There being no hard evidence that postop antibiotics reduce the incidence of endophthalmitis, we do this because it makes some logical sense, and if challenged we can say we did “something” to prevent endophthalmitis postop. But, we could also make a defensible argument that they are not necessary. That said, there is no “perfect” prophylactic drug, because there is no drug that you can count on to kill EVERY organism every time, so you have to pick your poison, so to speak, and I think you could defend the use of virtually any broad-spectrum antibiotic, whether it be a fluoroquinolone, Polytrim, aminoglycoside, or perhaps even a macrolide. Given that, by far, the predominance of organisms causing endophthalmitis are staph, either coag-positive or -negative, and the high percentage that have become methicillin resistant, and the high level of resistance to FQs of those organisms, and the better effectiveness of trimethoprim against those organisms, I think that you could make a compelling argument that polymixin (which kills virtually every gram-negative except Proteus) combined with trimethoprim (which has good gram-positive coverage and better than FQs against MRSA or MRSE), that Polytrim is, in fact, a PREFERRED medication for postop prophylaxis. So yes, I think it is well within the standard of care, and, if necessary, I would come to court with you to defend that point of view.
Our standard dosing post ASA is Besivance BID and a steroid QD. This regime allows 90% of our patients to reepithelialize in a few days with zero pain. Also using oral steroids eg medrol dosepak which allows you to dose topical steroid QD n also decreases pain