Iridolenticular contact decreases following laser iridotomy for pigment dispersion syndrome

Objective: To evaluate changes in anterior segment anatomy after laser iridotomy for pigment dispersion syndrome. Methods: Ultrasound biomicroscopy was performed on 7 eyes of 7 untreated patients with reverse pupillary block and pigment dispersion syndrome. A radially oriented image with the probe perpendicular to the eye in the superior meridian was obtained before and at least 1 week after laser iridotomy in each eye. We assessed changes in angle recess area and iris-lens contact distance. Results: Mean +/- SD patient age was 31.3 +/- 5.7 years and mean+/-SD refractive error was -5.0 +/- 3.9 diopters. Angle recess area (mean+/-SD, 0.78 +/- 0.28 vs 0.35 +/- 0.11 mm(2); P=.001, paired t test) and iris-lens contact distance (2.05 +/- 0.28 vs 10.79 +/- 0.13 mm; P<.001) decreased following iridotomy. Central anterior chamber depth did not change. Conclusion: Flattening of the iris following laser iridotomy for pigment dispersion syndrome causes a decrease in iris-lens contact and angle width while lens position remains constant.