Abstract
Purpose::
To compare the concentration of ascorbic acid in the aqueous humor of glaucoma patients with senile cataract subjects.
Methods::
Aqueous humor samples were obtained from glaucoma patients just before trabeculectomy for clinically uncontrolled primary open angle glaucoma. Aqueous humor (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber. The same procedure was performed for non-glaucoma patients with senile cataract just before cataract surgery. Immediately after collection, the aqueous humor was stored at -80°C. The concentration of ascorbic acid was determined by high performance liquid chromatography.
Results::
A total of 18 patients with senile cataract, 16 glaucoma patients with primary aqueous humor (no previous intraocular surgery), and 11 glaucoma patients with secondary aqueous humor (previous intraocular surgery) were included in this study. The mean (standard deviation) concentration of ascorbic acid in the aqueous humor of cataract patients was 1049 µM (433), in the glaucomatous primary aqueous humor was 919 µM (427), and in the glaucomatous secondary aqueous humor was 504 µM (213) (P=0.007).
Conclusions::
Glaucoma patients with secondary aqueous humor have about two-fold lower concentration of ascorbic acid in the aqueous humor in comparison to glaucoma patients with primary aqueous humor and cataract patients. This fact suggests a reduction in the antioxidant capacity of secondary aqueous humor in glaucoma patients.
Keywords: aqueous • antioxidants • cataract