Carotenoids have potential antioxidant and anti-inflammatory effects; their protective roles are of particular interest in the pathogenesis of metabolic syndrome (MetS). The reflection spectroscopy method has been recently developed to noninvasively measure skin carotenoid (SC) levels, which highly correlates with serum concentration of carotenoids. The relationship between SC levels and metabolic syndrome has been investigated. We aimed to identify the differences in patient characteristics and SC levels between participants with and without MetS in a large health examination population. In addition, the relationships between SC levels and various clinical parameters related to MetS were investigated. SC levels were measured using a reflection spectroscopy. A total of 1812 Japanese participants (859 male, 953 female; mean age ± standard deviation (SD), 57.8 ± 11.0 years) comprised the study population, i.e., participants with MetS (n = 151) and those without MetS (n = 1661). Multivariate logistic regression analysis was performed to identify variables associated with MetS. Compared to controls (377.3 ± 122.8), SC indices were significantly lower in patients with MetS (340.7 ± 112.5, p = 0.0004). Multivariate models also suggested that lower SC was significantly associated with MetS after adjustment for age, sex, smoking habit, and other potential risk factors for MetS. Furthermore, male gender (p < 0.0001), smoking habit (p < 0.0001) and worse lipid profiles (i.e., serum triglyceride (r = −0.1039, p < 0.0001), high-density lipoprotein (r = 0.1259, p < 0.0001), and usage of hypolipidemic agents (p = 0.0340)) were significantly associated with lower SC levels. The current study indicated that lower SC levels were significantly associated with MetS. This study highlights the antioxidant capacity of carotenoids in patients with MetS and the clinical utility of non-invasive and cost-effective SC measurement to detect participants who are at risk of developing MetS in a large population.

The antioxidant and anti-inflammatory effects of carotenoid have been determined to aid in the prevention of a wide range of oxidative disorders, arteriosclerosis, obesity, and various types of cancers. In order to keep high carotenoid levels in the body, much of the vegetable and fruit (V/F) intake is mandatory. However, the actual intake of V/F is not enough in many countries. The aim of this study was to assess whether brief dietary education using the Veggie Meter (VM) that could measure skin carotenoid (SC) levels could induce the increase in carotenoid levels via V/F intake. Two hundred and sixty-one elementary and junior high school students (ages 7–14 years old) received brief educational session and SC evaluation by VM, and the changes in SC levels were examined after 6 months. The baseline VM scores ranged from 131 to 825, and the average significantly increased from 400.0 ± 124.7 (standard deviation) to 447.4 ± 140.4 at Month 6 (p < 0.0001). The percentage of increase at month 6 was negatively correlated with the baseline values (r = −0.36, p < 0.0001). This finding implies that subjects who became aware of their inferiority tended to make a significant effort to change their behavior. The multivariate logistic regression analysis demonstrated that subjects taking much of green and yellow vegetables, drinking vegetable/tomato juice, and eating any fruit had higher VM scores than the average value. In conclusion, the educational approach using VM was supposed to be an effective method of raising awareness of the V/F shortage and increasing V/F intake that could indue the increase in SC levels.

Pseudoexfoliation syndrome (PE), which is often unilateral in 60% of cases, is a risk for exfoliation glaucoma (EXG) with elevated inflammatory cytokines. This study aimed to clarify the dynamics of these cytokines in unilateral PE (u-PE) patients. This study included 20 eyes from 10 u-PE patients (PE+ eyes and fellow PE− eyes) and 20 eyes from 10 cataract patients without PE (control group). Clinical parameters, including age, visual acuity, and intraocular pressure, were assessed. Anterior chamber aqueous humor cytokine levels (IL-8, SAA, ET-1, VEGF) were measured and compared among groups. SAA was elevated in PE+ eyes compared to PE− and control eyes. IL-8 and ET-1 were elevated in both PE+ and PE− eyes compared to controls. IL-8 was associated with worsening visual acuity, while ET-1 correlated inversely. Our findings suggest that SAA is associated with the manifest disease while IL-8 and ET-1 could be early biomarkers for PE and therapeutic targets to prevent glaucomatous damage, as these markers appear in the aqueous humor even before pseudoexfoliation material becomes clinically evident. These results may enable earlier diagnosis and therapeutic intervention before the clinical onset of PE in patients with risk factors.

