Causes of Childhood Blindness in the United States Using the IRIS® Registry (Intelligent Research in Sight).

PURPOSE: To investigate causes of childhood blindness in the United States using the IRIS® Registry (Intelligent Research in Sight). DESIGN: Cross-sectional study. PARTICIPANTS: Patients ≤ 18 years of age with visual acuity (VA) 20/200 or worse in their better-seeing eye in the IRIS Registry during 2018. METHODS: Causes of blindness were classified by anatomic site and specific diagnoses. MAIN OUTCOME MEASURES: Percentages of causes of blindness. RESULTS: Of 81 164 children with 2018 VA data in the IRIS Registry, 961 (1.18%) had VA 20/200 or worse in their better-seeing eye. Leading causes of blindness were retinopathy of prematurity (ROP) in 301 patients (31.3%), nystagmus in 78 patients (8.1%), and cataract in 64 patients (6.7%). The retina was the leading anatomic site (47.7%) followed by optic nerve (11.6%) and lens (10.0%). A total of 52.4% of patients had treatable causes of blindness. CONCLUSIONS: This analysis offers a unique cross-sectional view of childhood blindness in the United States using a clinical data registry. More than one-half of blind patients had a treatable cause of blindness. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Ocular Motor Nerve Palsy After Traumatic Brain Injury: A Claims Database Study.

BACKGROUND: Traumatic brain injury (TBI) is one of the common causes of ocular motor nerve (oculomotor nerve [CN3], trochlear nerve [CN4], and abducens nerve [CN6]) palsies, but there has been no large study of ocular motor nerve palsy caused by TBI. This study aimed to investigate the characteristics of and differences in ocular motor nerve palsy after TBI, according to patient age and severity of TBI. METHODS: This was a population-based retrospective cohort study that included patients who had ocular motor nerve palsy after TBI with ≥6 months of continuous enrollment using claims data from the IBM MarketScan Research Databases (2007-2016). We assessed sex, age at the first diagnosis of TBI, the severity of TBI, and the rates of strabismus procedures according to the age and severity of TBI. The rates of muscle transposition surgery and chemodenervation in CN3, CN4, and CN6 palsy were investigated. RESULTS: A total of 2,606,600 patients with TBI met the inclusion criteria. Among them, 1,851 patients (0.071%) had ocular motor nerve palsy after TBI. The median age of the patients was 39 (Q1-Q3: 19-54) years, and 42.4% of the patients were female. The median continuous enrollment period after the first diagnosis of TBI was 22 (Q1-Q3: 12-38) months. Of the 1,350,843 children with TBI, 454 (0.026%) had ocular motor nerve palsy. Of the 1,255,757 adults with TBI, 1,397 (0.111%) had ocular motor nerve palsy. Among these 1,851 patients, CN4 palsy (697, 37.7%) occurred most frequently, and strabismus procedures were performed in 237 patients (12.8%). CN6 palsy developed most frequently in children. More children (16.5%) underwent strabismus surgeries than adults (11.6%) ( P = 0.006). The proportion of CN4 palsy (52.3%) was higher while the proportion of CN3 palsy (15.5%) was lower in patients with mild TBI than in patients with moderate-to-severe TBI ( P < 0.001). CONCLUSIONS: CN4 palsy developed most frequently among patients of all ages, and only approximately 13% of the patients underwent strabismus procedures for ocular motor nerve palsy after TBI. The rate of development of ocular motor nerve palsy was approximately 4.3 times lower in children than adults, and children most frequently had CN6 palsy after TBI.

Long-term outcomes of prediction error after combined phacoemulsification and trabeculectomy in glaucoma patients.

