"Analysis of Macular Pigment Optical Density in Childhood: A Systematic Review".

PURPOSE: This systematic review studies the relationship between Macular Pigment Optical Density (MPOD) values and cognitive and visual function in childhood. METHODS: It included cross-sectional, observational studies or controlled clinical trials in humans between 0 and 18 years of age, analyzing MPOD values in 3 main databases: PubMed, Scopus and Web of Science. The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. RESULTS: Thirteen studies were included in this systematic review. The relationship of cognitive function, visual function and diverse variables with MPOD was analyzed in 4, 4 and 5 studies, respectively. The age of the participants ranged between premature infants to 12 years. Most of the studies used Heterochromatic Flicker Photometry (HFP) with macular densitometer to obtain MPOD values. MPOD values ranged between 0 (undetectable) to 0.66 ± 0.03 d.u. Only 4 articles studied the relationship between MPOD values and dietary intake of lutein and zeaxanthin using questionnaires about diet. CONCLUSIONS: Lutein and zeaxanthin accumulation plays an important role during the maturational stage and childhood development. Although cognitive function is more strongly correlated with MPOD values, the relationship with visual function remains unclear, and further studies are required to support this relationship.

A Corneal Biomechanical Study Measured with a Scheimpflug Dynamic Analyser in Soft Contact Lens Wearers.

The aim of this study was to evaluate the biomechanical changes in the cornea after wearing soft contact lenses (CLs) in healthy myopic patients measured with a Corvis ST® (CST, Oculus Optikgeräte GmbH, Wetzlar, Germany) analyser. This prospective, cross-sectional, single-centre study was performed on twenty-two Caucasian patients aged between 19 and 24 years (20.64 ± 1.21 years) range. Five device-specific biomechanical parameters, the central corneal thickness (CCT), and biomechanically corrected intraocular pressure (bIOP) were measured prior to fitting and one month after CL wear. Differences between the means of the deflection amplitude ratio (DA Ratio) and the standard deviation of the DA Ratio (SD DA Ratio) pre- and post-CL wear were found to be significant (p value = 0.002 in both cases). Significant differences were found between pre- and post-CL wear values in CCT (p value = 0.013). For all other biomechanical measures, no significant differences were observed before and after treatment. A significant association was found between changes in bIOP and classification according to changes in Int. Radius (p value = 0.047) and SSI (p value = 0.026) standard deviations. The corneal biomechanical indices provided by CST demonstrate that the fitting of soft CLs is a safe optical compensation method for the stability of corneal stiffness. No significant differences were found pre- and post-CL wear in the assessment of bIOP.

Tear Film Stabilization and Symptom Improvement in Dry Eye Disease: The Role of Hyaluronic Acid and Trehalose Eyedrops versus Carmellose Sodium.

This study evaluated the effectiveness of hyaluronic acid and trehalose (HA/trehalose) eyedrops in managing dry eye disease (DED) symptoms by measuring tear stability and administering a DED questionnaire. Sixty patients were treated with either HA/trehalose eyedrops (Tear A) or carmellose sodium eyedrops (Tear B) as controls. The tear breakup time (TBUT) and non-invasive breakup time (NIBUT) were monitored, and patients completed the standard patient evaluation of eye dryness (SPEED) questionnaire. After two months of twice-daily applications, patients treated with the HA/trehalose eyedrops demonstrated significant improvements in the NIBUT (12.98 ± 3.22 s) and TBUT (12.95 ± 2.98 s), indicating increased tear stability. Moreover, they reported lower dry eye sensation (6.70 ± 4.94 SPEED score points), suggesting a reduction in DED symptoms. These findings underscore the efficacy of HA/trehalose eyedrops in improving both the objective and subjective signs of DED, with twice-daily application enhancing ocular surface conditions and reducing patient-reported symptoms.

Contrast sensitivity function under three light conditions in patients with type 1 diabetes mellitus without retinopathy: a cross-sectional, case-control study.

