Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Damage mechanisms for near-infrared radiation induced cataract
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Ophthalmology.ORCID iD: 0000-0003-0654-5856
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Purpose: 1) To estimate the threshold dose and the time evolution for cataract induction by near infrared radiation (IRR) in seconds exposure time domain; 2) to determine the ocular temperature development during the threshold exposure; 3) to investigate if near IRR induces cumulative lens damage considering irradiance exposure time reciprocity; 4) to experimentally estimate the temperature in the lens indirectly from the measurement of temperature-induced light scattering increase.

Methods: Before exposure, 6-weeks-old albino rats were anesthetized and the pupils of both eyes were dilated. Then the animals were unilaterally exposed to 1090 nm IRR within the pupil area. Temperature was recorded with thermocouples placed in the selected positions of the eye. At the planned post-exposure time, the animal was sacrificed and the lenses were extracted for measurements of forward light scattering and macroscopic imaging (Paper I-III). In Paper IV, the lens was extracted from six-weeks-old albino Sprague-Dawley female rats and put into a temperature-controlled cuvette filled with balanced salt solution. Altogether, 80 lenses were equally divided on four temperature groups, 37, 40, 43 and 46 ºC. Each lens was exposed for 5 minutes to temperature depending on group belonging while the intensity of forward light scattering was recorded.

Results: The in vivo exposure to 197 W/cm2 1090 nm IRR required a minimum 8 s for cataract induction. There was approximately 16 h delay between exposure and light scattering development in the lens. The same radiant exposure was found to cause a temperature increase of 10 °C at the limbus and 26 °C close to the retina. The in vivo exposure to 96 W/cm2 1090 nm IRR with exposure time up to 1 h resulted in an average temperature elevation of 7 °C at the limbus with the cornea humidified and no significant light scattering was induced one week after exposure. Arrhenius equation implies that the natural logarithm of the inclination coefficient for light scattering increase is linearly dependent on the inverse of the temperature. The proportionality constant and the intercept, estimated as CI(0.95)s, were 9.6±2.4 x103 K and 22.8±7.7. Further, it implies that if averaging 20 measurements of inclination coefficients in a new experiment at constant heat load, the confidence limits for prediction of temperature correspond to ±1.9 °C.

Conclusions: It is indicated that IRR at 1090 nm produces thermal but not cumulatively photochemical cataract, probably by indirect heat conduction from absorption in tissues surrounding the lens. Applying the Arrhenius equation the in vivo temperature in the lens can be determined retrospectively with sufficient resolution.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. , p. 24
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 1284
Keywords [en]
infrared radiation, photochemical, thermal, forward light scattering, lens, cataract, temperature, Arrhenius equation, heat diffusion
National Category
Neurosciences
Identifiers
URN: urn:nbn:se:uu:diva-308835ISBN: 9789155497736 (print)OAI: oai:DiVA.org:uu-308835DiVA, id: diva2:1050967
Public defence
2017-01-20, Enghoffsalen, Entrance 50, 1st floor, Akademiska Sjukhuset, Uppsala, 13:00 (English)
Opponent
Supervisors
Available from: 2016-12-23 Created: 2016-11-30 Last updated: 2018-01-13
List of papers
1. 1090 nm infrared radiation at close to threshold dose induces cataract with a time delay
Open this publication in new window or tab >>1090 nm infrared radiation at close to threshold dose induces cataract with a time delay
Show others...
2015 (English)In: Acta Ophthalmologica, ISSN 1755-375X, E-ISSN 1755-3768, Vol. 93, no 2, p. e118-e122Article in journal (Refereed) Published
Abstract [en]

Purpose

To investigate if infrared radiation induced cataract is instant or is associatedwith a time delay between the exposure and the onset of lens light scattering after anexposure to just above threshold dose.

Methods

Six-weeks-old albino Sprague-Dawley female rats were unilaterally exposedto 197 W/cm2 infrared radiation at 1090 nm within the dilated pupil. In the firstexperiment, the animals were exposed with four exposure times of 5, 8, 13 and 20 s,respectively. At 24 h after exposure, the light scattering in both exposed andcontralateral not exposed lenses was measured. Based on the first experiment, fourpost exposure time groups were exposed unilaterally to 1090 nm infrared radiation of197 W/cm2 for 8 s. At 6, 18, 55 and 168 h after exposure, the light scattering in bothlenses was measured.

Results

A 197 W/cm2 infrared radiation induced light scattering in the lens withexposures of at least 8 s. Further, after exposure to infrared radiation of 197 W/cm2for 8 s, the light scattering increase in the lens was delayed approximately 16 h afterthe exposure.

Conclusion

There is a time delay between the exposure and the onset of cataract afterexposure to close to threshold dose implicating that either near infrared radiationcataract is photochemical or there is a time delay in the biological expression ofthermally induced damage.

Keywords
infrared radiation, forward light scattering, lens, photochemical, thermal
National Category
Basic Medicine Ophthalmology
Research subject
Ophtalmology
Identifiers
urn:nbn:se:uu:diva-226530 (URN)10.1111/aos.12508 (DOI)000349900200005 ()
Available from: 2014-06-18 Created: 2014-06-18 Last updated: 2018-01-11Bibliographically approved
2. Temperature-controlled in vivo ocular exposure to 1090-nm radiation suggests that near-infrared radiation cataract is thermally induced
Open this publication in new window or tab >>Temperature-controlled in vivo ocular exposure to 1090-nm radiation suggests that near-infrared radiation cataract is thermally induced
Show others...
2015 (English)In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 20, no 1, article id 015003Article in journal (Refereed) Published
Abstract [en]

The damage mechanism for near infrared radiation induced (IRR) cataract is unclear. Both a photochemical and a thermal mechanism were suggested.

