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Accommodative movements of the vitreous membrane, choroid, and sclera in young and presbyopic human and nonhuman primate eyes.

ABSTRACT: We report, for the first time to our knowledge, dynamic movements of the vitreous membrane and peripheral choroid during accommodation, and age-related changes in the anterior sclera.We studied 11 rhesus monkeys (ages 6-27 years) and 12 human subjects (ages 19-65 years). Accommodation was induced pharmacologically in human subjects and by central electrical stimulation in the monkeys. Ultrasound biomicroscopy, endoscopy, and contrast agents were used to image various intraocular structures.In the monkey, the anterior hyaloid membrane bows backward during accommodation in proportion to accommodative amplitude and lens thickening. A cleft exists between the pars plicata region and the anterior hyaloid membrane, and the cleft width increases during accommodation from 0.79 ± 0.01 mm to 1.01 ± 0.02 mm in young eyes (n = 2, P < 0.005), as fluid from the anterior chamber flows around the lens equator toward the cleft. In the older eyes the cleft width was 0.30 ± 0.19 mm, which during accommodation increased to 0.45 ± 0.20 mm (n = 2). During accommodation the ciliary muscle moved forward by approximately 1.0 mm, pulling forward the choroid, retina, vitreous zonule, and the neighboring vitreous interconnected with the vitreous zonule. Among the humans, in the older eyes the scleral contour bowed inward in the region of the limbus, compared to the young eyes.The monkey anterior hyaloid bends posteriorly during accommodation in proportion to accommodative amplitude and the sclera bows inward with increasing age in both species. Future descriptions of the accommodative mechanism, and approaches to presbyopia therapy, may need to incorporate these findings.

SUBMITTER: Croft MA

PROVIDER: S-EPMC3726242 | biostudies-other | 2013 Jul

REPOSITORIES: biostudies-other

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Accommodative movements of the vitreous membrane, choroid, and sclera in young and presbyopic human and nonhuman primate eyes.

Croft Mary Ann MA Nork T Michael TM McDonald Jared P JP Katz Alexander A Lütjen-Drecoll Elke E Kaufman Paul L PL

Investigative ophthalmology & visual science 20130726 7

<h4>Purpose</h4>We report, for the first time to our knowledge, dynamic movements of the vitreous membrane and peripheral choroid during accommodation, and age-related changes in the anterior sclera.<h4>Methods</h4>We studied 11 rhesus monkeys (ages 6-27 years) and 12 human subjects (ages 19-65 years). Accommodation was induced pharmacologically in human subjects and by central electrical stimulation in the monkeys. Ultrasound biomicroscopy, endoscopy, and contrast agents were used to image vari ...[more]

PMID: 23745005

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Dataset Information

Accommodative movements of the vitreous membrane, choroid, and sclera in young and presbyopic human and nonhuman primate eyes.

Publications

Accommodative movements of the vitreous membrane, choroid, and sclera in young and presbyopic human and nonhuman primate eyes.

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