PURPOSE: To determine whether patients with type 1 diabetes mellitus (T1DM), without any sign of diabetic retinopathy, have any alteration in Contrast Sensitivity Function (CSF), in relation to patients without this disease, and whether CSF assessment in three different light conditions can be an effective test in the early detection of diabetic retinopathy. METHODS: A prospective, cross-sectional, case-control study was preformed including 80 patients (40 with T1DM without diabetic retinopathy and 40 controls) between 11 and 47 years old. CSF was assessed at four spatial frequencies (3, 6, 12 and 18 cycles/degree) using the CSV-1000E test, under three light conditions: high (550 lx), medium (200 lx) and low (< 2 lx). RESULTS: A lower CSF in the T1DM group was found at the three light conditions studied. The most spatial frequency affected was 18 cpd, 0.08 log units (p = 0.048) in high, 0.10 log units (p = 0.010) in medium (p = 0.010) and 0.16 log units (p < 0.001) in low-light conditions in mean CS values. The least spatial frequency affected was 3 cpd (p > 0.05 in all three light conditions). CONCLUSION: Patients with T1DM, without diabetic retinopathy, presented a loss of CS to sine-wave gratings, with respect to people with the same characteristics without the disease, mainly at medium and high frequencies, and in medium and low-light conditions.

Contrast Sensitivity Assessment in Early Diagnosis of Diabetic Retinopathy: A Systematic Review.

INTRODUCTION: The purpose of this systematic review was to study whether contrast sensitivity assessment in people with diabetes could be a reliable test in early detection of diabetic retinopathy. A systematic search based on population, intervention, comparison, and outcome strategy was performed. METHODS: PubMed, Scopus, and Web of Science were searched for English articles of human patients with type 1 and type 2 diabetes and contrast sensitivity measurements as domain studied. RESULTS: Twentyone comparative cross-sectional studies were included. All of them showed significant loss of contrast sensitivity in people with diabetes and diabetic retinopathy regarding control patients of the same age, regardless of the method used. However, those without diabetic retinopathy, involve a loss of contrast sensitivity, although not always significant. CONCLUSION: Changes in contrast sensitivity suggest that there is damage to the retina prior to the vascular ones and that they could be detected by this test.

Dry eye disease and tear film assessment through a novel non-invasive ocular surface analyzer: The OSA protocol.

We describe the role of OSA as a new instrument in the study of dry eye, and we recommend a protocol for conducting the tests as well as describe the advantages and disadvantages compared with other instruments. A comparison with other ocular surface devices (Tearscope Plus, Keratograph 5M, anterior-segment ocular coherence tomography, Easy Tear View-Plus, LipiView, IDRA, and LacryDiag) were presented due to manual or automatic procedure and objective or subjective measurements. The purpose of this study was to describe the OSA as new non-invasive dry eye disease diagnostic device. The OSA is a device that can provide accurate, non-invasive and easy-to-use parameters to specifically interpret distinct functions of the tear film. This OSA protocol proposed a lesser to higher non-invasive ocular surface dry eye disease tear film diagnostic methodology. A complete and exhaustive OSA and OSA Plus examination protocol was presented within the subjective questionnaire (Dry Eye Questionnaire 5, DEQ5), limbal and bulbar redness classification (within the Efron grade Scale, interferometry lipid layer thickness (LLT) (according to Guillon pattern), tear meniscus height (manually or automatic), first and mean non-invasive break up time (objective and automatic) and meibomian gland (MG) dysfunction grade and percentage (objective and automatic). The OSA and OSA Plus devices are novel and relevant dry eye disease diagnostic tools; however, the automatization and objectivity of the measurements can be increased in future software or device updates. The new non-invasive devices supposed represent a renewal in the dry eye disease diagnosis and introduce a tendency to replace the classic invasive techniques that supposed less reliability and reproducibility.

Effect of macular pigment carotenoids on cognitive functions: A systematic review.

