Study: Circumferential Assessment of Changes in Anterior Seg
The purpose of this study was to investigate circumferential angle widening and iris changes after Laser peripheral iridotomy (LPI) using swept-source optical coherence tomography (SS-OCT) in Caucasian eyes with the use of novel anterior segment parameters.

A total of 130 eyes of 66 subjects underwent 360-degree SS-OCT angle imaging and gonioscopy in the dark before and 7, 30, 90 days after LPI. For each eye, 16 frames were selected for analysis from 128 cross-sectional images, and novel 2-dimensional and 3-dimensional anterior segment parameters namely angle opening distance area (AODA) and the trabecular-iris space volume (TISV) 750?microm from the scleral spur, as well as iris parameters such as iris thickness (IT750 and IT2000), iris curvature, and iris curvature area were measured for each image.

--AODA and TISV were significantly increased and the iris curvature and iris curvature area were significantly decreased at days 7, 30, and 90 after LPI when compared with their baseline but there was no significant change in the IT750 and IT2000.

--The multivariable linear regression model showed a significant association of AODA with refractive error, lens vault, and iris volume after adjusting for age and sex.

Conclusively, LPI widened the iridocorneal angle and flattened the iris circumferentially in Caucasian eyes in this study. Baseline refractive error, lens vault, and iris volume play a significant role in the circumferential angle widening by LPI.