Linking the activity of neurons, circuits and synapses to human behavior is a fundamental goal of neuroscience. Meeting this goal is challenging, in part because behavior, particularly perception, often masks the complexity of the underlying neural circuits, and in part because of the significant behavioral differences between primates and animals like mice and flies in which genetic manipulations are relatively common. Here we relate circuit-level processing of rod and cone signals in the non-human primate retina to a known break in the normal seamlessness of human vision - a surprising inability to see high contrast flickering lights under specific conditions. We use electrophysiological recordings and perceptual experiments to identify key mechanisms that shape the retinal integration of rod- and cone-generated retinal signals. We then incorporate these mechanistic insights into a predicti\\ve model that accurately captures the cancellation of rod- and cone-mediated responses and can explain the perceptual insensitivity to flicker.

OBJECTIVE: To evaluate mesopic and photopic contrast sensitivity in patients with congenital red-green color vision deficiency regarding with and without glare conditions and to compare these findings with age- and gender-matched healthy controls with normal color vision.
METHODS: Patients with congenital red-green color vision deficiency and age- and gender-matched healthy controls were included in this cross-sectional comparative study. Contrast sensitivity measurements were taken from all subjects in 4 different conditions; binocular mesopic-without glare, mesopic-with glare, photopic-without glare, photopic-with glare, and the results were compared.
RESULTS: Twenty one patients with color vision deficiency (13 deuteranopic, 8 protanopic) and 22 age- and gender-matched healthy controls were included in the study. The mean age was 35.2 ± 13.5 years in the protan group, 30.6 ± 7.7 years in the deutan group, 32.0 ± 8.8 years in the control group, and there was no significant difference in age between the groups (P > 0.05). The mean mesopic and photopic contrast sensitivity values of the groups at all spatial frequencies (1.5, 3, 6, 12, 18 cpd) were not statistically significant when evaluated by the multifactor repeated measures test of ANOVA to evaluate the effect of light conditions (with and without glare) (P > .05).
CONCLUSIONS: Mesopic and photopic contrast sensitivity values of patients with congenital red-green color vision deficiency were similar to healthy controls regarding with and without glare conditions.

暂无摘要。

Visual fields under mesopic and scotopic lighting are increasingly being used for macular functional assessment. This review evaluates its statistical significance and clinical relevance, and the optimal testing protocol for early/intermediate age-related macular degeneration (AMD). PubMed and Embase were searched from inception to 14/05/2022. All quality assessments were performed according to GRADE guidelines. The primary outcome was global mean sensitivity (MS), further meta-analysed by: AMD classification scheme, device, test pattern, mesopic/scotopic lighting, stimuli size/chromaticity, pupil dilation, testing radius (area), background luminance, adaptation time, AMD severity, reticular pseudodrusen presence, and follow-up visit. From 1489 studies screened, 42 observational study results contributed to the primary meta-analysis. Supported by moderate GRADE certainty of the evidence, global MS was significantly reduced across all devices under mesopic and scotopic lighting with large effect size (-0.9 [-1.04, -0.75] Hedge\'s g, P < 0.0001). The device (P < 0.01) and lighting (P < 0.05) used were the only modifiable factors affecting global MS, whereby the mesopic MP-1 and MAIA produced the largest effect sizes and exceeded test-retest variabilities. Global MS was significantly affected by AMD severity (intermediate versus early AMD; -0.58 [-0.88, -0.29] Hedge\'s g or -2.55 [3.62, -1.47] MAIA-dB) and at follow-up visit (versus baseline; -0.62 [-0.84, -0.41] Hedge\'s g or -1.61[-2.69, -0.54] MAIA-dB). Magnitudes of retinal sensitivity changes in early/intermediate AMD are clinically relevant for the MP-1 and MAIA devices under mesopic lighting within the central 10° radius. Other factors including pupil dilation and dark adaptation did not significantly affect global MS in early/intermediate AMD.
摘要: 中明视和暗视照明下的视野越来越多地用于黄斑功能评估。这篇综述评估了其统计学意义和临床相关性, 以及早期/中期年龄相关性黄斑变性 (AMD) 的最佳检测方案。检索PubMed和Embase自建库起至2022年5月14日的文献。所有质量评估均根据GRADE指南进行。主要结局是全局平均敏感性 (MS), 进一步meta分析指标包括: AMD分类方案、设备、测试模式、中位/暗位照明、刺激大小/色度、瞳孔扩张、测试半径 (面积) 、背景亮度、适应时间、AMD严重程度、网状假性玻璃膜疣的存在和随访。我们对筛选的 1489 项中的42 项观察性研究结果进行了meta分析。在中等GRADE质量证据的支持下及在中明视和暗视照明下, 所有设备的全、全视野MS均显著降低 (−0.9 [−1.04, −0.75] Hedge’s g, P < 0.0001) 。所使用的设备 (P < 0.01) 和照明 (P < 0.05) 是影响全视野MS的唯一可改变的变量, 因此中视MP-1和MAIA受影响最大, 并超过了重新测试的可变性。AMD严重程度 (中度 vs 早期AMD;−0.58 [−0.88, −0.29] Hedge’s g或−2.55[3.62, −1.47]MAIA-dB) 和随访 (与基线相比;−0.62[−0.84, −0.41]Hedge’s g或−1.61[−2.69, −0.54]MAIA-dB) 对全视野MS有显著影响。早期/中期AMD的视网膜敏感性变化幅度与MP-1和MAIA装置在中心10°半径内的中明视照明下具有临床相关性。瞳孔扩张和暗适应等其他因素对早期/中期AMD的全视野MS没有显著影响。.

