Is fluctuating vision normal after trabeculectomy?

What's normal

Vision that is better one day and worse the next is one of the most confusing parts of trabeculectomy recovery, and it is expected. Eye pressure is being actively adjusted. EyeWiki describes the surgeon managing pressure by releasing scleral flap sutures with laser suture lysis or by removing releasable sutures during the follow up visits, and BrightFocus Foundation describes the same office based suture cutting. Each adjustment changes how fast fluid leaves and therefore changes the pressure and the shape of the eye.

On top of that, the drops themselves blur vision, the surface is healing unevenly, and the old glasses prescription no longer matches. The American Academy of Ophthalmology says a new prescription is usually measured once the eye has healed, often in 6 to 8 weeks, which is roughly when the fluctuation typically calms down. The Glaucoma Research Foundation says vision usually returns to the same level after about six weeks.

Most pronounced during the suture adjustment weeks, usually settling by about 6 to 8 weeks, with slower drift for a few months.

When it stops being normal

Fluctuation that trends downward is different from fluctuation around a stable level. Report vision that is steadily getting worse, a sudden loss of vision, or new flashes of light or a shower of new floaters, which the American Academy of Ophthalmology treats as reasons to be seen promptly after eye surgery.

Also report fluctuation that arrives with pain, redness, or discharge, since EyeWiki lists those together as features of bleb associated infection.