BACKGROUND: To investigate long-term outcomes of prediction error after phacotrabeculectomy and to determine risk factors that may cause unstable prediction error after phacotrabeculectomy in glaucoma patients. METHODS: A total 120 eyes of 120 patients who had underwent uncomplicated phacotrabeculectomy (combined group) or phacoemulsification (phaco-only group) were included. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) were measured before and after surgery, and anterior segment parameters including anterior chamber depth (ACD), lens vault (LV), and anterior vault (AV) measured using anterior-segment optical coherence tomography were compared between the two groups. The mean absolute error (MAE) at 3, 6, 12, and 24 months postoperatively were compared. Risk factors associated with unstable prediction error (MAE ≥ 0.5) were investigated in the combined group. RESULTS: In both groups, BCVA was improved and IOP was decreased significantly. MAE at 3, 6, 12, 24 months postoperatively were not significantly different between two groups. The risk factors for unstable prediction error after 12 months of phacotrabeculectomy were old age and LV. Whereas, the only factor predicting unstable prediction error after 24 months of phacotrabeculectomy was LV. The cut-off value of LV for predicting unstable refractive error analyzed by the ROC curve was 0.855 mm. CONCLUSIONS: Phacotrabeculectomy may be an effective treatment with stable long-term outcomes of prediction error similar to phacoemulsification in patients with glaucoma. However, elderly patients or patients with large LV may be predisposed to unstable prediction error after phacotrabeculectomy.

Anterior Scleral Thickness in Myopic Eyes and Its Association with Ocular Parameters.

PURPOSE: This study was designed to determine whether the anterior scleral thickness is affected by axial elongation and to investigate the association between anterior scleral thickness and various ocular parameters in myopic eyes. METHODS: This cross-sectional study included 79 healthy myopic participants. Anterior scleral thickness was measured in 8 meridians (superior-nasal, superior, superior-temporal, temporal [T], inferior-temporal, inferior [I], inferior-nasal, and nasal [N]) using anterior segment optical coherence tomography. Bruch's membrane opening (BMO) area, width of ß-parapapillary atrophy with and without Bruch's membrane (PPA+BM and PPA-BM), and the global peripapillary and subfoveal choroidal thickness were additionally measured. Age- and sex-adjusted partial correlation analysis and linear regression analysis were performed to examine the effects of axial length and various ocular parameters on anterior scleral thickness in myopic eyes. RESULTS: The mean age of the included participants was 27.03 ± 2.70 years. Overall, the anterior scleral thickness varied topographically according to the meridians and distance from the scleral spur. In the partial correlation analysis controlled for the effect of age and sex, increasing axial length was related to anterior scleral thinning at several measurement points along the T, I, and N meridians. Among the several ocular parameters, multivariate linear regression analysis with age, sex, and axial length as covariates revealed that central corneal thickness, intraocular pressure, and BMO area were significantly associated with anterior scleral thickness. CONCLUSION: In conclusion, there was a close relationship between the anterior scleral thickness and several ocular parameters in myopic eyes. These features should be taken into consideration when managing myopia, and our results might have important implications for understanding the pathogenesis of scleral changes during axial elongation.

Influence of virtual reality on visual parameters: immersive versus non-immersive mode.

BACKGROUND: To investigate the differences in refraction, accommodative factors, visual parameters, and subjective symptoms after using two types of virtual reality (VR) content with different depths of perception. METHODS: Twenty-three volunteers, who played VR games in two modes (immersive and non-immersive) for 30 min, were enrolled. Visual parameters were examined before and after using VR. Accommodative factors were measured using static and dynamic methods. Subjective symptoms were assessed using a questionnaire. Differences according to VR content were compared, and correlations between each visual parameter were analyzed. RESULTS: There were no changes in refraction or accommodative factors after use of the VR. However, there was a significant increase in the near point of accommodation (NPA), the near point of convergence (NPC), and subjective symptom scores after using the immersive mode. Correlation analysis revealed a positive correlation between baseline values of near exophoria and mean accommodative lag of the dominant eye, and also revealed a negative correlation between NPA and mean accommodative lag in the non-dominant eye. CONCLUSIONS: The use of VR for 30 min increased NPA and NPC, especially after the immersive mode was used. In addition, higher exophoria and smaller NPA is associated with increased accommodative lag after using VR.

HDAC2 Regulates Glial Cell Activation in Ischemic Mouse Retina.

