Gaze Position Research Articles

Evaluation of Scleral Thickness in Patients With Keratoconus.

To evaluate scleral thickness of patients with keratoconus by anterior segment optical coherence tomography (AS-OCT). Fifty-two eyes of 42 patients with keratoconus (group 1) and 42 right eyes of 42 healthy individuals (group 2) were included. Scleral thickness measurements were taken with AS-OCT 6, 4, and 2 mm behind the scleral spur in four gaze positions: superior, inferior, temporal, and nasal. The data including central corneal thickness (CCT) by Pentacam from patients with keratoconus was also analyzed and its relationship with scleral thickness was evaluated. In group 1, mean scleral thickness from 6 mm posterior to scleral spur in superior, inferior, temporal, and nasal quadrants were 397±35.3 (320-482), 408±29.5 (341-467), 393±40.8 (297-469), and 403±35.8 (310-482) μm, respectively. In group 2, mean scleral thickness from 6 mm posterior to scleral spur in superior, inferior, temporal, and nasal quadrants were 440±42.2 (346-552), 461±33.9 (390-563), 451±46.6 (340-549) and 448±34.3 (350-521) μm, respectively. The mean scleral thickness in group 1 was significantly lower in all quadrants compared with group 2 (P<0.001). The mean CCT in group 1 was 478.22±87.55 (306-632) μm. Positive correlation was found between scleral thickness measurements taken at 4 mm (ϱ=0.312, P=0.037) and 2 mm (ϱ=0.308, P=0.039) posterior from the scleral spur in the inferior quadrant and CCT. Scleral thickness was significantly lower in patients with keratoconus. Scleral thickness and CCT were positively correlated in inferior quadrant. Even though it is not yet known whether scleral changes are progressive or not, scleral thickness measurement may also find a place in the diagnosis and follow-up of patients with keratoconus in the future.

Effect of virtual interactions through avatar agents on the joint Simon effect.

The joint Simon effect refers to inhibitory responses to spatially competing stimuli during a complementary task. This effect has been considered to be influenced by the social factors of a partner: sharing stimulus-action representation. According to this account, virtual interactions through their avatars would produce the joint Simon effect even when the partner did not physically exist in the same space because the avatars are intentional agents. To investigate this, we conducted two joint experiments in which participants controlled avatars as their agents in immersive virtual environments. In Experiment 1, participants were asked to touch a virtual button through their avatars when a target color of an object was presented. The target position was manipulated to be compatible with the button (compatible stimulus) or incompatible with the button (incompatible stimulus). In Experiment 2, the task was identical to that in Experiment 1 except that participants' gaze position was either visualized or not during the task. We hypothesized that visualizing the partner's gaze would enhance the joint Simon effect because gaze is a cue to mentalize others' internal states. The results showed that avatar-based interactions more significantly delayed responses for the incompatible than for the compatible stimulus. However, inconsistent with our hypothesis, visualizing the partner's gaze position did not influence responses for spatially competing stimuli. These results suggest that virtual interactions through avatar agents can produce the joint Simon effect even when the partner does not physically exist in the same space.

Genetic findings in paediatric patients with nystagmus

Nystagmus, a condition characterized by involuntary eye movements, can be classified into two primary categories: infantile nystagmus (IN) and acquired nystagmus. IN typically manifests within the first 3‐6 months of life and can be idiopathic or associated with various ocular conditions, including inherited retinal dystrophies (IRD), albinism, or congenital cataracts. Acquired nystagmus appears later in life.Diagnostic approaches for nystagmus involve comprehensive eye examinations, including optical coherence tomography (OCT), and electrophysiology testing to differentiate underlying ocular diseases. The advent of new medical devices allows for detailed recording of eye movements, capturing data on gaze positions, amplitude, frequency, intensity, phase speed, and other parameters, thereby enhancing diagnosis and management.Recent advancements in genetics have significantly impacted the diagnostic process for nystagmus. Genetic testing is increasingly recognized as a crucial component, especially given the development of gene therapies for ocular conditions. We advocate for the routine use of genetic testing in paediatric patients with nystagmus to achieve definitive diagnoses and inform treatment strategies.This study presents a retrospective review of paediatric nystagmus cases referred to our Genetics Department from January 1, 2020, to January 1, 2024. Our findings indicate a significant increase in molecular diagnostic rates following clinical phenotyping.Genetic testing is instrumental in the diagnosis and management of paediatric nystagmus, particularly in the context of ongoing advancements in gene therapy for IRDs.

