On clinical suspicion of endophthalmitis, if vitreous surgery was not contemplated in the next 6 hours, an anterior chamber tap was performed and the samples were subjected to gram staining, KOH staining, bacterial and fungal cultures, antibiotic sensitivity, and PCR for P. acnes, eubacterial and panfungal genomes. If surgery was contemplated, vitreous specimen was collected during vitrectomy and similar microbiological tests were conducted. On the basis of microbiological results, initial antibiotics were given. However, in cases of initial negative results of staining, choice of antibiotics was based on clinical judgment. Scleral or corneal scraping were taken for microbiological evaluation, when indicated.