Lutein and Zeaxanthin Supplementation Improves Dynamic Visual and Cognitive Performance in Children: A Randomized, Double-Blind, Parallel, Placebo-Controlled Study.

INTRODUCTION: Supplementation with dietary neuro-pigments lutein (L) and zeaxanthin (Z) has been shown to improve many aspects of visual and cognitive function in adults. In this study, we tested whether a similar intervention could improve such outcomes in preadolescent children. METHODS: Sixty children (age range 5-12 years) were randomized in a 2:1 ratio in this double-blind, placebo-controlled clinical trial. Subjects were supplemented with gummies containing either a combination of 10 mg lutein and 2 mg zeaxanthin (LZ) or placebo for 180 days. Macular pigment optical density (MPOD) was the primary endpoint. The secondary endpoints included serum levels of L and Z, and brain-derived neurotrophic factor (BDNF), critical flicker fusion (CFF), eye strain and fatigue using visual analogue scales (VAS), Children's Sleep Habits Questionnaire-Abbreviated (CSHQ-A), and Creyos Health cognitive domains like attention, focus/concentration, episodic memory and learning, visuospatial working memory, and visuospatial processing speed. Safety was assessed throughout the study on the basis of physical examination, vital signs, clinical laboratory tests, and monitoring of adverse events. RESULTS: The LZ group showed significant increases in MPOD at all visits post-supplementation, with significant increases as early as day 42 compared to placebo. The LZ group showed significant increases in serum lutein levels, reduced eye strain and fatigue, and improved cognitive performance (focus, episodic memory and learning, visuospatial working memory) at days 90 and 180 compared to placebo. Further, the LZ group showed significant increases in processing speed (CFF), attention, visuospatial processing, and serum Z and BDNF levels on day 180 compared to placebo. No safety concerns were observed. CONCLUSIONS: Supplementing LZ resulted in increased MPOD levels, along with increased serum levels of L, Z, and BDNF. These changes were associated with improved visual and cognitive performances and reduction in eye strain and eye fatigue in the children receiving LZ gummies. The investigational product was safe and well tolerated. TRIAL REGISTRATION: http://ctri.nic.in/ Identifier CTRI/2022/05/042364.

Association of macular pigment optical density with retinal layer thicknesses in eyes with and without manifest primary open-angle glaucoma.

OBJECTIVE: To investigate associations between baseline macular pigment optical density (MPOD) and retinal layer thicknesses in eyes with and without manifest primary open-angle glaucoma (POAG) in the Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2). METHODS AND ANALYSIS: MPOD was measured at CAREDS baseline (2001-2004) via heterochromatic flicker photometry (0.5° from foveal centre). Peripapillary retinal nerve fibre layer (RNFL), macular ganglion cell complex (GCC), ganglion cell layer (GCL), inner plexiform layer (IPL), and RNFL thicknesses were measured at CAREDS2 (2016-2019) via spectral-domain optical coherence tomography. Associations between MPOD and retinal thickness were assessed using multivariable linear regression. RESULTS: Among 742 eyes (379 participants), manifest POAG was identified in 50 eyes (32 participants). In eyes without manifest POAG, MPOD was positively associated with macular GCC, GCL and IPL thicknesses in the central subfield (P-trend ≤0.01), but not the inner or outer subfields. Among eyes with manifest POAG, MPOD was positively associated with macular GCC, GCL, IPL and RNFL in the central subfield (P-trend ≤0.03), but not the inner or outer subfields, and was positively associated with peripapillary RNFL thickness in the superior and temporal quadrants (P-trend≤0.006). CONCLUSION: We observed a positive association between MPOD and central subfield GCC thickness 15 years later. MPOD was positively associated with peripapillary RNFL superior and temporal quadrant thicknesses among eyes with manifest POAG. Our results linking low MPOD to retinal layers that are structural indicators of early glaucoma provide further evidence that carotenoids may be protective against manifest POAG.

Macular Pigment Optical Density and Skin Carotenoids in a Childhood Sample.

