Fluid pump, corneal

There are several most interesting observations concerning osmolarity. We have found that there is an important difference of osmolarity between the hyperosmolar stroma with 420 mOsmol/kg and the extra and intraocular fluids with lower osmolarities of about 320 mOsmol/kg. This results in an inversion of the water flux, when barriers like endothelium and epithelium are damaged. The immediate result of any membrane damage is that water starts to flow from the outside into the comeal stroma. This results in a corneal edema with turbidity. This is an indirect proof of the pumping function of the endothelium. 

All burnt comeal stroma show lower osmolarity due to the loss of ions by continuous rinsing. The higher osmolar Diphoterine adds some ions to the burnt corneal stroma, but its osmolarity is still much lower than the one of the aqueous humor. It is obvious that there is no change in osmolarity in aqeous humor in healthy and in burnt eyes due to autoregulation of this milien by the ciliary body secretion. The considerable differences in tissue osmolarity indicate that there will be a strong fluid uptake into the comeal tissue, resluting in opacity. This indicates a severe water uptake and a lack of the endothelial pumping function. 

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