Comparative Analysis of Physiological Vergence Angle Calculations from Objective Measurements of Gaze Position.

Eccentric photorefractometry is widely used to measure eye refraction, accommodation, gaze position, and pupil size. While the individual calibration of refraction and accommodation data has been extensively studied, gaze measurements have received less attention. PowerRef 3 does not incorporate individual calibration for gaze measurements, resulting in a divergent offset between the measured and expected gaze positions. To address this, we proposed two methods to calculate the physiological vergence angle based on the visual vergence data obtained from PowerRef 3. Twenty-three participants aged 25 ± 4 years viewed Maltese cross stimuli at distances of 25, 30, 50, 70, and 600 cm. The expected vergence angles were calculated considering the individual interpupillary distance at far. Our results demonstrate that the PowerRef 3 gaze data deviated from the expected vergence angles by 9.64 ± 2.73° at 25 cm and 9.25 ± 3.52° at 6 m. The kappa angle calibration method reduced the discrepancy to 3.93 ± 1.19° at 25 cm and 3.70 ± 0.36° at 600 cm, whereas the linear regression method further improved the accuracy to 3.30 ± 0.86° at 25 cm and 0.26 ± 0.01° at 600 cm. Both methods improved the gaze results, with the linear regression calibration method showing greater overall accuracy.

Appearance-Based Gaze Estimation With Deep Learning: A Review and Benchmark.

Human gaze provides valuable information on human focus and intentions, making it a crucial area of research. Recently, deep learning has revolutionized appearance-based gaze estimation. However, due to the unique features of gaze estimation research, such as the unfair comparison between 2D gaze positions and 3D gaze vectors and the different pre-processing and post-processing methods, there is a lack of a definitive guideline for developing deep learning-based gaze estimation algorithms. In this paper, we present a systematic review of the appearance-based gaze estimation methods using deep learning. First, we survey the existing gaze estimation algorithms along the typical gaze estimation pipeline: deep feature extraction, deep learning model design, personal calibration and platforms. Second, to fairly compare the performance of different approaches, we summarize the data pre-processing and post-processing methods, including face/eye detection, data rectification, 2D/3D gaze conversion and gaze origin conversion. Finally, we set up a comprehensive benchmark for deep learning-based gaze estimation. We characterize all the public datasets and provide the source code of typical gaze estimation algorithms. This paper serves not only as a reference to develop deep learning-based gaze estimation methods, but also a guideline for future gaze estimation research.

A continuum from predictive to online feedback in visuomotor interception.

Interception, essential for activities like driving and sports, can be characterized by varying degrees of predictive behaviour. We developed a visually guided task to explore how target predictability and visibility influenced interception actions. The task featured a falling dot influenced by horizontal velocity, gravity and air friction, with predictability manipulated through external forces that altered the target's trajectory. We also introduced spatial occlusion to limit visual information. Our results show that low target variability favoured predictive behaviours, while high variability led to more reactive responses relying on online feedback. Manual responses displayed increased variability with changes in target motion, whereas eye trajectories maintained constant curvature across conditions. Additionally, higher target variability delayed the onset of hand movements but did not affect eye movement onset, making gaze position a poor predictor of hand position. This distinction highlights the different adaptive patterns in hand and eye movements in response to target trajectory changes. Participants maintained stable interception behaviours within and across sessions, indicating individual preferences for either predictive or more reactive actions. Our findings reveal a dynamic interplay between target predictability and interception, illustrating how humans combine predictive and reactive behaviours to manage external variability.