BACKGROUND: Carotenoids are plant pigments with light filtering and antioxidant properties that deposit in human tissues, including retina and skin. Descriptive characteristics and covariates of carotenoid status in macula and skin have been examined in adults; however, similar studies in children are limited. Thus, this study aimed to delineate how factors of age, sex, race, weight status, and dietary carotenoid intake relate to macular and skin carotenoids in children. METHODS: Children (7-13 y, N = 375) completed heterochromatic flicker photometry to assess macular pigment optical density (MPOD). Participants underwent anthropometrics to measure weight status (BMI percentile [BMI%]), and parent/guardian provided demographic information. Subsample data were available for skin carotenoids (N = 181), assessed using reflection spectroscopy, and dietary carotenoids (N = 101) using the Block Food Frequency Questionnaire. Relationships between skin and macular carotenoids were assessed using partial Pearson's correlations controlling for age, sex, race, and BMI%. Relationships between dietary carotenoids and macular and skin carotenoids were assessed using stepwise linear regression including age, sex, race, and BMI% in the model. RESULTS: Mean MPOD was 0.56 ± 0.22 and skin carotenoid score was 282 ± 94.6. There was no significant correlation between MPOD and skin carotenoids (r = 0.02, P = 0.76). BMI% was negatively associated with skin (stdß = -0.42, P < 0.001), but not macular carotenoids (stdß = -0.04, P = 0.70). Neither MPOD nor skin carotenoids were associated with age, sex, or race (all P > 0.10). MPOD was positively associated with energy-adjusted reported lutein + zeaxanthin intake (stdß = 0.27, P = 0.01). Skin carotenoids were positively associated with energy-adjusted reported carotenoid intake (stdß = 0.26, P = 0.01). CONCLUSIONS: The mean MPOD values in children were higher than what has been reported in adult populations. Previous studies in adult samples report an average MPOD of 0.21. Although macular and skin carotenoids were not related, they were associated with dietary carotenoids relevant to the respective tissues; however, skin carotenoids may be more susceptible negative influence from higher weight status.

Contrast sensitivity functions measured using simple optics and computer testing.

PURPOSE: Contrast sensitivity function (CSF) testing is a common approach to assessing clinical changes to specific aspects of spatial vision. Different stimulus presentations and testing procedures, however, yield significant differences in CSF curves that are more a feature of the method than the observer. In this study, we designed a simple optical device for measuring CSF that could be directly calibrated and compared with a commonly used computer-based system. METHODS: Twenty-one participants (M = 28.95 ± 10.34 years; 66.7% female; 81.0% non-Hispanic White; best corrected visual acuity 6/9 or better) provided photopic CSFs (from measurements at 1.6, 3.2, 8, 16 and 24 cycles per degree, with spatial frequency presentation randomised) using both the Metropsis test platform and a simple optical device over two test sessions (one session/method, randomised, counterbalanced) separated by 1-7 days. The optical system used 520 nm lasers that were made Lambertian using two integrating spheres with a 3.5° circular exit port. These beams were combined with a beam splitter that allowed constant measurement of light output and contrast modulation using sine-wave gratings on glass. In Metropsis, 2° Gabor stimuli were presented for 0.5 s with either a vertical or a horizontal orientation via a two-alternative forced choice paradigm with contrast modulated until four (first) and eight (last) reversals were complete. RESULTS: Both methods took approximately the same amount of time to generate a CSF and yielded curves that were consistent with past studies using similar methods but different from each other. The optical system showed a 3.5 times higher maximum sensitivity and yielded higher test-retest reliability. CONCLUSIONS: Using simple optics to measure CSF yields low noise, high sensitivity and reliability. The ability to calibrate the stimuli directly is an advantage over computer-based methods.

The Effects of Blue-Light Filtering Intraocular Implants on Glare Geometry.

