ObjectiveTo investigate the value of pattern reversal visual evoked potential (PRVEP) and sweep pattern visual evoked potential (SPVEP) in evaluating the visual function of patients with central serous chorioretinopathy (CSC).MethodsA retrospective clinical trial. A total of 38 monocular CSC patients were enrolled from March 2016 to December2018 in Heping Hospital Affiliated Changzhi Medical College. There were 34 males and 4 females with the mean age of 40.0±5.2 years. All patients undergo PRVEP detection in both the acute phase (disease course ≤ 3 months) and the clinical cure phase (disease course ≤ 6 months) using the German Roland electrophysiological RETIport system.The stimulation pattern adopted a checkerboard with 1.00° and 0.25° stimulation angles. The P100 peak amplitude and peak time were observed. SPVEP inspection equipment and methods were the same as PRVEP, and the spatial frequency was 1, 2, 4, 6, 8, 12, 16, 22 cpd. The difference between SPVEP vision and subjective vision were compared. The PRVEP peak amplitude, peak time and SPVEP amplitude and phase of the affected eye and the contralateral eye were compared by paired t test; the subjective vision and SPVEP visual acuity of the affected eye and the contralateral eye were compared by Wilcoxon paired rank test; Pearson product-moment correlation analysis was performed on SPVEP vision.ResultsIn the acute phase, the peak amplitude of P100 in the affected eye was lower than that in the contralateral eye (t=30.26, 13.59), and the peak time was prolonged (t=－19.89, －29.41). The difference was statistically significant (P＜0.01); in clinically cured period, the P100 peak amplitude (t=1.49, －0.57) and peak time (t=－1.22, －1.84) of the affected eye and the contralateral eye showed no significant difference (P＞0.05). In the acute phase, the difference in SPVEP amplitude between the affected eye and the contralateral eye with different spatial frequencies was statistically significant (P＜0.01); the phase of the affected eye and the contralateral eye were compared about the spatial frequency 1, 2, 4, 6, 8, 12 cpd, the difference was statistically significant (P＜0.01). During the clinical cure period, the spatial frequency of 6, 8, 12, 16 cpd, the SPVEP amplitude of the affected eye and the contralateral eye, the difference was statistically significant (P＜0.01); on the spatial frequency of 6, 8, 12 cpd, the phase of SPVEP was compared between the affected eye and the contralateral eye, the difference was statistically significant (P＜0.01). During the acute phase and the clinical cure phase, the SPVEP visual acuity of the affected eye was lower than that of the contralateral eye, and the difference was statistically significant (P＜0.01); during the acute phase and clinical cure phase, the SPVEP visual acuity of the affected eye and the contralateral eye were lower than the subjective vision. The difference was statistically significant (acute phase: Z =－5.38, －3.00; P＜0.001, 0.003; clinical cure phase: Z=－5.36, －5.38; P＜0.001,＜0.001). In the acute phase, the subjective visual acuity of the affected eye was positively correlated with SPVEP visual acuity (r=0.847, P＜0.001).ConclusionsPRVEP and SPVEP are useful for objectively assessing the visual function of the patients with CSC. Especially, the slight and potential visual impairment in CSC can been detected by SPVEP.
