Endophthalmitis after pars plana vitrectomy. The Postvitrectomy Endophthalmitis Study Group.

To describe the clinical course and incidence of culture-proven postvitrectomy endophthalmitis in 18 patients from five academic centers and three private practices. Patients undergoing pars plana vitrectomy for recent trauma or endophthalmitis were excluded. The average age was 58 years (range, 21-85 year). Sixty-one percent of the patients (11/18) had diabetes mellitus. The indication for initial vitrectomy was vitreous hemorrhage (n = 10), macular epiretinal membrane (n = 3), recurrent retinal detachment with proliferative vitreoretinopathy (n = 2), retinal detachment with retinoschisis (n = 1), proliferative diabetic retinopathy with tractional retinal detachment (n = 1), and dislocated intraocular lens (n = 1). None of these eyes received prophylactic intraocular antibiotics during the vitrectomy. All eyes were treated with intraocular antibiotics after the diagnosis of postvitrectomy endophthalmitis was made. Final visual acuity ranged from 20/20 to no light perception and included five eyes with 20/50 or better visual acuity and 11 eyes with less than 5/200 visual acuity. Nine eyes had a final visual acuity of no light perception. Of the 16 eyes infected with a single organism, 71% (5/7) of eyes infected with coagulase-negative staphylococci retained 20/50 or better final visual acuity compared with no eyes (0/9) infected with other organisms (P = 0.005). Two eyes infected with both coagulase-negative Staphylococcus and Streptococcus had a final visual acuity of 20/400. Three eyes with a total hypopyon later had enucleation or evisceration. Based on the data from four medical centers, the incidence of endophthalmitis after pars plana vitrectomy performed over the last 10 years was 9/12,216 (0.07%). Endophthalmitis after vitrectomy is rare. Postvitrectomy bacterial endophthalmitis caused by organisms other than coagulase-negative staphylococci has a poor visual prognosis.