Hi pippa52, I've also been investigated for Sjogren's, with very dry eyes, mouth, nose, skin, etc. Worse since BSO a few years ago which led me to suspect the drop in testosterone might be implicated. I researched & came across articles like the one Marchlove has helpfully posted. I asked to start T & found it really helped, especially improving dryness in mouth, nose & eyes.
I've gone through a range of prescription eye drops over many years but those I use now are by far the best: Optive Plus. They have an oily ingredient that helps address the problem arising from reduced secretions from the Meibomian glands, resulting in the tear film evaporating too quickly. Please don't be put off by the mention of oil, they do blur vision a bit for a while after application but that clears & I find they provide good relief from the discomfort & control inflammation well - more than any others I've tried. Whatever you use, they should be preservative-free for long term use. Please feel free to PM me if you want any more info.
https://www.sjogrens.org/living-with-sjogrens/survival-tipsWx
P.S. forgot to say I also use Blephagel morning & night to keep lids & lashes clean.