What factors guide your decision to test for or start empiric treatment for Acanthamoeba keratitis in cases of corneal ulcers?

I can't say that I've ever started empiric treatment for acanthamoeba keratitis prior to other workup/testing/culture results, although I suppose if you have a slam dunk case with a known acanthamoeba exposure, I would do so.

The question of whether to test for AK is far more interesting. New-onset ...

Empiric treatment for Acanthamoeba keratitis should never be started, as you are committing the patient to 6-9 months of topical pool cleaners.

If AK is suspected, the patient should be referred EARLY to a center where it is possible to take a smear and/or culture. This should be suspected in all CL...