Methods A total of 65 patients (65 eyes) with infectious endophthalmitis after ophthalmic surgery and 195 postoperative non-infected patients (195 eyes) were selected as the study objects from January 2014 to December 2023. Among them, there were 156 males (156 eyes) and 104 females (104 eyes) with mean age of (65.2±10.0) years old (ranging from 4 to 88 years old). The basic data, preoperative examination results, post-infection examination results, postoperative medication, pathogenic bacteria, treatment methods and recovery of patients were collected. The average age, length of hospital stay, body mass index, and time of onset of infection symptoms follow a normal distribution expressed as 
±s and compared by independent sample t-test for inter group comparison. The counting data of smoking history, drinking history, diabetes, hypertension, hyperlipidemia, serious disease history, preoperative low hemoglobin, preoperative low serum albumin, preoperative failure to use antibacterial eye drops as required, daytime surgery, emergency surgery, general anesthesia surgery, preoperative presence of other infectious lesions, postoperative eye pollution history, and postoperative failure to use antibacterial eye drops as required were described by cases and percentages. The prognosis of visual acuity in patients with different pathogens did not follow a normal distribution and was described using median and interquartile intervals [M(IQR)]. The risk factors of endophthalmitis infection was calculated by multiple Logistic regression analysis.
Results Among of 65 cases (65 eyes) of infectious endophthalmitis after ophthalmic surgery, there were 39 males (39 eyes) and 26 females (26 eyes). There were 28 (28 eyes)cases of left eye and 37 cases (37 eyes)of right eye. There were 1 case (1 eye) with cataract surgery, 2 cases (2 eyes) with vitrectomy, 6 cases (6 eyes) with vitrectomy combined with cataract surgery, 4 cases (4 eyes) with glaucoma combined with cataract surgery, 2 cases (2 eyes) with intravitreal drug injection. There were 24 cases (24 eyes) in tertiary hospitals, 31 cases (31 eyes) in secondary hospitals and 10 (10 eyes)cases in private hospitals. There were 40 cases (40 eyes) with hyperacute endophthalmitis, 25 cases (25 eyes) with subacute endophthalmitis, and without chronic endophthalmitis. The mean age of patients with infectious endophthalmitis, length of hospital stay, body mass index were (66.4±14.7) years old, (3.29±1.45) d, (24.41±2.09) kg/m2. The patients with non-infectious endophthalmitis were (64.8±7.8 )years old, (3.06±0.97) d, (24.00±2.24) kg/m2. The difference was not statistically significant in the mean age length of hospital stay, body mass index between patients with infectious endophthalmitis and non-infectious endophthalmitis after ophthalmic surgery (t=1.171, 1.154, 0.261; P>0.05). The number patient of infectious endophthalmitis with smoking history, drinking history, diabetes mellitus, hypertension, hyperlipidemia, history of serious disease, preoperative low hemoglobin, preoperative low serum albumin, wrong use of antibacterial eye drops, day surgery, emergency surgery, general anesthesia surgery, other body infections before surgery, and postoperative history of eye contamination were 28 cases (28 eyes), 19 cases (19 eyes), 42 cases (42 eyes), 29 cases (29 eyes), 23 cases (23 eyes), 21 cases (21 eyes), 12 cases (12 eyes), 20 cases (20 eyes), 5 cases (5 eyes), 28 cases (28 eyes), 3 cases (3 eyes), 2 cases (2 eyes), 6 cases (6 eyes), 10 cases (10 eyes) and 4 cases (4 eyes), respectively, acctounting for 43.08%, 29.23%, 64.62%, 44.62%, 35.38%, 32.31%, 18.46%, 30.77%, 7.69%, 43.08%, 4.62%, 3.08%, 9.23%, 15.38% and 6.15%. The number patient of non-infectious endophthalmitis with those were 101 cases (101 eyes), 62cases (62 eyes), 79 cases (79 eyes), 58 cases (58 eyes), 63 cases (63 eyes), 22 cases (22 eyes), 30 cases (30 eyes), 19 cases (19 eyes), 8 cases (8 eyes), 93 cases (9 eyes), 11 cases (11 eyes), 4 cases (4 eyes), 9 cases (9 eyes), 12 cases (12 eyes) and 9 cases (9 eyes), respectively, acctounting for 51.79%, 31.79%, 40.51%, 29.74%, 32.31%, 11.28%, 15.38%, 9.74%, 4.10%, 47.69%, 5.64%, 2.05%, 4.62%, 6.15% and4.62%. Multivariate Logistic regression analysis showed that diabetes mellitus, low serum albumin before surgery and history of disease and, dirt getting into the eye after surgery were risk factors for infectious endophthalmitis after ophthalmic surgery (OR=2.039, 3.021, 2.803, 3.095; P<0.05). There were 41 strains of pathogenic bacteria, and no fungal infection cases were detected, the detection rate was 63.08%. Among them, there were 1 strain with G+ bacillus, 26 strains with G+ coccus and 14 strains with G-bacillus, accounting for 2.44%, 63.41% and 34.15%, respectively. The occurrence time of postoperative infection symptoms of 65 patients (65 eyes) of infectious endophthalmitis after ophthalmic surgery was (4.48±4.46) days. Among them, there were 53 cases (53 eyes), 55 cases (55 eyes), 35 cases (35 eyes), and 62 cases (62 eyes) with conjunctival congestion, eye pain, foreign body sensation, and blurred vision, accounting for 81.53%, 84.62%, 53.85%, and 95.38%, respectively. The onset time of infection symptoms in patients with G+ bacteria, G-bacteria, and sterile growth is (3.56±1.71) d, (1.85±1.21) d, and (4.87±3.75) d, respectively. Among 65 patients (65 eyes), 4 cases (4 eyes), 10 cases (10 eyes), 49 cases (49 eyes), and 2 cases (2 eyes) underwent intravitreal injection, anterior chamber lavage combined with intravitreal injection, vitrectomy, and enucleation, respectively, accounting for 15.38%, 6.15%, 75.38%, and 3.08%, respectively. The prognostic visual acuity of patients with G+ bacteria, G-bacteria, and sterile growth were 3.00 (1.65), 1.00 (1.50), and 3.30 (2.40), respectively.