Vision (Switzerland)最新文献

Points of Subjective Equality (PSE) are commonly measured using staircase or constant stimuli methods. However, the staircase method is highly dependent on the step size, and the constant stimuli method is time-consuming. Thus, we wanted to develop an efficient and quick method to estimate both the PSE and the slope of the psychometric function. We developed a random-step algorithm in which a one-up-one-down rule is followed but with a random step size in a pre-defined range of test levels. Each stimulus would be chosen depending on the previous response of the subject. If the subject responded "up", any random level in the lower range would be picked for the next trial. And if the subject responded "down", any random level in the upper range would be picked for the next trial. This procedure would result in a bell-shaped distribution of the test levels around the estimated PSE, while a substantial amount of trials would still be dispersed at both bounds of the range. We then compared this method with traditional constant stimuli procedure on a task based on the Pulfrich phenomenon while the PSEs of participants could be varied using different neutral density filters. Our random-step method provided robust estimates of both the PSE and the slope under various noise levels with small trial counts, and we observed a significant correlation between the PSEs obtained with the two methods. The random-step method is an efficient way to measure the full psychometric function when testing time is critical, such as in clinical settings.

Severe corneal ulcerations, causing major keratolysis with large perforation of the cornea or extending to the limbal region, are an ophthalmic emergency. In these cases, a larger corneoscleral graft can be transplanted to restore tectonic integrity, alleviate pain, save vision, and prevent loss of the eye. Chart review of 34 patients with a corneoscleral graft ≥9.5 mm was conducted. Primary endpoints of the study were tectonic stability defined as no need for another keratoplasty or enucleation. In addition, visual acuity, postoperative complications, and secondary procedures were analyzed. In total, 12 patients (35%) were female. The mean age at transplantation was 65 ± 19 years. The underlying disease was a perforated infectious corneal ulcer in 30 cases (88%). Mean follow up was 675 ± 789 days. Tectonic stability at the end of the follow-up was maintained with a probability of 56% in a Kaplan-Meier analysis. Another penetrating keratoplasty was necessary in six cases (17%) and enucleation in five cases (15%). A corneoscleral transplant remains a viable treatment option to prevent enucleation in severe keratolysis. In our study, this was possible in about half of the cases. Postoperative complications, secondary surgeries, and markedly reduced visual acuity put the advantages into perspective.

Despite having equal duration, stimuli in physical motion are perceived to last longer than static ones. Here, we investigate whether illusory motion stimuli produce a time-dilation effect similar to physical motion. Participants performed a duration discrimination task that compared the perceived duration of static stimuli with and without illusory motion to a reference stimulus. In the first experiment, we observed a 4% increase in the number of "longer" responses for the illusory motion images than static stimuli with equal duration. The time-dilation effect, quantified as a shift in the Point of Subjective Equality (PSE), was approximately 55 ms for a 2-second stimulus. Although small, the effect was replicated in a second experiment in which the total number of standard-duration repetitions was reduced from 73 to 19. In the third experiment, we found a positive linear trend between the strength of the illusory motion and the magnitude of the time-dilation effect. These results demonstrate that, similar to physical motion stimuli, illusory motion stimuli are perceived to last longer than static stimuli. Furthermore, the strength of the illusion influences the extent of the lengthening of perceived duration.

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.

A surgical technique was developed to enhance aqueous humor (AH) flow through the non-trabecular outflow pathway by rerouting it from the anterior chamber (AC) to the suprachoroidal space (SCS) without detaching the ciliary body from the scleral spur. Medium- and long-term surgical outcomes were retrospectively analyzed in a case series of 58 glaucoma patients. At 6, 12, and 24 months, the mean IOP decreased from 27.8 ± 8.3 to 14.9 ± 5.0 mmHg, median 15.0 (25th percentile (p²⁵)13.0; 75th percentile (p⁷⁵) 18.0) and 15.2 ± 3.3 mmHg, and hypotensive medication use reduced from a median (p²⁵; p⁷⁵) of 3 (2; 3) to 0 (0; 2), 0 (0; 2), and 0 (0; 1.5), respectively. Intra- and postoperative complications were few and manageable. Following surgery, no bleb formation occurred in any of the cases (as confirmed by optical coherence tomography). Conjunctival lymphatic vessels (CLVs) developed in 50% of eyes (29/58). Clinically, they developed directly from sclera and had no connection to the surgical site. Analysis further showed that the development of CLVs and their longer visibility period had poor prognostic value for IOP control. If the fluid flow from the SCS to CLVs was resistance-free, no CLV development was evident. However, if any resistance existed in the flow, the fluid accumulated in lymphatics, resulting in their engorgement. The proposed technique was safe and effective in decreasing IOP in glaucoma patients by enhancing AH flow from the SCS to CLVs via connecting intrascleral microchannels.

Purpose: The purpose of this study is to assess the satisfaction levels of people with VI with regard to infrastructure and outdoor activities. Furthermore, this study aims to develop an assessment model for the levels of difficulty in using public transport.

Methods: Participants in a standardized survey questionnaire included 74 participants with VI. Three assessment-ordered probit models were estimated based on self-reported responses.