OBJECTIVE: To explore the influence of preoperative factors, including varying pupil sizes and refractive attributes, on postoperative glare disability in patients undergoing implantable collamer lens (ICL) implantation.
METHODS: Second Affiliated Hospital, Nanchang University, Nanchang, Jiangxi, China.
METHODS: Prospective observational study.
METHODS: The preoperative ocular characteristics and 6-month postoperative glare status in eligible patients who underwent EVO-Visian ICL V4c (VICMO) implantation were analyzed. The glare disability criteria encompassed a glare symptom score >6 and glare sensitivity exceeding 1:2.7. Logistic regression analysis was used to explore the relationship between the preoperative ocular parameters and post-ICL glare.
RESULTS: The study included 95 patients (mean age, 26.04 ± 6.29 years), comprising 30 men (58 eyes) and 65 women (129 eyes). Multivariate analysis revealed a significant correlation between postoperative glare disability and increased spherical power in preoperative mesopic pupils (β = -0.124, P = .039), as well as elevated cylinder power in preoperative mesopic (β = -0.412, P = .009) and photopic pupils (β = -0.430, P = .007). Moreover, a larger preoperative mesopic pupil diameter (β = 0.561, P = .005) demonstrated a significant correlation with glare disability.
CONCLUSIONS: Preoperative mesopic pupil dimensions and associated refractive parameters, such as sphere and cylinder, were correlated with glare disability, including the cylinder aspect in photopic pupils, which can assist clinicians in optimizing preoperative selection for ICL implantation, aiding in the anticipation of potential glare disability risks.

OBJECTIVE: To investigate the visual function correlates of self-reported vision-related night driving difficulties among drivers.
METHODS: One hundred and seven drivers (age: 46.06 ± 8.24, visual acuity [VA] of 0.2logMAR or better) were included in the study. A standard vision and night driving questionnaire (VND-Q) was administered. VA and contrast sensitivity were measured under photopic and mesopic conditions. Mesopic VA was remeasured after introducing a peripheral glare source into the participants\' field of view to enable computation of disability glare index. Regression analyses were used to assess the associations between VND-Q scores, and visual function measures.
RESULTS: The mean VND-Q score was -3.96±1.95 logit (interval scale score: 2.46±1.28). Simple linear regression models for photopic contrast sensitivity, mesopic VA, mesopic contrast sensitivity, and disability index significantly predicted VND-Q score (P<0.05), with mesopic VA and disability glare index accounting for the greatest variation (21 %) in VND-Q scores followed by photopic contrast sensitivity (19 %), and mesopic contrast sensitivity (15 %). A multiple regression model to determine the association between the predictors (photopic contrast sensitivity, mesopic VA, mesopic contrast sensitivity, and disability index) and VND-Q score yielded significant results, F (4, 102) = 8.58, P < 0.001, adj. R2 = 0.2224. Seeing dark-colored cars was the most challenging vision task.
CONCLUSIONS: Changes in mesopic visual acuity, photopic and mesopic contrast sensitivity, as well as disability glare index are associated with and explain night driving-related visual difficulties. It is recommended to incorporate measurement of these visual functions into assessments related to driving performance.

OBJECTIVE: To examine relationships between mesopic visual sensitivity measurements on microperimetry and macular inner and outer retinal layer (IRL and ORL) thicknesses in healthy younger, middle-aged and older subjects.
METHODS: In total, 154 healthy adults were divided into three age groups each with similar mean sensitivity. Regional retinal sensitivity (determined by mesopic fundus-controlled microperimetry) and IRL (ganglion cell-related layer) and ORL thicknesses were measured in the five subfields: central fovea (1 mm diameter) and the quadrants temporal, nasal, superior and inferior of a parafoveal ring of outer diameter 3 mm and inner diameter 1 mm. Relationships between regional sensitivity and corresponding IRL and ORL thicknesses were assessed through a univariate and multivariate linear regression model.
RESULTS: Visual sensitivity means for each subfield differed across age groups (all p < 0.001). In each parafoveal ring quadrant, mean IRL thickness was reduced in the older eyes compared to the other groups (all p < 0.0001). In the inferior region, worse sensitivity was correlated with greater IRL thickness (p = 0.0207) in the middle-aged group and with a thicker ORL (p < 0.0001) and thinner IRL (p = 0.0003) in the older eyes (R2 = 0.51). The slopes of regression lines relating sensitivity to IRL thickness and age group (p = 0.0027) or to ORL thickness and age group (p = 0.0020) differed significantly.
CONCLUSIONS: The relationship observed between mesopic visual sensitivity and retinal layer thickness varied with age. A worse sensitivity was related to a thicker macular IRL layer in middle-aged eyes and to a thicker ORL and thinner IRL in older eyes.

