2011
DOI: 10.1590/s0034-72802011000500008
|View full text |Cite
|
Sign up to set email alerts
|

New concepts in accommodation and presbyopia

Abstract: The authors conducted a review of classical and conflicting theories of accommodation and presbyopia. They make a critical comparison with the findings of magnetic resonance imaging (MRI) that have been developed in recent decades. Based on these studies, formulates a new approach on the subject, shifting the focus of the discussion of the lens to the posterior pole of the eye.Keywords: Ocular accommodation ; Presbyopia RESUMOOs autores revisaram as teorias clássicas e conflitantes sobre acomodação e presbiopi… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1

Citation Types

0
4
0

Year Published

2013
2013
2021
2021

Publication Types

Select...
3

Relationship

0
3

Authors

Journals

citations
Cited by 3 publications
(4 citation statements)
references
References 9 publications
0
4
0
Order By: Relevance
“…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%
See 1 more Smart Citation
“…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%
“…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 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%