Results: Estimation results revealed that the use of public transport is extremely difficult for 83.47% of older participants. In addition, 84.2% of people with albinism have extreme difficulty using public transport. Furthermore, 53.98% of people with restricted horizontal and vertical fields face extreme difficulty using public transport. There was dissatisfaction with outdoor activities among 97.40% of people with macular disease. The results show that 51.70% of people with normal or near-normal horizontal visual fields and restricted vertical planes are satisfied with their level of outdoor activity while 72.65% of people with retinal diseases expressed dissatisfaction with the existing infrastructure.

Conclusion: This study revealed that the experiences of people with VI are heterogeneous and depend on their eye condition, access to assistive technology, and socioeconomic characteristics. Results clearly show evidence of heterogeneity among individuals with VI. The combination of horizontal and vertical restrictions yields random parameters, underscoring the heterogeneous experiences of people with VI, influenced by their eye condition and access to assistive devices. Our results have important implications for developing targeted interventions to enhance the mobility of people with VI.

Vision is thought to play a substantial role in hitting and fielding in cricket. An understanding of which visual skills contribute during cricket play could inform future clinical training trials. This paper reviews what has been reported thus far regarding the relationship of visual skills to cricket performance and reviews the results of clinical trials in which the impact of visual skills training on cricket performance has been addressed. Fundamental or low-level visual skills, with the exception of color vision and perhaps near stereopsis and dynamic visual acuity, are similar between cricket players and the general population. Simple reaction time has been found to be shorter in cricket players in some but not all studies. While there is mixed or no evidence that the aforementioned visual skills are superior in cricket players compared to non-players, comparisons of eye and head movements and gaze tracking have revealed consistent differences between elite cricket batters and sub-elite batters. Future training studies could examine whether teaching sub-elite batters to emulate the gaze tracking patterns of elite batters is beneficial for batting. Lastly, clinical trials in which visual skills of cricket players have been trained have in many cases resulted in positive effects on visual skills, or judgments required in cricket, or cricket play. However, clinical trials with larger and more diverse groups of participants and correlations to on-field metrics and on-field performance (i.e., domain-specific assessments) are necessary before conclusions can be drawn regarding the efficacy of vision training.

A number of authors have argued that the art of conjuring can assist the development of theories and knowledge in visual cognition and psychology more broadly. A central assumption of the so-called science of magic is that magicians possess particular insight into human cognition. In a series of experiments, we tested the Insight hypothesis by assessing three factors that magicians argue are important for a popular illusion. Participants viewed videos of a magician performing the French Drop sleight whilst gaze, motion, and muscular tension were manipulated across experiments. Contrary to what the community of conjurers state, results showed that none of these influenced the perceived success of the effect. We also found that a visual priming technique, one suggested of many and used by an eminent magician, does not influence participant responses. Overall, these findings fail to support the Insight hypothesis. We suggest that scientists of magic have erroneously imbued magicians with insights they do not possess.

The visual inspection of scenes is disrupted when participants are forced to begin inspection away from the centre of an image. The present study explored the effect of the starting point on the visual inspection of paintings. Eye movements were recorded while participants viewed paintings for later identification in a yes/no discrimination task. The viewing of each painting was preceded by the presentation of a pseudo-randomly positioned Navon figure. Participants were instructed using a cue to attend to either the local or global level of the Navon figure. Each painting was split into regions of interest (ROIs) defined by face, theme, and context to allow the analysis of eye movements. These data were directly compared with a subset of those initially reported in our previous study in which the same experiment was run but without the inclusion of the Navon figure. The inclusion of the Navon task lowered the discrimination accuracy in the yes/no discrimination task. More importantly, eye movements to the paintings were disrupted across the entire period over which they were viewed and not just in the period following the offset of the Navon figure. The results show the sensitivity of eye movements to the conditions present at the beginning of viewing. The results have implications for the viewing of paintings (and other images) in the real world, where the starting conditions for inspection cannot be controlled.

Background: The aim of this study was to present the clinical outcomes of IOP monitoring in and out of office time and determine its value in our clinical practice.

Material and methods: We reviewed the records of 1500 patients (glaucoma suspects or glaucoma patients), who were admitted for IOP monitoring during almost 12 years. All patients were hospitalized because their within-office-hours exams were considered inadequate and inconclusive for decision making.

Results: A total of 744 patients (49.6% out of 1500) needed change of treatment. A total of 121 patients (8% out of 1500) were programmed for interventional therapy (laser or surgery). A total of 68 patients (4.5% out of 1500) were declassified as overdiagnosed and overtreated. In 250 patients (16.7% out of 1500), hidden adherence problem appeared. In 720 patients (48% out of 1500), peak IOP occurred during out-of-office hours.

Conclusions: IOP phasing is a useful tool in clinical practice. In many cases with inconclusive diagnosis, as well as in patients with advanced or labile glaucomas, IOP monitoring data add complementary information, useful for decision making, and may contribute not only to diagnosis and successful IOP modulation, but also in personalized therapeutic strategy and individual patients' motivation.