Cataract from Ultraviolet Radiation
Year: 2001
Type: dissertation
Abstract: Cataract is the major cause of low vision and blindness in the world.\nEpidemiological and experimental studies link cataract to (solar)\nultraviolet radiation (UVR) exposure. Current safety limits of UVR\nexposure are based on animal experiments, but many factors are less well\nknown in UVR cataractogenesis. This thesis aims at strengthening the\nfoundation for experimental UVR cataract research and to aid in future\nrevisions of UVR safety limits.\n\nUsing lactate as a marker of glycolytic activity, it was shown that in\nvivo UVR exposure, but not blue light, inhibits lens glycolysis. With\noptimised histochemistry of the glycolytic enzyme lactate dehydrogenase\n(LDH), it was determined that lens epithelium and nucleus have high LDH\nactivity and cortex lower activity. LDH in the anterior parts of the lens\nwas inhibited by in vivo UVR exposure, probably by direct photochemical\naction. A short penetration of UVR-B in the lens was shown using LDH\nactivity as end-point. After in vivo exposure, young rats develop more\nsevere cataract than old rats, with no difference between sexes, and the\ntime for maximal cataract to develop is dependent on age. The degree of\ncataract was quantified by measurement of in vitro lens forward fight\nscattering. Iris pigmentation is highly UVR protective, with little\nimportance of pupil size in pigmented eyes, while the opposite holds for\nalbino eyes where a large pupil is more protective than a small pupil. In\nvitro UVR exposed lenses from albino rats are more sensitive than lenses\nfrom pigmented rats. The cataract type is similar in the two strains\nafter in vitro UVR exposure, opposite of the in vivo exposure situation,\nwhere cataract type differs.
Source: Figshare
Author: Stefan Löfgren
Language: English
Subfield: Ophthalmology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1569228396