Carotenoids, having strong antioxidant properties, have been associated with neurodegenerative conditions like dementia and glaucoma, characterized by neuronal loss leading to cognitive and visual dysfunction. Therefore, carotenoids have attracted attention as factors predictive of the onset and progression of these neurodegenerative diseases. However, the impact of carotenoids on cognitive impairment and glaucomatous visual field defects remains unexplored. We conducted a retrospective, observational clinical study to investigate the association between skin carotenoid (SC) levels and cognitive impairment, as screened by the Mini-Cog test, in glaucoma patients. The study included 406 participants and 812 eyes were examined (average age: 69.7 ± 11.4 years; 228 men, 178 women) with various types of glaucoma: primary open angle (57.6%), exfoliation (18.6%), and other types (23.8%). SC levels were estimated via pressure-mediated reflection spectroscopy. Mixed-effects regression models were utilized to examine the relationship between SC levels, visual field defects, and Mini-Cog results. Of the participants, 28 (6.9%) tested positive on the Mini-Cog, suggesting cognitive impairment. The average SC level in the Mini-Cog positive group was significantly lower than in the negative group (269.5 ± 86.4 A.U. vs. 329.2 ± 120.4 A.U., respectively; p = 0.01). Additionally, the visual field mean deviation (MD) in the Mini-Cog positive group was notably worse than that in the negative group (−19.64 ± 9.07 dB vs. −12.46 ± 9.28 dB, respectively; p < 0.0001). The mixed-effects regression analysis revealed a significant association between Mini-Cog positivity and lower SC levels (p = 0.0006), although SC levels did not significantly correlate with MD (p = 0.3). Our findings suggest that cognitive impairment in glaucoma patients is associated with lower SC levels, underscoring the potential benefits of maintaining carotenoid levels to slow cognitive function decline. The protective role of carotenoids in glaucoma merits further investigation.

Background: Narrowing of the trabecular–iris angle (TIA) is a key anatomical feature of primary angle-closure disease and contributes to impaired aqueous humor outflow; however, conventional angle assessment requires specialized expertise or costly imaging equipment. This study aimed to develop an artificial intelligence model for quantitative TIA estimation from anterior-segment images acquired with a smartphone-attached slit-lamp microscope. Methods: In this retrospective study, 127,512 candidate frames were extracted from anterior-segment videos obtained from 2654 eyes. After automated diagnosability filtering, 59,412 frames suitable for TIA500 estimation were retained and assigned to the training, validation, and test datasets using patient-level grouping. A ResNet50-based model was trained to estimate inferior, nasal, and temporal TIA500 values using the corresponding measurements obtained by anterior-segment optical coherence tomography (AS-OCT) as the ground-truth reference. Model performance was evaluated by comparing the AI-predicted values with the AS-OCT measurements using mean absolute error (MAE), root mean squared error (RMSE), Spearman’s rank correlation coefficient, and the intraclass correlation coefficient (ICC). Results: Per-eye MAEs were 7.01° ± 5.69°, 7.28° ± 5.80°, and 7.90° ± 6.37° for inferior, nasal, and temporal TIA, respectively. Corresponding correlations with reference measurements were 0.683, 0.696, and 0.646, while ICCs were 0.769, 0.764, and 0.743 (all p < 0.001). Conclusions: These findings demonstrate the feasibility of estimating TIA500 from smartphone-based slit-lamp images. However, the moderate correlations with AS-OCT measurements indicate that the present model is not yet sufficiently accurate for independent clinical diagnosis or screening, and further model improvement and external validation are required.