PURPOSE To investigate the natural history of dark adaptation (DA) function as measured by the change in rod intercept time (RIT) over 4 years and to correlate RIT change with age-related macular degeneration (AMD) severity. DESIGN Longitudinal, single-center, observational study. PARTICIPANTS A total of 77 participants aged ≥50 years with a range of AMD severities. METHODS Participants each contributing a single study eye to the analysis were assigned into person-based AMD severity groups based on fundus characteristics (drusen, pigmentary changes, late AMD, and subretinal drusenoid deposits [SDDs]). The DA function was assessed in study eyes at baseline and 3, 6, 12, 18, 24, 36, and 48 months. Mean change in DA function over time was calculated using the slope of linear regression fits of longitudinal RIT data. Patient-reported responses on a Low Luminance Questionnaire (LLQ) were obtained at baseline and yearly. Nonparametric statistical testing was performed on all comparisons. MAIN OUTCOME MEASURE The RIT, defined as the time taken after a photobleach for visual sensitivity to recover detection of a 5×10-3 cd/m2 stimulus (a decrease of 3 log units), was monitored in study eyes over 4 years, and the mean rate of change was computed. RESULTS Longitudinal analysis of 65 study eyes followed on the standard testing protocol (mean age, 71±9.3 years; 49% were female) revealed that higher rates of RIT prolongation were correlated with AMD severity group assignment at baseline (P = 0.026) and with severity group assignments at year 4 (P = 0.0011). Study eyes that developed SDD during follow-up demonstrated higher rates of RIT prolongation relative to those that did not (P < 0.0001). Overall, higher rates of RIT prolongation were significantly correlated with greater 4-year decreases in LLQ scores (total mean score, P = 0.0032). CONCLUSIONS Longitudinal decline in DA function, which correlated with patient-reported functional deficits, was accelerated in eyes with greater AMD severity and especially in eyes with SDD both at baseline and at 4 years. The RIT prolongation as a measure of changing DA function may be a functional outcome measure in AMD clinical studies.

中文翻译：

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黑暗适应作为年龄相关性黄斑变性的功能结果指标的纵向研究。

目的调查暗适应 (DA) 功能的自然史，通过 4 年内杆拦截时间 (RIT) 的变化来衡量，并将 RIT 变化与年龄相关性黄斑变性 (AMD) 的严重程度相关联。设计 纵向、单中心、观察性研究。参与者 共有 77 名年龄≥50 岁且具有各种 AMD 严重程度的参与者。方法 根据眼底特征（玻璃膜疣、色素改变、晚期 AMD 和视网膜下玻璃膜疣沉积物 [SDD]），将每只对分析贡献单个研究眼睛的参与者分为基于个人的 AMD 严重程度组。在基线和 3、6、12、18、24、36 和 48 个月时，在研究眼中评估 DA 功能。使用纵向 RIT 数据的线性回归拟合的斜率计算 DA 函数随时间的平均变化。患者在低亮度问卷 (LLQ) 上报告的反应是在基线和每年获得的。对所有比较进行了非参数统计检验。主要结果测量 RIT，定义为在光漂白后视觉灵敏度恢复检测到 5×10-3 cd/m2 刺激（减少 3 个对数单位）所花费的时间，在 4 年内在研究眼睛中进行监测，并且计算平均变化率。结果 根据标准测试方案（平均年龄，71±9.3 岁；49% 为女性）对 65 只研究眼进行的纵向分析显示，较高的 RIT 延长率与基线时的 AMD 严重程度分组相关（P = 0.026）和第 4 年的严重性组分配（P = 0.0011）。在随访期间出现 SDD 的研究眼显示出 RIT 延长率高于未出现的眼 (P < 0.0001)。总体而言，较高的 RIT 延长率与 LLQ 评分的 4 年下降幅度显着相关（总平均评分，P = 0.0032）。结论 与患者报告的功能缺陷相关的 DA 功能的纵向下降在 AMD 严重程度较高的眼睛中加速，尤其是在基线和 4 年时患有 SDD 的眼睛中。作为改变 DA 功能的量度的 RIT 延长可能是 AMD 临床研究中的功能结果量度。这与患者报告的功能缺陷相关，在 AMD 严重程度较高的眼睛中加速，尤其是在基线和 4 年时患有 SDD 的眼睛中。作为改变 DA 功能的量度的 RIT 延长可能是 AMD 临床研究中的功能结果量度。这与患者报告的功能缺陷相关，在 AMD 严重程度较高的眼睛中加速，尤其是在基线和 4 年时患有 SDD 的眼睛中。作为改变 DA 功能的量度的 RIT 延长可能是 AMD 临床研究中的功能结果量度。