Abstract
Purpose :
To compare changes in anterior segment optical coherence tomography (AS-OCT) parameters in patients with primary angle closure suspect (PACS) undergoing laser peripheral iridotomy (LPI).
Methods :
One-hundred eyes with PACS underwent prophylactic LPI in the temporal iris. Clinical exam including visual acuity, intraocular pressure (IOP) and gonioscopy were assessed. AS-OCT parameters including anterior chamber (AC) depth, lens vault (LV), trabecular iris space area (TISA), angle opening distance (AOD), and nasal and temporal iris thickness were measured at baseline and repeated at 1week, 1 month and 3 months post-laser. Data were analyzed with paired t-test, one-way ANOVA and Wilcoxon test using SPSS V27.
Results :
Seventy-six percent of enrolled participants were female (mean age 58.5±11 years). LPI was performed temporally in all eyes at an average 43.4mJ/eye. Clinically on gonioscopy, 82% of angles were deeper at 3-month follow-up (p=0.000). The mean visual acuity (logmar 0.12 to logmar 0.08, p=0.001) and mean IOP improved from baseline (15.4mmHg) to 3-months (14.9mmHg; p<0.001) post-LPI. AOD at 500um and 750um showed significant deepening in the temporal quadrant at 1 week that persisted until 3-months post-LPI (p=0.001). Similarly, deepening of the LV, TISA at 500um and 750um from Schwalbe’s line and thinning of the temporal iris at 500 um and 750um showed significant improvements at 3-months post-LPI (p=0.005, p=001, p=001, p=0.001, p=0.001), respectively. Nasal iris thickness at 500um from the angle was also significantly reduced (p=0.009) from baseline, although LPI was performed only in the temporal quadrant. Further, deepening of the ACD (p=0.001) was observed at 3-months follow-up.
Conclusions :
Deepening of the angle clinically by gonioscopy reflect the long-term changes on AS-OCT parameters demonstrated at 3-months follow-up. AS-OCT showed significant deepening of the angle by reducing lens vault, deepening the TISA, ACD and thinning the temporal and nasal iris. Gonioscopy and AS-OCT are useful tools for screening and assessing patients with PACS. Our results will provide all practicing ophthalmologists with a better understanding of the reliability of AS-OCT in screening and follow-up for patients with PACS to guide further clinical management.
This is a 2021 ARVO Annual Meeting abstract.