Vision Impairments in Young Adults with Down Syndrome.

People with Down syndrome have more visual problems than the general population. They experience premature ageing, and they are expected to also have an acceleration in worsening visual function. A prospective observational study which includes visual acuity, refractive error, accommodation, binocular and colour vision was performed on young adults with (n = 69) and without (n = 65) Down syndrome and on a senior group (n = 55) without Down syndrome. Results showed significant differences in visual acuity between groups (p < 0.001), and it can be improved with a new prescription in 40% of the participants with Down syndrome. Regarding the accommodative state, no significant differences were found between groups of young people. Concerning binocular vision, 64.7% of strabismus was observed in the group with Down syndrome (p < 0.001). Visual abnormalities are significant in young adults with Down syndrome and are different from those of older people without Down syndrome, some of which can be improved by providing the optimal prescription as well as regular eye examinations.

Comparison of Visual Skills between Federated and Non-Federated Athletes.

Background: To perform motor tasks, athletes must gather a considerable amount of visual information quickly. Evidence shows that visual skills vary between athletes and non-athletes, and impact athletic performance. However, there is no scientific evidence suggesting that there are any differences between the visual skills of federated and non-federated athletes. As such, the objective of this paper was to compare how visual skills influence the sports performance of federated and non-federated athletes, respectively. Methods: A visual examination has been conducted on a total of 52 athletes between 18 and 37 years of age. The COI-Sport Vision system screen (International Optometry Center, Madrid, Spain) was used to examine static visual acuity, dynamic visual acuity, contrast sensitivity, stereopsis, fixation disparity, visual memory, identification, anticipation time, peripheral awareness, and hand-eye coordination. Results: On average, federated athletes train more hours per day than non-federated athletes (1.4 ± 0.8) (p = 0.046). A significant correlation was observed between the average time of visual memory (ß = −0.0683, p < 0.001), the average time of anticipation (ß = 0.006, p = 0.009), the average time of peripheral awareness (ß = 0.026, p = 0.002), hand-eye coordination (ß = 0.028, p = 0.004), dynamic visual acuity (ß = 0.055, p < 0.001), and the number of training hours. Conclusion: Results suggest that federated athletes are more concerned about their ocular health. Nonetheless, no differences were found in the oculomotor skills of both groups. Further investigation is required to consider each sport discipline individually.

Evaluación de oftalmólogos no expertos en el análisis de la retinopatía del prematuro / Assessment of non-expert ophthalmologists in the analysis of retinopathy of prematurity

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Retinal Protection from LED-Backlit Screen Lights by Short Wavelength Absorption Filters.

(1) Background: Ocular exposure to intense light or long-time exposure to low-intensity short-wavelength lights may cause eye injury. Excessive levels of blue light induce photochemical damage to the retinal pigment and degeneration of photoreceptors of the outer segments. Currently, people spend a lot of time watching LED screens that emit high proportions of blue light. This study aims to assess the effects of light emitted by LED tablet screens on pigmented rat retinas with and without optical filters. (2) Methods: Commercially available tablets were used for exposure experiments on three groups of rats. One was exposed to tablet screens, the other was exposed to the tablet screens with a selective filter and the other was a control group. Structure, gene expression (including life/death, extracellular matrix degradation, growth factors, and oxidative stress related genes), and immunohistochemistry in the retina were compared among groups. (3) Results: There was a reduction of the thickness of the external nuclear layer and changes in the genes involved in cell survival and death, extracellular matrix turnover, growth factors, inflammation, and oxidative stress, leading decrease in cell density and retinal damage in the first group. Modulation of gene changes was observed when the LED light of screens was modified with an optical filter. (4) Conclusions: The use of short-wavelength selective filters on the screens contribute to reduce LED light-induced damage in the rat retina.

Development of a Method to Potentially Substitute Direct Evaluation of Mesopic Visual Acuity in Drivers.

