The Association of the Position of Lens with the Plateau Iris Configuration

Abstract

Purpose: : The aim of this study is to investigate the association of lens vault (LV) and anterior chamber depth (ACD) with plateau iris in narrow angle subjects.

Methods: : Forty three subjects with narrow angle (consisting of primary angle closure suspect, primary angle closure, and primary angle closure glaucoma) were divided into two groups depending on iris configuration (i.e., plateau iris and non-plateau iris). Parameters of LV and ACD were compared. Lens vault was defined as the perpendicular distance between the anterior pole of the crystalline lens and the horizontal line joining the 2 scleral spurs, on horizontal anterior-segment optical coherence tomography (AS OCT) scans. Anterior chamber depth was defined as the perpendicular distance between the corneal endothelial surface to anterior lens surface using AS OCT. For accuracy and reproducibility, two separate observers had independent and consecutive measurements and determination of iris configuration and inter-observer reproducibility was achieved.

Results: : Among the 43 narrow angle subjects (mean age = 62.9), 21 had plateau iris configuration, and 22 had non-plateau iris. Significant differences between plateau iris and non-plateau iris eyes were found for LV (914 ± 263 vs. 517 ± 235 µm, P < 0.001), but no significant differences were found for ACD (1.84 ± 318 vs. 2.15 ± 378 mm, P = 0.053).

Conclusions: : The new parameter, LV is associated with the plateau iris configuration. This result regarding LV, which represents the anterior position of lens, may be related with the anterior position of ciliary process in plateau iris configuration.

Keywords: iris • trabecular meshwork • imaging/image analysis: clinical