V. Mody

Drinking water supplementation with ascorbate is not protective against UVR-B-induced cataract in the guinea pig.

Purpose:  To study if ascorbate supplementation decreases ultraviolet radiation (UVR)‐induced cataract development in the guinea pig.

High lenticular tolerance to ultraviolet radiation-B by pigmented guinea-pig; application of a safety limit strategy for UVR-induced cataract.

Purpose:  The purpose of this study was to determine a threshold measure, maximum tolerable dose (MTD), for avoidance of UVR‐B‐induced cataract in the pigmented guinea‐pig.

Macular protection with IOLs

The clinical outcome within one month after phacoemulsification cataract extraction with implantation of the blue-blocking SN60AT IOL was examined prospectively and compared to a retrospectively examined material of implantations of the equivalent SA30AL without blue-blocker. There was no difference in best corrected visual acuity gain between the two lenses. In addition, the subjective color perception was examined for with a questionnaire after the first implantation of blue-blocking IOL and after the second implantation of blue-blocking IOL. Only one patient noted a changed color perception. There are thus strong theoretical reasons to block blue light in IOLs and no short term clinical inconvenience. But, it remains to be proven in long term follow up studies that the blue-blocking IOL protects against macular degeneration.

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.