Effects of dexamethasone on posterior capsule opacification-likechanges in a rat lens explant model

[摘要] Purpose: Many patients whose sight is initially restored by cataractsurgery eventually suffer secondary loss of vision because of posteriorcapsule opacification (PCO; after-cataract), a condition in which lensepithelial cells left behind at surgery become aberrant and migrate intothe light path. The aim of this study was to determine whetherdexamethasone (DEX), an anti-inflammatory agent widely used before andafter cataract surgery, influences the behavior of lens cells underconditions relevant to PCO development.Methods: An established rat PCO model was used in which explantedepithelial cells attached to the lens capsule are exposed sequentiallyto TGFβ2 and FGF-2. Cultures with or without DEX (100 nM), andappropriate controls, were maintained for up to 30 days and assessed bylight and scanning electron microscopy or immunolocalization of PCOmarkers (α-smooth muscle actin or fibronectin) or a marker for lensepithelial cell phenotype (Pax-6).Results: In the absence of DEX, explants become multilayered andplaques that express PCO markers form. Cells tend to gather up into theplaques, leaving the surrounding lens capsule denuded. Changes in lenscell behavior with addition of DEX included rapid formation of long,needle-like cells, less extracellular matrix deposited on explantsurface, and plaques surrounded by a monolayer of migratory cells.Immunolocalization confirmed that the latter were not normal lensepithelial cells.Conclusions: Lens cell behavior in this PCO model was significantlyaffected by inclusion of DEX, highlighting the possibility that its useas an anti-inflammatory at the time of cataract surgery may influencePCO development.

[学科分类] 生物化学/生物物理