Y. Van Tenten et al., The effect of photodynamic therapy with bacteriochlorin a on lens epithelial cells in a capsular bag model, EXP EYE RES, 72(1), 2001, pp. 41-48
Photodynamic therapy (PDT) with bacteriochlorin a (BCA) has proved to be a
successful treatment for many cancers and to be cytocidal for different cel
l lines in culture. The present study aimed to investigate in vitro the pot
ential of this treatment for killing lens epithelial cells (LECs) left in t
he human capsular bag after extracapsular cataract extraction (ECCE). Capsu
lar bags were prepared from donor eyes using an ECCE procedure and incubate
d in various concentrations of bacteriochlorin a (16-50 mug ml(-1)) during
various incubation periods (2-10 min). Subsequently, the capsules were illu
minated during various exposure times (2-15 min) with a diode laser (wavele
ngth 760 nm). After treatment, the capsular bags were cultured for 7 days i
n Eagle's minimal essential medium supplemented with 2% fetal calf serum. T
he specimens were fixed in glutaraldehyde/paraformaldehyde and examined wit
h routine light microscopy, Hoechst staining for DNA and transmission elect
ron microscopy. Proliferation of LECs on the posterior capsule was assessed
in flat mounts. Capsular bags receiving BCA without illumination and capsu
lar bags receiving illumination only served as controls.
BCA alone or light alone have no effect on structure and proliferative acti
vity of LECs. At a threshold protocol of incubation in BCA at 10 mug ml(-1)
for 10 min and subsequent illumination for 15 min, proliferative activity
of cells is largely arrested and nearly all LECs on the capsule exhibit sev
ere signs of apoptosis.
Photodynamic therapy with bacteriochlorin a induces cell death and suppress
ion of proliferation inlens epithelial cells and could be a promising means
of prevention of posterior capsule opacification. (C) 2000 Academic Press.