Role of lens vault in subtypes of angle closure in Iranian subjects

Purpose The purpose of this study is to quantify anterior chamber (AC) parameters and to determine the proportion of eyes with exaggerated lens vault (LV) in different subtypes of angle closure disease using anterior segment optical coherence tomography (AS-OCT). Patients and methods In this prospective study, 115 eyes of 115 Iranian patients with angle closure disease were included and categorized into three groups: (1) fellow eyes of acute angle closure (AAC; 40 eyes); (2) primary angle closure glaucoma (PACG; 39 eyes); and (3) primary angle closure suspect (PACS; 36 eyes). Complete ophthalmic examination including gonioscopy, A-scan biometry, and AS-OCT were performed. Angle parameters, LV, and iris thickness (IT) were measured using AS-OCT. An exaggerated LV was defined as LV more than one-third the distance between the corneal endothelium and a line drawn to connect the nasal and temporal scleral spurs. Results Fellow eyes of AAC had the shallower AC ( P =0.01), greater iris curvature (I-curve; P =0.01), and higher LV ( P =0.02) as compared with PACS and PACG eyes. There was no statistically significant difference in the mean IT at 750 μ m from scleral spur among the three groups ( P =0.45). Exaggerated LV was found in 67.5, 35.9, and 40% of fellow eyes of AAC, PACG, and PACS, respectively, ( P =0.008) with an odds ratio of 1.92 ( P =0.005) for fellow vs PACG and 1.68 ( P =0.01) for fellow vs PACS. Conclusions Exaggerated LV is highly prevalent in fellow eyes of AAC. These eyes have shallower AC depth, greater I-curve, and higher LV when compared with PACG and PACS.