Lutein and zeaxanthin-xanthophyll carotenoids with antioxidant and anti-inflammatory characteristics-are present in the retina and the brain. High concentrations of these carotenoids have been positively related to cognitive performance. Therefore, this systematic review analyses the relationship between macular pigment density and cognitive functions. Most relevant databases were scoured for studies on healthy people relating cognitive functions to macular pigment optical density (MPOD). There were no age, sex, or race limitations. PROSPERO registration: CRD42021254833. Nineteen studies were included, seven randomized controlled trials (RCT) and eleven observational studies. The general aim of the studies was to examine the association between carotenoids (lutein, meso­zeaxanthin and zeaxanthin) and cognitive function. Most observational studies correlates MPOD levels with cognitive function or brain activity. Besides, RCTs compared the cognitive function and/or brain activity after increasing lutein and zeaxanthin intake though dietary supplementation or avocado consumption. Dietary lutein and zeaxanthin intake increased MPOD in six of the seven clinical trials and significantly improved most of the cognitive functions studied. A wide variety of test and methodologies for measuring cognitive functions were observed. Memory, processing speed, attention and reasoning were the cognitive function significantly related to MPOD levels in adults. Brain activity also was related to MPOD, but the results were inconsistent. Only four of the eleven observational studies were based on young people and all studies showed a significant relationship between MPOD and cognitive functions. This systematic review showed a direct relationship among cognitive functions, macular pigment and the intake of lutein and zeaxanthin.

Efficacy of hyaluronic acid 0.3%, cyanocobalamin, electrolytes, and P-Plus in menopause patients with moderate dry eye disease.

PURPOSE: To study the treatment efficacy of hyaluronic acid 0.3%, cyanocobalamin (vitamin B12), electrolytes, and P-Plus in menopausal patients with moderate dry eye disease. METHODS: Thirty female patients of mean age 53.06 ± 5.20 years (45-65) were enrolled in this prospective longitudinal study. Meibomian gland loss assessment was determined using a scale with four levels. The Ocular Surface Disease Index (OSDI) questionnaire, phenol red thread (PRT) test, and tear film break-up time (TFBUT) were also completed by the patients. Tear eye drops were formulated with 0.3 g of sodium hyaluronate, P-Plus ™, vitamin B12, sodium chloride, potassium chloride, calcium chloride, magnesium chloride, and SCO® (stabilized complex oxychloride). After 30 days, the patients were re-evaluated. RESULTS: The mean meibomian gland loss percentage was 37.97 ± 19.02 % (7.20 to 88.30%). Before treatment, the OSDI was 22.53 ± 14.03 score points (6.25 to 77.08). Posterior OSDI decreased to 16.26 ± 13.69 score points (0.00 to 70.83) (W = 58.00, P < 0.01). Before treatment, PRT was 10.31 ± 4.48 mm (4.00 to 21.00). Posterior PRT increased to 15.41 ± 6.27 mm (4.00 to 21.00) (W = 1520.50, P < 0.01). Before treatment, TFBUT was 6.23 ± 1.75 s (3.00 to 9.00). The posterior TFBUT increased to 8.10 ± 2.06 s (4.00 to 14.00) (W= 1382.50, P < 0.01). CONCLUSION: The hyaluronic acid 0.3% and vitamin B12 eye drops effectively decreased dry eye symptoms in menopausal women and improved tear stability and volume.

Effect of Blue Light Filters on Tear and Contrast Sensitivity in Individuals Using Electronic Devices.

OBJECTIVES: To investigate the effect of contact lenses with blue light filters on contrast sensitivity and any alteration in tear quantity and quality. METHODS: This prospective longitudinal pilot study required three visits by each participant. Monocular visual acuity, contrast sensitivity, phenol red thread test, and tear breakup time were measured at each visit. RESULTS: There were significant differences in logarithmic contrast sensitivity between the groups. The breakup time (BUT) was significantly lower after using video display terminals than before (P<0.05). No differences in BUT were found between groups video display terminals and contact lenses having the blue filter (P>0.05). However, higher mean values were observed in the group after video display terminal use with contact lenses having the blue filter than that with standard contact lenses (P>0.05 in both groups). Furthermore, the mean value of phenol red thread test on the group after video display terminal use with contact lenses having the blue filter was lower than the group before its use (P>0.05). CONCLUSION: The results establish a possible relationship between tear stability, improved contrast sensitivity, and the use of a blue filter in contact lenses.