At intermediate (mesopic) light levels, rods and cones are both active and can contribute to vision. This presents a challenge to the retina because the visual responses originating with rods and cones are distinct, yet their visual responses must be seamlessly combined. The current study aimed to establish how the circadian clock regulates rod and/or cone vision in these conditions, given the strong time-of-day change in the reliance on each photoreceptor. Visual responses were recorded in the retina and visual thalamus of anaesthetized male mice at distinct circadian time points, and the method of receptor silent substitution was used to selectively stimulate different photoreceptor types. With stimuli designed to only activate rods, responses in the mesopic range were highly rhythmic and peaked in amplitude in the subjective night. This rhythm was abolished following intravitreal injection of the gap junction blocker meclofenamic acid, consistent with a circadian variation in the strength of electrical coupling of photoreceptors. In contrast, responses to stimuli designed to only activate cones were arrhythmic within the mesopic to photopic range when adapted to the background irradiance. The outcome was that combined rod-plus-cone responses showed a stable contrast-response relationship across mesopic-photopic backgrounds in the circadian day, whereas at night, responses were significantly amplified at lower light levels. These data support the idea that the circadian clock is a key regulator of vision, in this case defining the relative amplitude of rod/cone vision across the mesopic transition according to time of day.SIGNIFICANCE STATEMENT Although the importance of circadian clocks in regulating vision has been long recognized, less is known about how the clock shapes vision in conditions where both rods and cones are active (mesopic conditions). Here, the novel approach of receptor silent substitution has been applied to trace rod and cone visual responses in mice across the circadian cycle and has identified pronounced rhythms in rod, but not cone, vision. This has the effect of boosting responses in dimmer backgrounds at night at the cost of impaired contrast-response stability across the mesopic to photopic range. Thus, the circadian clock drives anticipatory changes in the relative contribution of rods versus cones to vision, which match the prevailing visual environment.

To establish age-related, normal limits of monocular and binocular spatial vision under photopic and mesopic conditions.
Photopic and mesopic visual acuity (VA) and contrast thresholds (CTs) were measured with both positive and negative contrast optotypes under binocular and monocular viewing conditions using the Acuity-Plus (AP) test. The experiments were carried out on participants (age range from 10 to 86 years), who met pre-established, normal sight criteria. Mean and ± 2.5σ limits were calculated within each 5-year subgroup. A biologically meaningful model was then fitted to predict mean values and upper and lower threshold limits for VA and CT as a function of age. The best-fit model parameters describe normal aging of spatial vision for each of the 16 experimental conditions investigated.
Out of the 382 participants recruited for this study, 285 participants passed the selection criteria for normal aging. Log transforms were applied to ensure approximate normal distributions. Outliers were also removed for each of the 16 stimulus conditions investigated based on the ±2.5σ limit criterion. VA, CTs and the overall variability were found to be age-invariant up to ~50 years in the photopic condition. A lower, age-invariant limit of ~30 years was more appropriate for the mesopic range with a gradual, but accelerating increase in both mean thresholds and intersubject variability above this age. Binocular thresholds were smaller and much less variable when compared to the thresholds measured in either eye. Results with negative contrast optotypes were significantly better than the corresponding results measured with positive contrast (p < 0.004).
This project has established the expected age limits of spatial vision for monocular and binocular viewing under photopic and high mesopic lighting with both positive and negative contrast optotypes using a single test, which can be implemented either in the clinic or in an occupational setting.

Drivers have different visual demands across varying contrast and luminance conditions. However, vision assessments for driving are typically conducted under photopic conditions. This study investigated the sensitivity of photopic and mesopic conditions to detect contrast sensitivity (CS) loss in drivers with simulated media opacities. CS was measured in forty-seven healthy drivers aged 18-50 years (mean ± SD: 25.5 ± 6.5) under photopic and mesopic-adapted luminance levels with the Pelli-Robson chart and the Mesotest II (without glare). Media opacities were simulated using white-opacity containing Lee Fog filters (1-5) and CS measured in a randomised order. A significant (p < 0.001) reduction in photopic CS (logCS) was measured with the Pelli-Robson chart only when media opacity was simulated with Fog filter 5 (1.53 ± 0.15, 2.8 triplets reduction) compared to baseline (1.95 ± 0.03). Mean mesopic CS demonstrated a significant (all p < 0.001) reduction from baseline (1.67 ± 0.14) for Fog filters 3 (1.4 triplets, 1.45 ± 0.16), 4 (2.4 triplets, 1.31 ± 0.14) and 5 (4.3 triplets, 1.02 ± 0.15). For Mesotest II, only Fog filter 5 produced a significant reduction (0.10 ± 0.09; p < 0.001) in mean mesopic CS from baseline (0.30 ± 0.01). Mesopic CS is more vulnerable to different levels of simulated media opacity, hence should be considered clinically when assessing visual function in older drivers at risk of media opacity.