Owsley Cynthia, McGwin Gerald, Jackson Gregory R, Kallies Katherine, Clark Mark
Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294-0009, USA.
Ophthalmology. 2007 Sep;114(9):1728-35. doi: 10.1016/j.ophtha.2006.12.023.
To examine impairment in cone- versus rod-mediated dark adaptation in the parafovea of persons with age-related maculopathy (ARM).
Cross-sectional.
Older adults with ARM at various severity levels from early to advanced (n = 83) and in good retinal health (n = 43), as determined by stereo fundus photographs evaluated with the Age-Related Eye Disease Study severity scale.
Dark adaptation, both cone- and rod-mediated components, was measured with a modified Humphrey Field Analyzer using a target located 12 degrees in the inferior visual field on the vertical meridian, after exposure to a 98% bleach. Information was collected on self-reported problems for activities at night or under dim illumination (Low Luminance Questionnaire [LLQ]) and for activities during daytime conditions (modified National Eye Institute Visual Function Questionnaire [NEI VFQ]).
Cone- and rod-mediated parameters of dark adaptation.
Compared with older adults in normal retinal health, ARM patients had significant impairments in rod-mediated parameters of dark adaptation (rod-cone break, rod slope, rod sensitivity) (P<0.0001), which were increasingly abnormal as disease severity increased. Cone-mediated parameters (cone time constant and cone sensitivity) were not impaired. Low Luminance Questionnaire scores and NEI VFQ scores decreased with increased ARM severity (P = 0.0004 and P = 0.0005, respectively); the percent decrease in LLQ scores as a function of disease severity was larger in magnitude than the percent decrease in NEI VFQ scores.
Disturbances in rod-mediated but not cone-mediated dark adaptation in the parafovea at 12 degrees in the inferior field on the vertical meridian are characteristic of ARM even in its early phases.
研究年龄相关性黄斑病变（ARM）患者近黄斑中心凹处视锥细胞介导与视杆细胞介导的暗适应功能损害情况。
横断面研究。
根据年龄相关性眼病研究严重程度量表对立体眼底照片进行评估，纳入不同严重程度（从早期到晚期）的ARM老年患者（n = 83）以及视网膜健康状况良好的老年人（n = 43）。
使用改良的 Humphrey 视野分析仪，在垂直子午线下方视野12度处设置目标，在98%漂白后测量视锥细胞介导和视杆细胞介导的暗适应成分。收集关于夜间或低光照条件下活动的自我报告问题（低亮度问卷[LLQ]）以及白天条件下活动的信息（改良的美国国立眼科研究所视觉功能问卷[NEI VFQ]）。
视锥细胞介导和视杆细胞介导的暗适应参数。
与视网膜健康的老年人相比，ARM患者视杆细胞介导的暗适应参数（视杆 - 视锥转折点、视杆斜率、视杆敏感度）存在显著损害（P<0.0001），且随着疾病严重程度增加，异常情况愈发明显。视锥细胞介导的参数（视锥时间常数和视锥敏感度）未受损。随着ARM严重程度增加，低亮度问卷得分和NEI VFQ得分降低（分别为P = 0.0004和P = 0.0005）；LLQ得分随疾病严重程度下降的百分比幅度大于NEI VFQ得分下降的百分比。
垂直子午线下方视野12度处近黄斑中心凹处视杆细胞介导而非视锥细胞介导的暗适应功能障碍是ARM的特征，即使在早期阶段也是如此。
