Laser peripheral iridotomy increases width of narrow drainage angles

Laser peripheral iridotomy results in a significant increase in angle width in Chinese patients with narrow drainage angles, a prospective study found.

Mingguang He, MD, MPH, and colleagues used ultrasound biomicroscopy to assess the short-term effect of laser peripheral iridotomy on the anterior segment anatomy of one randomly selected eye in 72 Chinese angle-closure patients aged 50 to 79 years, according to the study.

The proportion of patients with iridotrabecular contact in one or more quadrants dropped from 95% to 59% postop, the authors reported.

Additionally, the mean angle opening distance at 250 µm increased from 0.064 mm to 0.085 mm (P < .001), the angle recess area increased from 0.04 mm² to 0.07 mm² (P < .0001) and the trabecular-ciliary process distance increased from 0.537 mm to 0.561 mm (P = .001). Iris thickness also increased from 0.44 mm to 0.459 mm (P = .094) at 750 µm and from 0.471 mm to 0.488 mm (P = .0001) at 1,000 µm.

Eyes with angles that remained closed after iridotomy tended to have shallower angle opening distance at both 250 µm (P = .09) and 500 µm (P = .001), a thicker iris at 750 µm (P = .041) and a more anterior positioned ciliary body (P = .03) preoperatively, the authors noted.

This study is published in the August issue of Ophthalmology.