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Diabetic retinopathy (DR) is a microvascular complication associated with diabetes mellitus. Pregnancy is a major risk factor for DR in diabetic women. Recent evidenced suggests that in course of DR functional changes including damage of pre-ganglionic and ganglionic cells in retina precede structural microvascular changes. A number of studies in the past have highlighted the role of pattern visual evoked potential (VEP) in detecting such functional changes. However, the study of VEP changes in diabetic pregnancies remains unexplored. This case series has the objective of exploring VEP changes in symptomatic OVD cases, who had no signs of DR on fundoscopy. We present two cases of overt diabetic women who complaint of straining of eyes, headache, and difficulty in reading during pregnancy. Complete ophthalmic examination was done in both the cases followed by a VEP test. VEP test was done as a part of a research project. The ethical clearance for the project was obtained from the Institute’s Ethics Committee before the commencement of the study. Fundoscopic examination in both cases revealed that the retina was within normal limits with no signs of retinopathy. In Case 1, P100 latency was increased for the left eye and was normal for the right eye during the first visit. While P100 latency was increased for both left and right eye during the second visit. There was a substantial increase in P100 latency for both eyes in second visit as compared to first visit. In Case 2, P100 latency was increased for both left and right eye and amplitude decreased for the left eye. This is a case series consisting of symptomatic overt diabetic pregnant women who had increased P100 latency despite no signs of retinopathy in fundoscopy. The previous studies have reported that multiple follow-ups with ophthalmoscopy may not be cost-effective in diabetic pregnant women. VEP provides a window for detection of early functional changes that may help identify at risk patients for follow-up and early intervention.
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Objective:To improve the users’ comfort of steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) through high-frequency stimulation and overcome the problem of accuracy decline caused by high frequency by combining dual-frequency encoding.Methods:Two dual-frequency high-frequency 60-instruction paradigms based on left and right visual fields and checkerboard stimuli were designed based on the 25.5 - 39.6 Hz frequency. Thirteen subjects participated in the experiment, and spectrum and spatial characteristics analyses were performed on SSVEP signals. The filter bank parameters were optimized based on the spectrum characteristics. Extended canonical correlation analysis (eCCA), ensemble task-related component analysis (eTRCA), and task-discriminant component analysis (TDCA) were used for SSVEP recognition.Results:Stable SSVEP was successfully induced in both the left and right visual fields and the checkerboard grid paradigm. The left and right visual fields had high signal-to-noise ratios for the fundamental frequency and its harmonics and weak signal-to-noise ratios for intermodulation components, whereas the intermodulation components of the 2 stimulus frequencies of the checkerboard grid, f1 + f2, had significantly higher signal-to-noise ratios than the second harmonic components above 30 Hz, and there was also a f2 ? f1 component and a 2 f1 ? f2 component. Combined with brain topography, it can be seen that the f1 and f2 response components of the left and right visual fields are located on opposite sides of the visual field, while the checkerboard grids are both concentrated in the center of the occipital region. Regarding the lateralization of brain topography amplitude and signal-to-noise ratio, the mean values of the PO3 and PO4 signal-to-noise ratios at the stimulation frequency of the left and right visual fields are consistent with the contralateral response characteristics. The 5 fb ? 1 method is the optimal filter set setting method, and the recognition correctness rate of TDCA for the left and right visual fields is the highest. However, the comparison of the recognition correctness rate of tessellated lattice eTRCA and TDCA is not statistically significant ( P > 0.05). The information transmission rates of the three algorithms all increase and then decrease with the increase in data length. Conclusions:The designed dual-frequency, high-frequency SSVEP-BCI paradigm is able to better balance performance and comfort and provides a basis for practical large instruction set BCI design methods.
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Steady-state visual evoked potential (SSVEP) has been widely used in the research of brain-computer interface (BCI) system in recent years. The advantages of SSVEP-BCI system include high classification accuracy, fast information transform rate and strong anti-interference ability. Most of the traditional researches induce SSVEP responses in low and middle frequency bands as control signals. However, SSVEP in this frequency band may cause visual fatigue and even induce epilepsy in subjects. In contrast, high-frequency SSVEP-BCI provides a more comfortable and natural interaction despite its lower amplitude and weaker response. Therefore, it has been widely concerned by researchers in recent years. This paper summarized and analyzed the related research of high-frequency SSVEP-BCI in the past ten years from the aspects of paradigm and algorithm. Finally, the application prospect and development direction of high-frequency SSVEP were discussed and prospected.
