Interesting, definitely agree it likely shares an underlying cause with tinnitus. It's also linked to migraine and was sometimes conflated with unusual forms of migraine in the past, although it's since been found to be a distinct disorder. There's been a few studies done on visual snow patients, including a 2023 fMRI study which implicated regions rich in glutamate and 5HT2A receptors.

I actually suspected 5HT2A might be involved before that study came out, since my visual distortions sometimes resemble those caused by psychedelics. It's also known that both psychedelics and anecdotally from patient's groups SSRIs too can cause a similar symptoms to visual snow syndrome, I had a bad experience with SSRIs for example but serotonin antagonists actually fixed my vision temporarily - albeit with intolerable side-effects so I had to stop.

It's definitely a bit of a faff that people have never heard of it, I had to see a neuro-ophthalmologist and a migraine specialist to get a diagnosis. On the other hand being relatively unknown does mean doctors can be willing to experiment. My headaches at least are controlled well these days.