(1) Background: In mesopic lighting conditions, or under adverse environmental circumstances, visual information is reduced, which increases the risk of traffic accidents. This effect could be reduced with a precise evaluation of the visual function under mesopic conditions, but it is difficult to replicate in clinics. This study aims to develop an easy-to-adopt method to evaluate mesopic visual acuity (VA) in drivers. (2) Methods: Prospective and observational study in drivers. logMAR mesopic VA was compared with photopic VA measured under different combinations of contrast charts and filters to find the combination that responds best to mesopic conditions. (3) Results: Fifty-six drivers were examined. The best correlation was found with an 80% density filter and a Weber contrast chart of 20%. The logMAR VA for this combination was 0.01 ± 0.11, which was close to the mesopic VA values (0.01 ± 0.12). The difference between both logMAR VA was 0.00 ± 0.06 (R = 0.86; p ≤ 0.001; ICC = 0.86). (4) Conclusions: The use of 20% contrast optotypes and the interposition of an 80% filter under photopic conditions provide VA values similar to those measured under mesopic lighting conditions, making this simple system a good predictor of mesopic VA values.

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.

Mesopic pupillary reflex in patients treated with fluoxetine.

INTRODUCTION: currently the treatment of mental illness by antidepressants is very frequent. Selective serotonin reuptake inhibitors are the most prescribed antidepressants worldwide and have been associated with alterations in accommodation or pupil. The objective of this study is to evaluate the effects of fluoxetine on the pupillary reflex and the accommodation in young population. METHODOLOGY: The study group included seven patients diagnosed with depression and treated with fluoxetine; 22 subjects were included as a control group. The pupillary reflexes and the accommodative state were evaluated using the Power Refractor II pupilometer. Five phases of 3 seconds each were measured. In phase 2 there was a glare with a white light. RESULTS: For the pupil diameter, maximum and minimum values were obtained in the group of patients treated with fluoxetine than in the control in all the measurement phases. For the control group, a maximum pupillary contraction is observed in the glare phase, however, in the study group it is observed in the phase after glare. As for the accommodation, there are no significant differences between the two groups. CONCLUSIONS: In patients treated with fluoxetine there are pupillary alterations like a bigger pupillary diameters and slower pupillary contraction. The lack of conclusive results in terms of accommodation does not mean that there are no changes related to it, whose detection requires future studies with different methodologies and with a larger sample size.

Reflejo pupilar mesópico en pacientes tratados con fluoxetina / Mesopic pupillary reflex in patients treated with fluoxetine

INTRODUCCIÓN: Actualmente el tratamiento de enfermedades mentales mediante antidepresivos es muy frecuente. Los inhibidores selectivos de la recaptación de serotonina son los antidepresivos más prescritos a nivel mundial y han sido asociados con alteraciones en la acomodación o la pupila. El objetivo de este estudio es evaluar los efectos de la fluoxetina sobre el reflejo pupilar y la acomodación en población joven. METODOLOGÍA: El grupo de estudio contó con siete pacientes diagnosticados de depresión y tratados con fluoxetina; como grupo control se incluyeron 22 sujetos. Se evaluaron los reflejos pupilares y el estado acomodativo mediante el pupilómetro Power Refractor II. Se midieron 5 fases de 3 segundos cada una. En la fase 2 se produjo un deslumbramiento con una luz blanca. RESULTADOS: Para el diámetro pupilar se han obtenido valores máximos y mínimos mayores en el grupo de pacientes tratados con fluoxetina que en el control en todas las fases de medida. Para el grupo control se observa una contracción pupilar máxima en la fase de deslumbramiento, sin embargo, en el grupo de estudio se observa en la fase tras el deslumbramiento. En cuanto a la acomodación no se obtuvieron diferencias significativas entre ambos grupos. CONCLUSIONES: En pacientes tratados con fluoxetina existen alteraciones pupilares observándose diámetros pupilares mayores y menor velocidad de contracción pupilar. La falta de resultados concluyentes en cuanto a la acomodación no significa que no existan cambios relacionados con esta, cuya detección requerirá de futuros estudios utilizando diferentes metodologías y con un tamaño muestral mayor

INTRODUCTION: currently the treatment of mental illness by antidepressants is very frequent. Selective serotonin re-uptake inhibitors are the most prescribed antidepressants worldwide and have been associated with alterations in accommodation or pupil. The objective of this study is to evaluate the effects of fluoxetine on the pupillary reflex and the accommodation in young population. METHODOLOGY: The study group included seven patients diagnosed with depression and treated with fluoxetine; 22 subjects were included as a control group. The pupillary reflexes and the accommodative state were evaluated using the Power Refractor II pupilometer. Five phases of 3 seconds each were measured. In phase 2 there was a glare with a white light. RESULTS: For the pupil diameter, maximum and minimum values were obtained in the group of patients treated with fluoxetine than in the control in all the measurement phases. For the control group, a maximum pupillary contraction is observed in the glare phase, however, in the study group it is observed in the phase after glare. As for the accommodation, there are no significant differences between the two groups. CONCLUSIONS: In patients treated with fluoxetine there are pupillary alterations like a bigger pupillary diameters and slower pupillary contraction. The lack of conclusive results in terms of accommodation does not mean that there are no changes related to it, whose detection requires future studies with different methodologies and with a larger sample size

Removal of the blue component of light significantly decreases retinal damage after high intensity exposure.

Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400-500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.

Short term visual outcomes of a new trifocal intraocular lens.

BACKGROUND: Today, patients often expect to achieve spectacle independance after cataract surgery. New trifocal intraocular lenses have been developed to try and fullfill this demand. The purpose of this study is to report the short-term visual outcomes of a new trifocal intraocular lens (AcrySof PanOptix™). METHODS: Consecutive adult patients undergoing cataract surgery with bilateral implantation of the study intraocular lens in a private practice clinic were considered for inclusion. Exclusion criteria were the presence of other ocular pathologies or preoperative astigmatism >1.5 diopters (D). Patients with intraoperative complications were excluded from analysis. One month after surgery patients underwent: monocular defocus curve; monocular and binocular uncorrected visual acuity in photopic and mesopic conditions, for far (4 m), intermediate (60 cm) and near (33 cm) distances and binocular contrast sensitivity. Patients completed a visual satisfaction questionnaire between 9 and 12 months after surgery. RESULTS: One hundred and sixteen eyes of fifty-eight patients receiving bilateral implantation of the study intraocular lens were analysed. Mean binocular uncorrected visual acuity in photopic conditions was 0.03 LogMAR for far, 0.12 for intermediate and 0.02 for near distances. All patients achieved a binocular uncorrected visual acuity better than 0.3 LogMAR (20/40 Snellen equivalent) for distance and near vision and 94.8% of patients for intermediate vision. Mesopic binocular uncorrected visual acuity values were similar to photopic values. The monocular defocus curves showed that the best visual acuity was reached at a vergence of 0.00D. Visual acuity dropped slightly at -1.00D and peaked again at -2.00D. Visual acuities better than 0.2 LogMAR were maintained between -2.50D and +0.50D. Contrast sensitivity was high and similar in photopic and mesopic conditions. As regards patient-evaluated outcomes, only 2 patients (3.4%) were fairly dissatisfied with their sight after surgery. Three patients (5.1%) reported the need for spectacle correction for certain activities. All other patients (94.8%) reported never using spectacle correction. CONCLUSIONS: The PanOptix trifocal IOL provides good short-term visual outcomes, with good intermediate performance and excellent patient-reported satisfaction. The similar values achieved in mesopic and photopic conditions in binocular uncorrected visual acuity and contrast sensitivity suggest low pupillary dependence for light distribution. TRIAL REGISTRATION NUMBER: ISRCTN60143265 , retrospectively registered on the 24th of April 2017.

Visual Discrimination Increase by Yellow Filters in Retinitis Pigmentosa.

PURPOSE: The objective of this study was to evaluate, by halometry and under low illumination conditions, the effects of short-wavelength light absorbance filters on visual discrimination capacity in retinitis pigmentosa patients. METHODS: This was an observational, prospective, analytic, and transversal study on 109 eyes of 57 retinitis pigmentosa patients with visual acuity better than 1.25 logMAR. Visual disturbance index (VDI) was determined using the software Halo 1.0, with and without the interposition of filters which absorb (totally or partially) short-wavelength light between 380 and 500 nm. RESULTS: A statistically significant reduction in the VDI values determined using filters which absorb short-wavelength light was observed (p < 0.0001). The established VDIs in patients with VA logMAR <0.4 were 0.30 ± 0.05 (95% CI, 0.26-0.36) for the lens alone, 0.20 ± 0.04 (95% CI, 0.16-0.24) with the filter that completely absorbs wavelengths shorter than 450 nm, and 0.24 ± 0.04 (95% CI, 0.20-0.28) with the filter that partially absorbs wavelengths shorter than 450 nm, which implies a 20 to 33% visual discrimination capacity increase. In addition, a decrease of VDI in at least one eye was observed in more than 90% of patients when using a filter. CONCLUSIONS: Short-wavelength light absorbance filters increase visual discrimination capacity under low illumination conditions in retinitis pigmentosa patients. Use of such filters constitutes a suitable method to improve visual quality related to intraocular light visual disturbances under low illumination conditions in this group of patients.