PURPOSE: One common complaint with natural opacified lenses is the deleterious effects of higher-order ocular aberrations and intraocular scatter, such as halos and starbursts, which are not always remedied with surgery and intraocular lens (IOL) implantation. Blue-light filtering (BLF) IOL filter scatter-prone short-wave light. Here, we determine whether BLF IOL reduce halo and starburst size. METHODS: This study was a case-control design, between- and within-subjects (contralateral implantation). Sixty-nine participants with either the BLF IOL (n = 25; AlconSN60AT), clear IOL (n = 24; AlconSA60AT or WF), or both (n = 20) IOL participated. Participants were exposed to a point source of broadband simulated sunlight, which created the appearance of halos/starbursts. Dysphotopsia was measured as the diameter of broadband light-induced halos and starbursts. RESULTS: A case-control analysis. Halo size was significantly larger (t[35.05] = 2.98, p = 0.005) in participants with the clear control lens (M = 3°55' ± 2°48'), compared to the BLF IOL (M = 1°84' ± 1°34'). Starburst size was not significantly different between groups. Contralateral analysis. Halo size was significantly smaller (t = -3.89, p = .001) in test eyes with the BLF (M = 3°16' ± 2°35') compared to the fellow control eyes (M = 5°42' ± 3°17'). Starburst size was also significantly smaller (t = -2.60, p < 0.018) in BLF test eyes (M = 9°57' ± 4°25') than the fellow eye with the clear IOL (M = 12°33' ± 5°25'). CONCLUSIONS: BLF IOL filter short-wave light and mimic retinal screening by the young, natural crystalline lens. Such filtering can reduce some deleterious effects of bright light by decreasing ocular diffusion/halos and starbursts.

A Dietary Strategy for Optimizing the Visual Range of Athletes.

Visual range is quantified by assessing how far one can see clearly (an ability crucial to many athletes). This ability tends to vary significantly across individuals despite similar personal characteristics. We hypothesize that the primary driver of these differences is the individual response to scattered short-wave light in the environment moderated by the dietarily derived retinal pigments lutein and zeaxanthin.

The effect of a short-wave filtering contact lens on color appearance.

We assessed the effect of a contact lens that filters short-wavelength (SW) visible light on color appearance. These effects were modeled and measured by direct comparison to a clear contact lens. Sixty-one subjects were enrolled, and 58 completed as cohort; 31 were 18 to 39 years old (mean ± SD, 29.6 ± 5.6), 27 were 40 to 65 years old (50.1 ± 8.1). A double-masked contralateral design was used; participants randomly wore a SW-filtering contact lens on one eye and a clear control lens on the other eye. Subjects then mixed three primaries (including a short-wave primary, strongly within the absorbance of the test lens) until a perceived perfect neutral white was achieved with each eye. Color appearance was quantified using chromaticity coordinates measured with a spectral radiometer within a custom-built tricolorimeter. Color vision in natural scenes was simulated using hyperspectral images and cone fundamentals based on a standard observer. Overall, the chromaticity coordinates of matches that were set using the SW-filtering contact lens (n = 58; x = 0.345, y = 0.325, u' = 0.222, v' = 0.470) and clear contact lens (n = 58; x = 0.344, y = 0.325, u' = 0.223, v' = 0.471) were not significantly different, regardless of age group. Simulations indicated that, for natural scenes, the SW-filtering contact lens that was evaluated changes L/(L+M) and S/(L+M) chromatic contrast by no more than -1.4% to +1.1% and -36.9% to +5.0%, respectively. Tricolorimetry was used to measure color appearance in subjects wearing a SW-filtering lens in one eye and a clear lens in the other, and the results indicate that imparting a subtle tint to a contact lens, as in the SW-filtering lens that was evaluated, does not alter color appearance for younger or older subjects. A model of color vision predicted little effect of the lens on chromatic contrast for natural scenes.

The influence of the macular carotenoids on women's eye and brain health.

Introduction: The mortality-morbidity paradox refers to the inconsistency in survival and disease between males and females: females live longer but tend to suffer greater age-related disease and disability. Many aspects of the latter can be targeted by lifestyle interventions, such as changes in dietary behavior.Methods: The relevant literature is reviewed.Conclusion: Dietary intake of the pigmented carotenoids appears to be particularly important for issues such as visual and cognitive loss. This may be due to the highly selective presence of a fraction of carotenoids, namely lutein (L) and zeaxanthin (Z), in specific tissues of the eye and brain. At those sites, L and Z have been shown to directly improve function and prevent central nervous system degeneration. On the palliative side, retinal LZ reduce glare disability, discomfort and photostress, improve chromatic contrast and visual range (e.g., the ability to see through blue atmospheric haze). These effects on input reflect changes in neural output such as improved visual processing speed, problem solving, memory and executive function (presumably due, also, to local effects in areas such as the hippocampus and frontal cortex). These effects on function throughout the central nervous system are mirrored by effects on disease progression. As potent antioxidants/anti-inflammatory agents, and "blue-blockers" within the retina, the pigments prevent loss that precedes neurodegenerative diseases such as age-related macular degeneration and some forms of dementia.

