ~ 2

Author(s):

Louis E Probst ◽

Jack T Holladay

Keyword(s):

Refractive Power ◽

Corneal Refractive Power

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Refractive Eerror According to the Anterior Chamber Depth and Corneal Refractive Power in Short Eyes

Journal of the Korean Ophthalmological Society ◽

10.3341/jkos.2013.54.1.65 ◽

2013 ◽

Vol 54 (1) ◽

pp. 65 ◽

Cited By ~ 3

Author(s):

Jeong Ah Shin ◽

Kyu Yeon Hwang ◽

Man Soo Kim

Keyword(s):

Anterior Chamber ◽

Anterior Chamber Depth ◽

Refractive Power ◽

Corneal Refractive Power

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

Bangabandhu Sheikh Mujib Medical University Journal ◽

10.3329/bsmmuj.v13i4.50499 ◽

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.

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