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Humans , Brain-Computer Interfaces , Evoked Potentials, Visual , AlgorithmsABSTRACT
Purpose: To analyze the clinical presentations, risk factors, and management outcomes in patients presenting with dysthyroid optic neuropathy (DON). Methods: This is a retrospective, single?center study carried out on consecutive patients presenting with DON over a period of 4 years (2013–2016). The VISA classification was used at the first visit and subsequent follow?ups. The diagnosis was based on optic nerve function tests and imaging features. Demographic profiles, clinical features, risk factors, and management outcomes were analyzed. Results: Thirty?seven eyes of 26 patients diagnosed with DON were included in the study. A significant male preponderance was noted (20, 76.92%). Twenty patients (76.9%, P = 0.011) had hyperthyroidism, and 15 (57.69%, P = 0.02) were smokers. Decreased visual acuity was noted in 28 eyes (75.6%). Abnormal color vision and relative afferent pupillary defects were seen in 24 (64.86%) eyes, and visual field defects were seen in 30 (81.01%) eyes. The visual evoked potential (VEP) showed a reduced amplitude in 30 (96.77%, P = 0.001) of 31 eyes and delayed latency in 20 (64.51%, P = 0.0289) eyes. Twenty?six (70.27%) patients were treated with intravenous methyl prednisolone (IVMP) alone, whereas 11 (29.72%) needed surgical decompression. The overall best?corrected visual acuity improved by 0.2 l logMARunits. There was no statistically significant difference in outcome between medically and surgically treated groups. Four patients developed recurrent DON, and all of them were diabetics. Conclusion: Male gender, hyperthyroid state, and smoking are risk factors for developing DON. VEP, apical crowding, and optic nerve compression are sensitive indicators for diagnosing DON. Diabetics may have a more defiant course and are prone to develop recurrent DON.
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Background: Visual evoked potentials (VEPs) are electrical potential differences recorded from the occipital lobe in response to different visual stimulus. In myopic individuals, there is blurring of the stimuli, causing defocusing which tends to affect the VEP parameters. Aim and Objective: The study was designed and done to evaluate the effect of various degrees of myopia on VEP in medical students of age 18–24 years. Materials and Methods: A total of 120 subjects were included in this study, consist of 60 individuals without having any refractive disorders and 60 individuals having various degree of myopia, that is, 22 subjects with mild myopia of <?3D, 26 subjects with moderate myopia of ?3 to ?6D, and 12 subjects with severe myopia of > ?6D. The study was approved by Ethical and Research Committee, Govt. Medical College, Patiala. Results: In the present study, mean values for P100 latency were significantly high in myopic group as than in control group. Furthermore, mean values for N75 latency were significantly high in the myopic group as compared to the control group and mean values for N145 latency were significantly high in the myopic group as compared to the control group for both the right and left eyes. Mean values for amplitude (N75-P100) was significantly lower for the myopic group as compared to the control group for both the left and right eyes. There is prolongation of latencies in myopic individuals as compared to the control and latencies increase with the increase in degree of myopia. Furthermore, there is decrease in the amplitude in myopic individuals and it decreases with the increase in degree of myopia. Conclusion: The mean values for latencies were found to be comparable and the mean values of latencies were found to be increasing with increase of degree of myopia. Probably, the reason behind this result may be the optical blurring of the stimulus which lead to defocusing, therefore causes the prolongation of latency. The mean values for amplitude were found to be comparable and the mean values of amplitude were found to be decreasing with increase of degree of myopia. Probably, the reason for our finding is that in a pattern reversal VEP, the amplitude relies on the visual system’s ability to determine the pattern and on the degree of retinal image focus.
