Laser peripheral iridotomy (PI) results in significant angle widening and iris profile flattening at the temporal and nasal angles according to a study recently published in Clinical & Experimental Ophthalmology.

Drs Ghee S. Ang and Anthony P. Wells, Capital Eye Specialists, Wellington, New Zealand, examined the changes in the anterior structures in Caucasian eyes after laser PI using anterior segment optical coherence tomography (AS-OCT). There were a total of 71 eyes of 71 patients that were examined over a 25-month period who were suffering from primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle closure glaucoma (PACG). All eyes in the study were analysed before and after laser PI using AS-OCT images of the temporal and nasal angles in light and dark.

It was found that although the iris thickness did not significantly change after PI the trabecular-iris angle, angle opening distance and trabecular-iris space area all increased but the maximum iris brow height decreased in both light and dark. Additionally, there was no difference in the magnitude of change observed between the temporal and nasal angles or between PACS/PAC and PACG eyes.

Based on the data the researchers found that laser PI resulted in significant angle widening and iris profiling flattening at the temporal and nasal angles based on AS-OCT imaging in both light and dark.