Primary open angle glaucoma (POAG)

A primary open angle glaucoma is a genetic dysfunction of the connective tissue in the eye. Thereby, the aqueous fluid is blocked and the pressure of the eyeball rises. Ultimately, the optic nerve and the retina are damaged leading from partial to complete blindness. Symptoms include widened pupils, red eyeballs, cloudy cornea and increased eye pressure. Raising eye-pressure causes pain, which leads to the dog loses its appetite, scratches the eyes, rubbing its head on walls and exhibit aggressive behaviour. Early diagnosis allows treatment in decreasing the eye-pressure constantly and thereby preventing damage on the optic nerve and retina. The onset of the disease varies between breeds. While first symptoms in the Beagle show between eight and sixteen months, the Norwegian Elkhound shows symptoms at a middle to later age.
In the breed Petit Basset Griffon Vendeen, POAG causes a small, sustained rise in intraocular pressure (IOP) and lens subluxation. First clinical signs emerge at the age of 3-4 years and develop progressively. In later stages of the disease, globe enlargement, retinal degeneration and optic disc deformation could be observed. Since POAG does not cause pain in this breed, ownes only become aware of the disease as soon as the globe enlargement and the vision problems become noticeable.