Abstract
Purpose:
To determine the cause of sterile endophthalmitis after intravitreal triamcinolone acetonide (IVTA).
Methods:
The clinical records of 21 eyes that developed sterile endophthalmitis after IVTA were reviewed. Cytological studies were performed and cytokine and chemokine profiles of the aqueous humor (AqH) were determined. The effects of direct contact of TA crystals with cultured lens epithelial cells (B3) or retinal pigment epithelial cells (ARPE-19) on cytokine production were determined. Non-contact culture studies were performed in a Boyden chamber. 11-deoxycortisol was used for non-bioactive crystals.
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 AqH were granulocytes. The concentrations of interleukin (IL)-6 (447.8 to <5000 pg/mL) and IL-8 (47.2 to <5000 pg/mL) were significantly increased but IL-1β, IL-10, IL-12p70 and tumor necrosis factor-α were not significantly changed. The level of IL-8 increased significantly when B3 cells made direct contact with TA crystals (1.33X times that of PBS; P <0.05, Student’s t test) but not in non-contact cultures. A similar reaction was found in ARPE-19 cells. These effects were also observed when the cells were exposed to 11-deoxycortisol crystals.
Conclusions:
Sterile endophthalmitis after IVTA is characterized by an immediate granulocytic infiltration and an increase of IL-6 and IL-8 in the AqH. TA crystals can cause mechanical stress on the lens epithelial cells leading to the up-regulation of IL-8.
Keywords: 513 endophthalmitis •
490 cytokines/chemokines •
503 drug toxicity/drug effects