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find Keyword "Vision" 40 results
  • An improved Vision Transformer model for the recognition of blood cells

    Leukemia is a common, multiple and dangerous blood disease, whose early diagnosis and treatment are very important. At present, the diagnosis of leukemia heavily relies on morphological examination of blood cell images by pathologists, which is tedious and time-consuming. Meanwhile, the diagnostic results are highly subjective, which may lead to misdiagnosis and missed diagnosis. To address the gap above, we proposed an improved Vision Transformer model for blood cell recognition. First, a faster R-CNN network was used to locate and extract individual blood cell slices from original images. Then, we split the single-cell image into multiple image patches and put them into the encoder layer for feature extraction. Based on the self-attention mechanism of the Transformer, we proposed a sparse attention module which could focus on the discriminative parts of blood cell images and improve the fine-grained feature representation ability of the model. Finally, a contrastive loss function was adopted to further increase the inter-class difference and intra-class consistency of the extracted features. Experimental results showed that the proposed module outperformed the other approaches and significantly improved the accuracy to 91.96% on the Munich single-cell morphological dataset of leukocytes, which is expected to provide a reference for physicians’ clinical diagnosis.

    Release date:2023-02-24 06:14 Export PDF Favorites Scan
  • Patterns of fundus autofluorescence and optical coherence tomography in diabetic macular edema and functional correlations

    ObjectiveTo assess and classify the features of fundus autofluorescence (FAF) with optical coherence tomography (OCT) in clinically significant diabetic macular edema according to the criteria reported by ETDRS. Methods Eighty-four eyes of 47 diabetic patients with untreated clinically significant macular edema (CSME) diagnosed by OCT/FAF examination were enrolled in this study. The mean BCVA was 0.38±0.26, CRT was (360.23±139.40) μm and volume was (9.59±1.97) mm3. According to the FAF patterns, the CSME patients were divided into normal group (30 eyes), single-spot group (20 eyes), and multiple-spot group (22 eyes). There were 44, 18 and 22 eyes with diffuse edema, cystoid edema and serous retinal detachment, respectively. The correlation of visual acuity with central retinal thickness and total volume of macular was analyzed between different groups. ResultsIn the normal group and the single-spot group, the prevalence of the diffuse type was highest in the OCT (83.3%, 60.0%). In the multiple-spot group, the prevalence of the SRD type was highest in the OCT (50.0%). In the three FAF pattern groups, the BCVA were 0.47±0.26, 0.43±0.30, 0.28±0.19; the CRT were (272.41±48.62), (402.84±134.89), (505.67±135.20) μm; the total volume was (8.67±1.03), (8.94±1.63), (10.79±2.20) mm3. The BCVA were 0.43±0.25, 0.45±0.30, 0.22±0.14; the CRT were (272.41±48.62), (402.84±134.89), (505.67±135.20) μm; the total volume was (8.58±0.95)、(9.22±1.33)、(12.03±2.01) mm3 in eyes with diffuse edema, cystoid edema and serous retinal detachment, respectively(r=-0.31, -0.34; P > 0.05). Correlation analysis showed CRT positively correlated to volume (r=0.85, P < 0.05), BCVA negatively correlated to CRT and volume(r=-0.31, -0.34; P > 0.05). ConclusionThere are more diffuse edema eyes in normal group and single-spot group, while serous retinal detachmen in multiple-spot group. FAF correlates better with visual acuity than OCT patterns.

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  • Visual function before and after photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration

    Objective To evaluate the visual function before and after photodynamic therapy(PDT) in patients with subfoveal choroidal neovascularization ( CNV) caused by age-related macular degeneration (AMD). Methods Twenty-five consecutive patients (34 eyes) treated with PDT (verteporfin) for subfoveal CNV in age-related macular degeneration diagnosed by fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT). Visual function including best corrected visual acuity, contrast sensitivity frequency, binocular function, confusion, stereo-vision, color vision, metamorphopsis and central scotoma were examed before photodynamic therapy and 1 week, 1 month, 3 month after photodynamic therapy. The follow-up time varied from 3 months to 2 years (mean 7.6 months). Results The changes of visual function at the 3rd month after photodynamic therapy revealed improving in 13 eyes (38.24%), without any change in 17 eyes (50.00%), and decreasing in 6 eyes (17.65%). Visual acuity with logMRA improved after photodynamic therapy, but without statistic difference. All spatial contrast sensitivity improved. Contrast sensitivity for spatial frequencies 5 cycles per degree (cpd) was better after photodynamic therapy with significant difference (P=0.045).Binocular function, fusion function, stereo function and color vision were slightly improved without statistic difference. Conclusion Damage of visual function in macular degeneration is many-sided. The treatment of PDT for exudative AMD can improve part visual function. (Chin J Ocul Fundus Dis,2004,20:289-291)