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Purpose: To study the effect of refractive errors on pattern visual evoked potential (VEP) recordings in the pediatric population. Methods: This cross?sectional observational study assessed 240 eyes of 120 participants attending the outpatient department of a tertiary care center in North India. Participants were between 8 and 18 years of age; 30 participants each were recruited into four groups, namely emmetropia, myopia, hypermetropia, and amblyopia. They were then subjected to pattern reversal VEP, with P?100 amplitude and latency recorded for each participant. Results: The emmetropic group in this study provided normal values of P?100 parameters, namely P?100 latency and P?100 amplitude with readings of 115.78 ± 10.19 ms and 11.11 ± 4.08 ?V, respectively. P?100 amplitude was significant compared to P?100 latency in detecting the presence or absence of a specific type of refractive error. It was found that there was a significant association between severity of myopia and P?100 latency (both unaided and aided) with P < 0.05. The severity of hypermetropia showed a significant association with P?100 amplitude (unaided) (P < 0.05). Receiver operating characteristics analysis revealed P?100 amplitude to be a good predictor of refractive error and the cut?offs were calculated. Conclusion: The P?100 parameters of the pediatric Indian population were comparatively higher than conventional values. P?100 latency seemed to better correlate with myopia, while hypermetropia correlated with P?100 amplitude. P?100 amplitude appears to be the most significant predictor of the presence of refractive error in an individual.
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Purpose: This study aimed to identify an easy?to?apply biomarker by correlating visual evoked potential (VEP) with optical coherence tomography angiography (OCTA) results in multiple sclerosis (MS). Methods: Our study was planned prospectively. Patients with MS were divided into two groups, VEP prolonged group 1 and VEP normal group 2. Age?matched and gender?matched healthy individuals (group 3) were included as the control group. Vascular density (VD) of the optic nerve head (ONH) and radial peripapillary capillaries (RPCs) were measured and recorded by OCTA. The optic nerve damage of patients was measured and recorded with a VEP device. Results: Thirty?two eyes were included in group 1, 50 eyes were included in group 2, and 51 healthy eyes were included in group 3. In terms of visual acuity, group 1 was significantly lower than the other groups (P < 0.001). Regardless of the prolongation of p100 latency in patients with MS, whole image, inside disc ONH VD and in the same sectors in RPC VD were found to be significantly lower than the control group (P < 0.05). Retinal nerve fiber layer thickness was found to be significantly lower in group 1 than in group 2 and group 3 (P < 0.05). There was a significant correlation between low ONH VD and RPC VD and prolonged VEP P100 (P < 0.05). Conclusion: VEP measurements can be correlated with OCTA measurements in patients with MS and can be used as a biomarker to determine the degree of optic nerve damage
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Background: Visual Evoked Potentials (VEPs) was studied in asymptomatic Human Immunodeficiency Virus (HIV) positive persons and corresponding controls to detect subclinical visual system involvement in the early stage of HIV. Aim and Objectives: To study VEPs in asymptomatic HIV-positive persons and corresponding controls. Materials and Methods: In this study,100 participants in the age group 25–45 years were recruited, fifty were HIV positive and asymptomatic (CD4 count >350 cells/mm3) and were not on Anti-Retroviral Treatment, and 50 were healthy age-matched individuals who were HIV negative. Results: P 100 latency was significantly prolonged in the study group than in the control group. No significant difference was observed between the control group and study group for the amplitude of VEP. Conclusion: Study of VEPs in asymptomatic HIV positive persons suggests subclinical visual nervous system involvement in early stages of HIV, as evidenced by prolonged P 100 latency. Hence, VEPs is important to detect subclinical nervous system involvement in the early stages of HIV.
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Purpose: There are no effective treatments currently available for optic nerve transection injuries. Stem cell therapy represents a feasible future treatment option. This study investigated the therapeutic potential of human umbilical cord–derived mesenchymal stem cell (hUC?MSC) transplantation in rats with optic nerve injury. Methods: Sprague–Dawley (SD) rats were divided into three groups: a no?treatment control group (n = 6), balanced salt solution (BSS) treatment group (n = 6), and hUC?MSCs treatment group (n = 6). Visual functions were assessed by flash visual evoked potential (fVEP) at baseline, Week 3, and Week 6 after optic nerve crush injury. Right eyes were enucleated after 6 weeks for histology. Results: The fVEP showed shortened latency delay and increased amplitude in the hUC?MSCs treated group compared with control and BSS groups. Higher cellular density was detected in the hUC?MSC treated group compared with the BSS and control groups. Co?localized expression of STEM 121 and anti?S100B antibody was observed in areas of higher nuclear density, both in the central and peripheral regions. Conclusion: Peribulbar transplantation of hUC?MSCs demonstrated cellular integration that can potentially preserve the optic nerve function with a significant shorter latency delay in fVEP and higher nuclear density on histology, and immunohistochemical studies observed cell migration particularly to the peripheral regions of the optic nerve.
