Purchase this article with an account.
Ralph Michael, Gijs F. J. M. Vrensen, Jan van Marle, Stefan Löfgren, Per G. Söderberg; Repair in the Rat Lens after Threshold Ultraviolet Radiation Injury. Invest. Ophthalmol. Vis. Sci. 2000;41(1):204-212.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. To investigate the development and recovery of lens damage after in
vivo close-to-threshold exposure to ultraviolet B radiation.
methods. One eye of young, female Sprague–Dawley rats was exposed to 5
kJ/m2 narrowband ultraviolet radiation (UVR)
(λmax = 302 nm) for 15 minutes. Groups of rats were
killed 1, 7, and 56 days after exposure. The structure of the exposed
and nonexposed lenses was examined with light microscopy, scanning
electron microscopy, transmission electron microscopy,
freeze–fracture, fluorescent membrane staining, and Fourier transform
results. One day after UVR exposure the lens surface had flakelike opacities.
Seven days after exposure, the lens surface appeared opaque and
corrugated, and the equatorial cortex had small opacities. At 56 days
postexposure, the surface and equator appeared clear, but the cortex
had a subtle shell-shaped opacity. At 1 day postexposure, apoptotic
cell death occurred in the lens epithelium, but the cortical fibers
were normal. At 7 days postexposure, the epithelium and the fibers
between the 10th and 40th growth shell below the capsule contained
extracellular spaces of different sizes. After 56 days, the epithelial
layer appeared normal, and the extracellular spaces had disappeared;
but abnormal fibers were found between the 60th and 100th growth shell
below the capsule. Fibers above and below the damaged growth shells
appeared fully normal.
conclusions. A close-to-threshold dose of UVR causes cataract, which is largely
reversible. The UVR exposure leads to apoptosis in the lens epithelium,
and after a latency period of several days, lens fibers are abnormal.
Extracellular spaces develop in the epithelium and fibers. Within
several weeks after exposure, the epithelium fully recovers and new
fibers develop normally. The originally affected fibers are repaired.
However, this repair is incomplete, leaving a small zone of enhanced
light scattering in the equatorial
This PDF is available to Subscribers Only