Abstract
Purpose: :
To assess the iridocorneal angle in patients with plateau iris syndrome (PIS) before and after argon laser peripheral iridoplasty (ALPI) using slit-lamp-adapted ocular coherence tomography (SL-OCT).
Methods: :
Eyes with PIS and prior laser iridotomy underwent circumferential ALPI. Laser parameters were: 500 µm spot size, 0.5-0.7sec, 190-360mW and a total of 24-58 burns. Vertical and horizontal cross-sectional angle images were taken in dark and light room conditions before and 3-12 weeks after ALPI using SL-OCT (Heidelberg Engineering, Germany). Anterior chamber angle (ACA), angle opening distance (AOD) and trabecular iris surface area (TISA) at 500µm and 750 µm anterior to the scleral spur were analyzed and compared before and after ALPI.
Results: :
Ten eyes of eight patients (mean age, 61.6±12.6 yrs; range 43-78 yrs; 6 women, 2 men) were enrolled. The anterior chamber angle widened in all eyes (Mean values pre/post-laser: ACA 500µm (°): 22.90 ± 10.35 / 41.20 ± 6.79, p=0.005; TISA 750µm (mm2): 0.166 ± 0.076 / 0.258 ± 0.048, p=0.017 and AOD 500µm (mm): 0.228 ± 0.089 / 0.374 ± 0.101, p=0.013). The mean change of all parameters in the inferior angle was more than that of the superior angle (p values: 0.139/TISA 750; 0.169/AOD 750; 0.313/ACA 750; Wilcoxon signed rank test) but this was not statistically significant.
Conclusions: :
SL-OCT can be used for non-invasive, quantitative assessment of the anterior chamber angle before and after iridoplasty and could be used as a measurable parameter in studies of laser treatment for angle-closure.
Keywords: anterior segment • imaging/image analysis: clinical • laser