ObjectiveTo observe the changes of central visual acuity and extracentral visual acuity in eyes with non-arteritic central retinal artery occlusion (NA-CRAO). MethodsA retrospective clinical study. From January 1, 2017 to December 31, 2024, 140 patients (140 eyes) diagnosed with NA-CRAO through ophthalmic examination at Department of Ophthalmology of First People's Hospital of Xianyang City were included in the study. All affected eyes underwent best corrected visual acuity (BCVA), visual field, intraocular pressure, fundus color photography, optical coherence tomography (OCT), and fluorescein angiography (FFA) examinations. After a clear diagnosis, conservative treatment such as reducing intraocular pressure, relieving spasms, and dilating blood vessels should be given immediately. Simultaneously, intravenous and/or arterial thrombolysis therapy should be administered based on the patient's overall condition. Under the same treatment conditions as other treatments, 33 eyes were treated with hyperbaric oxygen therapy within 24 hours after seeking medical attention. The changes in central visual acuity (BCVA) and peripheral visual acuity of the affected eye one month after treatment were observed. BCVA improvement of ≥ 1 line was defined as the increase of no light sensitivity to light sensitivity or above, and the increase of light sensitivity to 0.01 or above. The visual acuity outside the center was determined by the 0 ° axis in front of the eyeball at eye level, and was 10 ° outside visual acuity on the temporal side. Multivariate analysis using logistic regression analysis. ResultsAmong the 140 cases (140 eyes), there were 84 males (84 eyes) and 56 females (56 eyes). The mean age was (63.89±10.78) years. The duration of illness from the onset of symptoms to the time of diagnosis was 48 (2-720) hours. 6, 1, 14, 47, 41, 16, and 15 eyes were diagnosed with BCVA without light perception, uncertain light perception, manual/anterior, digital/anterior, 0.01-0.10, and ≥ 0.10, respectively. FFA examination revealed delayed arm retinal circulation time and filling of the retinal artery trunk to the peak, with changes in the "arterial front" observed in 126 eyes. OCT examination showed extensive edema and unclear structure in the inner layer of the retina in all patients. Out of 140 eyes, 122 were treated with intravenous thrombolysis and 4 with arterial thrombolysis; 14 eyes did not receive thrombolytic therapy. After treatment, 38 eyes (27.1%) showed an improvement of BCVA ≥ 1; 67 eyes (47.9%) did not show an improvement in BCVA, and the affected eye had a BCVA of approximately 0.6 without light perception; 17 eyes (12.1%) showed improvement in peripheral vision, and the peripheral vision of the affected eyes ranged from 0.01 to 0.1, all of whom were patients undergoing intravenous thrombolysis, and prior to treatment, this group of patients had complete blindness in the coarse side visual field of the Amsler grid, and their out of center visual acuity could not be measured. Among the 33 eyes treated with hyperbaric oxygen therapy, 24 eyes (72.7%) showed an increase in BCVA after treatment; 9 eyes did not improve, among which 4 eyes (12.1%) showed improvement in out of center visual acuity. Among the 107 eyes that did not receive hyperbaric oxygen therapy, 49 eyes (45.8%) showed an increase in BCVA after treatment. There was no improvement in 58 eyes (54.2%), among which 13 eyes (12.1%) showed an improvement in out of center visual acuity. The results of logistic regression analysis showed that intravenous thrombolysis and hyperbaric oxygen therapy were independent predictive factors for the improvement of central and extra central visual acuity (P＜0.05). ConclusionsHyperbaric oxygen therapy within 24 hours of seeking medical attention for patients with NA-CRAO disease course ≤ 1 month has a significant effect on the recovery of central and extra central vision. Intravenous thrombolysis and hyperbaric oxygen therapy are independent predictive factors for the improvement of central and extra central vision.
objective To observe the differences between four- and single-channel recording of normal multifocal visual evoked potential (mfVEP). Methods mfVEP of 35 health individuals (70 eyes) were detected by both four- and single-channel recording with VERIS apparatus. The root mean square (RMS) value of reactive amplitude was obtained from the results of the two kinds of recording. Each stimulated patch was analyzed to compare the variational degree of each patch between the two recording methods. Responase sasymmetry coefficient (RAC) was introduced to evaluate the symmetry property between the two eyes in an individual. Results Compared with the single-channel recording,the responses of the stimulated patches of the four- channel recording were increased statistically, with most of the patches below the horizontal meridian and some of patches in the upper field, and there was distinct symmetry property between the two eyes in the same individual recorded by four-channel recording. Conclusion The four-channel recording is better than the single one and could be clinically applied and popularized.(Chin J Ocul Fundus Dis，2004，20：156-159)
