Assessment of blood-born biochemical markers in primary open angle glaucoma

Purpose: To independently test, in a masked study of POAG patients and age-matched controls, 7 different factors previously reported by other investigators as being associated with glaucoma. Methods: Blood samples from 31 well-characterizod POAG patients and 28 age-matched controls were analyzed for: leukocyte 3a-hydroxysteroid dehydrogenase (HSD) activity, erythrocyte ouabain binding, plasma cortisol, serum creatinine, serum albumin, thyroid indicators, autoimmune markers, as well as a general blood chemistry profile. Results: Contrary to previous reports, we found no statistical differences in ouabain binding, plasma cortisol, serum albumin, serum creatinine, or incidence of hypothyroidism between POAG patients and controls. However, POAG patients had a statistically significant decrease in average leukocyte HSD activity (9.0 ± 6.6 for controls vs 5.7 ± 4.5 for POAG, p = 0.0236) which has been previously reported by Weinstein and colleagues (IOVS 35:1573, 1994). There were no differences in the expression of autoimmune markers in POAG patients compared to controls as has been reported in patients with normal tension glaucoma. Conclusions: Except for a decrease in the average leukocyte HSD activity, we were unable to confirm previous reports of altered biochemical markers associated with POAG. Differences between this study and other studies may reflect heterogeneity in the POAG population or may be due to "random" but statistically significant alterations in biochemical markers which are not involved in glaucoma.