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Action spectrum for photobleaching of human lenses by short wavelength visible irradiation.

Kessel L, Larsen M - PLoS ONE (2015)

Bottom Line: For a 75 year old lens an effect corresponding to elimination of 15 years or more of optical ageing was obtained.This study of the spectral characteristics and intensity needed to bleach the human lens with single-photon laser effects found an action-spectrum peak at 420 nm tailing gradually off toward longer wavelengths and more steeply toward shorter wavelengths.The results may be used to guide experiments with two-photon bleaching.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Glostrup Hospital, Glostrup, Denmark.

ABSTRACT

Purpose: Cataract is the world-leading cause of blindness. In search for a new treatment of cataract we have found that the yellow discolouration of aged human lenses can be photobleached using a non-invasive, infra-red, femtosecond laser treatment. These results were presented in an earlier PlosOne publication. The objective of the study was to characterize the single-photon photobleaching action spectrum of the aged human lens in vitro.

Methods: Ninety-one human donor lenses were irradiated with continuous wave laser light at 375, 405, 420, 445, 457 or 473 nm. Photobleaching was monitored by photography and transmission measurements.

Results: The action spectrum peaked at 420 nm followed by, in order of decreasing effect, 445, 457, 473, 405 and 375 nm. Younger and less absorbent lenses showed smaller changes than older and more absorbent lenses. There was a dose-dependent increase in lens transmission with increasing laser irradiation.

Conclusions: For a 75 year old lens an effect corresponding to elimination of 15 years or more of optical ageing was obtained. This study of the spectral characteristics and intensity needed to bleach the human lens with single-photon laser effects found an action-spectrum peak at 420 nm tailing gradually off toward longer wavelengths and more steeply toward shorter wavelengths. The results may be used to guide experiments with two-photon bleaching.

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Related in: MedlinePlus

Dose-dependency of photobleaching on the transmission of blue light computed using the mathematical expressions presented in Table 1 for a 75 year old lens for each of the six irradiation wavelengths used.
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pone.0123732.g004: Dose-dependency of photobleaching on the transmission of blue light computed using the mathematical expressions presented in Table 1 for a 75 year old lens for each of the six irradiation wavelengths used.

Mentions: When evaluated by blue light lens transmission, photobleaching effects were most pronounced at 420 nm and lowest at 375 nm, see Fig 4. The peak of the photobleaching action spectrum at 420 nm was followed, in decreasing order of effect by 445, 457, 473, 405 and 375 nm.


Action spectrum for photobleaching of human lenses by short wavelength visible irradiation.

Kessel L, Larsen M - PLoS ONE (2015)

Dose-dependency of photobleaching on the transmission of blue light computed using the mathematical expressions presented in Table 1 for a 75 year old lens for each of the six irradiation wavelengths used.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401553&req=5

pone.0123732.g004: Dose-dependency of photobleaching on the transmission of blue light computed using the mathematical expressions presented in Table 1 for a 75 year old lens for each of the six irradiation wavelengths used.
Mentions: When evaluated by blue light lens transmission, photobleaching effects were most pronounced at 420 nm and lowest at 375 nm, see Fig 4. The peak of the photobleaching action spectrum at 420 nm was followed, in decreasing order of effect by 445, 457, 473, 405 and 375 nm.

Bottom Line: For a 75 year old lens an effect corresponding to elimination of 15 years or more of optical ageing was obtained.This study of the spectral characteristics and intensity needed to bleach the human lens with single-photon laser effects found an action-spectrum peak at 420 nm tailing gradually off toward longer wavelengths and more steeply toward shorter wavelengths.The results may be used to guide experiments with two-photon bleaching.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Glostrup Hospital, Glostrup, Denmark.

ABSTRACT

Purpose: Cataract is the world-leading cause of blindness. In search for a new treatment of cataract we have found that the yellow discolouration of aged human lenses can be photobleached using a non-invasive, infra-red, femtosecond laser treatment. These results were presented in an earlier PlosOne publication. The objective of the study was to characterize the single-photon photobleaching action spectrum of the aged human lens in vitro.

Methods: Ninety-one human donor lenses were irradiated with continuous wave laser light at 375, 405, 420, 445, 457 or 473 nm. Photobleaching was monitored by photography and transmission measurements.

Results: The action spectrum peaked at 420 nm followed by, in order of decreasing effect, 445, 457, 473, 405 and 375 nm. Younger and less absorbent lenses showed smaller changes than older and more absorbent lenses. There was a dose-dependent increase in lens transmission with increasing laser irradiation.

Conclusions: For a 75 year old lens an effect corresponding to elimination of 15 years or more of optical ageing was obtained. This study of the spectral characteristics and intensity needed to bleach the human lens with single-photon laser effects found an action-spectrum peak at 420 nm tailing gradually off toward longer wavelengths and more steeply toward shorter wavelengths. The results may be used to guide experiments with two-photon bleaching.

Show MeSH
Related in: MedlinePlus