Objective To verify the feasibility and accuracy of the "lung surface intersegmental constant proportion landmarks", developed by our center, in identifying intersegmental planes during pulmonary segmentectomy. MethodsWe prospectively enrolled the patients who planned to receive thoracoscopic segmentectomy in West China Hospital of Sichuan University and The Third People's Hospital of Chengdu from September 2021 to October 2021. We took a relatively objective and feasible method, intravenous injection of indocyanine green, in identifying intersegmental planes as standard control. We intraoperatively judged the consistency between "lung surface intersegmental constant proportion landmarks" and intravenous injection of indocyanine green in identifying intersegmental planes. We discerned main landmarks of intersegmental plane by the constant proportion segment module, which was built based on the "lung surface intersegmental constant proportion landmarks", as well as distinguished the planes with discrepant fluorescence by peripheral intravenous indocyanine green injection. When the distance between the landmarks determined by the "ung surface intersegmental constant proportion landmarks" and the segmental boundaries displayed by indocyanine green fluorescence staining was ≤1 cm, the landmarks were judged to be consistent with the planes with discrepant fluorescence. As long as one of the landmarks was judged to be consistent, the method was considered to be feasible and accurate. Results A total of 21 patients who underwent thoracoscopic segmentectomy were enrolled, with 5 male and 16 female patients. The median age was 55 years, ranging from 34 to 76 years. A total of 11 patients received left-side surgery, while 10 patients received right-side surgery. In the operations of 21 pulmonary segmentectomies, at least one intersegmental landmark determined by the "lung surface intersegmental constant proportion landmarks" was consistent with the intersegmental plane determined by indocyanine green fluorescence staining in each patient. ConclusionThe intersegmental landmarks determined by the "lung surface intersegmental constant proportion landmarks" are consistent with that determined by indocyanine green fluorescence staining. The method of "lung surface intersegmental constant proportion landmarks" is feasible and accurate in identifying intersegmental planes during pulmonary segmentectomy.
The effect of deep brain stimulation (DBS) surgery treatment for Parkinson's disease is determined by the accuracy of the electrodes placement and localization. The subthalamic nuclei (STN) as the implant target is small and has no clear boundary on the images. In addition, the intra-operative magnetic resonance images (MRI) have such a low resolution that the artifacts of the electrodes impact the observation. The three-dimensional (3D) visualization of STN and other nuclei nearby is able to provide the surgeons with direct and accurate localizing information. In this study, pre- and intra-operative MRIs of the Parkinson's disease patients were used to realize the 3D visualization. After making a co-registration between the high-resolution pre-operative MRIs and the low-resolution intra-operative MRIs, we normalized the MRIs into a standard atlas space. We used a special threshold mask to search the lead trajectories in each axial slice. After checking the location of the electrode contacts with the coronal MRIs of the patients, we reconstructed the whole lead trajectories. Then the STN and other nuclei nearby in the standard atlas space were visualized with the grey images of the standard atlas, accomplishing the lead reconstruction and nerve nuclei visualization near STN of all patients. This study provides intuitive and quantitative information to identify the accuracy of the DBS electrode implantation, which could help decide the post-operative programming setting.
As a complex system, the topology of human’s brain network has an important effect on further study of brain’s structural and functional mechanism. Graph theory, a kind of sophisticated analytic strategies, is widely used for analyzing complex brain networks effectively and comparing difference of topological structure alteration in normal development and pathological condition. For the purpose of using this analysis methodology efficiently, it is necessary to develop graph-based visualization software. Thus, we developed VisConnectome, which displays analysis results of the brain network friendly and intuitively. It provides an original graphical user interface (GUI) including the tool window, tool bar and innovative double slider filter, brain region bar, runs in any Windows operating system and doesn’t rely on any platform such as Matlab. When importing the user-defined script file that initializes the brain network, VisConnectome abstracts the brain network to the ball-and-stick model and render it. VisConnectome allows a series of visual operations, such as identifying nodes and connection, modifying properties of nodes and connection such as color and size with the color palette and size double slider, imaging the brain regions, filtering the brain network according to its size property in a specific domain as simplification and blending with the brain surface as a context of the brain network. Through experiment and analysis, we conclude that VisConnectome is an effective visualization software with high speed and quality, which helps researchers to visualize and compare the structural and functional brain networks flexibly.
