Department of Ophthalmology, Kobe City Medical Center General Hospital, 2-1-1, Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan,
Graefes Arch Clin Exp Ophthalmol. 2013 Oct;251(10):2395-402. doi: 10.1007/s00417-013-2378-4. Epub 2013 May 21.
The purpose of this study was to investigate and measure light-dark changes in iris thickness (IT) and anterior chamber angle width in eyes with occludable angles and open angles by using anterior segment optical coherence tomography (AS-OCT).
We examined 153 eyes of 153 Japanese patients with primary angle closure suspect, primary angle closure, primary angle closure glaucoma, or primary open angle glaucoma. AS-OCT was used to determine pupil diameter, IT, angle opening distance at 500 μm (AOD₅₀₀), and trabecular-iris space area at 500 μm (TISA₅₀₀) in each quadrant of the anterior chamber angle (superior, inferior, temporal, and nasal) under light and dark conditions.
In the angle closure cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark varied significantly among the four quadrants (P < 0.05, analysis of variance). In contrast, in the open angle cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark did not differ significantly among the four quadrants. In the angle closure cases and the open angle cases, significant negative associations were found between IT difference [IT(light)-IT(dark)] and AOD₅₀₀ difference [AOD₅₀₀(light)-AOD₅₀₀(dark)] (R = -0.411, P < 0.001 and R = -0.501, P = 0.001, respectively) and between IT difference and TISA₅₀₀ difference [TISA₅₀₀(light)-TISA₅₀₀(dark)] (R = -0.475, P < 0.001 and R = -0.462, P = 0.002, respectively).
Our results suggest that thickening of the iris root under dark conditions is related to the mechanism of primary angle closure. It is important to analyze both the angle structure and peripheral IT in each quadrant.
本研究旨在使用眼前节光学相干断层扫描（AS-OCT）来研究和测量可闭角和开角眼的虹膜厚度（IT）和前房角宽度的明暗变化。
我们检查了 153 名日本原发性闭角型青光眼疑似患者、原发性闭角型青光眼、原发性闭角型青光眼或原发性开角型青光眼患者的 153 只眼。AS-OCT 用于确定瞳孔直径、IT、前房角 500μm（AOD₅₀₀）的开口距离和小梁虹膜空间面积在 500μm（TISA₅₀₀）在前房角（上、下、颞和鼻）的四个象限中在明、暗条件下。
在闭角病例中，暗室条件下 IT、AOD₅₀₀ 和 TISA₅₀₀ 在四个象限中差异有统计学意义（P<0.05，方差分析）。相比之下，在开角病例中，暗室条件下 IT、AOD₅₀₀ 和 TISA₅₀₀ 在四个象限中差异无统计学意义。在闭角病例和开角病例中，IT 差异[IT（亮）-IT（暗）]与 AOD₅₀₀ 差异[AOD₅₀₀（亮）-AOD₅₀₀（暗）]之间存在显著负相关（R=-0.411，P<0.001 和 R=-0.501，P=0.001），IT 差异与 TISA₅₀₀ 差异[TISA₅₀₀（亮）-TISA₅₀₀（暗）]之间存在显著负相关（R=-0.475，P<0.001 和 R=-0.462，P=0.002）。
我们的结果表明，暗室条件下虹膜根部增厚与原发性闭角型青光眼的发病机制有关。分析每个象限的角度结构和周围 IT 非常重要。
