controlMelanopsinStimulus.

PurposeTo test whether differences in pupil responses to melanopsin-isolating spectral stimuli in glaucoma may be useful as a diagnostic biomarker.MethodsSpectral stimuli were presented to 20 glaucoma and 15 age-similar healthy control participants. Stimuli were pairs of silent-substitution spectra designed to provide (1) equal stimulation to cone photoreceptors but maximum (~325%) contrast to melanopsin or (2) equal stimulation to melanopsin but ~325% contrast to cones. Narrowband long-wavelength/red (657 nm) and short-wavelength/blue (471 nm) pulses were also presented from a dark background to 16 glaucoma and 12 control participants. Pulses lasted 3 seconds and pupil size was measured for 15 seconds. Pupil response metrics were compared by t-test and relationships with visual field and OCT summary indices were assessed by Spearman’s rank correlation. Diagnostic accuracy was measured by area under the receiver operating characteristic curve (AUC).ResultsPupil constriction was more persistent after pulse offset for the melanopsin-directed stimulus (2% mean paired difference 6s post-pulse offset, p 0.05). Diagnostic accuracy for all pupil parameters was poor, with AUC 95% confidence intervals overlapping 0.5 for all but time to maximal constriction for the cone-directed stimulus.ConclusionsPupil responses to melanopsin-isolating spectra were similar between glaucoma and control participants. Pupillary responses to melanopsin-isolating silent substitution spectra are unlikely to be useful as a diagnostic biomarker for glaucoma.

研究目的：验证青光眼患者对视黑素（melanopsin）隔离型光谱刺激的瞳孔反应差异是否可作为青光眼的诊断生物标志物。
研究方法：本研究纳入20名青光眼患者与15名年龄匹配的健康对照受试者。实验采用两类静默替换（silent substitution）光谱刺激对：其一为对视锥光感受器（cone photoreceptors）产生同等刺激，但对视黑素产生约325%最大对比度的刺激；其二为对视黑素产生同等刺激，但对视锥光感受器产生约325%对比度的刺激。此外，本研究还向16名青光眼患者与12名健康对照受试者呈现来自暗背景的窄带长波长/红光（657 nm）与短波长/蓝光（471 nm）刺激脉冲。脉冲时长为3秒，同步记录15秒内的瞳孔尺寸变化。采用t检验对瞳孔反应指标进行组间比较，通过斯皮尔曼秩相关分析评估瞳孔反应与视野及光学相干断层扫描（OCT, Optical Coherence Tomography）汇总指标的相关性；采用受试者工作特征曲线下面积（AUC, Area Under the Receiver Operating Characteristic Curve）评估诊断准确性。
研究结果：相较于健康对照受试者，青光眼患者在接受视黑素定向刺激后，脉冲偏移后的瞳孔收缩持续时间更长（脉冲偏移后6秒的平均配对差值为2%，p=0.05）。所有瞳孔参数的诊断准确性均较差，仅视锥定向刺激的最大收缩时间除外，其余参数的AUC 95%置信区间均与0.5重叠。
研究结论：青光眼患者与健康对照受试者对视黑素隔离型光谱的瞳孔反应无显著差异。针对视黑素隔离型静默替换光谱的瞳孔反应，不太可能作为青光眼的诊断生物标志物。