Forty-two randomised clinical trials were included in the review. The total number of patients in the review was not reported.
Carbonic Anhydrase Inhibitors (50 treatment arms): When topical carbonic anhydrase inhibitors were added to a β-blocker regimen, the additional decrease in IOP ranged from 11.3% to 23.1% at trough and from 10.2% to 23.1% at peak; the additional decrease in IOP on the diurnal curve ranged from 14.4% to 26.9%.
Hypotensive Lipids (16 treatment arms): When prostaglandin analogues were added to a β-blocker regimen, the additional decrease in IOP ranged from 25.5% to 26.0% at trough and from 23.5% to 27.7% at peak; the additional decrease in IOP on the diurnal curve ranged from 24.0% to 29.9%.
α2-Adrenoceptor Agonists (19 treatment arms): When α2-adrenoceptor agonists were added to a β-blocker regimen, the additional decrease in IOP ranged from 7.3% to 14.9% at trough and 15.7% to 27.6% at peak; the additional decrease in IOP on the diurnal curve in one treatment arm was 12.5%.
β-Adrenoceptor Antagonists (four treatment arms): When β-adrenoceptor antagonists were added to a prostaglandin analogue, the additional decrease in IOP at peak ranged from 19.2% to 20.2%; the additional decrease in IOP on the diurnal curve ranged from 10.6% to 15.0%.