Night blindness in Sorsby's fundus dystrophy reversed by vitamin A.
Sorsby's fundus dystrophy (SFD) is an autosomal dominant retinal degeneration caused by mutations in the tissue inhibitor of metalloproteinases-3 (TIMP3) gene. Mechanisms of the visual loss in SFD, however, remain unknown. In a SFD family with a novel TIMP3 point mutation, we tested a hypothesis that their night blindness is due to a chronic deprivation of vitamin A at the level of the photoreceptors caused by a thickened membrane barrier between the photoreceptor layer and its blood supply. Vitamin A at 50,000 IU/d was administered orally. Within a week, the night blindness disappeared in patients at early stages of disease. Nutritional night blindness is thus part of the pathophysiology of this genetic disease and vitamin A supplementation can lead to dramatic restoration of photoreceptor function.
Jacobson
S G
SG
Department of Ophthalmology, University of Miami School of Medicine, Bascom Palmer Eye Institute, Florida 33136, USA.
Cideciyan
A V
AV
Regunath
G
G
Rodriguez
F J
FJ
Vandenburgh
K
K
Sheffield
V C
VC
Stone
E M
EM
D000328:Adult; D016570:Bruch Membrane / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004252:DNA Mutational Analysis; D004058:Diffusion; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D009755:Night Blindness / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D010375:Pedigree; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011506:Proteins / Q000235:genetics*; D012162:Retinal Degeneration / Q000150:complications* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D017948:Retinal Rod Photoreceptor Cells / Q000098:blood supply*; D012607:Scotoma / Q000188:drug therapy / Q000209:etiology; D019717:Tissue Inhibitor of Metalloproteinase-3; D014801:Vitamin A / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*
D005136:Eye Proteins; D011506:Proteins; D019717:Tissue Inhibitor of Metalloproteinase-3; D014801:Vitamin A