Anterior segment morphology after laser iridotomy in primary angle closure suspects

Area of Science:

• Ophthalmology
• Anterior Segment Imaging
• Glaucoma Research

Background:

• Primary angle closure suspects (PACS) are at risk of developing angle-closure glaucoma.
• Laser peripheral iridotomy (LPI) is a common treatment to improve aqueous humor flow.
• Understanding the morphological changes post-LPI is crucial for managing PACS.

Purpose of the Study:

• To evaluate and compare anterior segment parameter changes in PACS before and after LPI.
• To assess the intrasession repeatability of measurements using a Scheimpflug-Placido topographer.
• To identify predictors of iridocorneal angle widening after LPI.

Main Methods:

• Fifty-six eyes of 56 PACS patients were analyzed using the Sirius Scheimpflug-Placido topographer.
• Anterior segment parameters (e.g., anterior chamber depth, volume, iridocorneal angle) were measured pre- and post-LPI.
• Intrasession repeatability was assessed via intraclass correlation coefficient; multivariate regression identified predictors.

Main Results:

• LPI significantly increased central anterior chamber depth (p=0.04), anterior chamber volume (p<0.0001), and iridocorneal angle width (p=0.01).
• Measurements showed high intrasession repeatability (ICC 0.982-0.998).
• Older age and larger anterior chamber volume were positive predictors of iridocorneal angle widening post-LPI.

Conclusions:

• LPI induces significant 3D anterior segment morphological changes in PACS patients.
• Scheimpflug-Placido topography offers reproducible measurements for assessing potentially occludable angles.
• Older age and greater anterior chamber volume predict greater iridocorneal angle widening after LPI.