In which cases of post-injection endophthalmitis should early vitrectomy be considered if there is little to no improvement 48 hours after a tap and inject and there is no organism isolated?  

Prompt vitrectomy should be considered in all patients with post-injection endophthalmitis (PIE) if there is no improvement 48 hrs after a tap and inject. The initial tap did not identify the organism. Non-infectious endophthalmitis can be included in the differential diagnosis of persistent inflamm...