Factors Defining the Intraocular Pressure-Lowering Effect of Phacoemulsification and Laser Peripheral Iridotomy in Patients with Primary Angle Closure

To identify whether gonioscopic ciliary body visibility and factors including anterior chamber depth (ACD), axial length (AL), acute attack history, and preoperative intraocular pressure (IOP) had any effect on IOP decrease in primary angle closure (PAC) and primary angle-closure glaucoma (PACG) after phacoemulsification (PE) and/or laser peripheral iridotomy (LPI). This retrospective-design study was conducted with 81 eyes with PAC and PACG; 33 eyes whose IOP was controlled with LPI and PE constituted group 1, and 48 eyes whose IOP was controlled using LPI alone comprised group 2. The effects on preoperative and last-visit IOP levels, ciliary body visibility, ACD, AL, and acute attacks were analyzed. Eyes within the groups were similar in AL, ACD, and preoperative IOP except for acute attack history, which was found to be higher in group 1. For group 1, none of the factors was found to have a differentiative effect on IOP decrease after PE, except eyes with preoperative IOP > 21 mm Hg, which had significantly more IOP reduction. For group 2, no difference was found in ciliary body visibility, and higher or lower ACD. However, eyes with AL ≥ 22 mm, positive acute attack history, and higher preoperative IOP were associated with significantly better IOP reduction. We found no relationship between ciliary body visibility and an IOP-reducing effect of PE and LPI. Although we found PE effective in IOP reduction in all eyes, we determined LPI to have a lesser IOP-reducing effect in eyes with IOP ≤ 21 mm Hg and AL < 22 mm.