Enhancing children's cognitive function and achievement through carotenoid consumption: The Integrated Childhood Ocular Nutrition Study (iCONS) protocol.

Lutein and zeaxanthin (L + Z) are carotenoids that accumulate in neural tissue and potentially confer benefits to cognition. Whereas cross-sectional studies have revealed positive associations between macular carotenoids (MC) and cognition, no studies have investigated whether L + Z supplementation impacts MC and cognition in childhood. Accordingly, the Integrated Childhood Ocular Nutrition Study aims to investigate the impact of L + Z supplementation over 9-months on academic abilities, attentional control, memory, and MC among preadolescent children. Children 8-10 years (N = 288) will enroll in a 9-month double-blind, placebo-controlled, randomized trial. The study is registered and approved as a clinical trial on the U.S. National Library of Medicine http://ClinicalTrials.gov registry (NCT05177679). Participants will be randomized into an active (10 mg lutein+2 mg zeaxanthin) or waitlist placebo-controlled group. Primary outcomes include hippocampal-dependent memory, attentional inhibition, and academic achievement using a spatial reconstruction task, an Eriksen flanker task, and the Kaufman Test of Academic and Educational Achievement 3rd edition, respectively. Secondary outcomes include event-related brain potentials of attentional resource allocation and information processing speed (i.e., P3/P300 amplitude and latency) recorded during the flanker task. Macular pigment optical density (MPOD) will be assessed using heterochromatic flicker photometry. Cognitive assessments will be completed prior to and after completion of the supplementation period. MPOD will be quantified prior to, at the mid-point of (4-5 months), and after (9 months) the supplementation period. It is hypothesized that L + Z supplementation will improve cognition and academic achievement. Further, benefits for cognition and achievement are anticipated to be mediated by increases in MC among treatment group participants.

The Influence of HEV-Filtering Contact Lenses on Behavioral Indices of Glare.

OBJECTIVES: We assessed the effects of a HEV-filtering contact lens on positive dysphotopsia (halos and starbursts) and a behavioral index of scatter measured using two-point light thresholds. These effects were assessed by direct comparison to a clear (i.e., non-HEV filtering) contact lens tested in the fellow eye. METHODS: Sixty-one subjects were randomized and fit with study lenses and 58 subjects completed the study. A double-masked contralateral design was used. Subjects were randomized to test lens-OD, control lens-OS, or vice versa. Participants were exposed to a point source of broadband simulated sunlight (a 403-nm condition was also tested) that created the appearance of halos/starbursts. The degree of dysphotopsia was measured as the diameter of broadband and violet-induced halos, and broadband light-induced starbursts. Two-point thresholds were assessed as the minimum resolvable distance between two pinpoints of light. RESULTS: The HEV-filtering lens was statistically superior ( P <0.0001) to the clear lens in all the conditions tested. The HEV-filtering lens significantly reduced halo diameter by 30%, starburst diameter by 23%, and resolvable distance in the two-point condition by 18% (white) and 30% (violet). CONCLUSIONS: HEV-filtering contact lenses can reduce some deleterious effects of bright broadband light by decreasing light scatter, halos, and starbursts.

Reduction of Glare Discomfort and Photostress Recovery Time Through the Use of a High-Energy Visible-Filtering Contact Lens.

