The vitreous humor is an excellent growth base for bacteria and microorganisms, and the entry of bacteria and other microorganisms into the vitreous humor can lead to vitreous inflammation, also known as endophthalmitis. A. Etiology: 1. Endogenous Pathogenic microorganisms enter the eye from the bloodstream or lymph or become infected due to immune function suppression and immune deficiency. For example, bacterial endocarditis and pyelonephritis can cause bacterial infection of the vitreous humor. Organ transplantation or tumor patients after chemotherapy or the use of a large number of broad-spectrum antibiotics often occur fungal infections, the common causative organisms are Candida albicans. 2, exogenous (1) post-surgical endophthalmitis: post-surgical endophthalmitis can occur after any endophthalmic surgery, such as cataract, glaucoma, corneal transplantation, vitrectomy and ocular penetrating injury repair. The most common causative organism is Gluconococcus. The pathogenic bacteria can be present in the eyelids, eyelashes, and tear ducts, and surgical sutures and IOLs can also be sources of infection. (2) Ocular rupture injury and intraocular foreign body 2. Clinical manifestations: 1. Symptoms: endogenous endophthalmitis symptoms are blurred vision; postoperative bacterial endophthalmitis usually occurs l to 7 days after surgery, with sudden eye pain and vision loss; fungal infection often occurs three weeks after surgery. 2. Signs (1) Endogenous infection usually starts at the back of the eye and can be accompanied by inflammatory retinal disorders. The lesions are white, well-defined, and initially scattered, but later become larger and spread to the front of the retina to produce vitreous opacities, and pus accumulation in the anterior chamber may also occur. (2) Bacterial infection after surgery often has pain in the operated eye, loss of vision, redness of the eyelid, mixed congestion of the bulbar conjunctiva, purulent exudation from the wound, pus in the anterior chamber or pus in the vitreous volume, and rapid loss of vision if left untreated. (3) Post-surgical fungal infection often invades the anterior vitreous, and the anterior vitreous surface accumulates pus or forms membranes, and the infection can spread to the posterior vitreous cavity and anterior chamber without timely treatment. Treatment: 1, antibiotics or antifungal drugs depends on the results of bacterial culture and drug sensitivity assay, but the initial administration can be based on the atrial fluid and vitreous Gram stain results. Route of administration: 1, intraocular injection; 2, subconjunctival injection; 3, conjunctival sac spotting; 4, intravenous administration. 2, vitrectomy Vitrectomy can exclude vitreous cavity abscess, remove pathogenic bacteria, rapidly restore transparency, and facilitate the discharge of infected material in the anterior chamber, and is now widely used in the treatment of endophthalmitis. At the beginning of the procedure, vitreous fluid can be extracted for staining and bacterial culture staining including Gram stain, Gimsa stain and special fungal stain in order to identify the causative organism.