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Journal of Vision Apr 2024We obtain large amounts of external information through our eyes, a process often considered analogous to picture mapping onto a camera lens. However, our eyes are never...
We obtain large amounts of external information through our eyes, a process often considered analogous to picture mapping onto a camera lens. However, our eyes are never as still as a camera lens, with saccades occurring between fixations and microsaccades occurring within a fixation. Although saccades are agreed to be functional for information sampling in visual perception, it remains unknown if microsaccades have a similar function when eye movement is restricted. Here, we demonstrated that saccades and microsaccades share common spatiotemporal structures in viewing visual objects. Twenty-seven adults viewed faces and houses in free-viewing and fixation-controlled conditions. Both saccades and microsaccades showed distinctive spatiotemporal patterns between face and house viewing that could be discriminated by pattern classifications. The classifications based on saccades and microsaccades could also be mutually generalized. Importantly, individuals who showed more distinctive saccadic patterns between faces and houses also showed more distinctive microsaccadic patterns. Moreover, saccades and microsaccades showed a higher structure similarity for face viewing than house viewing and a common orienting preference for the eye region over the mouth region. These findings suggested a common oculomotor program that is used to optimize information sampling during visual object perception.
Topics: Humans; Saccades; Male; Female; Adult; Fixation, Ocular; Young Adult; Visual Perception; Photic Stimulation; Pattern Recognition, Visual
PubMed: 38656530
DOI: 10.1167/jov.24.4.20 -
Taiwan Journal of Ophthalmology 2024The purpose of the study was to report the complications of sutureless intrascleral (SIS) intraocular lens (IOL) fixation and its management.
PURPOSE
The purpose of the study was to report the complications of sutureless intrascleral (SIS) intraocular lens (IOL) fixation and its management.
MATERIALS AND METHODS
A multicenter, retrospective, consecutive interventional case series of patients with intra or postoperative complications after SIS IOL fixation during the technical learning curve of vitreoretinal surgeons from three Taiwanese referral hospitals. The used surgical techniques were the Scharioth technique for intrascleral tunnel fixation, Yamane technique (double-needle scleral fixation), and modified Yamane technique (double-needle flanged haptic scleral fixation). The IOL models and surgical instruments used as well as each patient's ocular characteristics and complication management were recorded.
RESULTS
Of the eight included patients, the complications of 3 (37.5%) and 5 (62.5%) were noted intraoperatively and postoperatively, respectively. Haptic-related complications, including haptic breakage, slippage, and haptic disinsertion, occurred in six eyes. Other complications included uveitis-glaucoma-hyphema syndrome, retinal detachment, and IOL tilt. For the two patients with haptic slippage, repositioning was achieved using a modified cow-hitch technique that resulted in favorable IOL centration and restored visual acuity.
CONCLUSION
Most complications surgeons encountered during their early exposure to SIS IOL fixation were haptic related. Surgeons should be aware of such complications to prevent and manage them during surgery. Our modified cow-hitch technique could be used to reposition IOLs with unilateral haptic slippage.
PubMed: 38654989
DOI: 10.4103/tjo.TJO-D-23-00163 -
Journal of Cataract and Refractive... May 2024To compare flange depth for a modified scleral pocket (SP) vs no scleral pocket (NSP) technique (Yamane technique) for intrascleral intraocular lens (IOL) fixation. (Randomized Controlled Trial)
Randomized Controlled Trial Observational Study Comparative Study
PURPOSE
To compare flange depth for a modified scleral pocket (SP) vs no scleral pocket (NSP) technique (Yamane technique) for intrascleral intraocular lens (IOL) fixation.
SETTING
Instituto de Oftalmología Santa Fe, Santa Fe, Argentina.
DESIGN
Prospective, randomized, single-surgeon, observational study.
METHODS
Eyes with aphakia and no capsular support were included. They were divided into 2 groups: one was programmed for a double-needle flanged intrascleral IOL fixation as originally described by Shin Yamane with NSP and the second group had a modified SP technique. Flange depth was measured with anterior-segment optical coherence tomography (AS-OCT) at 1 month, 3 months, 6 months, and 12 months postoperatively, and the results were compared.
RESULTS
Each group comprised 18 eyes of 18 patients, giving a total of 36 flanges per group. The groups were comparable preoperatively. At 12 months, uncorrected distance visual acuity and corrected distance visual acuity (CDVA) were not statistically different for both groups (P = .333; P = .448). Spherical equivalent (SEQ) was not significantly different between groups at 12 months postoperatively (P = .078). AS-OCT revealed a significantly deeper flange position for the SP group at 1 month, 3 months, 6 months, and 12 months postoperatively (P < .05).
CONCLUSIONS
When performing a double-needle intrascleral IOL fixation in aphakic eyes with no capsular support, a modified scleral pocket technique provides a significantly deeper flange position with no difference in CDVA or SEQ 12 months postoperatively.
