Department of Ophthalmology, Nara Medical University School of Medicine, Nara, Japan.
Department of Epidemiology, Nara Medical University School of Medicine, Nara, Japan.
JAMA Ophthalmol. 2020 Apr 1;138(4):405-411. doi: 10.1001/jamaophthalmol.2020.0206.
Cataract surgery, which increases perception of light, may increase melatonin secretion. Melatonin secretion has been associated with depression, diabetes, cognitive impairment, and breast cancer. To date, no evidence from a randomized clinical trial exists to support this cataract surgery hypothesis.
To determine whether cataract surgery modifies the melatonin secretion at 3 months after cataract surgery in 169 adult patients.
DESIGN, SETTING, AND PARTICIPANTS: A parallel-group randomized clinical trial was conducted at a single referral center from July 1, 2014, to June 30, 2017. Data were analyzed from January 1, 2018, to March 31, 2019. Patients were aged 60 years or older, had no history of cataract surgery, and had cataracts with grade 2 or higher nuclear opacifications based on the Lens Opacities Classification System III. Analyses were based on intention to treat.
Patients were randomized 1:1:1:1 to receive cataract surgery using artificial clear intraocular lens (IOL) or yellow IOL. Group 1 received prompt surgery with clear IOL, group 2, prompt surgery with yellow IOL, group 3, delayed surgery with clear IOL, and group 4, delayed surgery with yellow IOL. The intervention group consisted of groups 1 and 2, and the control group consisted of groups 3 and 4.
Urinary melatonin excretion in the intervention group was measured at 3 months after surgery, and urinary melatonin excretion in the control group was measured before delayed surgery.
Of the 169 randomized patients, 97 were men (57.4%). The mean (SD) age was 75.7 (6.7) years. Mean urinary melatonin excretion was calculated as standardized urinary concentration, the ratio of urinary concentration to urinary creatinine concentration (nanograms per milligram of creatinine), in the intervention group after cataract surgery. Mean urinary melatonin excretion was significantly higher than in the control group (adjusted mean difference of creatinine concentration, 0.159 log ng/mg, 95% CI, 0.045-0.273; P = .007) independent of baseline urinary melatonin excretion and potential confounders. Subgroup analysis comparing group 1 with group 3 revealed that concentration of urinary melatonin excretion in patients who received clear IOLs was higher than the control group by creatinine concentration 0.212 log ng/mg (95% CI of the difference, 0.058-0.365; P = .008). However, the difference between patients in group 2 and group 4 was not significant (adjusted mean difference for creatinine excretion, 0.083 log ng/mg, 95% CI, -0.087 to 0.253; P = .33). The difference of concentration of mean urinary melatonin excretion between patients in group 1 and those in group 2 was not significant (95% CI of the difference for creatinine concentration, -0.19 to 0.40 log ng/mg; P = .48).
The findings in this study support the hypothesis that cataract surgery increases melatonin secretion. The effect of clear IOLs vs yellow IOLs on these outcomes was not shown to be different.
UMIN-CTR Identifier: UMIN000014559.
白内障手术增加了对光的感知，可能会增加褪黑素的分泌。褪黑素的分泌与抑郁症、糖尿病、认知障碍和乳腺癌有关。迄今为止，尚无随机临床试验证据支持这一白内障手术假说。
在 169 名成年患者中，确定白内障手术后 3 个月时白内障手术是否会改变褪黑素的分泌。
设计、地点和参与者：这是一项在 2014 年 7 月 1 日至 2017 年 6 月 30 日期间在一家转诊中心进行的平行组随机临床试验。数据分析于 2018 年 1 月 1 日至 2019 年 3 月 31 日进行。患者年龄在 60 岁或以上，无白内障手术史，晶状体混浊分级系统 III 级核混浊程度为 2 级或以上。分析基于意向治疗。
患者被随机分为 1:1:1:1 组，分别接受人工透明晶状体（IOL）或黄色 IOL 的白内障手术。第 1 组患者接受透明 IOL 的即刻手术，第 2 组患者接受即刻黄色 IOL 手术，第 3 组患者接受延迟透明 IOL 手术，第 4 组患者接受延迟黄色 IOL 手术。干预组包括第 1 组和第 2 组，对照组包括第 3 组和第 4 组。
术后 3 个月，干预组患者的尿褪黑素排泄量进行测量，对照组患者延迟手术前的尿褪黑素排泄量进行测量。
在 169 名随机患者中，97 名是男性（57.4%）。平均（SD）年龄为 75.7（6.7）岁。标准化尿浓度的平均（SD）尿褪黑素排泄量被计算为术后干预组的尿浓度与尿肌酐浓度的比值（每毫克肌酐的纳克数）。与对照组相比，术后干预组的尿褪黑素排泄量明显更高（肌酐浓度调整平均差值，0.159 log ng/mg，95%CI，0.045-0.273；P = .007），与基线尿褪黑素排泄量和潜在混杂因素无关。比较第 1 组和第 3 组的亚组分析显示，接受透明 IOL 的患者尿褪黑素排泄量的浓度比对照组高 0.212 log ng/mg（差异的 95%CI，0.058-0.365；P = .008）。然而，第 2 组和第 4 组患者之间的差异不显著（肌酐排泄调整平均差值，0.083 log ng/mg，95%CI，-0.087 至 0.253；P = .33）。第 1 组患者与第 2 组患者之间的平均尿褪黑素排泄量浓度差异无统计学意义（肌酐浓度差异的 95%CI，-0.19 至 0.40 log ng/mg；P = .48）。
本研究结果支持白内障手术增加褪黑素分泌的假说。透明 IOL 与黄色 IOL 对这些结果的影响尚未显示出不同。
UMIN-CTR 标识符：UMIN000014559。
