Effect of Brimonidine on Corneal Thickness

Brimonidine, an alpha-2 adrenoceptor agonist, is an effective and safe medication that is widely used in glaucoma treatment. Although it is known that it is quickly taken up by the cornea following topical administration and that the cornea has alpha-2 adrenoceptors, there are only few studies available on the impact brimonidine has on the cornea. Twenty healthy test persons (12 female and 8 male subjects)-mean age about 33 years (22 to 38 years)-were tested in a double-blind, prospective, randomized study. Intraocular pressure as well as epithelial, stromal, and endothelial thickness was measured before, at 25 days while, and at 5 days after administration of brimonidine 0.1% eye drops twice daily. To check the impact of this medication, placebo (proper solution of preservative) eye drops were administered to the other eye twice daily. Administration of brimonidine 0.1% resulted in a reduction of intraocular pressure from an initial value of 14 to 9 mmHg after 5 days (P=0.001) as well as an increase in total corneal thickness from 556 μm from the time of the baseline examination to 578 μm (P=0.001), an increase of epithelial thickness from 58 to 66 μm (P