Ocular Duction Measurement Using Three Convolutional Neural Network Models: A Comparative Study.

This study primarily aimed to compare the accuracy of three convolutional neural network (CNN) models in measuring the four positions of ocular duction. Further, it secondarily aimed to compare the accuracy of each CNN model in the training dataset versus the ophthalmologist measurements. This study included 526 subjects aged over 18 who visited the ophthalmology outpatient department. Ocular images were captured using mobile phones in various gaze positions and stored anonymously as JPEG files. Ocular duction was measured by assessing corneal light reflex deviation from the central cornea. Ductions were classified into 30, 60, and 90 prism diopters (PD) and full ductions from the primary position. Three CNN models, MobileNet, ResNet, and EfficientNet, were used to classify ocular duction. Their predictive ability was evaluated using the area under the receiver operating characteristic (AUROC) curve. The dataset was divided into the training (2,001 images), evaluation (213 images), and testing (190 images) groups, which were reconstructed using the routine follow-up data of volunteers at the Ophthalmology Department of Phramongkutklao Hospital between February 2023 and June 2023. To evaluate the data, the MobileNet_V3_Large, ResNet101, and EfficientNet_B5 models were utilized to measure duction angles with the receiver operating characteristic (ROC) curves. The training times for MobileNet, ResNet, and EfficientNet were 5.54, 9.56, and 26.39 minutes, respectively. In the testing phase, MobileNet, ResNet, and EfficientNet were used to measure each duction position: 30 PD with corresponding ROC curve values of 0.77, 0.5, and 0.58; 60 PD with ROC curve values of 0.71, 0.83, and 0.81; 90 PD with ROC curve values of 0.7, 0.73, and 0.81; and full duction with ROC curve values of 0.91, 0.93, and 0.94, respectively. Analysis of variance revealed no significant difference in the mean AUROC curves among the models, yielding a p-value of 0.936.MobileNet has the narrowest confidence intervals for average prediction accuracy across three CNN models. The three CNN models did not significantly differ in terms of efficacy in detecting various duction positions. However, MobileNet stands out, with a narrower confidence interval and shorter training time, which indicates its potential application.

Implications of Retrograde Behaviours on Visual and Cycling Behaviour of Normal Cyclists

In China and other developing countries, some bicycle riders exhibit retrograde behaviour, which affects the riding safety of normal cyclists. The effect of retrograde behaviour on visual search and cycling behaviours of normal cyclists is investigated and quantified in this study. First, cyclists are instructed to wear an SMI iView ETG head-mounted mobile eye tracker and a mobile phone equipped with a Global Positioning System real-time location monitoring function to cycle on a road to obtain the times of fixation, saccade and blink, as well as the pupil diameter, gaze position and velocity in normal and retrograde conditions. Subsequently, the effect of retrograde behaviour on the attention of normal cyclists is analysed using three indexes: proportion of fixation time, coefficient of variation of pupil diameter and area of interest. Then, the effect of cycling behaviour is analysed using three indexes: the cycling trajectory, the velocity at three stages and the coefficient of variation of velocity. Finally, polynomial regression analysis is performed to analyse the visual and cycling behaviour impact indexes under the retrograde condition. The results show that retrograde behaviour significantly affects the vision and cycling behaviour of normal cyclists and that the two indexes are positively correlated.

Exploring horses’ (Equus caballus) gaze and asymmetric ear position in relation to human attentional cues

Studies have shown that horses are sensitive to human attentional cues. Also, there is some evidence that they might be able to infer the knowledge state of a human and communicate intentionally with us. However, this ability is not fully characterized and certain behaviors, like gaze, asymmetric ears position or vocalizations, which could work as attention-getting behaviors, have been scarcely studied in this context. The aim of the present study was to assess whether horses’ gaze toward a person, asymmetric ears position and vocalizations are subject to audience effects and adjust to human attentional cues, which would suggest a communicative function. For this purpose, we adapted a protocol used with domestic dogs [Kaminski et al. 2017] and observed horses’ spontaneous behavior (gaze, asymmetric ears position and vocalizations) in the presence of a human holding and not holding food in an attentive position (facing the horse with open eyes) and in a non-attentive position (with her back turned towards the horse). We found significant evidence of horses being sensitive to human attentional cues (reflected in the horses’ gaze duration and asymmetric position of the ears), but not of intentional communication towards humans.