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Steady-state visual evoked potential (SSVEP) is one of the commonly used control signals in brain-computer interface (BCI) systems. The SSVEP-based BCI has the advantages of high information transmission rate and short training time, which has become an important branch of BCI research field. In this review paper, the main progress on frequency recognition algorithm for SSVEP in past five years are summarized from three aspects, i.e., unsupervised learning algorithms, supervised learning algorithms and deep learning algorithms. Finally, some frontier topics and potential directions are explored.
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Algorithms , Brain-Computer Interfaces , Electroencephalography/methods , Evoked Potentials, Visual , Photic StimulationABSTRACT
OBJECTIVES@#To study the quantitative and qualitative differences of visual evoked potential (VEP) in monocular visual impairment after different parts of visual pathway injury.@*METHODS@#A total of 91 subjects with monocular visual impairment caused by trauma were selected and divided into intraocular refractive media-injury group (eyeball injury group for short), optic nerve injury group, central nervous system injury and intracranial combined injury group according to the injury cause and anatomical segment. Pattern Reversal visual evoked potential (PR-VEP) P100 peak time and amplitude, Flash visual evoked potential (F-VEP) P2 peak time and amplitude were recorded respectively. SPSS 26.0 software was used to analyze the differences of quantitative (peak time and amplitude) and qualitative indexes (spatial frequency sweep-VEP acuity threshold, and abnormal waveform category and frequency) of the four groups.@*RESULTS@#Compared with healthy eyes, the PR-VEP P100 waveforms of the intraocular eyeball injury group and the F-VEP P2 waveforms of the optic nerve group showed significant differences in prolonged peak time and decreased amplitude in injured eyes (P<0.05). The PR-VEP amplitudes of healthy eyes were lower than those of injured eyes at multiple spatial frequencies in central nervous system injury group and intracranial combined injury group (P<0.05).The amplitude of PR-VEP in patients with visual impairment involving central injury was lower than that in patients with eye injury at multiple spatial frequencies. The frequency of VEP P waveforms reaching the threshold of the intraocular injury group and the optic nerve injury group were siginificantly different from the intracranial combined injury group, respectively(P<0.008 3), and the frequency of abnormal reduction of VEP amplitude of threshold were significantly different from the central nervous system injury group, respectively(P<0.008 3).@*CONCLUSIONS@#VEP can distinguish central injury from peripheral injury, eyeball injury from nerve injury in peripheral injury, but cannot distinguish simple intracranial injury from complex injury, which provides basic data and basis for further research on the location of visual impairment injury.
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Humans , Evoked Potentials, Visual , Eye , Optic Nerve , Optic Nerve Injuries , Vision Disorders/etiologyABSTRACT
Brain-computer interface (BCI) has great potential to replace lost upper limb function. Thus, there has been great interest in the development of BCI-controlled robotic arm. However, few studies have attempted to use noninvasive electroencephalography (EEG)-based BCI to achieve high-level control of a robotic arm. In this paper, a high-level control architecture combining augmented reality (AR) BCI and computer vision was designed to control a robotic arm for performing a pick and place task. A steady-state visual evoked potential (SSVEP)-based BCI paradigm was adopted to realize the BCI system. Microsoft's HoloLens was used to build an AR environment and served as the visual stimulator for eliciting SSVEPs. The proposed AR-BCI was used to select the objects that need to be operated by the robotic arm. The computer vision was responsible for providing the location, color and shape information of the objects. According to the outputs of the AR-BCI and computer vision, the robotic arm could autonomously pick the object and place it to specific location. Online results of 11 healthy subjects showed that the average classification accuracy of the proposed system was 91.41%. These results verified the feasibility of combing AR, BCI and computer vision to control a robotic arm, and are expected to provide new ideas for innovative robotic arm control approaches.
