Could driving help us to "see better"? A comparative assessment of saccadic efficiency, visual speed, and attention.

BACKGROUND: This study aimed at comparing drivers' and non-drivers' results in the Adult Developmental Eye Movement with Distractors test (ADEMd) and the Useful Field of View test (UFOV). METHODS: One hundred and twenty Spaniards (mean age 50.90 ± 17.32 years) without eye disease voluntarily participated in this cross-sectional descriptive study. Participants in a single experimental session completed a questionnaire on sociodemographic, health, eyesight, and driving information. They also performed the ADEMd and UFOV tests randomly following standardized protocols. The ADEMd is a visual-verbal test that measures saccadic efficiency and visual attention. Brown-Forsythe (B-F) tests with Games-Howell post-hoc adjustments were conducted to assess differences between groups. Groups were formed according to sex, age (young adults, adults, and older adults), and driver/non-driver for further analysis. Additionally, associations between dependent variables were assessed through Spearman's correlations. RESULTS: Drivers obtained significantly better results in the ADEMd compared with non-drivers. Non-significant differences between drivers and non-drivers were encountered in the UFOV. Additionally, significant differences were observed between sexes and age groups. It is worth highlighting that non-driver's age significantly correlated with worse ADEMd performance (rho = .637 to .716). This correlation was non-significant in drivers. Similarly, reading hours significantly correlated with better ADEMd performance in non-drivers (rho = - .291 to - .363), but not in drivers. The only significant correlations between ADEMd and UFOV tests were found in drivers (rho = .307 to .410). CONCLUSION: Considering all the discussed results, it could be hypothesized that the driving task promotes abilities, such as oculomotor and cognitive function, which are relevant for the performance in the ADEMd. However, this hypothesis is based on correlational outcomes and further studies should causally assess this possible relation.

Validation of a method to assess night myopia in a clinical setting.

A study was conducted with 115 subjects who regularly drove at night to validate a refraction protocol for detecting refractive visual changes from daytime to nighttime conditions. Objective and subjective refractions were performed in both photopic and mesopic conditions, with a dark adaptation period before the mesopic subjective refraction. The results showed that in mesopic conditions, visual acuity decreased by 0.2 logMAR units on average (p < 0.01), and there was a myopic refractive shift of - 0.36 ± 0.20 D (p < 0.01). Most subjects (92.2%) exhibited a myopic refractive shift of at least 0.12 D. Compensation of refractive shift improved mesopic visual acuity by 0.06 logMAR on average (p < 0.01) and higher refractive shifts showed higher improvement. Night Rx was preferred by 82.1% of subjects with myopic refractive shift. Gender and age did not significantly affect the refractive shift, although myopes showed a higher shift compared to emmetropes (p < 0.01). The refractive shift remained stable over time when the time slot of the day did not change (p < 0.01). Night Rx protocol proved to be a robust and accurate method for identifying drivers with refractive changes when transitioning from photopic to mesopic conditions. The high prevalence and inter-individual variability of Rx shift highlight the need of customized refraction.

Risk Factors for Myopia: A Review.

Due to the myopia prevalence increase worldwide, this study aims to establish the most relevant risk factors associated with its development and progression. A review search was carried out using PubMed, Web of Science, and Scopus databases to identify the main myopia risk factors. The inclusion criteria for the articles were those related to the topic, carried out in subjects from 5 to 30 years, published between January 2000 and May 2023, in English, and with the full text available. Myopia etiology has proven to be associated with both genetic and environmental factors as well as with gene-environment interaction. The risk of developing myopia increases in children with myopic parents (one parent ×2 times, two parents ×5 times). Regarding environmental factors, education is the main risk factor correlated with myopia prevalence increase. Further, several studies found that shorter distance (<30 cm) and longer time spent (>30 min) for near work increase the risk of myopia. Meanwhile, increased outdoor activity (>40 min/day) has been shown to be a key factor in reducing myopia incidence. In conclusion, the interventional strategy suggested so far to reduce myopia incidence is an increase in time outdoors and a reduction in the time spent performing near-work tasks.

Effects of squatting with elastic bands or conventional resistance-training equipment at different effort levels in post-exercise intraocular pressure of healthy men.

