Oh poor Stumpy, he doesn't look very happy.
At least his other eye looks OK from this angle.
One of the things the surgeon did with my leg abscess (after they'd cut them out to remove them) was to insert a special surgical wicking strip into the wound and pack it (to keep it from closing and help draw out fluids (exudate). In my case this was replaced daily while in hospital and daily by visiting nurse while I was healing and recouperating at home (over a period of 8 months).
And about 15 years ago when I was in the habit of using little ear plugs (designed mind you for the job and used very commonly by people in noisy industrial workplaces like the bar and rod mills (where I was working) to protect their hearing, rather than helmet mounted airmuffs, and I developed a nasty inner ear infection. My GP lanced the airdrum to release the puss and fluid pressure builtup , and inserted a special ear wick to drain the inner ear. (A similar sized structure as Stumpy's eye).
Maybe the vet can try this with the damaged tearduct , this will ensure it drains continuously and pressure / fluids are not allowed to accumulate (as I think these accumulated reserviours of fluid will likely harbour bacteria and be a perfect place for bacteria to grow).
Maybe he needs to insert an "Eye Spear" or an "Eye Fluid Wick" see
http://www.hurricanemedical.com/hm_microsurgical.htm
Just a thought