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Humans , Augmented Reality , Brain-Computer Interfaces , Computers , Electroencephalography , Evoked Potentials, Visual , Photic Stimulation , Robotic Surgical ProceduresABSTRACT
OBJECTIVE@#To observe clinical effect of acupuncture combined with conventional visual stimulation on cerebral visual impairment (CVI) in children aged 3-10 years and influence on the pattern visual evoked potential (P-VEP).@*METHODS@#A total of 60 cases of children aged 3-10 years with CVI were randomly divided into an observation group and a control group, 30 cases in each group. The children in the control group received conventional visual stimulation therapy, 1 month as a course of treatment. On the basis of the control group, the children in the observation group was treated with acupuncture at Baihui (GV 20), Jingming (BL 1), Taiyang (EX-HN 5), Sibai (ST 2), etc. 3 times a week, and the treatment was given 4 weeks continuously as a course. Both groups received 3 courses of treatment. The visual acuity and P-VEP improvement were compared between the two groups before and after treatment.@*RESULTS@#After treatment, the incubation period (P100-L) of the two groups was shorter than before treatment, and the amplitude (P100-A) was higher than before treatment (@*CONCLUSION@#Acupuncture combined with conventional visual stimulation can improve the incubation period (P100-L) and amplitude (P100-A) of P-VEP in children with CVI, and improve the best corrected visual acuity in children, the clinical effect is better than the conventional visual stimulation alone.
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Child , Child, Preschool , Humans , Acupuncture Points , Acupuncture Therapy , Brain Diseases , Evoked Potentials, Visual , Vision Disorders/therapyABSTRACT
@#AIM: To evaluate the diagnostic performance of the isolated-checked visual evoked potential(IC-VEP)in the detection of open angle glaucoma and compared it to the blue-yellow perimetry(B/YP)and optical coherent tomography(OCT).<p>METHODS: In a retrospective analysis, IC-VEP, perimetry and OCT were performed on 101 subjects(<i>n</i>=35, normal; <i>n</i>=30, early glaucoma; <i>n</i>=36, moderate and advanced glaucoma)from China. The sensitivity of IC-VEP, perimetry and OCT for detection of glaucoma, as well as the agreement within these 3 methods, were calculated to evaluate their clinic performance.<p>RESULTS: In the early primary open angle glaucoma(POAG)group the sensitivity of IC-VEP, blue-yellow perimetry and OCT were 70.00%, 70.00% and 63.33%, respectively. In the moderate advanced POAG group, the sensitivity of IC-VEP, OCT and blue-yellow perimetry were 86.11%, 88.89% and 91.67%, respectively. The specificity of IC-VEP was 91.43%. The results of IC-VEP were highly consistent with OCT and blue-yellow visual field tests(kappa: 0.721-1.000, <i>P</i><0.05).<p>CONCLUSION:As an objective examination of visual function, IC-VEP can be used for early diagnosis of glaucoma. It may be a useful tool for monitoring the function of RGCs in suspected glaucoma patients.
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@#AIM: To study the visual efficiency and characteristics of Top-down perceptual pathway in children.<p>METHODS: Totally 26 children volunteers in the outpatient department from January to June 2020 were selected. We adopted the photos of children's self-face as the Top-down perceptive fixation point pictures. The N75 time, P100 peak time, P100 amplitude and P100 repolarization time were recorded by graphic visual evoked potential(PVEP)examination.<p>RESULTS: Different visual perception pathway had no significant effect on the latency of N75, while different spatial frequencies have a significant effect on the N75 time. The latency of N75 was prolonged under high frequency spatial stimulation. The interaction between visual perceptual processing path and spatial frequency has a significant effect on the peak time of P100.Under Top-down condition, the peak time of P100 was significantly shortened under high-frequency spatial stimulus. Different visual perception paths and spatial frequencies had significant effects on P100 amplitude, and Top-down perceptual processing and spatial frequencies had significant effects on the time of P100 wave repolarization, while the interaction between processing paths and spatial frequencies had no significant effects.<p>CONCLUSION:Under Top-down visual perceptual, the visual conduction velocity and visual condition efficiency are improved in children's visual process.