Topics: Humans; Sclera; Lens Implantation, Intraocular; Prospective Studies; Visual Acuity; Tomography, Optical Coherence; Lenses, Intraocular; Female; Male; Middle Aged; Aged; Aphakia, Postcataract; Surgical Flaps; Suture Techniques; Pseudophakia; Refraction, Ocular
PubMed: 38651698
DOI: 10.1097/j.jcrs.0000000000001383 -
Eye and Brain 2024This review delineates the ocular motor disturbances across a spectrum of neurodegenerative disorders, including Alzheimer's Disease (AD) and related disorders (ADRD),... (Review)
Review
This review delineates the ocular motor disturbances across a spectrum of neurodegenerative disorders, including Alzheimer's Disease (AD) and related disorders (ADRD), Parkinson's Disease (PD), atypical parkinsonism, and others, leveraging advancements in eye-tracking technology for enhanced diagnostic precision. We delve into the different classes of eye movements, their clinical assessment, and specific abnormalities manifesting in these diseases, highlighting the nuanced differences and shared patterns. For instance, AD and ADRD are characterized by increased saccadic latencies and instability in fixation, while PD features saccadic hypometria and mild smooth pursuit impairments. Atypical parkinsonism, notably Progressive Supranuclear Palsy (PSP) and Corticobasal Syndrome (CBS), presents with distinct ocular motor signatures such as vertical supranuclear gaze palsy and saccadic apraxia, respectively. Our review underscores the diagnostic value of eye movement analysis in differentiating between these disorders and also posits the existence of underlying common pathological mechanisms. We discuss how eye movements have potential as biomarkers for neurodegenerative diseases but also some of the existing limitations.
PubMed: 38617403
DOI: 10.2147/EB.S384769 -
Digital Biomarkers 2024Visual acuity and image stability are crucial for daily activities, particularly during head motion. The vestibulo-ocular reflex (VOR) and its suppression (VORS) support... (Review)
Review
BACKGROUND
Visual acuity and image stability are crucial for daily activities, particularly during head motion. The vestibulo-ocular reflex (VOR) and its suppression (VORS) support stable fixation of objects of interest. The VOR drives a reflexive eye movement to counter retinal slip of a stable target during head motion. In contrast, VORS inhibits this countermovement when the target stimulus is in motion. The VORS allows for object fixation when it aligns with the direction of the head's movement, or when an object within or outside the peripheral vision needs to be focused upon.
SUMMARY
Deficits of the VORS have been linked to age-related diseases such as balance deficits associated with an increased fall risk. Therefore, the accurate assessment of the VORS is of particular clinical relevance. However, current clinical assessment methods for VORS are mainly qualitative and not sufficiently standardised. Recent advances in digital health technology, such as smartphone-based videooculography, offer a promising alternative for assessing VORS in a more accessible, efficient, and quantitative manner. Moreover, integrating mobile eye-tracking technology with virtual reality environments allows for the implementation of controlled VORS assessments with different visual inputs. These assessment approaches allow the extraction of novel parameters with potential pathomechanistic and clinical relevance.
KEY MESSAGES
We argue that researchers and clinicians can obtain a more nuanced understanding of this ocular stabilisation reflex and its associated pathologies by harnessing digital health technology for VORS assessment. Further research is warranted to explore the technologies' full potential and utility in clinical practice.
PubMed: 38617128
DOI: 10.1159/000537842 -
Physiology & Behavior Jun 2024Children born very preterm often exhibit atypical gaze behaviors, affect recognition difficulties and are at risk for cerebral white matter damage. This study explored...
Children born very preterm often exhibit atypical gaze behaviors, affect recognition difficulties and are at risk for cerebral white matter damage. This study explored links between these sequalae. In 24 12-year-old children born very preterm, ventricle size using Evans and posterior ventricle indices, and corpus callosum area were used to measure white matter thickness. The findings revealed a correlation between less attention towards the eyes and larger ventricle size. Ventricle and posterior corpus callosum sizes were correlated to affect-recognition proficiency. Findings suggest a link between white matter damage, gaze behavior, and affect recognition accuracy, emphasizing a relation with social perception.
Topics: Humans; Pilot Projects; Magnetic Resonance Imaging; Female; Child; Male; Infant, Extremely Premature; White Matter; Recognition, Psychology; Corpus Callosum; Cerebral Ventricles; Fixation, Ocular
PubMed: 38615730
DOI: 10.1016/j.physbeh.2024.114553 -
Neuropsychologia Jul 2024Left smooth pursuit eye movement training in response to large-field visual motion (optokinetic stimulation) has become a promising rehabilitation method in left spatial...
Left smooth pursuit eye movement training in response to large-field visual motion (optokinetic stimulation) has become a promising rehabilitation method in left spatial inattention or neglect. The mechanisms underlying the therapeutic effect, however, remain unknown. During optokinetic stimulation, there is an error in visual localisation ahead of the line of sight. This could indicate a change in the brain's estimate of one's own direction of gaze. We hypothesized that optokinetic stimulation changes the brain's estimate of gaze. Because this estimate is critical for coding the locus of attention in the visual space relative to the body and across sensory modalities, its change might underlie the change in spatial attention. Here, we report that in healthy participants optokinetic stimulation causes not only a directional bias in the proprioceptive signal from the extraocular muscles, but also a corresponding shift of the locus of attention. Both changes outlasted the period of stimulation. This result forms a step in investigating a causal link between the adaptation in the sensorimotor gaze signals and the recovery in spatial neglect.
