Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom.
Division of Human Communication, Development & Hearing, University of Manchester, Manchester, United Kingdom.
PLoS One. 2018 Oct 11;13(10):e0204833. doi: 10.1371/journal.pone.0204833. eCollection 2018.
Visual impairment has been associated with lower cognitive ability among older adults, yet little is known about whether improving visual function with cataract surgery would be associated with slower cognitive decline. This study aimed to assess whether trajectories of cognitive decline differed before and after cataract surgery and compare those trajectories between older adults with cataract surgery and without cataract.
Data were drawn from the English Longitudinal Study of Ageing (ELSA) Wave 1 (2002/03) until Wave 7 (2014/15). The study population consisted of 2,068 individuals who underwent cataract surgery between Wave 2 and Wave 6 as the treatment group and 3,636 individuals with no cataract as the control group. We included only respondents who took part in a minimum three waves. Propensity score matching method was used to match the individuals in the treatment group with those in the control group. After we put an "artificial" intervention point for the individuals in the control group at the point that the matched person has cataract surgery, spline method was used to identify differences in cognitive trajectories pre- and post-cataract surgery. In the treatment group, we found that cataract surgery was positively associated with episodic memory scores after controlling for the potential covariates (β = 4.23, p<0.001). Episodic memory scores declined with older age, but the decline in episodic memory scores was slower after cataract surgery (β = -0.05, p<0.001) than before cataract surgery (β = -0.1, p<0.001). Although the episodic memory among respondents in the control group before intervention (β = -0.08, p<0.001) declined slower than those in the intervention group (β = -0.1, p<0.001), the declines in episodic memory scores were similar in both groups after the intervention (control: β = -0.05, p<0.001; intervention: β = -0.05, p<0.001).
Cataract surgery may have a positive impact on trajectories of cognitive decline in later life. Further research is required to identify the mechanism to explain the association between cataract surgery and cognitive ageing, and whether early intervention towards vision correction results in a reduction in dementia risk.
视力障碍与老年人认知能力下降有关，但尚不清楚通过白内障手术改善视力是否会与认知能力下降速度减慢有关。本研究旨在评估白内障手术后认知能力下降的轨迹是否与手术前不同，并比较白内障手术组和无白内障组之间的轨迹差异。
数据来自英国老龄化纵向研究（ELSA）第 1 波（2002/03 年）至第 7 波（2014/15 年）。研究人群由 2068 名在第 2 波至第 6 波之间接受白内障手术的个体（治疗组）和 3636 名无白内障的个体（对照组）组成。我们只纳入了参加至少 3 波的受访者。采用倾向评分匹配方法将治疗组个体与对照组个体进行匹配。在对照组个体的匹配点上人为地干预白内障手术后，采用样条法确定白内障手术前后认知轨迹的差异。在治疗组中，我们发现，在控制了潜在混杂因素后，白内障手术与情景记忆评分呈正相关（β=4.23，p<0.001）。情景记忆评分随年龄增长而下降，但白内障手术后情景记忆评分下降速度较慢（β=-0.05，p<0.001），而白内障手术前下降速度较快（β=-0.1，p<0.001）。尽管对照组中干预前的情景记忆评分（β=-0.08，p<0.001）下降速度比干预组慢（β=-0.1，p<0.001），但干预后两组的情景记忆评分下降速度相似（对照组：β=-0.05，p<0.001；干预组：β=-0.05，p<0.001）。
白内障手术可能对晚年认知衰退轨迹产生积极影响。需要进一步研究以确定解释白内障手术与认知老化之间关联的机制，以及早期针对视力矫正的干预是否会降低痴呆风险。