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@#AIM: To detect the visual dysfunction, and investigate the changes of Tau and its phosphorylated Ser396/Ser404 forms in retinas and optic nerves in traumatic optic neuropathy(TON)model rats by using FVEP technique.<p>METHODS: Totally 30 SD rats were conducted FVEP electrode implantation. One week later, all rates were implemented TON operation with the optic nerve of left eye crushed and the optic nerve of right eye exposed(sham-operated). FVEP detections were performed respectively in these TON model rats at 1, 3, 7, 14, and 28d post crush, with 5 rats tested at each time point. After FVEP tests were taken, rats were sacrificed and then retinas and optic nerves of left eyes were separated for detecting the expression levels of Tau and pTau-Ser396/404 by Western Blot.<p>RESULTS: Typical FVEP waves were observed in the sham-operated eyes. Compared to the sham group, the N2 waves were significantly delayed and the amplitude of N2-P2 were greatly reduced at each time point in the operation eyes. However, the differences of N2 wave and the amplitude reduction of N2-P2 were not significant at each time point after crush. The contents of total Tau protein in retinas of TON rats sharply decreased at 1d post crush, briefly recovered at 7d post crush, and remained a slightly lower level than normal condition till 28d. The changes of pTau-Ser396/404 were consistent with the changes of total Tau in retains and the Ser396 was the main phosphorylation site. However, the total Tau contents in optic nerves of TON rats increased gradually, and peaked at the 14d post crush and remained till 28d. The changes of pTau-Ser396/404 were similar to the changes of total Tau in optic nerves, which peaked at 7d post crush. However, Ser404 was the main phosphorylation site of Tau in optic nerves.<p>CONCLUSION: The related indexes of N2 and P2 waves in FVEP can be used to detect the visual dysfunction in TON rats. After TON, the content changes of total Tau in retinas and optic nerves were much different while the changes of pTau-Ser396/404 followed the alterations of total Tau in the two locations. However, the main phosphorylation site of Tau was differnet according to the locations.
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Objective To explore a kind of visual evoked potential test equipment and method that is more suitable for the application of forensic clinical visual acuity evaluation. Methods Thirty-four volunteers （68 eyes） were selected, including 15 males and 19 females, aged between 20 and 40 years. Test lenses were placed before the tested eyes of volunteers to induce refractive myopia with insert method, and the diopter lenses were adjusted so that the visual acuity level of one eye of volunteers was above 0.8, and the visual acuity of the other eye was at moderate damage level （<0.3 and ≥0.1）. The tests were carried out under the binocular simultaneous asynchronous stimulation mode （hereinafter referred to as "binocular mode"） and monocular separate stimulation mode （hereinafter referred to as "monocular mode"） of virtual reality-pattern visual evoked potential （VR-PVEP）, and the amplitude of PVEP of volunteers under the two modes was compared at four spatial frequencies of 8×8, 16×16, 24×24 and 32×32. Results The differences in the amplitude of P100 wave between monocular and binocular modes at 8×8 spatial frequency had no statistical significance and the differences in amplitude of P100 wave between monocular and binocular modes at 16×16, 24×24, and 32×32 spatial frequencies had statistical significance （P<0.05）. The amplitude of the same eye in monocular mode was higher than that in binocular mode. Through correlation analysis, it was found that the amplitude of P100 wave in monocular mode was moderately correlated with amplitude of P100 wave in binocular mode. Conclusion In forensic identification practice, VR-PVEP is helpful for overcoming the disturbance of poor fixation, and to increase the reliability of PVEP evaluation results. It can greatly shorten the detection time of PVEP and improve work efficiency.
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Adult , Female , Humans , Male , Young Adult , Evoked Potentials, Visual , Eye , Reproducibility of Results , Virtual Reality , Visual AcuityABSTRACT
To investigate associations between central visual function and inner retinal structure in primary open-angle glaucoma (POAG). This study enrolled 78 POAG patients and 58 healthy controls. POAG was classified into early glaucoma and moderate to advanced glaucoma. The following tests were performed on all participants: isolated-check visual evoked potential (icVEP) testing, 24–2 standard automated perimetry (SAP), and Cirrus optical coherence tomography (OCT) examinations. Signal-to-noise ratio (SNR) measures obtained from icVEP responses to isolated checks presented at four depths of modulation (DOMs; 8%, 14%, 22%, and 32%) were explored. Mean macular sensitivity (mMS) was assessed by calculating the mean sensitivities of central 12 SAP points. Ganglion cell layer+ inner plexiform layer thickness (GCL+IPLT) and peripapillary retinal nerve fiber layer thickness (pRNFLT) were measured by OCT scanning. For each group of subjects, linear relationships among the following measures were analyzed: SNR, mMS, GCL+IPLT, and pRNFLT. SNR, mMS, GCL+IPLT, and pRNFLT were all more significantly decreased in glaucoma than in controls (P<0.001). A significant positive association was found between SNR at 14% DOM and GCL+IPLT at the inferior sector in early glaucoma (r=0.465, P=0.004). In moderate to advanced glaucoma, significant correlations were found between SNR at 32% DOM and mean GCL+IPLT (r=0.364, P=0.023), superior GCL+IPLT (r=0.358, P=0.025), and mean pRNFLT (r=0.396, P=0.025). In addition, in moderate to advanced glaucoma, there were significant correlations between mMS and all relevant measures of retinal thickness (r=0.330−0.663, P<0.010). In early glaucoma, significant correlations were found between mean mMS and minimum GCL+IPLT (r=0.373, P=0.023), and between inferior mMS and superior GCL+IPLT (r=0.470, P=0.003). Linear models provided a good explanation for the relationship between SNR and inner retinal thickness (IRT), whereas nonlinear models better explained the relationship between mMS and IRT. In early glaucoma, both SNR and mMS were related moderately and significantly to IRT, whereas in moderate to advanced glaucoma, mMS was more strongly correlated with IRT than SNR.
