New concepts in accommodation and presbyopia

Santos-Neto, Edson dos; Alves, Mílton Ruiz

doi:10.1590/s0034-72802011000500008

Cited by 3 publications

(4 citation statements)

References 9 publications

(23 reference statements)

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“…Helmholtz's best-known theory proposes that the ciliary muscle contracts and produces a relaxation of the zonular fibers, increasing the thickness and curvature of the lens and, consequently, increasing its dioptric power. (1) It is commonly known that around the age of 40 years, it becomes difficult for the patient to focus on nearby objects. According to this theory, when the zonules are relaxed, the crystalline lens can no longer change its shape; therefore, presbyopia is a condition that can only be reversed by replacing the elasticity of the capsule or the lens.…”

Section: Considerations Regarding the Crystalline Lens Lens Accommodationmentioning

confidence: 99%

“…With aging, changes in the crystalline lens induce gradual loss of transparency, increase in density, and start of presbyopia. (1) Stage one of DLS is often observed in patients aged between 40 and 50 years with accommodation loss, and relatively low light scatter. In the second stage (usually presented in patients aged > 50 years), increased ocular scatter and higher-order aberrations (HOA), decreased contrast sensitivity, and lens opacity occurs.…”

Section: Introductionmentioning

confidence: 99%

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Dysfunctional lens syndrome: a prospective review

Haddad¹,

Rocha²,

Waring³

et al. 2021

Revista Brasileira De Oftalmologia

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The term dysfunctional lens syndrome has gained acceptance in the field and encompasses natural changes due to aging of crystalline lens. The evolution of diagnostic devices has been a key factor in better staging, understanding and characterizing of these degenerative changes. Even with these technological advances and the use of subjective classifications, such as the classic Lens Opacities Classification System, an objective staging of early dysfunctional lens syndrome has yet to be established. Ocular wavefront aberrometry and objective scatter index, associated with Scheimpflug backscatter densitometry, have proven instrumental in detecting early dysfunctional lens syndrome. Staging of early dysfunctional lens syndrome has been proposed in the literature, but no classification has been recognized worldwide. The purpose of this literature review is to assess the current state of dysfunctional lens syndrome from a technological perspective and propose a new staging system to assist surgeons in making surgical decisions.

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Section: Considerations Regarding the Crystalline Lens Lens Accommodationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dysfunctional lens syndrome: a prospective review

Haddad¹,

Rocha²,

Waring³

et al. 2021

Revista Brasileira De Oftalmologia

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“…The mechanism of accommodation has been one of the most researched in the last century and probably the biggest mystery surrounding the modern ophthalmology. Accommodation refers to the process whereby chances in the dioptric power of the crystalline lens occur so that an in-focus retinal image of an object of regard is obtained and maintained at the high-resolution fovea [5]. Good near vision is important, even among populations who use it for tasks other than reading and writing.…”

Section: Introductionmentioning

confidence: 99%

The Prevalence of Presbyopia in optometry clinic for one year

Ahmed

Mahmud

2017

KJAR

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Presbyopia is a natural part of the aging process of the eye in which the loss of flexibility of the crystalline lens takes place over a number of years. This study aimed to determine the prevalence of presbyopia for all cases in the clinic of optometry in Erbil Technical Medical Institute for one year. During the study period optometric and ophthalmologic examinations were performed on all participants. Near vision was tested and corrected to the nearest 0.5 diopters. Presbyopia was defined as at least 1 line of improvement on a near visual acuity chart with an addition of a plus lens. presbyopic correction coverage was calculated and the results were analyzed using SPSS Program. A total of 750 participants' records were evaluated. Of those, 450 cases were females and 300 cases were males. Two hundred-twenty -five (30 %) of patients were presbyopia. Fifty-one patients of presbyopic patients (22.66%) were with ages between 39-45 year, seventy-five patients (33.33%) were with ages between 46-50 year, forty patients (17.77%) were with ages between 51-55 year, seventeen patients (7.55%) were with ages between 56-60, thirteen patients (5.77%) were with ages between 61-65 year, twenty patients (8.88%) were with ages between 66-70 year, six patients (2.66%) were with ages between 71-76 year, three patients (1.33%) were with ages between 76-80 year. Our study is the first population-based investigation of presbyopia in Erbil Clinics, with the aim of determining the prevalence of presbyopia in the clinic of Optometry that it is a sample of Kurdistan Region population. The results of this study indicate that the presbyopia was a common problem of the vision in Erbil.

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“…The mechanism of presbyopia involves changes both in the contraction and relaxation capacity of the ciliary muscle and in the lens, such as: loss of elasticity of the lens capsule and fibres, increased volume and thickness, changes in protein composition, formation of high molecular weight aggregates, changes in the insertion point on the zonule, shortened radius of curvature of the anterior surface, and decreased light transmission capacity (2)(3)(4)(5)(6)(7)(8) .…”

mentioning

confidence: 99%

Perfil refracional dos présbitas na Amazônia brasileira

Chaves¹,

Filho²,

Chaves³

2013

Rev. bras.oftalmol.

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Resultados: Dos pacientes atendidos, 53,0% eram do sexo feminino; a faixa etária mais prevalente era de 51 a 60 anos; 66,0% não são aposentados e ainda desenvolvem alguma atividade laborativa; a maior prevalência das ametropias registrada foi de astigmatismos diversos (43,0%) e a acuidade visual para longe, sem correção, foi de 15,0% com 20/200 e, com correção, foi de 45,0% com 20/30 ou mais; em relação à visão para perto, a acuidade visual foi de 40,0% para J6, sem correção e, de 82,0% para J2 e J1, com correção; as adições utilizadas em 75,0% foram de +2,50 dioptrias ou mais; e 52,0% dos atendimentos foram realizados em Manaus. Conclusão Esta pesquisa, ao examinar populações pobres da Amazônia brasileira, corrobora que a falta de óculos para corrigir a visão para perto constitui-se em importante problema de saúde pública nas pessoas acima dos 40 anos, principalmente naquelas que têm dificuldade de acesso a serviços de Oftalmologia.

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New concepts in accommodation and presbyopia

Cited by 3 publications

References 9 publications

Dysfunctional lens syndrome: a prospective review

Dysfunctional lens syndrome: a prospective review

The Prevalence of Presbyopia in optometry clinic for one year

Perfil refracional dos présbitas na Amazônia brasileira

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