Initial intraocular pressure reduction by mono- versus multi-therapy in patients with open-angle glaucoma: results from the Glaucoma Intensive Treatment Study.

Intensive treatment led to considerably greater IOP reduction than mono-therapy. Among patients with IOP ≥30 mmHg at diagnosis an IOP of <16 was reached in 2/3 of those with multi-therapy but in none with mono-therapy. The IOP reduction was highly dependent on the untreated IOP level.