Broken Ring enVision Search (BReViS): A New Clinical Test of Attention to Assess the Effect of Layout and Crowding on Visual Search.

The assessment of attention in neuropsychological patients could be performed with visual search tests. The Broken Rings enVision Search test (BReViS) here proposed represents a novel open access paper-and-pencil tool in which layout and crowding are varied among four cards. These manipulations allow the assessment of different components of attention: a selective component, the visuo-spatial orientation of attention, and the focal attention, involved in a crowding phenomenon. Our purpose was to determine the characteristics of the BReViS test, provide specific normative data, and assess these components across the lifespan. The test was administered to a sample of 550 participants aged between 20 and 79 years old and to a series of patients. Three indexes targeting different components of visuo-spatial attention (selective attention, strategic orientation of visual attention, focal attention) were obtained by combining execution times and accuracy together with the total errors. The results showed that age, education and gender influenced, in different combinations, the four indexes, for which specific norms were developed. Regression-based norms were provided in percentiles and equivalent scores. All patients showed pathological scores and specific patterns of attentional deficits. The BreViS test proved to be a free and easy valuable tool which can be used in the clinical environment to assess attentional deficits in neuropsychological patients.

Normative Values of the Groffman Visual Tracing Test for the Assessment of Oculomotor Performance in the Adult Population.

The Groffman visual tracing (GVT) test is an indirect psychometric measure of oculomotor performance, used for the clinical assessment of eye movements. The test consists of two cards with five contorted lines of increasing overlap, crowding, and difficulty. The task starts from each of the letters at the top of the page, follows the line from the letter to the corresponding number at the bottom of the page, and the number is named. Although the GVT test was developed for the evaluation of children, it has also been applied to adults with visual and cognitive deficits. However, it lacks reference values. Therefore, the aim of the study was to assess oculomotor behavior across the typical human lifespan and to define normative data in an adult population. A total of 526 adults aged between 20 and 79 years, all without neurological or psychiatric deficits, were enrolled in the study. The results were analyzed by considering the accuracy and execution times separately. An influence of age, education and sex for accuracy was found, and age for the execution times was found. Norms for adults were developed considering the specific structure of the test and the accuracy and the execution time separately. The GVT test can now be applied in healthy and neurological adult populations for the evaluation of oculomotor performance.

Comparison, within-session repeatability and normative data of three phoria tests

Purpose : Phoria measurements form a routine part of the examination of binocular vision. Various studies have compared different methods of phoria measurement and their repeatability between sessions. However, no studies have accounted for within-session repeatability, and few norms have been available to date. Our aims were to assess the short-term within-session repeatability, the agreement and the comparisons between three phoria tests and the delineation of normative data.Method: The participants comprised 315 refractive corrected participants with a normal binocular vision, with ages between 20 and 80 years. Phoria was measured using three methods: von Graefe (VG), modified Thorington (MT) and Thorighton (TH) procedures. Each measurement was taken 3 consecutive times at far and near.Results: The repeatability between measurements was high (0.87 to 0.96), but the relationship between tests was medium (0.407 to 0.682). About the mean bias, VG show more exo values (0.02 to 0.14 at far and 0.07 to 0.14 at near) and MT and TH similar values (−0.04 to 0.08 at far and −0.1 to 0.03 at near). The best agreement between tests was for TH and MT (LoA = 2.33 at far and LoA = 4.44 at near). Normative data for non-presbyopic were provided.Conclusion : Overall, there is a high agreement between MT and TH. Conversely, VG shows more exo values at near and shows large limits of agreement. We recommend that subjective measurements of phoria can best be quantified once using the MT or TH techniques in free space and the values compared with updated norms. (AU)

Evaluation of stereoacuity with a digital mobile application.

