K Galichanin

Exposure to subthreshold dose of UVR-B induces apoptosis in the lens epithelial cells and does not in the lens cortical fibre cells.

The aim of this study was to investigate in which part of the lens in vivo exposure to subthreshold dose of UVR‐B radiation induces apoptosis.

Near infrared radiation damage mechanism in the lens

The current data strongly indicates that there is no photochemical effect of in vivo exposure to 1090 nm near IRR radiation within the pupil. Four groups of 20 Sprague-Dawley rats were unilaterally exposed in vivo to 96 W·cm-2 centered inside the pupil for 10, 18, 33 and 60 min, respectively depending on group belonging. This resulted in radiant exposure doses of 57, 103, 198 and 344 kJ·cm-2. Temperature evolution at the limbus during the exposure and difference of intensity of forward light scattering between the exposed and the contralateral not exposed eye was measured at 1 week after exposure. The temperature at the limbus was found to increase exponentially towards an asymptote with an asymptote temperature of around 7 °C and a time constant (1/k) of around 15 s. No increase of light scattering was found despite that the cumulated radiant exposure dose was [80;250] times the threshold for photochemically induced cataract suggested by previous empirical data. It is concluded that at 1090 nm near IRR there is no photochemical effect.

Ocular temperature rise and light scattering development in the lens correlating with exposure time after in vivo exposure to 1090 nm infrared radiation

Purpose To investigate the relationship between light scattering development in the lens and ocular temperature rise after in vivo exposure to high intensity 1090 nm radiation with exposure time up to 60 minutes.

In vivo quantitative measurement of oxidation repair of glutaredoxin-1

Purpose Quantitative determination of the impact of glutaredoxin‐1 on sensitivity to oxidative stress induced by in vivo exposure to ultraviolet radiation in the 300 nm wavelength region.

Evolution of light scattering after in vivo close to threshold dose of ultraviolet radiation 300 nm

Purpose: To determine the evolution of light scattering in the albino rat lens after in vivo close to threshold UVR-300 nm. Methods: Alltogether 4 groups of 20 6 weeks old albino Sprague-Dawley rats were exposed unilaterally in vivo to 8 kJ/m2 UVR-300 nm. The animals were sacrificed at 1, 7, 48 and 336 hrs after exposure after exposure to UVR, depending on group belonging and the lenses were removed for macroscopic imaging of dark-field anatomy, and quantitative measurement of intensity of forward light scattering. Results: The intensity of light scattering increased exponentially declining with a rate constant (1/k) of 71 hrs and an asymptote maximum light scattering of 0.16 tEDC. This is consistent with findings for a dose of 30 kJ/m2 although the current time constant was higher. There was an indication of a transient increase of light scattering on the contralateral side peaking at 7 hrs after expsoure. There was an indication for some repair at 336 hrs. Conclusions: Light scattering evolves quicker, the higher the dose, but increases exponentially declining towards an assymptote. The current study suggest that observations of damage from close to threshold in vivo UVR exposure should be made at 1 week after exposure in order to detect the maximum damage.