This study aimed to compare intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and central corneal thickness (CCT) acute adaptations to squat exercise using elastic bands (EB) or weight plates (WP) together with the weight of the bar and applying maximal or submaximal efforts. Cardiovascular parameters (pulse pressure, mean blood pressure, heart rate), rate of perceived exertion, kilograms, and number of repetitions served to monitor psychophysiological acute variations. Twenty physically active males (25.55 ± 4.75 y.o.) underwent two sessions (one for familiarization and one for the experimental trial). In the experimental session, ocular and cardiovascular pre-exercise measurements were taken. Then, two sets using WP and two using EB attached to the bar with the same load were performed by each subject in random order. Immediately after finishing each set, the subjects rated perceived exertion, and cardiovascular and ocular measurements were taken, in this order. An ANOVA with post-hoc LSD evaluated differences between sets. IOP significantly decreased (p < 0.001, ƞp2 = 0.513), and MOPP (p < 0.001, ƞp2 = 0.413) and cardiovascular variables significantly increased due to the exercise effect; CCT changes were non-significant. No significant effect of the material, level of effort, or their interaction was observed in the IOP and MOPP (p > 0.05). EB permitted more repetitions to be performed and led to non-significantly lower post-exercise IOP values (effect size [d] compared to resting 0.79 and 1.00) in comparison to WP (d = 0.73-0.74). IOP and ocular and systemic hemodynamic responses are similar when using EB instead of WP to load the bar, with EB allowing a larger number of repetitions. Data presented in this paper may help with the prescription of resistance training for people with glaucoma risk factors.

Do Age and Sex Play a Role in the Intraocular Pressure Changes after Acrobatic Gymnastics?

To evaluate the effects of an acrobatic gymnastics (AG) training session on intraocular pressure (IOP), a familiarization session was employed to confirm the participant's suitability for the study. Forty-nine gymnasts (63.27% females, 18-40 years old) voluntarily agreed to participate. As age, sex, baseline IOP, and central corneal thickness (CCT) were considered as potential predictors of the IOP variations, in the second session measurements of the above parameters were taken before and after 90 min of AG. A mixed-factorial analysis of variance evaluated differences. Linear regression was conducted to potentially predict the IOP variation with the exercise. After the scheduled exercise, highly significant (p < 0.001, effect size: 0.73) reductions in IOP, but no significant changes in CCT (p = 0.229), were observed. IOP was significantly modified in males, older than 25 years, and subjects with baseline IOP > 14 mmHg (p ≤ 0.001, effect sizes: 0.57-1.02). In contrast, the IOP of females, younger participants, and subjects with baseline IOP ≤ 14 mmHg was not significantly modified (p = 0.114). With the regression analyses, we concluded that both sex and baseline IOP levels were significant predictors of the IOP fluctuation with AG. These findings could be of interest for gymnasts, coaches, ophthalmologists, and/or optometrists in the prevention and control of risk factors associated with glaucoma.

Validation of a modified version of the adult developmental eye movement test.

This study evaluates in terms of reliability, internal consistency, and validity a modification of the Adult Developmental Eye Movement (ADEM) test, ADEM with distractors (ADEMd), designed to analyse oculomotor system, visual processing and visual attentional behaviour. 302 healthy subjects participated in the study (20-86 years old). Intrasession repeatability was evaluated by analysing the correlation between the time needed to read different parts of the test. Inter-session analyses were carried in 40 subjects by calculating intraclass correlation coefficients and using the Bland-Altman method. Validity was assessed in the outcomes obtained according to age as well as investigating the correlation between ADEMd and attentional useful field of vision (UFOV) test. Correlation coefficients between times need to read each sheet were ≥ 0.95 (p < 0.001). The inter-session intraclass correlation coefficient ranged from 0.81 in the horizontal distractor sheet to 0.97 in the vertical sheet. Bland-Altman analysis showed clinically acceptable limits of agreement. Statistically significant correlations were found between age and ADEMd outcomes (r ≥ 0.55, p < 0.001). Processing velocity, divided attention and selective attention measured with the UFOV were correlated with the horizontal distractor times (r ≥ 0.32, p < 0.001). ADEMd test may be a useful clinical tool to evaluate the combined interaction of ocular movements and visual attentional behaviour.

Comparing oculomotor efficiency and visual attention between drivers and non-drivers through the Adult Developmental Eye Movement (ADEM) test: A visual-verbal test.