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@#AIM: To analyze the differences of retinal structure, visual evoked potential and visual function in different types of amblyopia children.<p>METHODS: One hundred and twenty children with 136 eyes with moderate amblyopia treated in our hospital from May 2014 to May 2018 were enrolled as the observation group(31 cases with 31 eyes of anisometropy, 35 cases with 70 eyes of refractive ametropia, and 26 cases with 35 eyes of strabismus); meanwhile, 29 children with 58 eyes with normal vision in the eye examination from our hospital were selected as the control group. Optical coherence tomography(OCT)imager was used to detect the foveal thickness of the macula, the thickness of the retinal nerve fiber layer(RNFL)around the optic disc and the quadrants, and the changes in retinal function were detected using visual electroencephalography. The P100 amplitude and latency of visual evoked potentials were observed and stereoscopic inspection being performed. <p>RESULTS: The thickness of macular fovea, the thickness of the optic disc and the RNFL in the quadrants of children with anisometropy and ametropia were significantly higher than those in the control group and children with strabismic amblyopia(<i>P</i><0.01). Compared with the control group, patients with refractive amblyopia had lower light peak potentials and longer light peak times. The dark valley potential of myopia children was higher in children with refractive amblyopia, and the Arden ratio and Gliern ratio were lower(All <i>P</i><0.01). The P100 wave amplitudes of the visual evoked potentials of the three types of amblyopia children were significantly lower than those of the control group, and the 1° and 15' spatial frequency latency periods were significantly delayed(all <i>P</i><0.01). The number of cross parallaxes, non-cross parallaxes, near-zero parallaxes, and far-sighted stereoscopic aberrations in the ametropic amblyopia group were significantly higher than those in the strabismic amblyopia group(<i>P</i><0.05), but were no different from those in the ametropic amblyopia group in terms of each indicators. <p>CONCLUSION: Retinal structure of patients with ametropic amblyopia and ametropic amblyopia has obvious abnormalities, and the P100 wave latency is delayed; strabismic amblyopia has the largest effect on stereoscopic function, while refractive amblyopia has the least effect.
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@#AIM: To investigate the changes of visual function and multifocal visual evoked potential in children with strabismus after intermittent exotropia operation.<p>METHODS: Totally 91 children with intermittent exotropia from January 2014 to December 2017 were enrolled in the study. All children were treated with surgery. The changes of visual function before and after operation were observed, and the level of multifocal visual evoked potential before and after operation were detected. <p>RESULTS: The total effective rate was 88% at one week after operation, 86% at 6mo after operation, the mean preoperative strabismus was-38.12△, and the mean postoperative strabismus was-5.8△. At 6mo after operation, the number of children with simultaneous vision, fusion and distant stereopsis decreased significantly as compared with that before operation(<i>P</i><0.01). The orthopedic rate was 68% at 6mo after operation, and the majority of the patients with all or only one or two grade visual function before the operation were positive, which was significantly higher than that of the patients who lost it after operation(<i>P</i><0.05). From before operation to 6mo after operation, the amplitude response density of the characteristic peak and the latency of the nasal and temporal retinas in the fourth and sixth rings of the children were significantly increased, while the latent period of the inferior retina was significantly decreased(<i>P</i><0.05).<p>CONCLUSION: Intermittent exotropia operation can effectively improve the visual function of children and promote the recovery of eye position in children, and the level of multifocal visual evoked potential in children after operation is also improved to some extent. The clinical effect is outstanding, and it is worth popularizing and applying.