Topics: Humans; Attention; Male; Perceptual Disorders; Female; Adult; Fixation, Ocular; Photic Stimulation; Space Perception; Young Adult; Motion Perception; Proprioception; Pursuit, Smooth
PubMed: 38599567
DOI: 10.1016/j.neuropsychologia.2024.108883 -
Attention, Perception & Psychophysics May 2024Competing theories attempt to explain what guides eye movements when exploring natural scenes: bottom-up image salience and top-down semantic salience. In one study, we...
Competing theories attempt to explain what guides eye movements when exploring natural scenes: bottom-up image salience and top-down semantic salience. In one study, we apply language-based analyses to quantify the well-known observation that task influences gaze in natural scenes. Subjects viewed ten scenes as if they were performing one of two tasks. We found that the semantic similarity between the task and the labels of objects in the scenes captured the task-dependence of gaze (t(39) = 13.083; p < 0.001). In another study, we examined whether image salience or semantic salience better predicts gaze during a search task, and if viewing strategies are affected by searching for targets of high or low semantic relevance to the scene. Subjects searched 100 scenes for a high- or low-relevance object. We found that image salience becomes a worse predictor of gaze across successive fixations, while semantic salience remains a consistent predictor (X(1, N=40) = 75.148, p < .001). Furthermore, we found that semantic salience decreased as object relevance decreased (t(39) = 2.304; p = .027). These results suggest that semantic salience is a useful predictor of gaze during task-related scene viewing, and that even in target-absent trials, gaze is modulated by the relevance of a search target to the scene in which it might be located.
Topics: Humans; Semantics; Fixation, Ocular; Attention; Male; Female; Young Adult; Adult; Pattern Recognition, Visual; Eye Movements
PubMed: 38594445
DOI: 10.3758/s13414-024-02883-w -
Scientific Reports Apr 2024Altered nonverbal communication patterns especially with regard to gaze interactions are commonly reported for persons with autism spectrum disorder (ASD). In this study...
Impaired recognition of interactive intentions in adults with autism spectrum disorder not attributable to differences in visual attention or coordination via eye contact and joint attention.
Altered nonverbal communication patterns especially with regard to gaze interactions are commonly reported for persons with autism spectrum disorder (ASD). In this study we investigate and differentiate for the first time the interplay of attention allocation, the establishment of shared focus (eye contact and joint attention) and the recognition of intentions in gaze interactions in adults with ASD compared to control persons. Participants interacted via gaze with a virtual character (VC), who they believed was controlled by another person. Participants were instructed to ascertain whether their partner was trying to interact with them. In fact, the VC was fully algorithm-controlled and showed either interactive or non-interactive gaze behavior. Participants with ASD were specifically impaired in ascertaining whether their partner was trying to interact with them or not as compared to participants without ASD whereas neither the allocation of attention nor the ability to establish a shared focus were affected. Thus, perception and production of gaze cues seem preserved while the evaluation of gaze cues appeared to be impaired. An additional exploratory analysis suggests that especially the interpretation of contingencies between the interactants' actions are altered in ASD and should be investigated more closely.
Topics: Adult; Humans; Autism Spectrum Disorder; Intention; Fixation, Ocular; Social Perception; Nonverbal Communication
PubMed: 38594289
DOI: 10.1038/s41598-024-58696-2 -
Scientific Reports Apr 2024Eye contact is a central component in face-to-face interactions. It is important in structuring communicative exchanges and offers critical insights into others'...
Eye contact is a central component in face-to-face interactions. It is important in structuring communicative exchanges and offers critical insights into others' interests and intentions. To better understand eye contact in face-to-face interactions, we applied a novel, non-intrusive deep-learning-based dual-camera system and investigated associations between eye contact and autistic traits as well as self-reported eye contact discomfort during a referential communication task, where participants and the experimenter had to guess, in turn, a word known by the other individual. Corroborating previous research, we found that participants' eye gaze and mutual eye contact were inversely related to autistic traits. In addition, our findings revealed different behaviors depending on the role in the dyad: listening and guessing were associated with increased eye contact compared with describing words. In the listening and guessing condition, only a subgroup who reported eye contact discomfort had a lower amount of eye gaze and eye contact. When describing words, higher autistic traits were associated with reduced eye gaze and eye contact. Our data indicate that eye contact is inversely associated with autistic traits when describing words, and that eye gaze is modulated by the communicative role in a conversation.
Topics: Humans; Autistic Disorder; Communication; Nonverbal Communication; Fixation, Ocular; Intention
PubMed: 38589489
DOI: 10.1038/s41598-024-58701-8