OBJECTIVE: The objective of this study was to assess and compare drivers' and non-drivers' outcomes in the Adult Developmental Eye Movement test (ADEM), a visual-verbal test that measures the time needed to read series of numbers in both a vertical and horizontal reading pattern. A set of driving parameters (i.e., experience, risk exposure, and day and night perceived difficulty) and demographic variables (i.e., age, gender, and academic level) were considered as potential predictors of the test performance. METHODS: For this cross-sectional study, 302 healthy subjects (age range 20 to 86 years old) completed a self-reported questionnaire aimed at retrieving data on the independent variables, and underwent the ADEM in order to obtain the dependent outcomes. 214 (70.9%) of the participants were drivers. Non-parametric analyses and multilevel linear regression were used to assess differences between the variables and a prediction model. Also, some correlations were evaluated through the Spearman test. RESULTS: Drivers showed significantly better test performance than non-drivers. The age, driving experience, and perceived difficulty in driving at night were obtained as potential predictors of the test performance with the applied linear regression model. CONCLUSION: The ADEM may be a practical, non-expensive, easy-to-apply tool in the assessment of drivers, useful for obtaining or renewing the driving license. This test may help in the detection of impairments in the saccadic efficiency that could have a detrimental effect on the driving performance.

Adding the Load Just Above Sticking Point Using Elastic Bands Optimizes Squat Performance, Perceived Effort Rate, and Cardiovascular Responses.

Modifying basal elongation of elastic bands (EB) has been proven useful to increase some parameters of the intensity in variable resistance training. Therefore, the question arises as to whether the pertinent resistance could be applied with EB immediately above the sticking point in squat exercises to optimize the performance. The purpose was to analyze some variables of the external (kilograms and number of repetitions) and internal load (heart rate, blood pressure, and rate of perceived exertion) after six different conditions of the squat exercise when using weight plates (WP) or EB (placed at different points of the range of motion) and applying maximal or submaximal effort. Twenty physically active males (25.50 ± 5.26 yrs) underwent two sessions for familiarization and one for assessment. The six conditions (three with WP and three with EB) were randomly performed. The sticking point of each subject was measured using the knee joint angle and the resistance was applied with EB at this height. Immediately after finishing each set subjects reported perceived effort rate and cardiovascular measurements were taken. Repetitions completed, and kilograms used were recorded. Repeated measures testing evaluated differences between conditions. EB permitted performing 8 more repetitions compared to WP when the same load was added at standing position. Adding the load immediately above the sticking point significantly (p < 0.05) increased 24.7% the kilograms used and permitted participants to perform 3 more repetitions. Internal load measurements suggested that EB could significantly (p < 0.05) reduce the perceived effort rate and/or physiological stress depending on their application. EB are a suitable device to load the bar for squat exercises in fit young men. According to the necessities of the subjects, if the load with EB is added at different points of the range of motion, it could be possible to overcome the sticking point, to maximize the performance and/or modulate cardiovascular and perceptual responses.

Characterization of the effect of intracorneal ring segment in corneal ectasia after laser refractive surgery.

PURPOSE: To evaluate the visual, refractive, topographic, pachymetric, and biomechanical outcomes after intracorneal ring segment implantation in corneas with post-LASIK ectasia. METHODS: Retrospective longitudinal study enrolling 26 eyes of 22 patients with post-LASIK ectasia and undergoing intracorneal ring segment implantation (KeraRing®, Mediphacos) using a 60-kHz femtosecond laser (IntraLase®, IntraLase Corp.) for corneal tunnelization. Visual, refractive, anterior, and posterior corneal topographic (Pentacam HR, Oculus), pachymetric, and corneal biomechanical changes (Ocular response Analyzer, Reichert) were evaluated during a 12-month follow-up. Vector analysis of astigmatic changes was performed. RESULTS: A statistically significant reduction of sphere (p = 0.043) was observed at 1 month after surgery, with a significant improvement of uncorrected distance visual acuity associated (p = 0.019). Likewise, a significant reduction of anterior corneal power measurements (p ⩽ 0.014) and steepest posterior keratometric reading (p = 0.006) were observed at 1 month postoperatively, with no significant changes afterwards (p ⩾ 0.133). No significant changes were observed in manifest cylinder (p ⩾ 0.175), corrected distance visual acuity (p ⩾ 0.174), flattest posterior keratometric measurement (p ⩾ 0.282), volumetric measurements (p ⩾ 0.051), and corneal biomechanical parameters (p ⩾ 0.068). Vector analysis revealed an initial trend to overcorrection of astigmatism, with a trend to undercorrection at the end of follow-up and a significant variability in the outcome achieved in each patient. CONCLUSION: The implantation of KeraRing segments in post-LASIK corneal ectasia generates a significant modification of spherical refraction and a visual improvement due to a central corneal flattening generated. More refined nomograms of implantation in these cases should be developed to achieve a more predictable correction of astigmatism.