Factors Associated with Retinal Microvasculature Dropout Induced by Elevation of Intraocular Pressure in Primary Open-Angle Glaucoma.

To investigate the risk factors related to decrease in vessel density (VD) observed in primary open-angle glaucoma (POAG), due to acute increase in intraocular pressure (IOP) by an ophthalmodynamometer (OPD). This cross-sectional study involved 42 eyes of participants (22 Controls and 20 POAG patients) that underwent optical coherence tomography angiography (OCT-A) to assess VD in the peripapillary region in three examination sets: primary gaze position (1), 25-degree adduction (2) and 25-degree adduction with OPD compression (3). Individual relationships between IOP levels and changes in the superficial complex VD were evaluated after image processing and exclusion of large retinal vessels. Multivariable regression analysis was used to verify factors associated with differences in VD induced by IOP elevation. A significant increase in IOP was induced by OPD compression during adduction (mean ± SD, Control: + 13.8 ± 2.8; POAG: + 13.4 ± 2.1mmHg). Only during IOP elevation (set 3), a significant VD decrease was observed both in POAG eyes (p = 0.008) and controls (p = 0.022). Baseline IOP (p = 0.022), maximum IOP (p = 0.003), and scleral rigidity (p = 0.029) were significantly associated with VD decreases in eyes with POAG. No changes were observed in VD during adduction gaze exclusively. Acute IOP elevation induced with OPD, but not adduction gaze, decreased peripapillary VD measured with OCT-A imaging. IOP levels and scleral rigidity significantly affected VD reduction in POAG patients. Thus, high scleral rigidity may decrease the ability of the globe to dampen the well-known effects of IOP fluctuation on glaucoma onset and progression. What is known Decrease vascular density in the peripapillary retina was associated with POAG, but factors related to the vascular response to elevated IOP are unexplored. What is new OCT-A quantification shows decreases in vascular density of the superficial layers of the peripapillary retina during an acute elevation in IOP. High IOP levels and scleral rigidity significantly affected vascular density reduction in POAG patients.

Comparison between surgical outcome of bilateral recession and unilateral recession-resection in intermittent exotropia

Purpose The aim of this study was to compare the postoperative drift after bilateral lateral rectus recession (BLR) compared to unilateral lateral rectus recession combined with medial rectus resection (R&amp;R) in children with intermittent exotropia. Patients and methods This is a prospective comparative study that included 52 patients with intermittent exotropia [range=20–50 prism diopters (PD)] who were recruited from the Pediatric Ophthalmology Clinic of the Research Institute of Ophthalmology, Giza, and Beni-Suef University Hospital, Beni-Suef, Egypt between February and September 2020. The patients were randomly divided into two equal groups: BLR group and R&amp;R group, each of 26 patients. The patients were subjected to complete ophthalmic examination including best corrected visual acuity and a full cycloplegic refraction. An alternate prism cover test with accommodative target was used to measure the deviations in the nine positions of gaze, both for distance and near. The cover test was used to examine the control of exodeviation. The ocular dominance was measured by hole in card test. Accommodative convergence/accommodation ratio was measured using the gradient method. The amblyopia cases were not included in this study. According to the postoperative results after 1 year, the patients were assigned to one of the following groups: success [esophoria or esotropia≤5 PD or exophoria or exotropia≤10 PD], overcorrection (esophoria or esotropia &gt;5 PD), and undercorrection or recurrence (exophoria or exotropia &gt;10 PD). Results There was a statistically significant improvement in the angle of deviation after surgery in both groups. In the BLR group, the mean angle of deviation significantly improved from 37.5±5.34 PD preoperatively to 0.58±1.39 PD at 6 months (P&lt;0.00001) and to −2.73±5.95 PD at 12 months (P&lt;0.00001), while in the R&amp;R group, it significantly improved from 39.62±6.15 PD preoperatively to −1.38±2.06 PD at 6 months (P&lt;0.00001) and to −4.42±7.5 PD at 12 months (P&lt;0.00001). At 12 months, the surgical success rate was 92.3% in the BLR group and 84.62% in the R&amp;R group, with no statistically significant difference (P&gt;0.05). There were no serious intraoperative or postoperative complications in either group. Conclusion With long-term follow up, the BLR group appeared to have more stable results on ocular alignment compared to the R&amp;R group.

CANVAS For A Diagnosis: Can You Hear The Hooves Of Zebras?

Abstract Background A 75year old male presented to a Movement Disorder Service with complex multimorbidity including: chronic pain, type 2 diabetes mellitus, hypoventilatory obesity syndrome, biliary calculus, moderate aortic stenosis, marked orthostatic hypotension, pulmonary hypertension, coronary artery bypass grafting, permanent pacemaker for complete atrioventricular block, carpal tunnel release bilaterally, polypharmacy and bilateral cataracts. History elucidated a distal to proximal sensory loss over 20years and neuropathic pain without nerve conduction confirmation; and progressively ataxic gait over several years. He also complained of hypophonia, bruxism, excessive daytime somnolence, passages, transitions, visual agnosia, textural illusion, oscillopsia, irritability, inflexibility, hoarding, impulsivity, disorganisation, inattention, apathy, depression and aspontaneity. He was intolerant of nocturnal continuous positive airway pressure device. Epworth score was 21. Methods Examination demonstrated: marked orthostatic hypotension, preserved cognition, hypersomnolence, dyspraxic dysgraphia, palmar and antecubital agraphaesthesia, downbeat horizontal nystagmus at eccentric gaze positions, square wave jerks, bidirectionally impaired head impulse test, dysmetric saccades, asymmetric cerebellar signs in upper and lower limbs, rightward Pisa syndrome, kinesigenic dystonic axial posturing, rightward laterocollis and equivocal Babinski/Oppenheim reflexes. Gait assessment demonstrated sensory and cerebellar ataxic features with marked apraxia. No pes cavus. Results Computed tomography of brain had Fazekas 1 small vessel disease, Medial temporal atrophy score 1, Koedam 1 and age-commensurate cerebral and cerebellar atrophy. RFC1 gene testing confirmed biallelic intronic AAGGG repeat expansion disorder. Conclusion Cerebellar Ataxia Neuropathy and Vestibular Areflexia Syndrome (CANVAS) should be considered in patients with presentations from mid-life of progressive sensory ataxic neuropathy, altered vestibular ocular reflex, gaze evoked nystagmus and prominent dysautonomia. CANVAS is a rare autosomal recessive genetic disorder with a protean presentation. Referral to Genetics Services should be undertaken for family counselling. Keeping an open mind in complex, multimorbid patients to a potentially unifying diagnosis is important to guide prognostication. The rumble of hooves in the distance is not always that of horses.

