Area and depth of surfactant-induced XXXX correlates with cell death.

@entity267 @entity146 @entity5611 @entity10857 @entity95 @entity735
PURPOSE: In previous studies in which in vivo confocal microscopy (CM) was used, quantifiable differences were identified in the corneal epithelium and stroma for surfactants producing different degrees of @entity146 . In the present study, in vivo confocal microscopy was used to determine area and depth of the initial corneal changes, and the correlation of the data to cell death was characterized by ex vivo live-dead assay. METHODS: In four groups of @entity95 (12 animals each), 10 microl surfactants known to produce slight, mild, moderate, or severe @entity146 was applied to the central @entity735 ; 4 untreated @entity95 served as controls. Measurements of group total mean epithelial thickness, epithelial cell area, and depth of keratocyte loss in four corneal regions were made by in vivo CM in 6 @entity95 of each group and in 4 control animals at 3 hours and in the remaining @entity95 at 3 hours and 1 day. Corneas were then removed and fixed for conventional histologic examination (two eyes/treatment/group), or regions were excised and placed in culture media containing 2 microM @entity10857 ( @entity10857 ) and 4 microM @entity5611 homodimer. Using laser scanning CM, the number of dead epithelial or stromal cells in a 300 x 300 x 170 microm (in the x, y, and z axes, respectively) volume of the @entity267 was determined. RESULTS: Confocal microscopy showed that application of the slight irritant resulted in decreased epithelial thickness at 3 hours (41.2+/-2.6 microm in treated eyes versus 43.6+/-3 microm in control eyes; n=6 and 4, respectively) and a significant decrease (P < 0.001) in epithelial cell size (630+/-203 microm2 versus 1427.2+/-90.7 microm2). On day 1, mild, moderate, and severe @entity146 caused complete loss of epithelium and disappearance of keratocytes to a depth of 30.8+/-10.7 microm, 47.2+/-10.4 microm, and 764.6+/-159.6 microm (n=6, 5, and 6), respectively. At 3 hours, live-dead assay detected more dead epithelial cells as a percentage of total surface cells (49.2+/-4.5% in slightly @entity146 versus 20.9+/-3.2% in control eyes), significantly correlating with the measurement by in vivo CM of average epithelial cell size in each eye (r=-0.96; P < 0.005). On day 1, mild and moderate @entity146 showed increasing stromal cell death from 9.8+/-16.2 cells to 36.4+/-17.7 cells, which significantly correlated with the depth of stromal injury determined by in vivo CM (r=0.79; P < 0.00001). No surviving keratocytes were detected in severely @entity146 . CONCLUSIONS: The data support the hypothesis that differences in surfactant-induced @entity146 are directly related to area and depth of acute @entity267 .
