
The thing about the condition, which COULD lead to glaucoma, is in my own breed (may be different in other breeds, idk) is that's not necessarily the case by a long way. Yes it's perhaps a good idea to do the gonio test, but as said elsewhere, so often this rules out an otherwise exceptional dog being used in a gene pool when glaucoma developing isn't a certainty, just a possibility. I'm not sure why the OP says 'severely affected because with the goniodysgenesis test, you either get a pass or a fail - don't you? The only certainty with getting this done, under the KC/BVA Scheme is the result is published in the KCSB Records and goes on the registration paperwork of any offspring.
A lot of breeders in my main breed are having this done these days which I suppose as glaucoma is around now, more than in it was years ago in the breed, can only be good really. Just to add, I was phoned by a leading Eye Specialist at the time, when others with puppies from a sire I'd used, were in trouble. The man came at me saying 'we'd better test your puppies'. I said hang on, I have NO reason to suspect the puppies I have from this male, are likely to be affected. He backed off totally, leaving me thinking kerching. It was later discovered by checking the lines on both sides, that this came from the dam's side in the case of those other puppies from this sire. And those puppies we had from him, went through life fully sighted.
If the option to test for the pre-disposition to a condition, is there, I suppose it makes sense to have it done. I tended not to rush into testing, unless I started to get a problem in our limited number of litters.