The current study was undertaken to investigate whether histone deacetylases (HDACs) can modulate the viability of retinal ganglion cells (RGCs) and the activity of glial cells in a mouse model of retinal ischemia-reperfusion (IR) injury. C57BL/6J mice were subjected to constant elevation of intraocular pressure for 60 min to induce retinal IR injury. Expression of macroglial and microglial cell markers (GFAP and Iba1), hypoxia inducing factor (HIF)-1α, and histone acetylation was analyzed after IR injury. To investigate the role of HDACs in the activation of glial cells, overexpression of HDAC1 and HDAC2 isoforms was performed. To determine the effect of HDAC inhibition on RGC survival, trichostatin-A (TSA, 2.5 mg/kg) was injected intraperitoneally. After IR injury, retinal GFAP, Iba1, and HIF-1α were upregulated. Conversely, retinal histone acetylation was downregulated. Notably, adenoviral-induced overexpression of HDAC2 enhanced glial activation following IR injury, whereas overexpression of HDAC1 did not significantly affect glial activation. TSA treatment significantly increased RGC survival after IR injury. Our results suggest that increased activity of HDAC2 is closely related to glial activation in a mouse model of retinal IR injury and inhibition of HDACs by TSA showed neuroprotective potential in retinas with IR injuries.

Postural effects on intraocular pressure and ocular perfusion pressure in patients with non-arteritic anterior ischemic optic neuropathy.

BACKGROUND: To investigate postural effects on intraocular pressure (IOP) and ocular perfusion pressure (OPP) in patients with non-arteritic ischemic optic neuropathy (NAION). METHODS: IOP and blood pressure (BP) were measured in 20 patients with unilateral NAION 10 min after changing to each of the following positions sequentially: sitting, supine, right lateral decubitus position (LDP), supine, left LDP, and supine. IOP was measured using a rebound tonometer and OPP was calculated using formulas based on mean BP. The dependent LDP (DLDP) was defined as the position when the eye of interest (affected or unaffected eye) was placed on the dependent side in the LDP. RESULTS: IOPs were significantly higher (P = 0.020) and OPPs were significantly lower (P = 0.041) in the affected eye compare with the unaffected eye, with the affected eye in DLDP. Compared with the mean IOP of the unaffected eyes, the mean IOP of the affected eyes increased significantly (+2.9 ± 4.4 versus +0.7 ± 3.1 mmHg, respectively; P = 0.003) and the mean OPP decreased significantly (-6.7 ± 9.4 versus -4.9 ± 8.0 mmHg, respectively; P = 0.022) after changing positions from supine to DLDP. In addition, changing position from supine to DLDP showed significantly larger absolute changes in IOP (4.13 ± 3.19 mmHg versus 2.51 ± 1.92 mmHg, respectively; P = 0.004) and OPP (9.86 ± 5.69 mmHg versus 7.50 ± 5.49 mmHg, respectively; P = 0.009) in the affected eye compared with the unaffected eye. In the affected eye, there was a significant positive correlation between absolute change in IOP and OPP when changing position from supine to DLDP (Rho = 0.512, P = 0.021). CONCLUSIONS: A postural change from supine to DLDP caused significant fluctuations in IOP and OPP of the affected eye, and may significantly increase IOP and decrease OPP. Posture-induced IOP changes may be a predisposing factor for NAION development.

Optic Disc Rotation as a Clue for Predicting Visual Field Progression in Myopic Normal-Tension Glaucoma.

PURPOSE: To investigate factors associated with visual field (VF) progression in myopic normal-tension glaucoma (NTG) and to determine the relationship between optic disc rotation and VF progression. DESIGN: Retrospective, observational study. SUBJECTS: Ninety-two patients with myopic NTG, with VF loss confined to a single hemifield, who were followed up over a 2-year period. METHODS: Systemic and ocular findings such as optic disc tilt and optic disc rotation were evaluated. The eyes with optic disc rotation accompanying a corresponding VF defect were defined as those with correspondence. Visual field progression was defined by Early Manifest Glaucoma Trial criteria. The Cox proportional hazards model was used to determine the risk factors for VF progression. MAIN OUTCOME MEASURES: Progression of VF. RESULTS: The mean age of subjects was 37.83±10.89 years, mean spherical equivalent refractive error was -5.51±3.37 diopters, and mean axial length was 26.18±1.79 mm. Mean follow-up duration was 55.78±30.12 months. Among 92 eyes, 37 showed VF progression. A multivariate Cox proportional hazard model revealed that percentage reduction in intraocular pressure (IOP) from baseline (hazard ratio [HR], 0.965; P = 0.013), optic disc hemorrhage (HR, 2.623; P = 0.019), and optic disc rotation-VF defect correspondence (HR, 0.441; P = 0.016) were associated with VF progression in myopic NTG eyes. CONCLUSIONS: In addition to the percentage reduction in IOP from baseline and optic disc hemorrhage, optic disc rotation-VF defect correspondence may be an important prognostic factor for patients with myopic NTG.

Characteristics of Optic Disc Rotation in Myopic Eyes.

PURPOSE: To investigate the characteristics of optic disc rotation and ocular parameters affecting optic disc rotation in healthy myopic eyes. DESIGN: Cross-sectional, comparative study. PARTICIPANTS: A total of 220 participants with healthy myopic eyes. METHODS: Spherical equivalent (SE) refractive error, axial length, central corneal thickness, and intraocular pressure (IOP) were evaluated. Optic disc tilt ratio, degree of optic disc rotation, and area of ß-zone parapapillary atrophy (PPA) were measured. Optic nerve head (ONH) parameters and thickness of the peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) were measured using Cirrus optical coherence tomography (Carl Zeiss Meditec Inc., Dublin, CA). Subjects were divided into 2 groups, group 1 with superior rotation and group 2 with inferior rotation of the optic disc, and various parameters were compared. Linear regression analysis was performed to evaluate the relationships between the degree of optic disc rotation and several parameters. MAIN OUTCOME MEASURES: Degree of optic disc rotation. RESULTS: Among 220 eyes, 147 showed superior rotation of the optic disc and 73 showed inferior rotation. The mean tilt ratio and rotation degree were 1.16 and -19.51°, respectively, in group 1 and 1.20 and 28.93°, respectively, in group 2, showing significant differences between the groups (P = 0.028 and P = 0.035, respectively). There were also significant between-group differences in IOP (15.59 vs. 16.34 mmHg), SE refractive error (-4.05 vs. -5.66 diopters [D]), axial length (25.51 vs. 26.26 mm), and area of ß-zone PPA (0.32 vs. 0.70 mm(2)). Overall, a multivariate linear regression analysis showed that IOP, axial length, and area of ß-zone PPA were significant parameters related to the degree of optic disc rotation (P = 0.011, P = 0.043, and P = 0.030, respectively). Group 2 showed thinner pRNFL and mGCIPL thickness in general compared with group 1. CONCLUSIONS: In healthy myopic eyes, superior rotation of the optic disc was more prevalent than inferior rotation. As the optic disc rotates inferiorly, there was a significant positive correlation with IOP, axial length, and area of the ß-zone PPA. Conversely, a significant negative correlation with pRNFL and mGCIPL thickness was observed.

Early macular ganglion cell-inner plexiform layer analysis in non-arteritic anterior ischemic optic neuropathy.

PURPOSE: To investigate the potential usefulness of early macular ganglion cell-inner plexiform layer (mGCIPL) measurement for detecting retinal ganglion cell damage in eyes with non-arteritic anterior ischemic optic neuropathy (NAION). METHODS: Thirteen patients with NAION were examined within 1 month of visual disturbance onset and underwent spectral domain optical coherence tomography (SD-OCT) measurement of the mGCIPL and peripapillary retinal nerve fiber layer (pRNFL). Complete ophthalmologic evaluations, including visual acuity and visual field (VF) test, were performed. The time to minimum and average mGCIPL and pRNFL thinning were investigated. The correlation between the area of mGCIPL thinning and the affected VF area was also analyzed. RESULTS: Thirteen eyes of 13 patients with NAION were included. The length of time from visual disturbance onset to minimum and average mGCIPL thinning was 32.5 ± 12.1 days and 46.1 ± 23.2 days, respectively, and the time to pRNFL thinning was 79.2 ± 19.7 days. There was a significant regional correlation between the area of mGCIPL loss and that of the VF defect in the early phase (r = 0.610; p = 0.027). However, the area of mGCIPL thinning in the late phase did not correlate with that of late VF defects. CONCLUSIONS: In the early phase, mGCIPL thinning was observed, and the area of mGCIPL thinning correlated with that of the VF defect in eyes with NAION. Therefore, early retinal ganglion cell damage and dysfunction may be detected in NAION by measurement of mGCIPL using SD-OCT.

Acute acquired comitant esotropia related to excessive Smartphone use.

BACKGROUND: To describe the clinical characteristics and outcomes of acute acquired comitant esotropia (AACE) related to excessive smartphone use in adolescents. METHODS: The medical records of 12 patients with AACE and a history of excessive smartphone use were retrospectively reviewed, and the duration of smartphone use, angle of deviation, refractive error, stereopsis, and treatment options were analyzed. RESULTS: All patients showed convergent and comitant esotropia ranging from 15 to 45 prism diopters (PD; average: 27.75 ± 11.47 PD) at far fixation. The angle of deviation was nearly equivalent for far and near fixation. Every patient used a smartphone for more than 4 h a day over a period of several months (minimum 4 months). Myopic refractive errors were detected in eight patients (average:-3.84 ± 1.68 diopters (D]), and the remaining four patients showed mild hyperopic refractive error (average: +0.84 ± 0.53 D). Reductions in esodeviation were noted in all patients after refraining from smartphone use, and bilateral medial rectus recession was performed in three patients with considerable remnant esodeviation. Postoperative exams showed orthophoria with good stereoacuity in these patients. CONCLUSION: Excessive smartphone use might influence AACE development in adolescents. Refraining from smartphone use can decrease the degree of esodeviation in these patients, and remnant deviation can be successfully managed with surgical correction.

Anterior segment configuration as a predictive factor for refractive outcome after cataract surgery in patients with glaucoma.

BACKGROUND: To compare refractive outcomes after cataract surgery between patients with closed-angle and open-angle glaucoma and evaluate the influence of preoperative factors on refractive outcomes in patients with glaucoma. METHODS: Patients diagnosed with glaucoma and who underwent uncomplicated cataract surgery were enrolled in this retrospective observational study. We collected data including age, history of prior laser peripheral iridotomy and trabeculectomy, type of glaucoma, manifest refraction, intraocular pressure, axial length, and various anterior segment parameters using anterior-segment optical coherence tomography. Factors associated with unsatisfactory refractive outcome at postoperative 6 month were evaluated. RESULTS: A total of 143 eyes (143 subjects) were included. Of these, 49 and 94 had closed-angle and open-angle glaucoma, respectively. At postoperative-6 month evaluation, the mean absolute error (MAE) predicted by the SRK-II and SRK-T formulae was 0.67 ± 0.61 and 0.81 ± 0.66 diopters (D), respectively. The overall predictability of achieving within ± 1.0 D of target was 76.92 % and 72.73 %, respectively. At a cutoff value of 1.0 D for MAE, there was no statistical significant difference in refractive outcome between the closed-angle and open-angle glaucoma groups. Logistic regression modeling showed that large lens vault (LV) was a significant predictor of unsatisfactory refractive outcome after cataract surgery in patients with glaucoma. CONCLUSIONS: When considering cataract surgery in patients with glaucoma, surgeons should recognize that the refractive outcomes may be unsatisfactory in eyes with large LV.

Evaluation of Fear Using Nonintrusive Measurement of Multimodal Sensors.

Most previous research into emotion recognition used either a single modality or multiple modalities of physiological signal. However, the former method allows for limited enhancement of accuracy, and the latter has the disadvantages that its performance can be affected by head or body movements. Further, the latter causes inconvenience to the user due to the sensors attached to the body. Among various emotions, the accurate evaluation of fear is crucial in many applications, such as criminal psychology, intelligent surveillance systems and the objective evaluation of horror movies. Therefore, we propose a new method for evaluating fear based on nonintrusive measurements obtained using multiple sensors. Experimental results based on the t-test, the effect size and the sum of all of the correlation values with other modalities showed that facial temperature and subjective evaluation are more reliable than electroencephalogram (EEG) and eye blinking rate for the evaluation of fear.

A Fuzzy-Based Fusion Method of Multimodal Sensor-Based Measurements for the Quantitative Evaluation of Eye Fatigue on 3D Displays.

With the rapid increase of 3-dimensional (3D) content, considerable research related to the 3D human factor has been undertaken for quantitatively evaluating visual discomfort, including eye fatigue and dizziness, caused by viewing 3D content. Various modalities such as electroencephalograms (EEGs), biomedical signals, and eye responses have been investigated. However, the majority of the previous research has analyzed each modality separately to measure user eye fatigue. This cannot guarantee the credibility of the resulting eye fatigue evaluations. Therefore, we propose a new method for quantitatively evaluating eye fatigue related to 3D content by combining multimodal measurements. This research is novel for the following four reasons: first, for the evaluation of eye fatigue with high credibility on 3D displays, a fuzzy-based fusion method (FBFM) is proposed based on the multimodalities of EEG signals, eye blinking rate (BR), facial temperature (FT), and subjective evaluation (SE); second, to measure a more accurate variation of eye fatigue (before and after watching a 3D display), we obtain the quality scores of EEG signals, eye BR, FT and SE; third, for combining the values of the four modalities we obtain the optimal weights of the EEG signals BR, FT and SE using a fuzzy system based on quality scores; fourth, the quantitative level of the variation of eye fatigue is finally obtained using the weighted sum of the values measured by the four modalities. Experimental results confirm that the effectiveness of the proposed FBFM is greater than other conventional multimodal measurements. Moreover, the credibility of the variations of the eye fatigue using the FBFM before and after watching the 3D display is proven using a t-test and descriptive statistical analysis using effect size.

Macular inner plexiform and retinal nerve fiber layer thickness in glaucoma.

PURPOSE: To compare the parameters of the macular ganglion cell-inner plexiform layer (mGCIPL) thickness measured by Cirrus high-definition optical coherence tomography in normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG). METHODS: Eighty patients with NTG, 80 patients with POAG, and 100 normal control subjects were enrolled. The mGCIPL and peripapillary retinal nerve fiber layer (pRNFL) thicknesses measured by Cirrus high-definition optical coherence tomography were compared in patients with glaucoma. The areas under the receiver operating characteristic curve (AROCs) were calculated to compare the diagnostic power of the mGCIPL thickness with that of the pRNFL thickness. Pearson correlation coefficients were determined to investigate the correlation between the mGCIPL or pRNFL thickness parameters and the mean deviation (MD) values of visual field tests. RESULTS: All parameters of the mGCIPL thickness were significantly different between normal control subjects and patients with glaucoma. The superior, superotemporal, and superonasal thickness of mGCIPL and the superior thickness of pRNFL showed significant reductions and significantly higher AROCs for distinguishing between normal eyes and eyes with glaucoma in POAG compared with those in NTG. In NTG or POAG groups, the mGCIPL and pRNFL parameters with the highest AROC were the minimum and average thickness, respectively. The average, minimum, inferior, inferotemporal, and inferonasal thickness of mGCIPL and the average and inferior thickness of pRNFL were correlated with MD in NTG (p < 0.05 for all parameters), whereas all parameters of the mGCIPL thickness except the inferonasal thickness and all parameters of the pRNFL thickness except the temporal thickness were correlated with MD in POAG (p < 0.05 for all parameters). CONCLUSIONS: The diagnostic ability of the mGCIPL thickness was comparable to that of the pRNFL thickness in patients with NTG or POAG. The mGCIPL loss in NTG was localized and mainly concentrated on the inferior portion compared with diffuse mGCIPL loss in POAG.

Nonwearable gaze tracking system for controlling home appliance.

A novel gaze tracking system for controlling home appliances in 3D space is proposed in this study. Our research is novel in the following four ways. First, we propose a nonwearable gaze tracking system containing frontal viewing and eye tracking cameras. Second, our system includes three modes: navigation (for moving the wheelchair depending on the direction of gaze movement), selection (for selecting a specific appliance by gaze estimation), and manipulation (for controlling the selected appliance by gazing at the control panel). The modes can be changed by closing eyes during a specific time period or gazing. Third, in the navigation mode, the signal for moving the wheelchair can be triggered according to the direction of gaze movement. Fourth, after a specific home appliance is selected by gazing at it for more than predetermined time period, a control panel with 3 × 2 menu is displayed on laptop computer below the gaze tracking system for manipulation. The user gazes at one of the menu options for a specific time period, which can be manually adjusted according to the user, and the signal for controlling the home appliance can be triggered. The proposed method is shown to have high detection accuracy through a series of experiments.

