Munch Inger Christine, Altuntas Cigdem, Li Xiao Qiang, Jackson Gregory R, Klefter Oliver Niels, Larsen Michael
Department of Ophthalmology, Zealand University Hospital, Sygehusvej 10, DK-4000, Roskilde, Denmark.
Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, København N, Denmark.
BMC Ophthalmol. 2016 Jul 11;16:105. doi: 10.1186/s12886-016-0273-6.
Dark adaptation is an energy-requiring process in the outer retina nourished by the profusely perfused choroid. We hypothesized that variations in choroidal thickness might affect the rate of dark adaptation.
Cross-sectional, observational study of 42 healthy university students (mean age 25 ± 2.0 years, 29 % men) who were examined using an abbreviated automated dark adaptometry protocol with a 2° diameter stimulus centered 5° above the point of fixation. The early, linear part of the rod-mediated dark adaptation curve was analyzed to extract the time required to reach a sensitivity of 5.0 × 10(-3) cd/m2 (time to rod intercept) and the slope (rod adaptation rate). The choroid was imaged using enhanced-depth imaging spectral-domain optical coherence tomography (EDI-OCT).
The time to the rod intercept was 7.3 ± 0.94 (range 5.1 - 10.2) min. Choroidal thickness 2.5° above the fovea was 348 ± 104 (range 153-534) μm. There was no significant correlation between any of the two measures of rod-mediated dark adaptation and choroidal thickness (time to rod intercept versus choroidal thickness 0.072 (CI95 -0.23 to 0.38) min/100 μm, P = 0.64, adjusted for age and sex). There was no association between the time-to-rod-intercept or the dark adaptation rate and axial length, refraction, gender or age.
Choroidal thickness, refraction and ocular axial length had no detectable effect on rod-mediated dark adaptation in healthy young subjects. Our results do not support that variations in dark adaptation can be attributed to variations in choroidal thickness.
暗适应是一个需要能量的过程，发生在外层视网膜，由血供丰富的脉络膜提供营养。我们推测脉络膜厚度的变化可能会影响暗适应的速率。
对42名健康大学生（平均年龄25±2.0岁，29%为男性）进行横断面观察研究，采用简化的自动暗适应测量方案，以2°直径的刺激光斑，位于注视点上方5°处进行检查。分析视杆细胞介导的暗适应曲线的早期线性部分，以提取达到5.0×10⁻³ cd/m²敏感度所需的时间（视杆细胞截距时间）和斜率（视杆细胞适应速率）。使用增强深度成像光谱域光学相干断层扫描（EDI-OCT）对脉络膜进行成像。
视杆细胞截距时间为7.3±0.94（范围5.1 - 10.2）分钟。黄斑中心凹上方2.5°处的脉络膜厚度为348±104（范围153 - 534）μm。视杆细胞介导的暗适应的任何两种测量指标与脉络膜厚度之间均无显著相关性（视杆细胞截距时间与脉络膜厚度的相关性为0.072（95%CI -0.23至0.38）分钟/100μm，P = 0.64，经年龄和性别校正）。视杆细胞截距时间或暗适应速率与眼轴长度、屈光不正、性别或年龄之间均无关联。
在健康年轻受试者中，脉络膜厚度、屈光不正和眼轴长度对视杆细胞介导的暗适应没有可检测到的影响。我们的结果不支持暗适应的变化可归因于脉络膜厚度变化的观点。