PURPOSE: Stereopsis is a fundamental skill in human vision and visual actions. There are many ways to test and quantify stereoacuity: traditional paper and new digital applications are both valid ways to test the stereoacuity. The aim of this study is to compare the results obtained using standard tests and the new Stereoacuity Test App developed by the University of Bergamo. METHODS: A group of 497 children (272 males), aged between 6 and 11 years old, were tested using different tests for the quantification of stereopsis at near. These tests were TNO, Weiss EKW, and the new developed Stereoacuity Test App. RESULTS: A one-way repeated measure ANOVA showed that the three tests give different thresholds of stereoacuity (p < 0.0001). Post hoc analyses with Bonferroni correction showed that all tests showed different thresholds (p < 0.0001). The lower threshold was obtained by Titmus Stereo Test followed by Stereoacuity App, Weiss MKW, and TNO. CONCLUSION: The stereoacuity based on global stereopsis showed that the better values were obtained in order by Stereoacuity Test App, TNO, and Weiss EKW. However, the clinical significance of their values is similar. The new digital test showed a greater compliance by the child, showing itself in tune with the digital characteristics of today's children.

Measurement of visual acuity with a digital eye chart: optotypes, presentation modalities and repeatability

Purpose: Digital or computerised eye charts are becoming standard in the examination of visual acuity. Each instrument allows the selection of different optotypes, presentation modalities, and crowding. The aim of this study was to examine the differences in visual acuity (VA) measurement using a digital eye chart, comparing different optotypes and procedures, together with an evaluation of the repeatability of the measurement.MethodsTwo groups of 52 participants aged between 18 and 31 years participated in the study. In the first experiment, VA thresholds were measured using LEA Symbols, Tumbling E, and Landolt Rings in monocular and binocular conditions using single line presentation and QUEST presentation. In the second experiment, we have compared all modalities of presentation together with a paper eye-chart and test the repeatability.ResultsThe results showed that thresholds for LEA Symbols are low. The modality of presentation affects these thresholds. For Landolt Rings and Tumbling E, the QUEST procedure gave significantly better thresholds than line presentation, while this difference was absent for LEA Symbols. In comparing all modalities of presentation, single letter and line presentation showed similar values, slightly better than block presentation. Paper eye-charts showed better values of VA. Repeatability and agreement were good for all presentations, but best for QUEST.ConclusionsThe QUEST modality of presentation provides a better threshold than line presentation except for LEA Symbols. Examiners using digital eye charts must take into account that not all modalities of presentation and optotypes are equivalent and give different VA thresholds. Specific thresholds need to be used for each optotype and presentation modality. (AU)

Comparison, within-session repeatability and normative data of three phoria tests.

PURPOSE: Phoria measurements form a routine part of the examination of binocular vision. Various studies have compared different methods of phoria measurement and their repeatability between sessions. However, no studies have accounted for within-session repeatability, and few norms have been available to date. Our aims were to assess the short-term within-session repeatability, the agreement and the comparisons between three phoria tests and the delineation of normative data. METHOD: The participants comprised 315 refractive corrected participants with a normal binocular vision, with ages between 20 and 80 years. Phoria was measured using three methods: von Graefe (VG), modified Thorington (MT) and Thorighton (TH) procedures. Each measurement was taken 3 consecutive times at far and near. RESULTS: The repeatability between measurements was high (0.87 to 0.96), but the relationship between tests was medium (0.407 to 0.682). About the mean bias, VG show more exo values (0.02 to 0.14 at far and 0.07 to 0.14 at near) and MT and TH similar values (-0.04 to 0.08 at far and -0.1 to 0.03 at near). The best agreement between tests was for TH and MT (LoA = 2.33 at far and LoA = 4.44 at near). Normative data for non-presbyopic were provided. CONCLUSION: Overall, there is a high agreement between MT and TH. Conversely, VG shows more exo values at near and shows large limits of agreement. We recommend that subjective measurements of phoria can best be quantified once using the MT or TH techniques in free space and the values compared with updated norms.

Measurement of visual acuity with a digital eye chart: optotypes, presentation modalities and repeatability.