OBJECTIVES: Glare discomfort (GDC) is the slight pain (discomfort) that arises when exposed to light that exceeds one's adaptive state. Such light can also cause a temporary loss in visual function (photostress, PS). We tested the hypothesis that filtering with a high-energy visible (HEV) light-filtering contact lens can reduce GDC and speed PS recovery time. METHODS: Sixty-one subjects were randomized and fit with study lenses and 58 subjects completed as cohort (20-65 years of age). A double-masked, randomized, contralateral design was used (HEV filter on one eye; control lens on the other). Participants were given a 5-s exposure to a broadband white photostressor. Video images were analyzed, and palpebral fissure size during exposure was measured, as was PS recovery time to a 2-degree mid-wave target. RESULTS: The HEV-filtering test lens was statistically superior ( P <0.0001) to the clear comparison contact lens with respect to the magnitude of squint (44.9% squint reduction) and photostress recovery time (24.3% faster recovery). CONCLUSIONS: High-energy visible light-filtering contacts can reduce GDC and speed PS recovery. Filtering HEV light before it is incident upon the retina is a natural strategy (e.g., by the lens and macular pigment) for attenuating some of the deleterious effects of bright broadband light.

Sex Differences Across the Life Course: A Focus On Unique Nutritional and Health Considerations among Women.

In the United States, women, while having a longer life expectancy than men, experience a differential risk for chronic diseases and have unique nutritional needs based on physiological and hormonal changes across the life span. However, much of what is known about health is based on research conducted in men. Additional complexity in assessing nutritional needs within gender include the variations in genetics, body compositions, hormonal milieus, underlying chronic diseases, and medication usage, with this list expanding as we consider these variables across the life course. It is clear women experience nutrient shortfalls during key periods of their lives, which may differentially impact their health. Consequently, as we move into the era of precision nutrition, understanding these sex- and gender-based differences may help optimize recommendations and interventions chosen to support health and weight management. Recently, a scientific conference was convened with content experts to explore these topics from a life-course perspective at biological, physiological, and behavioral levels. This publication summarizes the presentations and discussions from the workshop and provides an overview of important nutrition and related lifestyle considerations across the life course. The landscape of addressing female-specific nutritional needs continues to grow; now more than ever, it is essential to increase our understanding of the physiological differences between men and women, and determine how these physiological considerations may aid in optimizing nutritional strategies to support certain personal goals related to health, quality of life, sleep, and exercise performance among women.

Blue-Light Filtering Intraocular Implants and Darker Irises Reduce the Behavioral Effects of Higher-Order Ocular Aberrations.

PURPOSE: Higher order ocular aberrations (e.g. entopic scatter) arising from cornea and lens, decreases retinal image contrast by dispersing part of the image-forming optics over a broad retinal surface. Selective filtering of the light that is most susceptible to aberration (high-energy "blue" light) may reduce some of the behavioral effects. This was tested by comparing the performance of a blue-light filtering (BLF) vs a clear intraocular lens implant (IOL). METHODS: 52 participants with IOL (BLF: AlconSN60AT; clear: AlconSA60AT; N = 98 test eyes; M = 67.33 ± 7.48 years; 58.8% Female; 25.5% non-White) were recruited. Our outcome measure was based on the minimum resolvable distance between two points of light (two-point thresholds), formed using broadband xenon or isolated short-wave energy (425 nm). Iris color was measured by visual inspection and comparison against standard images. RESULTS: In the broadband condition, patients with BLF IOL had smaller two-point thresholds (M = 17.17 ± 5.71 mm; F[1,48] = 2.60; p = 0.045) than clear controls (M = 20.93 ± 10.22 mm). Similar improvements were found in the short-wave condition (MBLF=17.02 ± 5.30; Mclear=21.42 ± 10.99; p = 0.04). In the contralateral broadband comparison, eyes with the BLF had significantly smaller two-point thresholds (M = 18.10 ± 10.47 mm; t = -2.90, p < 0.001) than the clear IOL (M = 20.89 ± 10.61 mm). Similar effects were seen in the short-wave condition (MBLF=18.23 ± 9.88; Mclear = 21.06 ± 10.47; p = 0.001). Darker iris color was related to reduced scatter across IOL types, in both shortwave (F[2,48] = 4.62, p = 0.02) and broadband (F[2,48] = 5.27, p = 0.009) conditions. CONCLUSIONS: Anterior screening, be it by a darker iris or a BLF IOL, is directly related to decreases in two-point light thresholds.

The Effects of a Blue-Light Filtering Versus Clear Intraocular Implant on Color Appearance.