How to improve ZMC fracture reconstruction due to severe enophthalmos

Introduction and importanceZygomaticomaxillary (ZMC) fractures are common, often resulting from traffic accidents, and account for 17 % of facial fractures. These fractures can lead to issues such as enophthalmos, flattened cheeks, diplopia, maxillary hypoesthesia. If the reduction is inadequate to restore facial structure, long term-functional and aesthetic complications may arise. In such cases a computed tomography (CT) scan with 3-dimensional (3D) reconstruction is valuable to assessing the fracture and planning surgery, with current technological advancements, 3D printing can now be utilized for this purpose. Presentation of caseA 24-year-old male, after a motorcycle accident and initial surgery for maxillofacial fractures, experienced persistent diplopia and facial numbness. Physical examination showed malpositioning of the right eye, and a CT scan with 3D reconstruction revealed multiple fractures and prior internal fixation. A 3D-printed model was created to plan a second surgery using rib cartilage and a silicone orbital base for orbital rim reconstruction. Post-surgery, the patient reported minimal pain and no diplopia or blurred vision in the primary gaze position. Clinical discussions3D printing is beneficial in facial reconstruction, aiding in surgical planning by allowing precise measurement and design of graft. Rib cartilage can serve as an alternative for orbital rim reconstruction, and 3D printing facilitates accurate harvesting of the rib. ConclusionIn cases of severe ZMC fracture, 3D printing was utilized as a guide during surgical preparation to achieve improved outcomes.

Visuomotor predictors of interception.

Intercepting moving targets is a fundamental skill in human behavior, influencing various domains such as sports, gaming, and other activities. In these contexts, precise visual processing and motor control are crucial for adapting and navigating effectively. Nevertheless, there are still some gaps in our understanding of how these elements interact while intercepting a moving target. This study explored the dynamic interplay among eye movements, pupil size, and interceptive hand movements, with visual and motion uncertainty factors. We developed a simple visuomotor task in which participants used a joystick to interact with a computer-controlled dot that moved along two-dimensional trajectories. This virtual system provided the flexibility to manipulate the target's speed and directional uncertainty during chase trials. We then conducted a geometric analysis based on optimal angles for each behavior, enabling us to distinguish between simple tracking and predictive trajectories that anticipate future positions of the moving target. Our results revealed the adoption of a strong interception strategy as participants approached the target. Notably, the onset and amount of optimal interception strategy depended on task parameters, such as the target's speed and frequency of directional changes. Furthermore, eye-tracking data showed that participants continually adjusted their gaze speed and position, continuously adapting to the target's movements. Finally, in successful trials, pupillary responses predicted the amount of optimal interception strategy while exhibiting an inverse relationship in trials without collisions. These findings reveal key interactions among visuomotor parameters that are crucial for solving complex interception tasks.

Effects of head gaze and body position on attention in real-world scenes.

Effects of head gaze and body position on attention in real-world scenes.

Ultra-fine knowledge of gaze position in saccade planning

Ultra-fine knowledge of gaze position in saccade planning

Writing direction influences the spatial representations of past- and future-tense forms: Evidence from eye tracking.

The present study tests the hypothesis that the directionality of reading habits (left-to-right or right-to-left) impacts individuals' representation of nonspatial events. Using the blank screen paradigm, we examine whether eye movements reflect culture-specific spatial biases in processing temporal information, specifically, grammatical tense in Russian and Hebrew. Sixty-two native speakers of Russian (a language with a left-to-right reading and writing system) and 62 native speakers of Hebrew (a language with a right-to-left reading and writing system) listened to verbs in the past or future tense while their spontaneous gaze positions were recorded. Following the verb, a visual spatial probe appeared in one of the five locations of the screen, and participants responded manually to indicate its position. While participants' response latencies to the spatial probe revealed no significant effects, their gaze positions along the horizontal axis for past- and future-tensed verbs aligned with the reading and writing direction in their language. These results provide novel evidence that eye movements during auditory processing of grammatical tense are influenced by culturally specific reading and writing conventions, shifting leftward or rightward on the horizontal plane depending on the stimuli's time reference (past or future) and the participants' language (Russian or Hebrew). This spatial bias indicates a common underlying cognitive mechanism that uses spatial dimensions to represent temporal constructs.

