Presumed Capsular-Bag–Origin Endophthalmitis Following Anterior Vitrectomy for Posterior Capsule Opacification in a Patient with Proliferative Diabetic Retinopathy: A Case Report

Purpose: To report a rare case of presumed postoperative endophthalmitis after anterior vitrectomy (AVit) for dense posterior capsule opacification (PCO) in a patient with proliferative diabetic retinopathy (PDR). Observations: A 52-year-old woman with long-standing diabetes and prior pan-retinal photocoagulation and pars plana vitrectomy with phacoemulsification and intraocular lens implantation developed visually significant, fibrotic PCO in the right eye. Slit-lamp examination revealed dense, partially liquefied, milky PCO between the posterior capsule and the intraocular lens. Because the opacity was judged unsuitable for Nd:YAG laser posterior capsulotomy, a 23-gauge pars plana AVit with surgical posterior capsulotomy was performed. On postoperative day 4, the patient presented with ocular pain, 2+ anterior chamber cells, hypopyon, and dense vitreous opacities, with complete obscuration of the fundus, consistent with presumed postoperative endophthalmitis. Urgent anterior chamber lavage and repeat pars plana vitrectomy with intravitreal injection of vancomycin and ceftazidime led to rapid resolution of hypopyon, vitreous opacities, and pain, although vitreous cultures were negative. The clinical course—onset shortly after surgical manipulation of a chronically opacified capsular bag, low-grade fibrin reaction, and excellent visual recovery—suggested a low-virulence, capsular-bag–origin infection unmasked by AVit in a metabolically compromised eye (day-of-surgery glucose 259 mg/dL, HbA1c 7.2%). At 7-year follow-up, best-corrected visual acuity was 20/16 with a continuous ellipsoid zone on optical coherence tomography and no recurrent inflammation. Conclusions and Importance: This case illustrates that presumed capsular-bag–origin endophthalmitis can occur after AVit for dense PCO in high-risk diabetic eyes, even when cultures are negative. The findings underscore the importance of careful selection between Nd:YAG laser and surgical posterior capsulotomy, strict perioperative glycemic control, meticulous aseptic technique, and prompt surgical re-intervention with intravitreal antibiotics. Early recognition and management may allow excellent long-term anatomic and visual outcomes.