Purpose: More than a dozen studies have investigated whether blue-light filtering (BLF) intraocular lens (IOL) implants influence color vision, generally finding they do not. These studies have not tested color vision per se; rather, they have measured color vision deficiencies or chromatic discrimination. Here, we used additive trichromatic colorimetry to assess color appearance in participants with BLF and clear IOL. Methods: Seventy-six participants were recruited from two populations: older participants (n = 52) with BLF and clear IOL (n = 98 eyes; M = 67.33 ± 7.48 years; 58.8% female; 25.5% non-White), and young adult control participants (n = 24; M = 21.0 ± 5.13 years; 70.8% female; 41.5% non-White). Participants used a custom-built tricolorimeter to mix three primaries until a perceived perfect neutral white was achieved. Color appearance, expressed as chromaticity coordinates, was measured with a spectral radiometer (ILS950). Results: Between subjects, the BLF IOL chromaticity coordinates (x = 0.34, y = 0.35, u' = 0.21, v' = 0.48) were not significantly different from the clear IOL (x = 0.34, y = 0.33, u' = 0.22, v' = 0.48). BLF and clear IOL were also not different within-contralateral subjects (n = 21; BLF x = 0.34, y = 0.33, u' = 0.22, v' = 0.47; clear x = 0.34, y = 0.33, u' = 0.21, v' = 0.48). Both IOL groups differed from young adults (v'[0.45; P = 0.001], x[0.31; P = 0.008], and y[ 0.30, P < 0.000], but not u'[0.21]). Conclusions: One advantage of geometric representation of color space is the ability to specify the appearance (rather than spectral composition) of any light mixture by specific coordinates. Using this system, only minor differences in color appearance were found between a BLF, clear IOL, and young natural lens. Translational Relevance: When color perception is directly measured, the BLF and clear IOL are not meaningfully different.

Single Nucleotide Polymorphisms in CD36 Are Associated with Macular Pigment among Children.

BACKGROUND: High macular pigment optical density (MPOD) has been associated with improved eye health and better cognitive functions. Genetic variations have been associated with MPOD in adults. However, these associations between genetic variations and MPOD have not been studied in children. OBJECTIVES: This was a secondary analysis of the FK2 (Fitness Improves Thinking in Kids 2) trial (n = 134, 41% male). The aim was to determine differences in MPOD among children (aged 7-9 y) based on genetic variants that either are biologically relevant to lutein (L) and zeaxanthin (Z) accumulation or have been associated with MPOD in adults. METHODS: MPOD was measured using customized heterochromatic flicker photometry via a macular densitometer. DXA was used to assess whole-body and visceral adiposity. DNA was extracted from saliva samples and was genotyped for 26 hypothesis-driven single nucleotide polymorphisms and 75 ancestry-informative markers (AIMs). Habitual diet history was obtained via 3-d food logs completed by parents (n = 88). General linear models were used to compare MPOD between different genotypes. Principal component analysis was performed for the AIMs to account for ethnic heterogeneity. RESULTS: Children carrying ≥1 minor allele on ß-carotene-15,15'-monooxygenase (BCO1)-rs7501331 (T allele) (P = 0.045), cluster of differentiation 36(CD36)-rs1527483 (T allele) (P = 0.038), or CD36-rs3173798 (C allele) (P = 0.001) had significantly lower MPOD (range: 14.1%-26.4%) than those who were homozygotes for the major alleles. MPOD differences based on CD36-rs3173798 genotypes persisted after adjustment for dietary L and Z intake. CONCLUSIONS: The findings indicate that genetic variations of CD36 and BCO1 contribute to MPOD in children. The influence of genetic variation in CD36-rs3173798 persisted after adjusting for variation in dietary intake.This trial was registered at clinicaltrials.gov as NCT01619826.

The Effects of a Senofilcon A Contact Lens With and Without a Photochromic Additive on Positive Dysphotopsia Across Age.

