To investigate the relationships between preoperative factors and intraocular pressure (IOP) reduction after phacoemulsification in normal, open-angle glaucoma (OAG) and angle-closure glaucoma (ACG) patients.

IOP was measured before and 3 months after cataract surgery in 30 normal, 24 OAG and 31 ACG patients. The relationship between IOP reduction after cataract surgery and preoperative parameters including anterior chamber depth (ACD), axial length (AL), preoperative IOP/ACD ratio (PD ratio), preoperative IOP/AL ratio (PL ratio) were investigated in the 3 groups.

Significant IOP reduction was observed in all 3 groups after surgery (paired sample t-test; p < 0.05), and IOP reduction was correlated with preoperative IOP level in all 3 groups (Pearson's correlation; p < 0.05). Other preoperative parameters such as ACD and AL were not correlated with IOP reduction, and PD ratio was significantly correlated with IOP reduction only in the OAG group (Pearson's correlation; p < 0.001). PL ratio was significantly correlated with IOP reduction in all 3 groups (Pearson's correlation; p < 0.05) and showed the best sensitivity and specificity to predict significant reduction in IOP after cataract surgery among parameters including preoperative IOP, PD ratio and PL ratio.

PL ratio was significantly correlated with IOP reduction after cataract surgery in all 3 groups and showed a higher predictive value for IOP reduction in the OAG group than in the other groups.