Quantitative and qualitative analyses of transferrin in aqueous humor from patients with primary and secondary glaucomas.

By using a highly sensitive and specific radioimmunoassay and the slot-blot technique, transferrin was quantified in fresh samples of aqueous humor from patients with primary open-angle glaucoma (POAG, n = 36) or secondary glaucoma (SG, n = 18). The levels were compared with those in aqueous humor obtained from age-matched patients without glaucoma (n = 33) and in primary and secondary aqueous humor from normal dogs (n = 10) in which breakdown of the blood-aqueous barrier was induced experimentally. The concentration of transferrin in the aqueous humor of human control subjects ranged from 0.3-3.4 mg/dl (mean +/- standard deviation, 1.36 +/- 0.66 mg/dl); in POAG samples, from 0.34 to greater than 10 mg/dl (2.07 +/- 1.90 mg/dl); and in SG samples, from 0.29 to greater than 10 mg/dl (2.79 +/- 2.24 mg/dl). The level of transferrin in secondary aqueous humor samples obtained from dogs was as much as ninefold greater than that in primary aqueous humor. The protein concentration in the human aqueous humor samples was 11.87 +/- 4.47 mg/dl for control subjects, 62.11 +/- 56.74 mg/dl for patients with POAG, and 124.53 +/- 152.67 mg/dl for those with SG. In dogs, the protein levels were 7.97 +/- 3.12 mg/dl for primary aqueous humor and 191.9 +/- 149.8 mg/dl for secondary aqueous humor. A significant correlation (r = 0.744, P less than 0.01) was found between total protein and transferrin contents in the samples of aqueous humor from patients with glaucoma but not in the samples from age-matched control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)