Effects of Small-Incision Phacoemulsification and Intraocular Lens Implantation on Anterior Chamber Depth and Intraocular Pressure

Abstract

To examine prospectively the effects of small-incision phacoemulsification and intraocular lens implantation (PEA+IOL) on anterior chamber depth (ACD) and intraocular pressure (IOP) using a newly developed scanning peripheral ACD analyzer (SPAC). Twenty-eight eyes of 21 patients who underwent PEA+IOL without any complications were examined and divided into 7 eyes each of grades 1 to 4 according to the Van Herick technique. The SPAC measured ACD consecutively from the vicinity of the pupil center to the periphery at 0.4-mm intervals. Changes in ACD and IOP as a result of PEA+IOL were investigated, and the factors contributing to the changes in ACD and IOP were examined. PEA+IOL increased ACD significantly at all groups. The average changing rates were 3.19 +/- 0.67 times (Van Herick grade 1), 2.00 +/- 0.80 times (Van Herick grade 2), 1.92 +/- 0.32 times (Van Herick grade 3), and 1.36 +/- 0.65 times (Van Herick grade 4), respectively. The closer to the pupil center the measurement point was, the larger was the increase in ACD. However, the rates of increase in ACD were similar among the measurement points. The increases in ACD were significantly large in patients having a shallow preoperative ACD and a small optic axis length. The IOP reduction became significantly large in eyes with a shallow preoperative ACD. The SPAC enabled quantitative measurement of changes in ACD from the vicinity of the pupil center to the periphery as a result of PEA+IOL. Changes in ACD resulting from PEA+IOL were thought to exert a greater effect on aqueous humor outflow facility as the postoperative ACD became shallower.