Effect of Age on the Morphology and Optical Quality of the Avian Crystalline Lens

Priolo, S.; Sivak, J. G.; Kuszak, J.R.

doi:10.1006/exer.1999.0740

Cited by 27 publications

(3 citation statements)

References 34 publications

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“…Recent studies in the chick have shown that experimentally induced ametropia has no effect on isolated lens weight, dimensions, shape, morphology, focal length 36 or crystallin contents 37 . Nevertheless, the optics of lenses from form‐deprived eyes were degraded, leading to the conclusion that, in the chick, ‘lenticular development is influenced by both its genetic predetermined course and visual experience’.…”

Section: Factors Affecting Growthmentioning

confidence: 99%

Growth of the lens: in vitro observations

Augusteyn

2008

Clinical and Experimental Optometry

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Understanding the normal functioning of the human lens and its role in the development of disorders of vision, such as presbyopia and cataract, requires a thorough knowledge of how the lens grows and how its properties change with age. Many of these properties can be obtained only by studying the isolated organ in vitro. In addition, because of the difficulties in obtaining human tissues, animal lenses are frequently used as models for the human lens. Information is needed for these as well. In this review, current knowledge of lens growth and factors that affect growth are examined in a variety of species. Topics covered include changes in lens weight, dimensions, stiffness and refractive index distribution with age and the influence of other factors such as gender, environment and body size. From these, it has become clear that lens growth is not greatly affected by external influences. Although there are many similarities in the growth of lenses from different species, humans (and probably all primates) have distinctly different growth patterns, with prenatal and postnatal growth having different regulatory mechanisms. As a result, human lens properties are different from those of other species. Unfortunately, many of the published data are unreliable, presumably because of post-mortem changes, making it difficult to extrapolate in vitro observations to the in vivo situation.

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Section: Factors Affecting Growthmentioning

confidence: 99%

Growth of the lens: in vitro observations

Augusteyn

2008

Clinical and Experimental Optometry

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“…White leghorn ( Gallus gallus domesticus ) hatching chicks were obtained (Maple Leaf Poultry, New Hamburg, Ontario, Canada) and were unilaterally fitted with a velcro ring and translucent goggle, as described in previous studies (Irving et al ., 1992; Priolo et al ., 2000; Choh et al ., 2002). Ungoggled, contralateral eyes served as controls for the goggling procedure.…”

Section: Methodsmentioning

confidence: 95%

Ultrasound biomicroscopy of the anterior segment of the enucleated chicken eye during accommodation

Choh

Sivak

Irving

et al. 2002

Ophthalmic Physiologic Optic

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Ultrasound biomicroscopy produces real-time two-dimensional images of ocular structures measured non-invasively. Given recent work which shows that lenses from myopic eyes show shorter focal lengths and reduced accommodative amplitudes compared with controls, this study was undertaken to determine the structural characteristics of the anterior segment of chicken eyes during accommodation using the ultrasound biomicroscope (UBM). Form-deprivation myopia and hyperopia were induced in hatching chicks by the application of either translucent or +15 D defocus goggles. After 7 days, eyes were enucleated and ultrasound biomicrographs of the eye, at rest and during ciliary nerve-stimulated accommodation, were collected. For all eyes, accommodation was associated with a decrease in anterior chamber depth, an increase in lenticular thickness and a steepening of the front lenticular surface curvature. Changes related to refractive error were more difficult to detect. Myopic eyes showed deeper anterior chamber depths and differences in lenticular thicknesses just above the resolution limit for detection. In +15 D lens-treated eyes, anterior chamber differences were opposite but smaller, just at the limit of resolution, while differences in mean lenticular thickness were not resolvable at a pixel or above. The UBM is a good tool for measuring robust changes during accommodation, but is limited in its ability to detect subtle changes associated with experimentally induced ametropias.

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“…Priolo et al . found a two fold increase in lens focal length variability when chicks were raised with defocusing goggles.…”

Section: Introductionmentioning

confidence: 99%