Differential sensitivity at the cellular level in primary open-angle glaucoma: prednisolone and ouabain

The concentration of drug necessary to inhibit lymphocyte transformation by 50 per cent (I50 value) was determined for the glucocorticoid prednisolone-21-phosphate, and for the sodium-potassium adenosinetriphosphatase inhibitor ouabain, in 37 persons representing the full range of ocular and cellular glucocorticoid sensitivity. The lymphocytes of patients with primary open-angle glaucoma, and of high ocular responders to glucocorticoids, were more sensitive to prednisolone-21-phosphate than were those of ocular low and intermediate responders. By contrast, there was no significant difference in sensitivity to ouabain. There was also no significant correlation of lymphocyte sensitivity to prednisolone-21-phosphate with that to ouabain. These results provide indirect evidence that the increased cellular sensitivity to glucocorticoids in primary open-angle glaucoma is a specific effect, and not merely representative of a general vulnerability of "sick cells."