Plasma Cortisol Differences Between Normal and Glaucomatous Patients:  Before and After Dexamethasone Suppression

It is demonstrated that open-angle glaucoma patients with and without field loss differ significantly from normals in frequency distribution of levels of initial and final plasma cortisol in response to orally administered dexamethasone. Primary angle-closure and secondary glaucoma patients, who primarily had field loss, also differed significantly from normals in final cortisol values. Differences of frequency distributions of initial and final cortisol values could not be attributed to differences of age. The final cortisol values of all populations are significantly correlated with the initial values. Thus, a systemic endocrine marker separates patients with glaucoma, especially those with field loss, from normal patients. These observations substantiate the analogy between patients with glaucoma and Cushing's syndrome in both the elevated initial values and the lack of suppression of final values to orally administered dexamethasone.