Lens power loss in early adulthood

Iribarren, Rafael; Midelfart, Anna; Kinge, Bettina

doi:10.1111/aos.12552

Cited by 5 publications

(8 citation statements)

References 6 publications

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“…3 This combination of changes explains why myopes have lower lens power than emmetropic eyes in children and adults. 16,21 The suggestion that changes in lens power loss have a role in myopia was previously reported for the CLEERE study, where lens power loss ceased immediately at myopia onset. The Guangzhou twin study, 3 on the other hand, found no such variations in lens power loss, while our results confirmed those of the CLEERE study, albeit with a more gradual transition.…”

Section: Discussionmentioning

confidence: 77%

“…Based on animal studies, these lenticular changes are mostly passive in nature, 15 resulting from uncontrolled internal changes that gradually alter the lens thickness, curvature, and gradient index. 12,16,17 To explain lens thinning and associated power loss in ocular growth in humans, a theory implicating lens stretch by zonular traction has been proposed. 6,18 Axial length, on the other hand, undergoes a combination of somatic and regulated growth, and, therefore, can compensate for variations in lens power loss, 2 leading, for example, to longer emmetropic eyes with lower lens power.…”

Section: Discussionmentioning

confidence: 99%

“…6,18 Axial length, on the other hand, undergoes a combination of somatic and regulated growth, and, therefore, can compensate for variations in lens power loss, 2 leading, for example, to longer emmetropic eyes with lower lens power. 16 Up to 3 years before myopia onset, future myopes still have a near-emmetropic refraction. Their axial growth rates, however, are faster than in emmetropes, most likely affected by known risk factors, such as large amounts of near work activities and time spent indoors.…”

Section: Discussionmentioning

confidence: 99%

“…23 Several theories have been proposed as to why the lens loses its power over time. 16 Based on the longitudinal Orinda study, 6 Mutti et al 18 hypothesized that lens thinning was the result of zonular traction, mediated by ciliary muscle tension during ocular growth. Eventually lens thinning and power loss would reach a limit due to scleral expansion in myopic children, explaining their original observation of a slowing lens power loss at the age at 10 years, when myopia has a peak in incidence.…”

Section: Discussionmentioning

confidence: 99%

“…This internal remodeling might be the result of shape changes, which in turn could alter the curvatures of the isoindical surfaces of gradient index (i.e., surfaces of equal refractive index). 16,24 To simplify complex measurements, studies often use the equivalent index, which is the refractive index that a homogeneous lens must have to match the power of the lens surfaces and gradient index power. The CLEERE and Orinda 6 studies measured lens curvatures and lens equivalent index, finding decreasing values of both in school children.…”

Section: Discussionmentioning

confidence: 99%

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Axial Growth and Lens Power Loss at Myopia Onset in Singaporean Children

Rozema

Dankert

Iribarren

et al. 2019

Invest. Ophthalmol. Vis. Sci.

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105

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PURPOSE. We studied biometry changes before and after myopia onset in a cohort of Singaporean children. METHODS. All data were taken from the Singapore Cohort Study of the Risk Factors for Myopia (SCORM). Participants underwent refraction and biometry measurements with a follow-up of 3 to 6 years. The longitudinal ocular biometry (spherical equivalent refraction, axial length, and lens power) changes were compared between children who suffered myopia during the study (N ¼ 303), emmetropic children (N ¼ 490), and children myopic at baseline (N ¼ 509). RESULTS. At myopia onset, the myopic shift increased to 0.50 diopters (D)/y or more in new myopes compared to the minor changes in emmetropes of the same age. New myopes had higher axial growth rates than emmetropes, even years before myopia onset (0.37 and 0.14 mm/y, respectively; ANOVA with Bonferroni post hoc test, P < 0.001). After onset, the change in both parameters slowed down gradually, but significantly (P < 0.05). In new myopes, lens power loss (À0.71 D/y) was significantly higher up to 1 year before myopia onset compared to emmetropes (À0.46 D/y), after which lens power loss slows down rapidly. At age 7 years, (future) new myopes had lens power values close to those of emmetropes (25.12 and 25.23 D, respectively), while later these values approached those of children who were myopic at baseline (23.06 and 22.79 D, respectively, compared to 23.71 D for emmetropes; P < 0.001). CONCLUSIONS. New myopes have higher axial growth rates and lens power loss before myopia onset than persistent emmetropes.

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Section: Discussionmentioning

confidence: 77%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Axial Growth and Lens Power Loss at Myopia Onset in Singaporean Children

Rozema

Dankert

Iribarren

et al. 2019

Invest. Ophthalmol. Vis. Sci.

Self Cite

105

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Refractive lens power and lens thickness in children (6–16 years old)

Song

et al. 2021

Sci Rep

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To examine the refractive lens power (RLP) and lens thickness and their associated factors in children from North-Western China. Children from two schools (primary school and junior high school) in the North-Western Chinese province of Qinghai underwent a comprehensive ophthalmic examination including biometry and cycloplegic refractometry. The RLP was calculated using Bennett’s equation. The study included 596 (77.9%) individuals (mean age: 11.0 ± 2.8 years; range: 6–16 years) with a mean axial length of 23.65 ± 1.24 mm (range: 20.02–27.96 mm). Mean lens thickness was 3.30 ± 0.16 mm (range: 2.85–3.99 mm) and mean RLP was 24.85 ± 1.98D (range: 19.40–32.97). In univariate analysis, girls as compared to boys had a significantly thicker lens and greater RLP, shorter axial length, smaller corneal curvature radius and shorter corneal curvature radius (all P < 0.001). Both sexes did not differ significantly in refractive error (P = 0.11) and corneal thickness (P = 0.16). RLP was positively associated with refractive error (correlation coefficient r = 0.33; P < 0.001) and lens thickness (r = 0.62; P < 0.001) and negatively with axial length (r = − 0.70; P < 0.001). In univariate analysis, RLP decreased significantly with older age in the age group from age 6–13, while it plateaued thereafter, with no significant difference between boys and girls. In multivariate regression analysis, a higher RLP was associated with younger age (P < 0.001; standard regression coefficient β = − 0.07), female sex (P < 0.001; β = − 0.08), shorter axial length (P < 0.001; β = − 0.48) and higher lens thickness (P < 0.001; β = 0.42). In Chinese children, RLP with a mean of 24.85 ± 1.98D decreases with older age, male sex, longer axial length, and thinner lens thickness. Changes in RLP and axial length elongation are important players in the emmetropization and myopization.

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