Effects of light-emitting diode radiations on human retinal pigment epithelial cells in vitro.

Human visual system is exposed to high levels of natural and artificial lights of different spectra and intensities along lifetime. Light-emitting diodes (LEDs) are the basic lighting components in screens of PCs, phones and TV sets; hence it is so important to know the implications of LED radiations on the human visual system. The aim of this study was to investigate the effect of LEDs radiations on human retinal pigment epithelial cells (HRPEpiC). They were exposed to three light-darkness (12 h/12 h) cycles, using blue-468 nm, green-525 nm, red-616 nm and white light. Cellular viability of HRPEpiC was evaluated by labeling all nuclei with DAPI; Production of reactive oxygen species (ROS) was determined by H2DCFDA staining; mitochondrial membrane potential was quantified by TMRM staining; DNA damage was determined by H2AX histone activation, and apoptosis was evaluated by caspases-3,-7 activation. It is shown that LED radiations decrease 75-99% cellular viability, and increase 66-89% cellular apoptosis. They also increase ROS production and DNA damage. Fluorescence intensity of apoptosis was 3.7% in nonirradiated cells and 88.8%, 86.1%, 83.9% and 65.5% in cells exposed to white, blue, green or red light, respectively. This study indicates three light-darkness (12 h/12 h) cycles of exposure to LED lighting affect in vitro HRPEpiC.

Contrast sensitivity and disability glare in patients with dry eye.

PURPOSE: To evaluate contrast sensitivity and disability glare in patients with dry eye using the Contrast Glaretester 1000. METHODS: Contrast sensitivity and disability glare were determined in 33 eyes of 33 patients with dry eye and 30 eyes of 30 healthy control subjects for six target sizes with a visual angle of 6.3-0.7 degrees using the Contrast Glaretester 1000, whose working mechanism is similar to that of the conventional perimetry instrument. RESULTS: Contrast sensitivity was significantly worse in dry eye group when viewing all target sizes (reduction of 0.10-0.25 log contrast units, p < 0.01) except at 6.3 degrees. In the presence of glare, differences in log contrast sensitivity between the groups (0.10-0.25 units) were significant (p < 0.01) for all target sizes, with the dry eye group showing worse results. The reduction in contrast sensitivity induced by glare (disability glare) was significantly worse in the dry eye group versus the control group but only for the 2.5-degree size target, where 0.14 log contrast units were lost. CONCLUSIONS: Contrast sensitivity with and without glare was significantly reduced in patients with dry eye compared with control subjects, but the number of log contrast units lost with glare (disability glare) was similar in the two groups, except for the 2.5-degree size target.

Normal values of distance heterophoria and fusional vergence ranges and effects of age.

BACKGROUND: Although it is well known that age affects visual function, we still have much to learn about the impact of aging on binocular vision. Our aim was to establish distance heterophoria and distance fusional vergence ranges in a large non-clinical population of wide age range, to provide normal values for comparisons. METHODS: A cross-sectional study was performed on 271 non-clinical subjects stratified into six age groups. Distance heterophoria measurements were obtained using the von Graefe technique and distance horizontal fusional vergence ranges using Risley rotary prisms in each subject, with best spectacle correction. RESULTS: The mean heterophoria value for distance fixation was exophoric except for the 71-80 year age group, which was esophoric. No effects of age were observed on distance heterophoria and distance base-in and base-out break means. However, a significant effect of age was noted on base-in recovery and base-out recovery. Between the youngest and oldest age groups, mean base-in recovery decreased by 2.5 Delta and mean base-out recovery by 3.3 Delta. CONCLUSIONS: Distance base-in and base-out recovery means diminished significantly with age such that recovery values fell outside the norm in subjects in the 61-70 year age group and older. This study establishes statistical normal values for distance heterophoria and fusional vergence in a non-clinical population. Mean values such as these are valuable tools for identifying subjects with far binocular anomalies.

Effect of a yellow filter on contrast sensitivity and disability glare after laser in situ keratomileusis under mesopic and photopic conditions.

