Webster's New World Medical Dictionary

retinal vasculitis
Inflammation of the tiny blood
vessels of the retina. Retinal vasculitis ranges in sever-
ity from mild to severe. Damage to the blood vessels
of the retina can cause minimal, partial, or even com-
plete blindness. Retinal vasculitis by itself is painless,
but many of the diseases that cause it can also cause
painful inflammation elsewhere, such as in the joints.
Signs of retinal vasculitis can be observed by a physi-
cian using an ophthalmoscope. Further definition of
the blood vessel condition can be determined with a
special X-ray dye test (angiogram) of the retina.
Diseases that cause retinal vasculitis include Behcet’s
syndrome, systemic lupus erythematosus, antiphos-
pholipid antibody syndrome, systemic necrotizing
vasculitis, Wegener’s granulomatosus, Takayasu’s vas-
culitis, and giant cell arteritis. Treatment typically
involves use of high doses of cortisone-related med-
ications, such as prednisone. In addition, some
related diseases require immunosuppression with
medication, such as cyclosporine, chlorambucil, and
cyclophosphamide.
retinitis pigmentosa
A group of inherited disor-
ders in which abnormalities of the photoreceptors
(the rods and cones) of the retina lead to progressive
visual loss. Abbreviated RP. People with RP first expe-
rience defective dark adaptation (night blindness),
then constriction of the visual field (tunnel vision),
and eventually, late in the course of the disease, loss of
central vision. RP may be inherited in an autosomal
dominant, autosomal recessive, or X-linked recessive
manner or as a mitochondrial disorder. RP can occur
alone or as part of a syndrome involving other abnor-
malities. More than 30 different genes are known to
cause nonsyndromic RP (RP alone). Usher syndrome,
which is RP and deafness, is a form of syndromic RP.