Congenital stationary night blindness

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A retinal fundus photograph of a Briard dog with the inherited eye disease congenital stationary night blindness[1]

Congenital stationary night blindness (hereditary retinal dystrophy) is an autosomal-recessive genetic disease of Briards characterized by night blindness and variable visual deficits[2].

The disease, which has been sporadically reported in France and the USA[3], is caused by a missense mutation is in the retinal pigment epithelium-specific protein 65kD (RPE65) gene located on canine chromosome 6, leading to retinal dysfunction and accumulation of lipid vacuoles in the retinal pigment epithelium[4]. The pathology is located mainly in the central and tapetal areas of the retina and morphologically different from other hereditary canine retinopathies[5].

Briard dogs, showing structural changes of the rod outer segments in addition to pigment epithelial inclusions,

This disease manifests in Briard dogs from a young age (from 6 weeks-of-age onwards) as hemeralopia and can lead to permanent blindness in some pups.

A differential diagnosis would include progressive retinal atrophy, where night-vision is also affected.

There is no treatment for this condition and mildly affected dogs can achieve normal longevity.

References

  1. Cornell Uni
  2. Narfström K (1999) Retinal dystrophy or 'congenital stationary night blindness' in the Briard dog. Vet Ophthalmol 2(1):75-76
  3. Narfström K et al (1989) The Briard dog: a new animal model of congenital stationary night blindness. Br J Ophthalmol 73(9):750-756
  4. Aguirre GD et al (1998) Congenital stationary night blindness in the dog: common mutation in the RPE65 gene indicates founder effect. Mol Vis 4:23
  5. Wrigstad A et al (1992) Ultrastructural changes of the retina and the retinal pigment epithelium in Briard dogs with hereditary congenital night blindness and partial day blindness. Exp Eye Res 55(6):805-818