Correlation between type 2 diabetes, dry eye and Meibomian glands dysfunction / Correlación entre diabetes tipo 2, ojo seco y disfunción de las glándulas de Meibomio

PURPOSE: To assess the Meibomian glands, ocular surface and tear function in patients with type 2 diabetes, and study the correlation between these conditions. METHODS: Prospective study of 76 males, 37 with type 2 diabetes with an average of duration between 7 ± 5 years, and 36 males from control group. After completing an ocular surface disease index (OSDI) questionnaire, the non-invasive tear film break-up time (NIBUT) and the tear lipid layer pattern was performed using interferometry system and tear meniscus height/TMH. Ocular surface was studied with lissamine green staining and morphology of the glands with evaluation of Marx's line (lid margin abnormalities); meibomian secretion was expressed and was also assessed the quality. The results were analyzed using the statistical Kruskal-Wallis and Mann-Whitney, and correlations by Spearman Rho. RESULTS: The mean age was 59 ± 8 years; 71% of participants presented MGD (76% diabetics and 67% controls). OSDI were significantly higher (p = 0.01) in the diabetic group. A positive correlation was found between glycemia and symptoms (p = 0.0005) and strong correlation between Hb1Ac and OSDI in MGD. NIBUT was lower in the control group (2.47 ± 1.2s) than for the diabetic group (2.9 ± 1.2s), with a significant inverse correlation (52.22%) with MG inflammation. CONCLUSIONS: MGD in type 2 diabetic patients is more severe compared with nondiabetic patients. Longer duration of diabetes is associated with major symptoms and changes in MG. Diabetic group showed major changes in lids and tear function, accounting for evaporative dry eye and presenting a high degree of correlation with MG inflammation and obstruction

OBJETIVO: Evaluar las glándulas de Meibomio, la superficie ocular y la función de la lágrima en pacientes con diabetes tipo 2, y estudiar la correlación entre estas situaciones. MÉTODOS: Estudio prospectivo de 76 varones, 37 de ellos con diabetes tipo 2, con una media de duración de entre 7 ± 5 años, y 36 mujeres como grupo control. Tras completar el cuestionario del índice de enfermedad de la superficie ocular (OSDI), se obtuvieron el tiempo de ruptura lagrimal no invasivo (NIBUT) y el patrón de la capa lipídica de la lágrima utilizando interferometría y altura del menisco lagrimal/AML. Se estudió la superficie ocular con tinción verde de lisamina y la morfología de las glándulas con evaluación de la línea de Marx (anomalías del margen del párpado); se expresó la secreción de las glándulas de Meibomio, así como su calidad. Los resultados se analizaron utilizando la pruebas estadísticas Kruskal-Wallis y Mann-Witney, y las correlaciones con Rho de Spearman. RESULTADOS: La edad media fue de 59 ± 8 años; el 71% de los participantes presentaron DGM (76% diabéticos y 67% controles). OSDI fue significativamente superior (p = 0,01) en el grupo diabético. Se encontró una correlación positiva entre glucemia y síntomas (p = 0,0005), y una fuerte correlación entre Hb1Ac y OSDI en DGM. NIBUT fue inferior en el grupo control (2,47 ± 1,2 s) que en el grupo diabético (2,9 ± 1,2 s), con una correlación inversa significativa (52,22%) con la irregularidad del borde palbebral y queratinización del OM. CONCLUSIONES: DGM en los pacientes con diabetes tipo 2 es más grave, en comparación con los pacientes no diabéticos. La mayor duración de la diabetes se asocia a síntomas mayores y cambios en la GM. El grupo diabético reflejó cambios mayores en los párpados y la función de la lágrima, lo cual supone ojo seco evaporativo, y un alto grado de correlación con irregularidad del margen palpebral y obstrucción de la GM

Anterior Segment Biometry and Their Correlation with Corneal Biomechanics in Caucasian Children.