Objective To compare the effect of electrode positions on multifocal visual evoked potential(mf-VEP). Methods Ten healthy individuals were tested with RETIscan multifocal VEP system 3.20, each individual was tested with four electrode positions: the active and reference electrode were placed 2.0 cm above and below the inion in Ch1；3.0 cm above and 4.5 cm below the inion in Ch2；2.0 cm on both right and left side of the inion in Ch3 and 4.0 cm on both right and left side of the inion in Ch4. The summed amplitudes of hemifield mf-VEP were analyzed and compared according to different electrode positions. Results The difference among summed amplitudes of the upper or lower hemifield mf-VEP recorded with Ch1、Ch2、Ch3 and Ch4 was statistically significant；and the difference between Ch2 and the other channels was statistically significant too. The difference among summed amplitudes of the horizontal sites whose amplitudes were small when recorded with Ch2 and summed amplitudes of the corresponding sites recorded with Ch3 and Ch4 were statistically significant；and the difference between Ch4 and the other channels was statistically significant too. Conclusions compared to Ch1、Ch3 and Ch4, Ch2 can make a better recording of mf-VEP. As for some sites, especially those along horizontal line, horizontal electrodes could improve the amplitudes of mf-VEP recorded with vertical electrodes，and Ch4 could do better to improve the mf-VEP recorded with Ch2 than Ch3. (Chin J Ocul Fundus Dis，2004，20：346-348)
Objective To investigate the characteristics of multifocal visual evoked potential (mf-VEP) in healthy individuals, and provide normal reference values for its clinical application. Methods The mf-VEP of 37 healthy individuals (70 eyes) were examined by VERIS ScienceTM4.0. The visual stimulus was adart board with patterns consisted of 60 patches spanning a 25°visual field. The length of m-sequence was 214-1. The results were recorded by bipolar occipital straddle. The signal was amplified 100 K and was put through a band-pass filter between 3 and 100 Hz. The first slice of the second order kernel was analyzed by VERIS software. The summed responses of fields with different stimulus were a nalyzed and compared according to different ages, genders and eyes.Results The latencies and response densities of amplitude had statistically significant differences both in dimidiate and quartered field（Plt;0.05）. The latencies in ≥50 year group were much more delayed in some sectors of the visual field than those in lt; 50 year group（Plt;0.05）. The latencies of women were shorter than those of men（Plt;0.05）. There was no obvious difference of latencies and response densities of amplitude in each field sectors between both eyes（Pgt;0.05）. Conclusions The mf-VEP of healthy individuals can reflect the VEP at different field ocations objectively with its specific physiological characteristics, which may provide normal reference values for its clinical application.(Chin J Ocul Fundus Dis，2003，19：269-332)
Medical visual question answering (MVQA) plays a crucial role in the fields of computer-aided diagnosis and telemedicine. Due to the limited size and uneven annotation quality of the MVQA datasets, most existing methods rely on additional datasets for pre-training and use discriminant formulas to predict answers from a predefined set of labels. This approach makes the model prone to overfitting in low resource domains. To cope with the above problems, we propose an image-aware generative MVQA method based on image caption prompts. Firstly, we combine a dual visual feature extractor with a progressive bilinear attention interaction module to extract multi-level image features. Secondly, we propose an image caption prompt method to guide the model to better understand the image information. Finally, the image-aware generative model is used to generate answers. Experimental results show that our proposed method outperforms existing models on the MVQA task, realizing efficient visual feature extraction, as well as flexible and accurate answer outputs with small computational costs in low-resource domains. It is of great significance for achieving personalized precision medicine, reducing medical burden, and improving medical diagnosis efficiency.
Optometry involves knowledge from multiple fields such as biology, physics, chemistry, psychophysics, and medicine. Traditional undergraduate education in optometry mainly focuses on knowledge transmission and lacks interaction, resulting in low student interest and unsatisfactory teaching outcomes. In order to improve this situation, the teaching team of Department of Optometry and Visual Science, West China School of Medicine, Sichuan University proposed a method of integrating real visual experiences into teaching. By combining multimedia tools and existing methods, real visual phenomena and personal visual experiences are integrated into the curriculum. This new teaching method stimulates students’ interest in learning, increases classroom interaction, promotes knowledge understanding and application through vivid visual phenomena and students’ own visual experiences. This article will introduce the above teaching method.