    Release date:2016-09-02 05:58 Export PDF Favorites Scan
  • Eight cases of idiopathic hypertrophic meningitis with ophthalmic manifestations as the first symptom

    ObjectiveTo investigate the clinical, laboratory and imaging evaluation, treatment and prognosis of patients with idiopathic hypertrophic pachymeningitis (IHP) with ophthalmic manifestations as the first symptom.MethodsA retrospective case analysis. Eight patients displaying symptoms of IHP were recruited from the Neuro-ophthalmology Department in the First Medical Center of Chinese PLA General Hospital from January 2016 to April 2019 were inculed in this study. There were 6 males and 2 females, aged from 11 to 65 years, with an average age of 48.00±19.08 years. The course of disease ranged from 30 days to 7.5 years, with an average course of 17.00±30.08 months. The age, symptoms and signs of all patients were recorded. All patients underwent ophthalmic examination, orbit or brain MRI or CT examinations, blood routine examination, biochemistry, tumor markers, immunity, hepatitis B, syphilis, HIV, thyroid function and other laboratory tests, and lumbar puncture was performed to measure the cerebrospinal fluid (CSF) pressure and indicators. The clinical manifestations, orbital or brain MRI imaging and laboratory examination characteristics were summarized. Treatment and prognosis were also observed.ResultsIn total of 8 patients, visual loss was presented in 6 patients, visual loss and diplopia were presented in 1 patient, and diplopia was presented in 1 patient. Binocular involvement in 7 patients and monocular involvement in 1 patient. Other symptoms including headache and hear loss and so on. Optic disc edema in 1 eye and optic disc pallor in 6 eyes were reviewed by fundus examination. The laboratory examination showed that the angiotensin converting enzyme abnormal in 4 patients, the anti-thyroid peroxidase antibody abnormal in 3 patients and immunoantibodies positive in 3 patients. CSF measurements showed that the protein level elevated in all patients. Orbit and/or brain MRI and CT examination showed that optic nerve involvement in 6 patients, oculomotor nerve involvement in 1 patient, and cavernous sinus region involvement in 2 patients. Glucocorticoid was effective in all patients, and the visual acuity significantly improved in 4 patients, the diplopia was completely resolved in 2 patients, and the disease modifying therapy (DMT) was combined to prevent recurrence in 7 patients. No recurrence was observed in an average follow-up time of 26.63±16.55 months.ConclusionsIHP patients may be first visit an ophthalmologist due to vision loss in bilateral eyes simultaneous or sequentially. IHP patients are often associated with headache and other cranial nerve paralysis symptoms. Definitive diagnosis of IHP depends on imaging examination. Glucocorticoid treatment is effective in early phase, but it is tendency to progress and relapse, suggesting combined with DMT as early as possible.

    Release date:2020-05-19 02:20 Export PDF Favorites Scan
  • The characteristic of vernier acuity on age-related macular degeneration patients

    Objective To investigate the clinical characte ristic of vernier acuity in age-related macular degeneration (AMD) patients. Methods The vernier acuity test soft wear system was developed to detect the 23 cases (39 eyes) of AMD patients. Tweenty-one eyes were atrophic type and 17 eyes were exudative type. Two fixed targets and a movable target are shown on the computer screen. The examinee was asked to adjust the position of the central target and the relationship between it and align them by using a track ball. The computer automatically recorded the deviations of distances between the movable target and the specific one, and then computed and analysed the results of average threshold and variance.Results Both the atrophic and exudative AMD had higher vernier acuity threshold and its variance than normal subjects, and the differences were significant (P<0.01). The correlation coefficient between visual acuity and vernier acuity threshold was -0.78, and that between visual acuity and threshold variance was -0.80. The results suggest that vernier acuity thre shold and its variance were reliable parameters that reflect the visual acuity in AMD patients.Conclusions The results suggest that vernier acuity threshold and its variance were reliable parameters that reflect the visual acuity in AMD patients.(Chin J Ocul Fundus Dis,2003,19:201-268)

    Release date:2016-09-02 06:00 Export PDF Favorites Scan
  • Examination of full-field flash electroretinogram for retinal functi on of patients with retinopathy of prematurity