The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity.

Groups of 20 rats were unilaterally exposed to 96 W/cm2 IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, 344 kJ/cm2 respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was measured quantitatively.

The average maximum temperature increase for exposure time 10, 18, 33, 60 minutes was expressed as CI(0.95); 7.0±1.1, 6.8±1.1, 7.6±1.3, 7.4±1.1 ºC at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not exposed eyes was 0.00±0.02, 0.01±0.03, -0.01±0.02, -0.01±0.03 tEDC, respectively and no apparent morphological changes in the lens were observed.

An exposure to 96 W/cm2 1090 nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344 kJ/cm2 does not induce cataract if the temperature rise at the limbus is below 8 °C. This is consistent with a thermal damage mechanism for IRR induced cataract.

Keywords
infrared radiation, temperature, forward light scattering, lens
National Category
Ophthalmology
Identifiers
urn:nbn:se:uu:diva-240718 (URN)10.1117/1.JBO.20.1.015003 (DOI)000350206400007 ()25602780 (PubMedID)
Available from: 2015-01-08 Created: 2015-01-08 Last updated: 2017-12-05Bibliographically approved
3. Ocular temperature elevation induced by threshold in vivo exposure to 1090 nm infrared radiation and associated heat diffusion
Open this publication in new window or tab >>Ocular temperature elevation induced by threshold in vivo exposure to 1090 nm infrared radiation and associated heat diffusion
Show others...
2014 (English)In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 19, no 10, p. 105008-Article in journal (Refereed) Published
Abstract [en]

An in vivo exposure to 197 W/cm2 1090 nm infrared radiation (IRR) requires a minimum 8 s for cataract induction. The present study aims to determine the ocular temperature evolution and the associated heat flow at the same exposure conditions. Two groups of 12 rats were unilaterally exposed within the dilated pupil with a close to collimated beam between lens and retina. Temperature was recorded with thermocouples. Within 5 min after exposure, the lens light scattering was measured. In one group, the temperature rise in the exposed eye, expressed as CI(0.95), was 11±3 ºC at the limbus, 16±6 ºC in the vitreous behind lens and 16±7 ºC on the sclera next to the optic nerve, respectively. In the other group, the temperature rise in the exposed eye was 9±1 ºC at the limbus and 26±11 ºC on the sclera next to the optic nerve, respectively. The difference of forward light scattering between exposed and contralateral not exposed eye was 0.01±0.09 tEDC. An exposure to 197 W/cm2 1090 nm IRR for 8 s induces a temperature increase of 10 °C at the limbus and 26 °C close to the retina. IRR cataract is probably of thermal origin.

Keywords
infrared radiation, temperature, light scattering lens, heat diffusion
National Category
Neurosciences
Research subject
Ophtalmology
Identifiers
urn:nbn:se:uu:diva-232619 (URN)10.1117/1.JBO.19.10.105008 (DOI)000345837200015 ()
Available from: 2014-09-22 Created: 2014-09-22 Last updated: 2018-05-16Bibliographically approved
4. Measuring temperature in the lens during experimental heat load indirectly as light scattering increase rate
Open this publication in new window or tab >>Measuring temperature in the lens during experimental heat load indirectly as light scattering increase rate
2017 (English)In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 22, no 1, article id 015005Article in journal (Refereed) Published
Abstract [en]

The current study aims to experimentally estimate the temperature in the lens due to heat load indirectly from the measurement of increase rate of temperature-induced light scattering. The lens was extracted from Sprague-Dawley rats and put into a temperature-controlled cuvette filled with balanced salt solution. Altogether, 80 lenses were equally divided on four temperature groups. Each lens was exposed for 5 minutes to temperature depending on group belonging while the intensity of forward light scattering was recorded. The inclination coefficient of light scattering increase at the temperature 37, 40, 43, and 46 ºC was estimated as a CI(0.95), 3.1±0.8, 4.4±0.8, 5.5±0.9 and 7.0±0.8 x10-4 tEDC/s, respectively. The Arrhenius equation implies that the natural logarithm of the inclination coefficient is linearly dependent on the inverse of the temperature. The proportionality constant and the intercept were 9.6±2.4 x103 K and 22.8±7.7. The activation energy was 8.0±2.0 x101 kJ·mol-1. The current experiment implies that if averaging 20 measurements of inclination coefficients in a new experiment at constant heat load, the confidence limits for predicted temperature correspond to ±1.9 °C. With the proportionality constant and the intercept estimated in the current experiment, the in vivo temperature in the lens can be determined retrospectively with sufficient resolution.

Keywords
forward light scattering; lens; cataract; temperature; Arrhenius equation
National Category
Neurosciences
Research subject
Ophtalmology
Identifiers
urn:nbn:se:uu:diva-308820 (URN)10.1117/1.JBO.22.1.015005 (DOI)000396370600009 ()
Available from: 2016-11-30 Created: 2016-11-30 Last updated: 2018-01-13Bibliographically approved

Open Access in DiVA

fulltext(1412 kB)23689 downloads
File information
File name FULLTEXT01.pdfFile size 1412 kBChecksum SHA-512
39fa1c4d4a1f51eb5c4bd3c707dd2750104b5a7880028fd9b2b8109a3c1455a92f275864bdcf83a73c9ea3bee28ba4e8347f83efab7139f3b895b1f7eef4c24e
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Yu, Zhaohua
By organisation
Ophthalmology
Neurosciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 23689 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 934 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf