Vision, Volume 8, Issue 1 (March 2024) – 16 articles

The type and nature of refractive surgery procedures has greatly increased over the past few decades, allowing for almost all patient populations to be treated to extremely high satisfaction. Conventional photorefractive keratectomy involves the removal of the corneal epithelium through mechanical debridement or dilute alcohol instillation. An improvement to this method utilises laser epithelial removal in a single-step process termed transepithelial photorefractive keratectomy (transPRK). We explore the history of transPRK from its early adoption as a two-step process, identify different transPRK platforms from major manufacturers, and describe the role of transPRK in the refractive surgery armamentarium. This is a narrative review of the literature. This review finds that TransPRK is a safe and effective procedure that works across a variety of patient populations. Though often not seen as a primary treatment option when compared to other corneal-based procedures that offer a faster and more comfortable recovery, there are many scenarios in which these procedures are not possible. These include, but are not limited to, cases of corneal instability, previous refractive surgery, or transplant where higher-order aberrations can impair vision in a manner not amenable to spectacle or contact lens correction. We discuss refinements to the procedure that would help improve outcomes, including optimising patient discomfort after surgery as well as reducing corneal haze and refractive regression. Full article

While our direct observations of the features or behaviours of the stimuli around us tell us much about them (e.g., should they be feared?), the origin of much of our knowledge is often untethered from directly observable properties (e.g., through what we have learned or have been told about them, or “semantic knowledge”). Here, we ask whether otherwise neutral visual stimuli that participants learn to associate with emotional qualities in the lab cause the stimuli to be attended in a similar way as stimuli whose emotional qualities can be discerned through their visual properties. In Experiment 1, participants learned to associate negative or neutral characteristics with neutral faces, which then served as valid or invalid spatial cues to targets in an attentional disengagement paradigm. The performance of participants higher in trait anxiety was consistent with attentional avoidance of faces with learned negative associations, while participants lower in trait anxiety showed a general response slowing in trials with these stimuli, compared to those with neutral associations. In contrast, in Experiment 2, using (visually) expressive (angry) faces, the performance of participants higher in trait anxiety was consistent with difficulty disengaging from visually threatening faces, while the performance of those with lower trait anxiety appeared unaffected by the valence of the stimuli. These findings suggest that (1) emotionality acquired indirectly via learned semantic knowledge impacts how attention is allocated to face stimuli, and this impact is influenced by trait anxiety, and (2) there are differences in the effects of stimulus emotionality depending on whether it is acquired indirectly or directly via the perceptual features of the stimulus. These differences are discussed in the context of the variability of attention bias effects reported in the literature and the time course of impacts of emotionality on stimulus processing. Full article

The tremendous increase in the use of video-based eye tracking has made it possible to collect eye tracking data from thousands of participants. The traditional procedures for the manual detection and classification of saccades and for trial categorization (e.g., correct vs. incorrect) are not viable for the large datasets being collected. Additionally, video-based eye trackers allow for the analysis of pupil responses and blink behaviors. Here, we present a detailed description of our pipeline for collecting, storing, and cleaning data, as well as for organizing participant codes, which are fairly lab-specific but nonetheless, are important precursory steps in establishing standardized pipelines. More importantly, we also include descriptions of the automated detection and classification of saccades, blinks, “blincades” (blinks occurring during saccades), and boomerang saccades (two nearly simultaneous saccades in opposite directions where speed-based algorithms fail to split them), This is almost entirely task-agnostic and can be used on a wide variety of data. We additionally describe novel findings regarding post-saccadic oscillations and provide a method to achieve more accurate estimates for saccade end points. Lastly, we describe the automated behavior classification for the interleaved pro/anti-saccade task (IPAST), a task that probes voluntary and inhibitory control. This pipeline was evaluated using data collected from 592 human participants between 5 and 93 years of age, making it robust enough to handle large clinical patient datasets. In summary, this pipeline has been optimized to consistently handle large datasets obtained from diverse study cohorts (i.e., developmental, aging, clinical) and collected across multiple laboratory sites. Full article

This article examines empirical associations between qualities of the imagination, mental imagery, and cognitive abilities with special reference to autism. This study is the first to explore the empirical relationships between autistic-like traits and tests of imagery differences. Imaginative impairments and distinctive sensory characteristics in individuals with autism spectrum disorder (ASD) should be reflected in their interactions with mental imagery. However, the relationship between ASD and imaging traits remains unclear. Based on the hypothesis that the degree of autistic-like traits is reflected in imagery traits, this study examined how the individual Autism Spectrum Quotient (AQ) relates to imagery ability in 250 college students. Two vividness tests and one imagery-type test were used to assess imagery ability. Scores in each imagery test were compared between the high-scoring group classified by the AQ and the rest of the participants and between the low-scoring group classified by the AQ and the other participants. This study also directly compared imagery test scores between the high- and low-scoring groups. In terms of the total AQ score, the high-scoring group exhibited lower visualization scores. Regarding AQ subscales, “imagination” had the most extensive relationship with imagery traits, with the high-scoring group (unimaginative) showing lower imagery vividness across various modalities as well as lower visualization and verbalization scores. This was followed by the “attention to detail” subscale, on which the high-scoring group (attentive to detail) showed higher vividness of visual imagery. The results of the low-scoring group exhibited, on the whole, opposite imagery tendencies to the high-scoring group. The results indicate that autistic-like traits are associated with qualities of the imagination and especially mental imagery ability. Full article

Scottish Vision Group has become a yearly event for vision scientists based in Scotland since its inception in 2001. Each year, the conference is hosted at a different location and organised by a different team. The 2023 SVG meeting was hosted in the city of Dundee by Abertay University. Delegates travelled from the United Kingdom, Europe and beyond. The meeting started with a roundtable panel discussion sponsored by Meta Reality Labs. The roundtable, titled The Past, Present and Future of Visual Search, was organised and presented by Árni Kristjánsson (Iceland), Ioan Smart (Abertay) and Ian Thornton (Malta). The MDPI Keynote lecture was introduced by Professor Andrew Parker (Oxford University and Otto-von-Guericke University in Magdeburg, Germany) and presented by Prof. Timothy Ledgeway (Nottingham) on sensory eye dominance and plasticity in adult binocular vision. The remaining two days of the conference hosted a wide range of talks on topics ranging from insect navigation to visual illusions, facial recognition and binocular coding. The Saturday evening saw a special event where delegates explored the sensory properties of a range of single-malt whiskies. Here, we present a selection of abstracts for the various talks and posters. Full article

This prospective, double-masked, contralateral study aimed to analyze and compare daytime changes in pre-lens tear film (PLTF) stability and optical quality in symptomatic subjects wearing two contact lenses (CL). A secondary goal was to assess the performance of the PLTF by using dynamic topography techniques and analyzing surface asymmetry and irregularity indexes (SAI and SRI, respectively). Measurements were conducted on 20 symptomatic subjects (OSDI score > 13). Participants were fitted contralaterally and randomly with spherical Delefilcon A and Stenfilcon A CLs and underwent a series of measurements over 3 consecutive days: three in the morning (after 1–2 h of CL wear) and three in the afternoon (after 7–9 h of CL wear). High- and low-contrast visual acuity (HCVA and LCVA, respectively), pre-lens NIBUT, and dynamic topography were assessed. The contralateral fit of the two lenses allowed a direct and better comparison between them since they were exposed to the same conditions during the day. Consequently, both lenses demonstrated similar performance in HCVA, LCVA, and PLTF stability, with no statistically significant differences between them, although some fluctuations were observed throughout the day. Dynamic topography proved sensitive in evaluating temporal changes in the PLTF. The SRI index showed greater sensitivity to topographic changes due to lacrimal destabilization, making it potentially valuable for evaluating dry eye patients. Full article

Aim: Angioid streaks (ASs) are a rare retinal condition and compromise visual acuity when complicated with choroidal neovascularization (CNV). They represent crack-like dehiscences at the level of the Bruch’s membrane. This objective narrative review aims to provide an overview of pathophysiology, current treatment modalities, and future perspectives on this condition. Materials and Methods: A literature search was performed using “PubMed”, “Web of Science”, “Scopus”, “ScienceDirect”, “Google Scholar”, “medRxiv”, and “bioRxiv.” Results: ASs may be idiopathic, but they are also associated with systemic conditions, such as pseudoxanthoma elasticum, hereditary hemoglobinopathies, or Paget’s disease. Currently, the main treatment is the use of anti-vascular endothelial growth factors (anti-VEGF) to treat secondary CNV, which is the major complication observed in this condition. If CNV is detected and treated promptly, patients with ASs have a good chance of maintaining functional vision. Other treatment modalities have been tried but have shown limited benefit and, therefore, have not managed to be more widely accepted. Conclusion: In summary, although there is no definitive cure yet, the use of anti-VEGF treatment for secondary CNV has provided the opportunity to maintain functional vision in individuals with AS, provided that CNV is detected and treated early. Full article

Astigmatism management is a frequently encountered challenge in the world of modern cataract surgery. This review article investigates the importance of astigmatic correction and seeks to uncover the critical components of preoperative evaluation. With the rapid growth of new technologies and techniques, this article aims to also catalogue and clarify the multitude of astigmatism treatment options available for the cataract surgeon. Full article

Background: The prevalence of dry eye disease (DED) is increasing globally, resulting in a variety of eye symptoms characterized by discomfort and visual disturbances. The accurate diagnosis of the disease is often challenging and complex, requiring specialized diagnostic tools. This study aimed to investigate the impact of tear film instability on visual function and to evaluate the value of post-blink blur time (PBBT) as an alternative method for assessing tear film stability. Methods: The study included 62 subjects: 31 with subjective symptoms of DED (Group A) and a control group consisting of 31 healthy participants (Group B). Symptoms were assessed using the standard Schein questionnaire, supplemented with additional questions. PBBT was measured using standard Snellen charts to investigate a potential association between PBBT and tear film dysfunction. Additional clinical assessments included tear film break-up time (TBUT). Results: Statistically significant differences were observed in the average values of PBBT and TBUT between the examined groups. The average PBBT was 8.95 ± 5.38 s in the group with DED and 14.66 ± 10.50 s in the control group, p < 0.001. Group A exhibited an average TBUT of 4.77 ± 2.37 s, while Group B had a TBUT of 7.63 ± 3.25 s, p < 0.001. Additionally, a strong positive correlation was identified between PBBT and TBUT values (r = 0.455; p < 0.001). Conclusions: The research confirms that tear film stability has an important role in the refraction of light and the maintenance of optical quality of vision. PBBT could potentially function as an objective and clinically significant screening test for DED. Full article

Prior work has shown that perceived angular elevation relative to a visible horizon/ground plane is exaggerated with a gain of about 1.5. Here, we investigated whether estimates of angular elevation remain exaggerated when no such visual gravitational reference is provided. This was investigated using a series of five experiments, with most using a novel apparatus to view a large field-of-view stereoscopic virtual environment while lying supine, looking straight up. Magnitude estimation methods were used as well as psychometric matches to internal standards with a total of 133 human participants. Generally, it was found that the exaggerated scaling of elevation seemed to be a default for 3D space, even if testing was performed in virtual environments that were nearly empty. Indeed, for supine observers, a strong exaggeration was found even for azimuthal judgments, which is consistent with the idea that, when looking upward, all deviations are in elevation. This suggests that the overarching gravitational frame often serves as a default reference frame. Full article

Deficits in fine motor skills have been reported in some children with neurodevelopmental disorders such as amblyopia or strabismus. Therefore, monitoring the development of motor skills and any potential improvement due to therapy is an important clinical goal. The aim of this study was to test the feasibility of performing a kinematic assessment within an optometric setting using inexpensive, portable, off-the-shelf equipment. The study also assessed whether kinematic data could enhance the information provided by a routine motor function screening test (the Movement Assessment Battery for Children, MABC). Using the MABC-2, upper limb dexterity was measured in a cohort of 47 typically developing children (7–15 years old), and the Leap motion capture system was used to record hand kinematics while children performed a bead-threading task. Two children with a history of amblyopia were also tested to explore the utility of a kinematic assessment in a clinical population. For the typically developing children, visual acuity and stereoacuity were within the normal range; however, the average standardized MABC-2 scores were lower than published norms. Comparing MABC-2 and kinematic measures in the two children with amblyopia revealed that both assessments provide convergent results and revealed deficits in fine motor control. In conclusion, kinematic assessment can augment standardized tests of fine motor skills in an optometric setting and may be useful for measuring visuomotor function and monitoring treatment outcomes in children with binocular vision anomalies. Full article

Past research suggests a continuity between perception and memory, as reflected in influences of orienting of spatial attention by cues presented after a visual target offset (post-target cues) on target perception. Conducting two experiments, we tested and confirmed this claim. Our study revealed an elevated reliance on post-target cues for target detection with diminishing target visibility, leading to better performance in validly versus invalidly cued trials, indicative of contrast gain. We demonstrated this post-target cueing impact on target perception without a postcue response prompt, meaning that our results truly reflected a continuity between perception and memory rather than a task-specific impact of having to memorize the target due to a response prompt. While previous studies found an improvement in accuracy through valid compared to invalid cues using liminal targets, in Experiment 1, we further showed an influence of attention on participants’ response time by the post-target cues with cues presented away from a clearly visible target. This suggests that visual interactions at the target location provided no better explanation of post-target cueing effects. Our results generalize prior research with liminal targets and confirm the view of a perception–memory continuum so that visual target processing is not shielded against visuospatial orienting of attention elicited by events following the offset of the visual target. Full article