    Objective To observe the retinal function of infa nts with retinopat hy of prematurity (ROP). Methods A total of 78 infants (156 ey es) aged from 4-5 months underwent full-field flash electroretinogram (ERG) examination. The am p litude and implicit time of a-and b-wave of ERG were detected to evaluate the i nfants' retinal function. Seventy-eight infants (156 eyes) included 33 healthy a nd full-term infants (66 eyes), 25 healthy premature children (50 eyes), and 20 infants (40 eyes) with ROP. Results Obvious ERG waveforms were recorded in all the fullterm and healthy premature children. Amplitude of combined b-wave wa s 388.7 mu;V in full-term infants and 336.7 mu;V in healthy premature children, whi c h was 64.4% and 55.6% of that of the healthy adults respectively. In infants wit h ROP, ERG was nonrecordable in 20 eyes (50%); amplitude of combined b-wave was 183.8 mu;V in the other 20, whose implicit time delayed obviously compared with that of fullterm infants. The amplitude of ERG of healthy premature infants de c reased significantly compared with that of the full-term infants. Conclusions Retina keeps growing after birth. ERG of healthy full-term chi ldren is not as developed as those of adults. The progress of retinal maturation in infants with ROP is slower than that in the full-term infants. ERG examination is an effecti ve method in evaluating retinal function of infants with ROP.

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Visual acuity of patients of proliferative diabetic retinopathy after vitreoretinal surgery

    Objective To observe the visual acuity of different stages of proliferative diabetic retinopathy (PDR) eyes after vitrectomy and analyze the risk factors of blindness.Methods A total of 384 eyes of 300 patients underwent vitrectomy for PDR were followed up. All cases were divided into three groups according to different stage of PDR (stage Ⅳ, stageⅤ and stage Ⅵ), the effect of vitrectomy were compared among these groups.Results The final visual acuity increased in 271 eyes (70.6%), among them there were 171 eyes (85.5%) in stage Ⅳ-Ⅴ, and 100 eyes (54.3%) in stage Ⅵ, and there was statistical difference between these two groups(chi;2=44.78,P<0.05). 82.8% of early-treated and 64.6% of middle/late-treated stage Ⅵ patients had postoperative visual acuity above 0.05 (chi;2=4.861,P<0.05). 39.5% (131 eyes) of 332 eyes with diabetic blindness was still blind after surgery. Conclusion Visual acuity can be improved in the majority of PDR eyes after vitrectomy, early prevention and early treatment are the keys to avoid diabetic blindness.

    Release date:2016-09-02 05:40 Export PDF Favorites Scan
  • Clinical observation of the causes of metamorphopsia after scleral buckling surgery

    Objective To evaluate the causes of the metamorphopsia in patients with reattached retina after scleral buckling surgery. Methods Amsler grid test, ophthalmoscopic examination, fundus fluores cein angiography (FFA) and optical coherence tomography (OCT) were performed on 79 patients (79 eyes) with reattached retina at the 2nd week, 2nd, 6th month and 1st year after scleral buckling operation. Results Two weeks after the operation, 51 patients (51 eyes, 64.56%) complained of metamorphopsia,and 44 patients (44 eyes, including 35 with and 9 without metamorphopsia) were examined by OCT and FFA. In patients with metamorphopsia, the results of OCT in 31 (88.57%) revealed abnormal macula with seven kinds consisting mostly of stratum neuroepithelium detachment (74.29%), while of FFA in 6 patients showed abnormal macular (17.14%) including 4 with neuroepithelium detachment (66.67%). In patients without metamorphopsia, abnormal macula could be found in 2 by OCT while nothing special was seen in FFA. Most abnormal macula in patients followed-up 2 months, 6 months and 1 year postoperatively meliorated as time went by, with alleviative or disappeared metamorphopsia; while the patients with persistently existing macular membrane had aggravating metamorphopsia. Conclusions Abnormal macula is the main reason for metamorphopsia after scleral buckling surgery. Neuroepithelium detachment and macular membrane are the main causes of metamorphopsia at the early and terminal stage after operation.(Chin J Ocul Fundus Dis,2004,20:94-97)

    Release date:2016-09-02 05:58 Export PDF Favorites Scan
  • Analysis of the properties of visual acuity and fixation in eyes with idiopathic macular hole before and after surgery

