Biomedical subjects
Publications and source records attributed to K Bowman.
This investigation demonstrates that dextran passes into rabbit corneas stored in M-K medium prior to corneal transplantation. An equilibrium between dextran in the cornea and in the M-K medium is reached at about 24 hours. Post-keratoplasty dextran efflux is rapid with about 70 to 75 per cent being lost within one to three hours and 99 per cent being lost in 12 hours.
We investigated Brinolase, a substance producing enzymatic zonulysis, for effects on the physiological and anatomical function of the corneal endothelium in the specular microscope. Concentrations of 100 C2 units/ml perfused for ten minutes did not appear to damage the corneal endothelium. Longer perfusions or higher concentrations possibly produced alterations in the physiological functions of the endothelium, but no significant anatomic change was demonstrated. Longer perfusion times with high concentrations (1,600 C2 units/ml) resulted in the formation of holes which perforated the corneal stroma.
The glycosaminoglycans of isolated rabbit corneal stroma, clamped between two lucite plates at near normal hydration, were digested with testicular hyaluronidase in saline solution. After equilibration with 0.9 per cent saline solution alone the sodium and chloride content of the stroma was determined. Chloride was in equilibrium with both normal and hyaluronidase-treated stroma, allowing use of the Donnan calculation for excess or bound sodium to be made. Normal stromas contained 200 mEq. bound sodium per kilogram of dry weight calculated from the Donnan calculation; hyaluronidase-treated stromas contained 110 mEq. bound sodium per kilogram of dry weight. The data show that about half of the bound sodium in the corneal stroma is on nonsaccharide binding sites. Quantitative verification of the loss of glycosaminoglycans was performed.
Rabbit corneas were subjected to MK-medium or moist-chamber storage for periods up to 7 days. Sodium, potassium, and chloride concentrations and hydration were measured. The hydration of corneas stored in MK medium was less than that of those stored in moist chambers. The sodium concentration of MK corneas remained stable for up to 7 days; the potassium concentration, however, decreased with increasingly longer periods of storage. Chloride concentrations quickly equilibrated with the high chloride level of MK medium. The concentration of sodium and chloride in moist chamber-stored corneas fell with progressively longer storage periods. Potassium showed an initial decrease in concentration followed by an increase in concentration that paralleled, and equilibrated with, the increasing acqueous humor concentration.
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