It is one thing for everyday phrases like “seeing red” to link some emotions with certain colours (e.g., anger with red), but can such links measurably bias information processing? We investigated whether emotional face information (angry/happy/neutral) held in visual working memory (VWM) enhances memory for shapes presented in a conceptually consistent colour (red or green) (Experiment 1). Although emotional information held in VWM appeared not to bias memory for coloured shapes in Experiment 1, exploratory analyses suggested that participants who physically mimicked the face stimuli were better at remembering congruently coloured shapes. Experiment 2 confirmed this finding by asking participants to hold the faces in mind while either mimicking or labelling the emotional expressions of face stimuli. Once again, those who mimicked the expressions were better at remembering shapes with emotion-congruent colours, whereas those who simply labelled them were not. Thus, emotion–colour associations appear powerful enough to guide attention, but—consistent with proposed impacts of “embodied emotion” on cognition—such effects emerged when emotion processing was facilitated through facial mimicry. Full article

This retrospective study evaluates the effectiveness of combining 0.05% atropine with MF60 contact lenses in managing rapid myopia progression in children over one year. The study involved three groups: the treatment group (TG) with 15 children (53% male, average age 12.9 ± 1.04), the MF group (MF) with 12 children (50% male, average age 12.8 ± 0.8) using only MF60 lenses, and the control group (CG) with 14 children (43% male, average age 12.1 ± 0.76). Baseline myopia and axial length (AL) were similar across groups, with the TG, MF, and CG showing −4.02 ± 0.70 D, −4.18 ± 0.89 D, −3.86 ± 0.99 D, and 24.72 ± 0.73 mm, 24.98 ± 0.70 mm, 24.59 ± 1.02 mm, respectively. Prior to the study, all groups exhibited significant myopia and AL progression, with no previous myopia control management. The treatment involved daily 0.05% atropine instillation, the use of MF60 lenses and increased outdoor activity. Biannual cycloplegic refraction and slit lamp evaluations confirmed no adverse reactions. After one year, the TG showed a significant reduction in myopia and AL progression (−0.43 ± 0.46 D, p < 0.01; 0.22 ± 0.23 mm, p < 0.01), whereas the CG showed minimal change (−1.30 ± 0.43 D, p = 0.36; 0.65 ± 0.35 mm, p = 0.533). The MF group also exhibited a notable decrease (−0.74 ± 0.45 D, p < 0.01; 0.36 ± 0.23 mm). Increased outdoor activity during the treatment year did not significantly impact myopia control, suggesting its limited additional effect in this cohort. The study concludes that the combination of 0.05% atropine and peripheral defocus soft contact lenses effectively controls myopia progression in children. Full article

It has been suggested that there may be an imbalance of excitation and inhibitory processes in the visual areas of the brain in people with migraine aura (MA). One idea is thalamocortical dysrhythmia, characterized by disordered oscillations, and thus disordered communication between the lateral geniculate nucleus and the cortex. Cross-orientation suppression is a visual task thought to rely on inhibitory processing, possibly originating in the lateral geniculate nucleus. We measured both resting-state oscillations and cross-orientation suppression using EEG over occipital areas in people with MA and healthy volunteers. We found evidence of cross-orientation suppression in the SSVEP responses, but no evidence of any group difference. Therefore, inhibitory processes related to cross-orientation suppression do not appear to be impaired in MA. Full article

Faces and words are ever-present stimuli in social environments that require fine-grained, efficient discrimination of their constituents in order to acquire meaning. Provided that these stimuli share multiple characteristics, while simultaneously being different visual object categories in important ways, a debate has ensued pertaining to whether their processing can be reduced to a common mechanism or whether each category mobilizes exclusive resources. We thus first present briefly domain-specific and domain-general accounts, as opposing perspectives that highlight the absence and presence of commonalities in face and word processing, respectively. We then focus on how faces and words are processed. While faces are usually associated with holistic processing of facial features, to create a perceptual whole, there is no such consensus pertaining to word processing. Words have been argued to rely on either letter-by-letter processing or in a way closer to that of faces, since they are also objects of expertise. Lastly, we advance the debate by providing an overview of our latest research findings. These findings provide a more direct comparison of face and word processing, by incorporating both stimuli in one task concurrently. Full article