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Accommodation and presbyopia.
Ophthalmic Physiol Opt. 1995 Jul; 15(4):255-72.OP

Abstract

The mechanism of accommodation has been studied for at least four hundred years. The most interesting aspect of accommodation is that its time course is well in advance of other physiological functions--it begins to decline by adolescence and is lost about two-thirds of the way through the normal life span. The state of presbyopia is reached when accommodation has declined sufficiently to interfere with close tasks requiring acute vision. Presbyopia is generally considered to originate with the 'plant' of the accommodative system, either within the lens and its capsule or within their support structures. One of the lenticular theories, the Hess-Gullstrand theory, is distinguished from other theories by its claim that as age increases there is an increasing excess amount of ciliary muscle contraction beyond the ability of the lens and capsule to respond to it. For all other theories, the maximum possible amount of ciliary muscle contraction is always necessary to produce maximum accommodation, at least beyond the age at which it reaches its peak. From my review of the present understanding of the mechanisms of accommodation and the theories of the development of presbyopia, I conclude that there is overwhelming evidence against the Hess-Gullstrand theory and that it is unlikely that changes in the ciliary muscle contractility contribute significantly to the development of presbyopia.

Authors+Show Affiliations

Centre for Eye Research, School of Optometry, Queensland University of Technology, Red Hill Q, Australia.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

7667018

Citation

Atchison, D A.. "Accommodation and Presbyopia." Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists), vol. 15, no. 4, 1995, pp. 255-72.
Atchison DA. Accommodation and presbyopia. Ophthalmic Physiol Opt. 1995;15(4):255-72.
Atchison, D. A. (1995). Accommodation and presbyopia. Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists), 15(4), 255-72.
Atchison DA. Accommodation and Presbyopia. Ophthalmic Physiol Opt. 1995;15(4):255-72. PubMed PMID: 7667018.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Accommodation and presbyopia. A1 - Atchison,D A, PY - 1995/7/1/pubmed PY - 1995/7/1/medline PY - 1995/7/1/entrez SP - 255 EP - 72 JF - Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) JO - Ophthalmic Physiol Opt VL - 15 IS - 4 N2 - The mechanism of accommodation has been studied for at least four hundred years. The most interesting aspect of accommodation is that its time course is well in advance of other physiological functions--it begins to decline by adolescence and is lost about two-thirds of the way through the normal life span. The state of presbyopia is reached when accommodation has declined sufficiently to interfere with close tasks requiring acute vision. Presbyopia is generally considered to originate with the 'plant' of the accommodative system, either within the lens and its capsule or within their support structures. One of the lenticular theories, the Hess-Gullstrand theory, is distinguished from other theories by its claim that as age increases there is an increasing excess amount of ciliary muscle contraction beyond the ability of the lens and capsule to respond to it. For all other theories, the maximum possible amount of ciliary muscle contraction is always necessary to produce maximum accommodation, at least beyond the age at which it reaches its peak. From my review of the present understanding of the mechanisms of accommodation and the theories of the development of presbyopia, I conclude that there is overwhelming evidence against the Hess-Gullstrand theory and that it is unlikely that changes in the ciliary muscle contractility contribute significantly to the development of presbyopia. SN - 0275-5408 UR - https://www.unboundmedicine.com/medline/citation/7667018/Accommodation_and_presbyopia_ L2 - https://linkinghub.elsevier.com/retrieve/pii/027554089500020E DB - PRIME DP - Unbound Medicine ER -