Human patients with retinitis pigmentosa caused by certain rhodopsin
mutations (Pro-23-His and others) develop severe degeneration of rods in
the inferior retina, with slower degeneration in the superior half.
Transgenic (TG) mice with this rhodopsin mutation show similar
degeneration of the inferior retina when reared under overhead light, but
TG littermates reared in the dark show slower degeneration that is
uniform across the retina.
These observations suggest phototoxicity to mutant rod photoreceptors that
is more severe in the inferior hemiretina of humans, perhaps because most
lights are overhead.
But is this true? Does the inferior retina receive more light when the
source is overhead? Has this been measured?
I would greatly appreciate information and references!
Ann Milam
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Ann H. Milam Tel: (206) 543-9188 (Office)
Dept. of Ophthalmology Tel: (206) 543-7489 (Lab)
Box 356485
University of Washington FAX: (206) 543-7711
Seattle, WA 98195-6485 e-mail: annmilam@u.washington.edu
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