Limits...
A focus on the optical properties of the regenerated newt lens.

Wassmer S, Beddaoui M, Rajai P, Munger R, Tsilfidis C - PLoS ONE (2013)

Bottom Line: We compared the optical properties of 9- and 26-week regenerated lenses in the red spotted newt, Notophthalmus viridescens, with the original lenses removed from the same eyes.The 9 week lenses have greater light transmission, but significantly reduced focal length and refractive index than the original lenses.This suggests that following 9 weeks of regeneration, the lenses have not recovered the functionality of the original lens.

View Article: PubMed Central - PubMed

Affiliation: Ottawa Hospital Research Institute, Vision Research Program, Ottawa, Ontario, Canada ; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada.

ABSTRACT
Lens regeneration studies in the adult newt suggest that molecular aspects of lens regeneration are complete within 5 weeks of lentectomy. However, very little is known about the optical properties of the regenerated lens. In an aquatic environment, the lens accounts for almost all of the refractive power of the eye, and thus, a fully functional lens is critical. We compared the optical properties of 9- and 26-week regenerated lenses in the red spotted newt, Notophthalmus viridescens, with the original lenses removed from the same eyes. At 9 weeks, the regenerated lenses are smaller than the original lenses and are histologically immature, with a lower density of lens proteins. The 9 week lenses have greater light transmission, but significantly reduced focal length and refractive index than the original lenses. This suggests that following 9 weeks of regeneration, the lenses have not recovered the functionality of the original lens. By 26 weeks, the transmission of light in the more mature lens is reduced, but the optical parameters of the lens have recovered enough to allow functional vision.

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The optical properties of the original and 26-week regenerated lenses.A) Lens diameter is still significantly smaller in the regenerated lens, but the difference between the regenerated and original lenses is much smaller than at 9 weeks. Focal length (B) and refractive index (C) are similar in control and regenerated lenses. D) The transmitted light for the regenerated lens is significantly lower than the original lens, but should not significantly impact functional vision in the newt.
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pone-0070845-g004: The optical properties of the original and 26-week regenerated lenses.A) Lens diameter is still significantly smaller in the regenerated lens, but the difference between the regenerated and original lenses is much smaller than at 9 weeks. Focal length (B) and refractive index (C) are similar in control and regenerated lenses. D) The transmitted light for the regenerated lens is significantly lower than the original lens, but should not significantly impact functional vision in the newt.

Mentions: On average the 26-week regenerated lenses were significantly smaller (by 0.146 mm, Figure 4A, P = 0.026) than their original controls. Individual values are presented in the supplemental material (Table S2). Compared to the 9-week lenses (difference in median of 0.293) the difference between 26-week regenerated lenses and controls had decreased significantly (P<0.001). At 26 weeks the regenerated lenses transmitted significantly (P = 0.006) less light (by 17.3%) than the control lenses, the opposite of the results found for the lenses after 9 weeks of regeneration (Figure 4B). The differences in size and transmission did not translate into a difference in lens functionality. The calculated focal lengths in the eye (figure 4C, P = 0.138) and equivalent indices of refractions (Figure 4D, P = 0.448) were statistically the same for the 26-week regenerated and control lenses. Histologically, the lenses had developed mature features, and were virtually indistinguishable from the original lenses (Figure 5).


A focus on the optical properties of the regenerated newt lens.

Wassmer S, Beddaoui M, Rajai P, Munger R, Tsilfidis C - PLoS ONE (2013)

The optical properties of the original and 26-week regenerated lenses.A) Lens diameter is still significantly smaller in the regenerated lens, but the difference between the regenerated and original lenses is much smaller than at 9 weeks. Focal length (B) and refractive index (C) are similar in control and regenerated lenses. D) The transmitted light for the regenerated lens is significantly lower than the original lens, but should not significantly impact functional vision in the newt.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3750027&req=5

pone-0070845-g004: The optical properties of the original and 26-week regenerated lenses.A) Lens diameter is still significantly smaller in the regenerated lens, but the difference between the regenerated and original lenses is much smaller than at 9 weeks. Focal length (B) and refractive index (C) are similar in control and regenerated lenses. D) The transmitted light for the regenerated lens is significantly lower than the original lens, but should not significantly impact functional vision in the newt.
Mentions: On average the 26-week regenerated lenses were significantly smaller (by 0.146 mm, Figure 4A, P = 0.026) than their original controls. Individual values are presented in the supplemental material (Table S2). Compared to the 9-week lenses (difference in median of 0.293) the difference between 26-week regenerated lenses and controls had decreased significantly (P<0.001). At 26 weeks the regenerated lenses transmitted significantly (P = 0.006) less light (by 17.3%) than the control lenses, the opposite of the results found for the lenses after 9 weeks of regeneration (Figure 4B). The differences in size and transmission did not translate into a difference in lens functionality. The calculated focal lengths in the eye (figure 4C, P = 0.138) and equivalent indices of refractions (Figure 4D, P = 0.448) were statistically the same for the 26-week regenerated and control lenses. Histologically, the lenses had developed mature features, and were virtually indistinguishable from the original lenses (Figure 5).

Bottom Line: We compared the optical properties of 9- and 26-week regenerated lenses in the red spotted newt, Notophthalmus viridescens, with the original lenses removed from the same eyes.The 9 week lenses have greater light transmission, but significantly reduced focal length and refractive index than the original lenses.This suggests that following 9 weeks of regeneration, the lenses have not recovered the functionality of the original lens.

View Article: PubMed Central - PubMed

Affiliation: Ottawa Hospital Research Institute, Vision Research Program, Ottawa, Ontario, Canada ; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada.

ABSTRACT
Lens regeneration studies in the adult newt suggest that molecular aspects of lens regeneration are complete within 5 weeks of lentectomy. However, very little is known about the optical properties of the regenerated lens. In an aquatic environment, the lens accounts for almost all of the refractive power of the eye, and thus, a fully functional lens is critical. We compared the optical properties of 9- and 26-week regenerated lenses in the red spotted newt, Notophthalmus viridescens, with the original lenses removed from the same eyes. At 9 weeks, the regenerated lenses are smaller than the original lenses and are histologically immature, with a lower density of lens proteins. The 9 week lenses have greater light transmission, but significantly reduced focal length and refractive index than the original lenses. This suggests that following 9 weeks of regeneration, the lenses have not recovered the functionality of the original lens. By 26 weeks, the transmission of light in the more mature lens is reduced, but the optical parameters of the lens have recovered enough to allow functional vision.

Show MeSH
Related in: MedlinePlus