PURPOSE: To assess the relationship between the corneal biomechanical parameters and the anterior segment parameters in Caucasian children. METHODS: This study included 293 eyes from 293 healthy children aged between 6 and 17 years. Corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated with the Ocular Response Analyzer, axial length (AL) with IOLMaster and the anterior segment with Pentacam. Anterior segment parameters obtained were the following: central corneal thickness (CCT), corneal volume (CV), anterior chamber depth (ACD), anterior chamber volume (ACV) and mean anterior and posterior keratometry. Two multiple linear regression models were constructed to assess the association between CH and CRF with anterior segment parameters. A value of p < 0.05 was taken as the criterion for statistical significance in all analyses. RESULTS: The mean CH and CRF were 12.12 ± 1.71 and 12.30 ± 1.89 mmHg, respectively. Multiple linear regression revealed that CH and CRF were associated negatively with AL in both models, and positively with CCT and CV in the first and second model, respectively. Meanwhile ACD, ACV or mean keratometry did not correlated with CH and CRF. Moreover, when CCT was in the model, it explained more variability for both CH (22.1%) and CRF (30.9%) than when CV was included (16.2% for CH and 16.5% for CRF). CONCLUSIONS: CH and CRF were correlated positively with CCT and CV, and negatively with AL in healthy Caucasian children. Moreover, corneal parameters were the most contributory variables to CH and CRF changes.

Corneal biomechanics, retinal nerve fiber layer, and optic disc in children.

PURPOSE: To evaluate the possible associations between corneal biomechanical parameters, optic disc morphology, and retinal nerve fiber layer (RNFL) thickness in healthy white Spanish children. METHODS: This cross-sectional study included 100 myopic children and 99 emmetropic children as a control group, ranging in age from 6 to 17 years. The Ocular Response Analyzer was used to measure corneal hysteresis (CH) and corneal resistance factor. The optic disc morphology and RNFL thickness were assessed using posterior segment optical coherence tomography (Cirrus HD-OCT). The axial length was measured using an IOLMaster, whereas the central corneal thickness was measured by anterior segment optical coherence tomography (Visante OCT). RESULTS: The mean (±SD) age and spherical equivalent were 12.11 (±2.76) years and -3.32 (±2.32) diopters for the myopic group and 11.88 (±2.97) years and +0.34 (±0.41) diopters for the emmetropic group. In a multivariable mixed-model analysis in myopic children, the average RNFL thickness and rim area correlated positively with CH (p = 0.007 and p = 0.001, respectively), whereas the average cup-to-disc area ratio correlated negatively with CH (p = 0.01). We did not observe correlation between RNFL thickness and axial length (p = 0.05). Corneal resistance factor was only positively correlated with the rim area (p = 0.001). The central corneal thickness did not correlate with the optic nerve parameters or with RNFL thickness. These associations were not found in the emmetropic group (p > 0.05 for all). CONCLUSIONS: The corneal biomechanics characterized with the Ocular Response Analyzer system are correlated with the optic disc profile and RNFL thickness in myopic children. Low CH values may indicate a reduction in the viscous dampening properties of the cornea and the sclera, especially in myopic children.

Relationship among corneal biomechanics, refractive error, and axial length.

PURPOSE: To evaluate the relationship between different ocular and corneal biomechanical parameters in emmetropic and ametropic healthy white children. METHODS: This study included 293 eyes of 293 healthy Spanish children (135 boys and 158 girls), ranging in age from 6 to 17 years. Subjects were divided according to the refractive error: control (emmetropia, 99 children), myopia (100 children), and hyperopia (94 children) groups. In all cases, corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated with the Ocular Response Analyzer system. Axial length (AL) and mean corneal power were also measured by partial coherence interferometry (IOLMaster), and central corneal thickness (CCT) and anterior chamber depth were measured by anterior segment optical coherence tomography (Visante). RESULTS: Mean (±SD) CH and CRF were 12.12 (±1.71) and 12.30 (±1.89) mm Hg, respectively. Mean (±SD) CCT was 542.68 (±37.20) µm and mean (±SD) spherical equivalent was +0.14 (±3.41) diopters. A positive correlation was found between CH and CRF (p < 0.001), and both correlated as well with CCT (p < 0.0001). Corneal resistance factor was found to decrease with increasing age (p = 0.01). Lower levels of CH were associated with longer AL and more myopia (p < 0.001 and p = 0.001, respectively). Higher values of CH were associated with increasing hyperopia. Significant differences in CH were found between emmetropic and myopic groups (p < 0.001) and between myopic and hyperopic groups (p = 0.011). There were also significant differences in CRF between emmetropic and myopic groups (p = 0.02). Multiple linear regression analysis showed that lower CH and CRF significantly associated with thinner CCT, longer AL, and flatter corneal curvature. CONCLUSIONS: The Ocular Response Analyzer corneal biomechanical properties seem to be compromised in myopia from an early age, especially in high myopia.