PURPOSE: To analyze the effect of a yellow filter on contrast sensitivity and disability glare under mesopic and photopic luminance conditions in laser in situ keratomileusis (LASIK) patients and control subjects. METHODS: Contrast sensitivity with and without glare was determined in 27 patients who had undergone LASIK at least 1 year previously and in 30 control subjects. Tests were performed with and without a coated yellow filter (X-482 nm cut-off) using the Mesotest II or Mesoptometer II (Oculus, Wetzlar, Germany) under mesopic conditions, and the Contrast Glaretester 1000 (Takagi, Seiko Co Ltd, Nagano, Japan) under photopic conditions. RESULTS: Under mesopic conditions, log contrast sensitivity without glare decreased by 0.14 log units in the LASIK group. When the yellow filter was used, this variable showed a significant increase of 0.04 log units and the proportion of patients able to discriminate the mesopic contrast limit of 1:5 rose from 70% to 78%. With glare, the yellow filter also improved contrast sensitivity in LASIK patients, but not significantly. Under photopic conditions, no statistical differences were observed between results obtained with and without the yellow filter in the LASIK group or between the LASIK and control group without glare. CONCLUSIONS: Mesopic contrast sensitivity without glare was worse in LASIK patients and increased significantly with the yellow filter. The filter had no effect under photopic conditions. No disability glare differences were noted between the LASIK and control groups or between the LASIK without and with filter groups under mesopic and photopic conditions.

Normal values for photopic and mesopic letter contrast sensitivity.

PURPOSE: The exponential increase of patients having refractive surgery has increased the number of patients with night vision disturbances, such as decreased contrast sensitivity. However, there are no standard contrast sensitivity scales in normal persons in the mesopic range. We describe Pelli-Robson contrast sensitivity under photopic and mesopic luminance conditions in a large Spanish population over a wide range of age groups to provide normal values. A further aim was to evaluate the effect of photopic visual acuity on photopic and mesopic contrast sensitivity. METHODS: A cross-sectional study was performed on 292 participants stratified by age into six groups. Binocular contrast sensitivity was determined with best spectacle correction using the Pelli-Robson letter chart at 1 m under photopic (85 cd/m2) and mesopic (0.15 cd/m2) luminance conditions. RESULTS: Phototopic letter contrast sensitivity began to decrease gradually from the 61 to 70-year-old age group onward, and for mesopic conditions, from the 51 to 60-year-old age group onward. The reduction in mean contrast sensitivity between the oldest and the youngest age groups was 0.20 log units (photopic) and 0.33 log units (mesopic). Loss in contrast sensitivity due to luminance (two successive triplets) increased slightly with age. Both photopic and mesopic letter contrast sensitivity significantly improved as photopic visual acuity increased. CONCLUSIONS: Under mesopic conditions, Pelli-Robson contrast sensitivity began to decline 1 decade earlier than under photopic conditions and was affected by visual acuity. Normal values for mesopic contrast sensitivity could be of help in deciding whether mesopic function is normal or a decrease in contrast sensitivity is pathologic in nature.

Mesopic contrast sensitivity in the presence or absence of glare in a large driver population.

BACKGROUND: To evaluate mesopic contrast sensitivity in conditions of glare and no glare in a vehicle driver population, and to explore the effects of age, habitual spectacle correction, photopic visual acuity and driving exposure. METHODS: A cross-sectional study was performed on 297 drivers stratified by age into six groups. The mesopic contrast sensitivity was measured in the absence or presence of glare using the Mesotest II (Oculus, Germany) in each subject both with habitual and best spectacle correction. A questionnaire on the subject's driving habits was completed. RESULTS: There were no significant differences between contrast sensitivity measured with habitual or best spectacle correction. In conditions of no glare, the mesopic contrast sensitivity gradually got worse from 51 to 60 years onwards, and from 41 to 50 years onwards in the presence of glare. In both conditions, the total decrease in contrast sensitivity was 0.3 log units. The with-glare and without-glare mesopic contrast sensitivity improved as photopic visual acuity increased. Forty-five per cent of drivers who reported difficulties in driving at night were unable to perform any of the tests with glare, compared to 20% without glare. However, the effect of driving habits on contrast sensitivity was only significant in the oldest age group. CONCLUSIONS: The mesopic contrast sensitivity and glare sensitivity seem to be stable until the age of 50 years, from which point they start to decline at a rate of 0.1 log contrast sensitivity loss per decade. Drivers with poor visual acuity and/or older drivers who avoided night driving presented worse mesopic contrast sensitivity and greater glare sensitivity.