DEC 22, 2015
Glaucoma
This non-randomized clinical trial assessed the efficacy of 2% ibopamine, a topical drug that temporarily increases aqueous production, for diagnosing glaucoma.
Ibopamine is a prodrug of epinine and dopamine analogue that causes mydriasis and temporarily increases aqueous production for 45 minutes. A healthy eye will show no increase in IOP after applying ibopamine, but patients with glaucoma will experience a rise in IOP. Investigators conducted a challenge test in 61 patients with varying stages of glaucoma. Forty-five minutes after instilling 2 drops of 2% ibopamine, IOP and optic cup volume (OCV) measurements were taken.
The authors found that glaucoma suspects (GS) could be differentiated by their IOP response from patients with stable glaucoma (SG) and patients who demonstrated rapid progression (PG). IOP was increased by 1.8 mmHg for GS patients, 4.5 mmHg for SG patients (P=0.003) and 8.1 mmHg for PG patients (P<0.0001). Additionally, SG patients could be differentiated from PG patients by their change in OCV following an ibopamine challenge (0.6% vs. 5.5%, P<0.0001).
Despite the small number of patients in this study, the authors conclude that the ibopamine challenge test is a promising method for predicting which patients might develop glaucoma and which will progress towards blindness. As important, it’s an easier and quicker test to administer in the office than the water drinking test or postural IOP measurements.