PURPOSE: Digital or computerised eye charts are becoming standard in the examination of visual acuity. Each instrument allows the selection of different optotypes, presentation modalities, and crowding. The aim of this study was to examine the differences in visual acuity (VA) measurement using a digital eye chart, comparing different optotypes and procedures, together with an evaluation of the repeatability of the measurement. METHODS: Two groups of 52 participants aged between 18 and 31 years participated in the study. In the first experiment, VA thresholds were measured using LEA Symbols, Tumbling E, and Landolt Rings in monocular and binocular conditions using single line presentation and QUEST presentation. In the second experiment, we have compared all modalities of presentation together with a paper eye-chart and test the repeatability. RESULTS: The results showed that thresholds for LEA Symbols are low. The modality of presentation affects these thresholds. For Landolt Rings and Tumbling E, the QUEST procedure gave significantly better thresholds than line presentation, while this difference was absent for LEA Symbols. In comparing all modalities of presentation, single letter and line presentation showed similar values, slightly better than block presentation. Paper eye-charts showed better values of VA. Repeatability and agreement were good for all presentations, but best for QUEST. CONCLUSIONS: The QUEST modality of presentation provides a better threshold than line presentation except for LEA Symbols. Examiners using digital eye charts must take into account that not all modalities of presentation and optotypes are equivalent and give different VA thresholds. Specific thresholds need to be used for each optotype and presentation modality.

Different trajectories in the development of visual acuity with different levels of crowding: The Milan Eye Chart (MEC).

Eye charts are typically optimized to assess visual acuity (VA) with constant and controlled spacing, while close-to-acuity crowding limits letter identification in the normal fovea when adjacent letters are closely spaced. Here we developed a clinical tool that enables the assessment of acuity with different levels of crowding. In a cross-sectional study, we examined the developmental trajectories with our newly devised Milan Eye Chart (MEC). A total of 252 children of 1st, 3rd and 5th grade were assessed with the MEC using SLOAN letter optotypes with 100%, 50%, 25% and 12.5% inter-optotype spacing. Results show an interaction between spacing and grade. The performance to the 100% standard VA was not significantly different among grades, while the narrow spaced acuity (12.5% spacing) strongly improved with the grade. The different trajectories of acuity measured with high spaced and low spaced eye-charts suggest that the mechanisms able to reduce the crowding effects develops later than VA, and it is, at least in part, dissociated by the psychophysiological development of lower level visual mechanisms. The MEC charts are feasible and useful in assessing visual acuity with different level of crowding during the whole lifespan. The opportunity to assess crowding-limited acuity in early age is particularly relevant since it plays a significant role in amblyopia screening.

The Reliability of the DEM Test in the Clinical Environment.

The developmental eye movement (DEM) test is a practical and simple method for assessing and quantifying ocular motor skills in children. Different studies have previously assessed the reliability of the DEM test and they have generally found high values for vertical and horizontal time, whereas those for Ratio and Errors were medium and low, respectively. In the second application of test were found an improvement in performance in all subtests. Our aim was to evaluate the reliability of the DEM test using seconds and percentile scoring and looking in depth at the improvement in performance when the test is repeated. We tested the reliability of the DEM test on a group of 115 children from the 2nd to the 5th grade using different statistical methods: correlations, ANOVA, limits of agreement for results expressed in seconds and as percentile scoring and pass-fail diagnostic classification. We found high reliability with excellent values for vertical and adjusted horizontal time, medium-to-high for ratio and medium for errors. We have re-confirmed the presence of a significant improvement of performance on the second session for vertical time, horizontal time and ratio. The stability of binary classification of Pass-Fail criteria appears to be medium. We found high reliability for the DEM test when compared with the published results of other research but the improvement of performance, the learning effect was still present, but at a lower level than previously found. With the awareness of these limitations the DEM test can be used in clinical practice in evaluating performance over time.

Hyaluronic acid in hydrophilic contact lenses: spectroscopic investigation of the content and release in solution.

Two experimental spectroscopic methods for the determination of the content of hyaluronic acid in solution are provided based on the formation of complexes between the hyaluronic acid and cationic dyes with sensitivity down to concentrations of either 0.25 or 2.5 microg/ml. These techniques were applied to commercial hydrophilic contact lenses and allowed (i) distinguishing among contact lenses either loaded or non-loaded with hyaluronic acid, (ii) determining, for the loaded ones, the content of hyaluronic acid, (iii) evaluating the release of hyaluronic acid by the lens in solution, and (iv) determining the role of the hyaluronic acid in preventing the adsorption and the successive release by the contact lens of other components which can be present, for example, in the conservation solutions and/or in the blisters of the lenses. The results represent new physical chemistry insights for the field of contact lenses with impact on the advancement of current technology.