title: Particle-induced endophthalmitis: possible mechanisms of sterile endophthalmitis after intravitreal triamcinolone.
abstract: OBJECTIVE
  We determined the cause of sterile endophthalmitis after intravitreal triamcinolone acetonide (IVTA).
  
  
  METHODS
  The clinical records of 21 eyes that had sterile endophthalmitis after IVTA were reviewed. Cytologic studies were performed, and cytokine and chemokine profiles in the aqueous humor were determined. The effects of a direct contact of triamcinolone acetonide (TA) particles with cultured lens epithelial cells (B3) or retinal pigment epithelial cells (ARPE-19) on cytokine production were determined. Noncontact culture studies were performed in a Boyden chamber; 11-deoxycortisol was used for nonbioactive particles.
  
  
  RESULTS
  Inflammation appeared one day after the IVTA, and the incidence of severe sterile endophthalmitis was 13.0% (6/46), which was reduced to 4.3% (2/47) after switching to preservative-free TA. Most cells found in the aqueous humor were granulocytes. The concentrations of IL-6 (447.8-<5000 pg/mL) and IL-8 (47.2-<5000 pg/mL) were increased significantly, but IL-1β, IL-10, IL-12p70, and TNF-α were not significantly changed. In B3 cells, the level of IL-8 increased significantly when the cells made direct contact with TA particles (1.33 times that of PBS, P < 0.05, Student's t-test), but not in noncontact cultures. Similar reaction pattern was found in ARPE-19 cells. These effects also were observed when the cells were exposed to 11-deoxycortisol.
  
  
  CONCLUSIONS
  Sterile endophthalmitis after IVTA is characterized by an immediate granulocytic infiltration and an increase of IL-6/IL-8 in the aqueous humor. Preservatives may be a factor causing this condition, and mechanical/rheologic stress by particles presumably might be a new causative factor by increasing IL-6/IL-8.
authors: Department of Ophthalmology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors: Hiroki
authors: H
authors: Otsuka
authors: Hiroki
authors: H
authors: Kawano
authors: Shozo
authors: S
authors: Sonoda
authors: Makoto
authors: M
authors: Nakamura
authors: Taiji
authors: T
authors: Sakamoto
mesh_terms: D001082:Aqueous Humor / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000188:drug therapy; D009877:Endophthalmitis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005938:Glucocorticoids / Q000009:adverse effects* / Q000494:pharmacology; D006098:Granulocytes / Q000473:pathology; D015745:Granuloma, Foreign-Body / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D058449:Intravitreal Injections; D007908:Lens, Crystalline / Q000166:cytology; D008268:Macular Degeneration / Q000188:drug therapy; D055213:Retinal Pigment Epithelium / Q000187:drug effects / Q000378:metabolism; D012170:Retinal Vein Occlusion / Q000188:drug therapy; D014222:Triamcinolone Acetonide / Q000009:adverse effects* / Q000494:pharmacology
chemical_list: D016207:Cytokines; D005938:Glucocorticoids; D014222:Triamcinolone Acetonide