Argon laser peripheral iridoplasty for chronic primary angle-closure and angle-closure glaucoma in caucasians

Purpose To investigate whether the peripheral thinning and shrinking of the iris as induced with Argon laser peripheral iridoplasty (ALPI) has an effect on intraocular pressure (IOP), angle structure and 3-D anterior segment (AS) morphology in Caucasians with chronic primary angle-closure (PAC) and primary angle-closure glaucoma (PACG). Methods Twenty-four eyes of 24 patients (age 67.7 +/- 8.9 years; seven males; 17 females) diagnosed with PAC (n = 10) or PACG (n = 14) were assigned for ALPI prior to laser peripheral iridotomy (LPI) and consecutively enrolled in this prospective interventional study. Intraocular pressure (IOP) was measured with Goldmann applanation tonometry, angle structure with gonioscopy using the Shaffer grading system and AS morphology with the Pentacam rotating Scheimpflug camera prior to and 3 months after ALPI. Intraocular pressure (IOP)-lowering medication was not changed during follow-up. Results Intraocular pressure (IOP) changed statistically significantly from 18.8 +/- 3.6 to 14.7 +/- 3.1 mmHg (p < 0.001). Gonioscopy showed a statistically significant angle widening in all four quadrants: nasally from Shaffer 1.04 +/- 0.98 to 2.54 +/- 1.1 (p < 0.001), superiorly from 0.39 +/- 0.66 to 1.58 +/- 1.21 (p < 0.001), temporally from 0.87 +/- 1.01 to 2.17 +/- 1.24 (p = 0.001) and inferiorly from 1.22 +/- 0.74 to 2.75 +/- 0.9 (p < 0.001). Pentacam parameters like anterior chamber depth, volume and angle did not increase statistically significantly. Conclusion Argon laser peripheral iridoplasty (ALPI) is a safe and effective procedure for reducing appositional angle-closure and thus IOP in nonacute PAC and PACG patients.