    ObjectiveTo observe the changes of visual acuity and fixation properties of eyes with idiopathic macular hole (IMH) before and after surgery. MethodsA prospective clinical study. From September 2019 to December 2020, 25 patients with 25 eyes of IMH diagnosed in Department of Ophthalmology of The Fourth People's Hospital of Shenyang were included in the study. All patients underwent pars plana vitrectomy (PPV) combined with internal limiting membrane stripping. All eyes underwent best corrected visual acuity (BCVA), optical coherence tomography (OCT), and microperimetry before and after surgery. The BCVA examination was carried out using the Snellen visual acuity chart, which was converted into logarithmic minimum resolution angle (logMAR) visual acuity during statistics. The 12° macular sensitivity (MS) and bivariate contour ellipse area (BCEA) were measured by MP-3 microperimetry. The minimum diameter (MIN) and base diameter (BASE) of the macular hole were measured by OCT; the distance between the preferred retinal location (PRL) and the center of the fovea was measured by Image-proplus 6.0 image processing software. At 1 and 3 months follow-up after surgery, the same equipment and methods as before surgery were used to conduct related examinations. The changes of BCVA, PRL distance from the fovea, MS, BCEA, and macular hole shape before and after surgery were compared and observed. One-way analysis of variance was used to compare the indicators before and after surgery. Pearson correlation analysis was used for the correlation between BCVA and preoperative BCVA, PRL and foveal center distance at 3 months after surgery. The correlation between MIN, BCVA, PRL and foveal center before surgery distance, MS, BCEA and BCVA at 3 months after surgery were analyzed by multiple linear regression. ResultsAmong 25 eyes of 25 cases, 1 male had 1 eye, and 24 females had 24 eyes. The macular hole in stage Ⅲ and Ⅳ were 11 eyes and 14 eyes, respectively. MIN and BASE were 537.68±200.09 and 905.48±278.79 μm, respectively. One month after surgery, the hiatus was closed. Before surgery and 1 and 3 months after surgery, the logMAR BCVA of the affected eyes were 0.80±0.17, 0.70±0.21, 0.60±0.25, and the MS were 22.20±3.86, 23.60±3.14, 24.38±2.68 dB, the distances between PRL and the center of the fovea were 537.72±426.05, 402.00±395.06, 236.80±219.54 μm, and BCEA were 7.90±3.43, 6.40±2.67, 4.80±2.32 deg2. Compared with before operation, BCVA (F=7.047, 20.104) and MS (F=1.980, 5.390) were significantly improved at different time after operation, the distance between PRL and fovea center (F=1.265, 9.530), BCEA (F=2.762, 13.617) were decreased, the difference were statistically significant (P<0.05). The results of correlation analysis showed that BCVA at 3 months after surgery was significantly associated with preoperative MIN (r=0.810), BASE (r=0.664), BCVA before surgery and 1 month after surgery (r=0.854, 0.940), preoperative and surgical MS at 1 month after surgery (r=-0.548, -0.578), distance between PRL and foveal center before surgery and at 1 month after surgery (r=0.833, 0.915), BCEA before surgery and at 1 month after surgery (r=0.636, 0.732) were significantly correlated (P<0.05). The results of multiple linear regression analysis showed that the distance between PRL and foveal center before surgery and BCVA were risk factors for poor prognosis of BCVA at 3 months after surgery. ConclusionsThe BCVA and MS of eyes with IMH are significantly improved after surgery, and the distance between PRL and foveal center and BCEA decreased. BCVA, PRL and foveal center distance before surgery are risk factors for poor visual acuity after surgery.

    Release date:2022-11-16 03:11 Export PDF Favorites Scan
  • Epidemiological investigation of ocular fundus diseases in Tibetan above 40 in Maqin county, Qinghai Province

    Objective To investigate the morbidity of ocular fundus diseases in Tibetan above 40 in Maqin county, Qinghai Province. Methods A total of 2511 Tibetan above 40 in Maqin county, Qinghai Province were seelected by cluster sampling method. The sampling survey of ocular fundus diseases was performed on the individuals with indirect ophthalmoscope, and the results were compared with the domestic existing epidemiological data. Results Two hundred and thirty five (9.35%) cases were found to have abnormal ocular fundus, and the blindness rate due to the abnormal ocular fundus was 20.5% (80/391 eyes) which was lower than the blindness rate due to cataract (52.5%). Low vision and blindness led by ocular fundus diseases were found in 155 eyes (65.96%),including 74(47.74%) with age-related macular degeneration (AMD) and 23 (9.79%) with retinoangiopathy. Conclusions The morbidity of ocular fundus disorder is higher in high plateau than that in backland; AMD and retinoangiopathy are the main diseases leading to blindness. (Chin J Ocul Fundus Dis, 2006, 22: 321-323)

    Release date:2016-09-02 05:51 Export PDF Favorites Scan
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