OBJECTIVE: The visual effects of wearing a photochromic contact lens (test) were directly compared with a nonphotochromic contact lens (control). Positive dysphotopsia (halos, starbursts) and intraocular scatter (behaviorally determined) were assessed. Both younger and middle-aged subjects were evaluated to examine the influence of age. METHODS: Fifty-four subjects (18-62 years) were tested using a contralateral design. Subjects were fit with a photochromic contact lens on one eye and a nonphotochromic contact lens on the other eye, randomly assigned. Testing occurred with and without photochromic activation (darkened) by use of a violet activator (365 nm, half-bandwidth 20 nm). The extent of dysphotopsia (halos and spokes) was measured using an aperture (∼4 mm) that created a bright point source of light 45 inches from the plane of the eye. Between the point source and subject, a centering precision caliper was used to measure lateral spread. Two-point thresholds were determined by measuring the minimum distance between two points of broadband xenon light. RESULTS: The photochromic contact lens produced smaller halo diameters than the control contact lens, both activated (41% on average) and inactivated (21% on average), and age strata was a significant factor (P<0.001) with the older group showing a greater reduction. The photochromic contact lens produced smaller starburst diameters than the control contact lens, both activated (37% on average) and inactivated (23% on average), and age strata was a significant factor (P=0.001) with the older group showing a greater reduction. The two-point thresholds were reduced (25% activated, 9% inactivated) on average but the age effect was not significant (P<0.10). CONCLUSIONS: The senofilcon A lens with photochromic additive reduced the extent of positive dysphotopsia compared with the same lens without the additive, regardless whether the lens was activated or not. The visual benefit was greatest with the older subjects.

Measuring the Behavioral Effects of Intraocular Scatter.

Intraocular scatter, with its associated functional manifestations, is a leading cause of automotive accidents and a significant biomarker of covert and overt ocular disease (e.g., diseases of the cornea and lens). Nearly all current methods of measuring the behavioral consequences of light scatter, however, suffer from various limitations mostly reflecting a lack of construct and content validity: to wit, the measures do not adequately reflect real world conditions (e.g., artificial light vs. sunlight) or everyday tasks (e.g., recognition under visually demanding conditions). This protocol describes two novel, ecologically valid methods of measuring the behavioral effects of intraocular scatter by quantifying scatter geometry and visual recognition under glare conditions. The former was measured by assessing the diameter of halos and spokes that resulted from a bright point source. Light spread (essentially, the point spread function determined using Rayleigh criteria) was quantified by determining the minimum perceivable distance between two small points of broad-band light. The latter was done based on the identification of letters formed using apertures through which bright light was shone.

Temporal vision is related to cognitive function in preadolescent children.

The relation between visual processing speed (critical flicker fusion thresholds [CFF] and psychomotor reaction time) and higher-level cognitive function was assessed using a cross-sectional sample (n = 51) of 7 to 13-year-old preadolescent children. Data on visual processing speed (CFF and psychomotor reaction time) and cognitive function (Woodcock-Johnson III Tests of Cognitive Abilities) were collected. Woodcock-Johnson III composite standard scores (brief intellectual ability [BIA], cognitive efficiency, processing speed, and executive processes) were calculated to control for age in the cognitive variables. CFF was related to cognitive efficiency, r(46) = 0.26, p = 0.036, and executive processes, r(44) = 0.25, p = 0.05, and showed a trend toward relating to processing speed, r(46) = 0.19, p = 0.09. Both psychomotor reaction time measures (fixed and variable) were related to executive processes and global intelligence (BIA) such that higher cognitive scores were associated with shorter reaction times, rs ranged from -0.25 to -0.29, ps < 0.05. In addition, fixed reaction time was related to cognitive efficiency, r(47) = -0.26, p < 0.05. The small nature of many of these relations suggests that visual processing speed is only one of many possible influences on the higher cognitive function of children.

The effects of light scatter when using a photochromic vs. non-photochromic contact lens / Efectos de la dispersión luminosas al utilizar lentes de contacto fotocromáticas vs. no fotocromáticas