Analysis of head and eye dynamic may explain saccades in dizzy patients with normal VOR gain

ObjectiveCompare the vestibulo-ocular reflex (VOR) gain, compensatory saccades and head and eye coordination during head impulses between patients with dizziness but normal VOR gain and healthy controls. MethodsVideo head impulses test (vHIT; ICS impulse, Otometrics, Denmark) was reviewed in 40 participants (20 patients with dizziness; 20 controls). VOR gain, saccades characteristics (frequency of occurrence, amplitude, latency) and time difference between head and eye velocity was compared. ResultsNo significant difference between groups was observed for VOR gain. However, saccade frequency was greater and time difference between head and eye was prolonged in patients with dizziness. No significant difference was observed for saccade amplitude, nor for saccade latency between groups. ConclusionsThe present study highlights that saccades observed in patients with normal VOR gain could reflect a clinical marker for dizziness in patients with normal VOR gain. We propose that theses saccades are caused by a prolonged time delay between head and eye velocity leading to a gaze position error. SignificanceThe results support previous findings suggesting additional value of saccades and time delay when interpreting vHIT results. This study goes further by proposing time delay as a possible mechanism to explain increased saccade frequency in dizzy patients with normal VOR gain.

Superior rectus/levator complex in acquired anophthalmic socket repaired with spheric implant-a computed tomography scan and topographic study.

To determine whether the levator palpebrae superioris (LPS)/superior rectus (SR) muscle complex, can influence the position of the upper lid and fornix in acquired anophthalmic sockets. This comparative non-randomized and non-interventional study included retrospective data of 21 patients with unilateral acquired anophthalmic sockets repaired with spheric implants. High-resolution computed tomography (CT) measurements of the LPM/SR muscle complex and clinical topographic position of the upper lid, superior and inferior fornix depth in primary gaze position were evaluated. Demographic data were presented as frequency and percentage proportions and quantitative variables comparing the socket measurements with the normal contralateral orbit was statistically analyzed using non-parametric tests considering P<0.05. The anophthalmic orbits had a significantly shorter LPS length (P=0.01) and significantly thicker SR (P=0.02) than the normal orbit. Lagophthalmos was present in anophthalmic sockets but not in normal orbits (P=0.002), while levator function was normal in both (P>0.05, all comparisons). The superior fornix depth was similar in the anophthalmic socket and the contralateral normal orbit (P=0.192) as well the inferior fornix depth (P=0.351). Acquired anophthalmic sockets repaired with spheric implants have shorter LPS, thicker SR, and more lagophthalmos than normal orbits. The relationship of the LPS and SR with other orbital structures, associated with passive or active forces acting in the final position of the lids and external ocular prosthesis should be further investigated.

Assessment of silent reading ability among glaucoma patients using an eye tracking system with horizontally scrolling text.

There have been many reports suggesting that glaucoma patients with visual field defects may have decreased silent reading ability compared with individuals without glaucoma. This study used an eye tracking system to assess the ability of glaucoma patients to silently read horizontally scrolling text. Glaucoma patients who met the following criteria were recruited: age of ≤ 70 years, at least one eye with a 10 - 2 threshold on standard automated perimetry, a mean deviation value of n 4.0 dB or less, and corrected decimal visual acuity of 0.7 or better in both eyes. Using heat map images created from data from an eye tracking system operating during presentation of a video in which a sentence scrolled horizontally from right to left, reading time, average gaze position, and average fixation time (AFT) were compared between normal eyes (23 individuals, 46 eyes) and glaucomatous eyes (25 patients, 45 eyes). Four styles of sentences (large slow, large fast, small slow, and small fast) were scrolled in the top or bottom sections of the screen. Primary open-angle glaucoma was the most common type of glaucoma in 34 eyes (75.6%), followed by secondary glaucoma in six eyes (13.3%). In comparison with normal eyes, the reading time among right eyes was significantly longer in glaucomatous eyes when reading large fast text that was shown in the bottom area and left glaucomatous eyes showed a leftward shift in gaze position in the top, bottom, or both sections with all four sentence types. There was no significant difference in AFT between glaucomatous and normal eyes across the four sentence styles. In the left eye with inferior visual field loss, text presented at the top consistently showed a correlation with leftward shift of the gaze position across all scenarios. Glaucoma patients with central visual field defects in their left eyes may experience greater difficulty reading horizontally scrolling text than individuals with normal eyes.