To investigate the incidence, causative organisms, and visual acuity outcomes associated with endophthalmitis after pars plana vitrectomy

In this retrospective, comparative study the medical records of all patients who developed acute-onset postoperative endophthalmitis (within 6 weeks of surgery) after pars plana vitrectomy at Farabi Eye Hospital, Tehran, Iran, during a 12 year period between January 2004 and November 2015 were reviewed. To compare the endophthalmitis patients with other cases who underwent Pars Plana vitrectomy at the same day and also the same operating room, a control group was developed by gathering the data from surgical records.

During the 12 years study interval, the overall incidence rate of post vitrectomy endophthalmitis was 0.04% (16/39783). The organisms identified in aqueous or vitreous cultures (culture positive 44%) included Streptococcus pneumoniae (two patients, 12.5%), Pseudomonas aeruginosa (two patients, 12.5 %), fungi (two patients, 12.5%) and Streptococcus viridans (one patient, 6.25%). Visual acuity after treatment for endophthalmitis ranged from light perception (7 eyes) to hand motion (1 eye), and evisceration was performed in 8 eyes (50%). When comparing the cases (patients developing endophthalmitis) and controls (patients with no complications operated in the same day and place of operation with the case group), only not using tamponade showed a statistically significant relation with the occurrence of endophthalmitis (p=0.034).

The incidence of endophthalmitis after pars plana vitrectomy is low but the visual acuity outcomes after treatment are generally poor. It seems that not using tamponade might increase the risk of endophthalmitis.