PURPOSE: To assess the visual effects of wearing both an activated and an inactivated photochromic contact lens, with a direct comparison to a non-photochromic contact lens worn in the fellow eye. This study focused on the visual effects of scatter quantified as the minimum distance between two points of light, and the diameter of the halo and starbursts that surround a bright white point source. METHODS: 60 subjects (aged 18-65 years) were measured in a contralateral design where lens type was randomly assigned, one type to each eye. During activated testing, all visual measures of both study lenses were made while each eye was illuminated by a violet (Lambdamax = 365, half bandwidth 20 nm) activator, which caused steady-state activation of the photochromic lens during the period of testing. Two-point thresholds were determined by measuring the minimum distance between two points of broadband xenon light. Glare geometry was measured using an aperture (∼ 4 mm) that created a bright point source of light 45 inches from the plane of the eye. Between the point source and subject, a centering precision caliper was used to measure lateral spread of halos (diffusion around the source) and visual spokes. The head was stabilized using an adjustable head-rest assembly and the eye was aligned and monitored with a bore camera. RESULTS: Compared to the non-photochromic lens, and based on the stimulus conditions used in these measurements, the activated and inactivated photochromic lens reduced the light spread using the two-point threshold technique by 32% and 19% respectively; the diameter of the halos were reduced by 44% and 16% respectively; and the spokes were narrowed by 39% and 20% respectively. Based on 95% confidence interval testing, these effects were all statistically significant (p < 0.05). CONCLUSIONS: These results are consistent with previous data showing that soft contact lenses with a photochromic additive can improve many aspects of visual function, consistent with their level or activation. Our past data focused on visual function under bright light conditions (e.g., glare disability, discomfort, photostress recovery and chromatic contrast) with an activated photochromic. In this study, we found differences even in the inactivated state, using less intense stimuli (10cd/m2 at the source). This suggests that the photochromic lens improves the effects of light scatter even at lower luminance

OBJETIVO: Evaluar los efectos visuales del uso de lentes de contacto con activación e inactivación fotocromática, mediante comparación directa con el uso de lentes de contacto no fotocromáticas en el ojo contralateral. Este estudio se centró en los efectos visuales de la dispersión, cuantificada mediante la distancia mínima entre dos puntos luminosos, y el diámetro del halo y los destellos que rodean a una fuente fija blanca brillante. MÉTODOS: Se realizaron mediciones a 60 sujetos (de edades comprendidas entre 18 y 65 años) en un diseño contralateral en el que se asignó aleatoriamente un tipo a cada ojo. Durante la prueba con activación, se realizaron todas las medidas visuales de ambas lentes en estudio, mientras se iluminaba cada ojo con un activador violeta (lambdamáx.=365, ancho de banda medio 20 nm), que causó una activación del estado de equilibrio de las lentes fotocromáticas durante el periodo de prueba. Se determinaron los umbrales de dos puntos, midiendo la distancia mínima entre dos puntos de luz de xenón de banda ancha. Se midió la geometría del reflejo utilizando una apertura (∼ 4 mm) que creó una fuente fija brillante de luz a 45 pulgadas del plano del ojo. Entre la fuente fija y el sujeto se utilizó un calibrador de precisión de centrado para medir la expansión lateral de los halos (difusión alrededor de la fuente) y los destellos. La cabeza se estabilizó utilizando un reposacabezas, alineándose y supervisándose el ojo con una cámara. RESULTADOS: Realizando una comparación con las lentes no fotocromáticas, y sobre la base de las condiciones de estímulo utilizadas en estas medidas, las lentes con activación y desactivación fotocromática redujeron la expansión de la luz utilizando la técnica del umbral de dos puntos en un 32% y un 19% respectivamente; el diámetro de los halos se redujo en un 44% y 16% respectivamente; y los brillos se estrecharon en un 39% y 20% respectivamente. Basándonos en la prueba del intervalo de confianza del 95%, todos estos efectos fueron estadísticamente significativos (p < 0,05). CONCLUSIONES: Estos resultados son consistentes con los datos previos, que reflejan que las lentes de contacto fotocromáticas pueden mejorar muchos aspectos de la función visual, en consistencia con su nivel de activación. Nuestros datos anteriores se centraron en la función visual en condiciones de luz brillante (ej.: incapacidad por deslumbramiento, incomodidad, recuperación de foto-estrés y contraste cromático) con activación de adición fotocromática. En este estudio, encontramos diferencias incluso en el estado de inactivación, utilizando estímulos menos intensos (10 cd/m2 en la fuente), lo cual sugiere que las lentes fotocromáticas mejoran los efectos de la dispersión luminosa incluso con una luminancia menor