Assessment of eye fatigue caused by 3D displays based on multimodal measurements.

With the development of 3D displays, user's eye fatigue has been an important issue when viewing these displays. There have been previous studies conducted on eye fatigue related to 3D display use, however, most of these have employed a limited number of modalities for measurements, such as electroencephalograms (EEGs), biomedical signals, and eye responses. In this paper, we propose a new assessment of eye fatigue related to 3D display use based on multimodal measurements. compared to previous works Our research is novel in the following four ways: first, to enhance the accuracy of assessment of eye fatigue, we measure EEG signals, eye blinking rate (BR), facial temperature (FT), and a subjective evaluation (SE) score before and after a user watches a 3D display; second, in order to accurately measure BR in a manner that is convenient for the user, we implement a remote gaze-tracking system using a high speed (mega-pixel) camera that measures eye blinks of both eyes; thirdly, changes in the FT are measured using a remote thermal camera, which can enhance the measurement of eye fatigue, and fourth, we perform various statistical analyses to evaluate the correlation between the EEG signal, eye BR, FT, and the SE score based on the T-test, correlation matrix, and effect size. Results show that the correlation of the SE with other data (FT, BR, and EEG) is the highest, while those of the FT, BR, and EEG with other data are second, third, and fourth highest, respectively.

Quantitative measurement of eyestrain on 3D stereoscopic display considering the eye foveation model and edge information.

We propose a new method for measuring the degree of eyestrain on 3D stereoscopic displays using a glasses-type of eye tracking device. Our study is novel in the following four ways: first, the circular area where a user's gaze position exists is defined based on the calculated gaze position and gaze estimation error. Within this circular area, the position where edge strength is maximized can be detected, and we determine this position as the gaze position that has a higher probability of being the correct one. Based on this gaze point, the eye foveation model is defined. Second, we quantitatively evaluate the correlation between the degree of eyestrain and the causal factors of visual fatigue, such as the degree of change of stereoscopic disparity (CSD), stereoscopic disparity (SD), frame cancellation effect (FCE), and edge component (EC) of the 3D stereoscopic display using the eye foveation model. Third, by comparing the eyestrain in conventional 3D video and experimental 3D sample video, we analyze the characteristics of eyestrain according to various factors and types of 3D video. Fourth, by comparing the eyestrain with or without the compensation of eye saccades movement in 3D video, we analyze the characteristics of eyestrain according to the types of eye movements in 3D video. Experimental results show that the degree of CSD causes more eyestrain than other factors.

Arachnoid cyst accompanied by proptosis and unilateral high myopia.

An 8-year-old boy presented with proptosis of the left eye. On ophthalmic examination,unilateral axial elongation of the left eye was evident.Computed tomography and magnetic resonance imaging revealed an arachnoid cyst in the left middle cranial fossa, which expanded the bone and deformed the posterolateral wall of the left orbit. The lesion was observed with serial examinations and reviewed by a neurosurgeon and a radiologist. After 6 months of follow-up, there was no progression of the cyst. We believe this is the youngest reported case of an arachnoid cyst associated with isolated proptosis in the setting of unilateral high myopia. Neuroimaging should be considered in cases of prominent or progressive proptosis in the context of unilateral axial myopia in order to detect other possible etiologies.

Lack of Correspondence between Early Optic Disc Oedema and Macular Ganglion Cell Loss in Non-arteritic Anterior Ischaemic Optic Neuropathy.

A 73-year-old Asian male presented with a 2-week history of acute visual disturbance in his right eye. Visual acuity in his right eye was hand movement and fundus examination showed right optic disc oedema and splinter haemorrhages on the disc margin. Each time the patient visited our clinic, spectral domain optical coherence tomography (OCT) was performed. He was diagnosed to have non-arteritic anterior ischaemic optic neuropathy. Optical coherence tomography showed disagreement between the areas of early peripapillary retinal nerve fibre layer thickening and macular ganglion cell layer thickness reduction.