Eighteen untreated patients with unilateral exfoliation syndrome without glaucoma were studied with regard to differences in aqueous dynamics between the affected and unaffected fellow eyes. Additionally, both eyes of the patients with exfoliation were compared to the eyes of 18 age-matched and gender-matched control subjects. Intraocular pressure was significantly higher (13.9 +/- 3.0 mm Hg [mean +/- standard deviation]) in the affected compared with the unaffected eyes (12.2 +/- 2.5 mm Hg), but no difference in aqueous humor flow was detected when eyes in the three groups were compared (affected eyes, 2.40 +/- 0.60 microliter/min; unaffected eyes, 2.40 +/- 0.65 microliter/min; control eyes, 2.61 +/- 0.60 microliter/min). Anterior chamber volumes were significantly smaller in affected (122 +/- 37 microliters) and unaffected eyes (121 +/- 37 microliters) of the patients with exfoliation compared with the eyes of the control subjects (145 +/- 30 microliters). Apparent resistance was higher in the eyes with exfoliation (6.5 +/- 1.9 min mm Hg/microliters) compared with both unaffected (5.4 +/- 1.2 min mm Hg/microliters) and control groups (5.2 +/- 1.8 min mm Hg/microliters), although these differences were not statistically significant.