• <xmp id="1ykh9"><source id="1ykh9"><mark id="1ykh9"></mark></source></xmp>
      <b id="1ykh9"><small id="1ykh9"></small></b>
    1. <b id="1ykh9"></b>

      1. <button id="1ykh9"></button>
        <video id="1ykh9"></video>
      2. west china medical publishers
        Keyword
        • Title
        • Author
        • Keyword
        • Abstract
        Advance search
        Advance search

        Search

        find Keyword "Vision" 41 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
        • Preliminary observation of the therapeutic effects of vitrectomy on chronic and refractory Behcet′s disease

          Objective To evaluate the therapeutic effects of vitrectomy on chronic and refractory Behcet′s diseases. Methods The clinical data of 8 patients (10 eyes) with Behcet′s diseases from 0.5 to 3 years after vitrectomy were retrospectively analyzed. Pre-and post-operative visual acuity, control of inflammation after the surgery, and the recurrence were observed and analyzed. Both of the eyes were involved in all of the patients, including complete Behcet′s diseases in 5 and incomplete in 3. Results Vitreous opacity and liquefaction were found in all of the involved eyes, dark retina and thin retinal vessels were seen in most of the eyes, and vascular obstruction or sheath-like changes in different degrees were detected in some eyes. Improvement of visual acuity was observed in all of the eyes which had undergone the treatment after the operation. There was significant difference between the visual acuity before the surgery and at the 1st and 2nd week and the 1st and 6th month after the surgery. During the follow-up period, recurrence of the inflammation was found in 3 eyes within 1 month and in 6 eyes within 6 months; no recurrence was found in 4 eyes after the operation. No acute recurrence of inflammation was found after operation in the involved eyes. Conclusion Vitrectomy for chronic and refractory Behcet′s diseases may improve the visual acuity of the involved eyes, and the surgery is safe and effective. (Chin J Ocul Fundus Dis, 2005, 21: 357-359)

          Release date:2016-09-02 05:52 Export PDF Favorites Scan
        • Objective quantitative assessment of visual quality with a double-pass instrument for myopic foveoschisis patients

          ObjectiveTo objectively quantitative assess the visual quality in patients with myopic foveoschisis (MF) using a double-pass optical quality analysis system (OQASⅡ). MethodsSixty-two subjects participated in this cross-sectional, observational study, who were divided into three groups based on the pathologic conditions including myopic foveoschisis group (MFG), myopic control group (MCG) and normal control group (NCG). Measurements with OQASⅡwere performed for the modulation transfer function cut off frequency (MTF cut-off), the Strehl ratio (SR) and the objective scatter index (OSI). Visual data were analyzed using ANOVA and Pearson's correlation accompanied by logMAR BCVA and axial length (AL). ResultsThe mean values for MTF cut-off, SR and OSI of MFG, MCG and NCG were 18.18±4.81, 0.13±0.03, 3.50±0.44; 22.87±2.66, 0.14±0.02, 2.42±0.29; 33.68±4.70, 0.23±0.02, 1.68±0.20 respectively, and statistical difference were proved except SR between MFG and MCG, or BCVA between MCG and NCG (P < 0.05). LogMAR BCVA and AL have negative correlations to MTF cut-off (r=-0.928, -0.658; P < 0.05) and SR (r=-0.577, -0.893; P < 0.05) with high coefficients in MFG. Log MAR BCVA has negative correlations to MTF cut-off and SR (r=-0.659, -0.806; P < 0.05) in MCG. Log MAR BCVA has negative correlations to MTF cut-off and SR (r=-0.606, -0.602; P < 0.05) and positively correlated to OSI (r=0.561, P < 0.05) in NCG. ConclusionsThe mean value of BCVA, MTF cut-off, SR, OSI of myopic foveoschisis patients were lower than those myopic patients without foveoschisis and normal people. there exists a significant negative correlation between Log MAR BCVA, AL to MTF cut-off and SR. Compared with myopic and normal subjects, myopic foveoschisis have lower BCVA, MTF cut-off, SR but higher OSI.

          Release date: Export PDF Favorites Scan
        • Clinical features and visual function of recurrent neuromyelitis optica

          Objective To observe the clinical features and visual function of recurrent neuromyelitis optica (NMO). Methods Thirty-four patients with NMO were enrolled in this retrospective case series study. The patients included two males and 32 females. The average first onset age was (35.03plusmn;14.56) years old and the average recurrent rate were (4.24plusmn;2.45) times. The recurrent rate of optic neuritis (ON) ranged from two to 12 times. The recurrent rate of ON was two times in 15 eyes of 10 patients, ge;three times in 37 eyes of 24 patients. Vision acuity, direct ophthalmoscope, fundus pre-set lens examination, visual field and visual evoked potential (VEP) were evaluated. Clinical features were observed. The abnormal rate of optic nerve including optic edema and atrophy; abnormal rate of visual field including decreasing retinal sensitivity, central and paracentral scotoma, ring scotoma, half field defects, tunnel visual field, visual field centrality constriction; abnormal rate of VEP including Prolonged latent phase and/or decreasing amplitude of P100 wave from patients of first episode or recurrence was analyzed. Serum NMO-IgG was detected from 28 patients by indirect immunofluorescence technique to observe its positive rate. Results All patients were characterized by repeated episodes of ON and myelitis. The main clinical feature of ON was visual loss, and the main clinical features of myelitis included sensory disability, dyskinesia and vesicorectal disorder. Blindness rate was 41.67% after the first attack of ON, 33.33% after two relapses, and 64.86% after ge; three relapses. The difference of blindness rate between first attack and two episodes was not significant (chi;2=0.270,P=0.603). However, the blindness rate in patients having ge; three episodes was significantly higher than those having two episodes (chi;2=4.300,P=0.038). With recurrence rate increasing, the abnormal rate of the optic nerve (chi;2=6.750,P=0.034)and VEP(chi;2=6.990,P=0.030)increased. But the abnormal rate of visual field did not increase along with recurrent rate (chi;2=0.660,P=0.718). Seropositive rate of NMO-IgG did not differ significantly between patients with first attack ON and that with recurrent ON (chi;2=1.510,P=0.470). But the seropositive patients had significantly higher bilateral blindness rate than seronegative patients (chi;2=5.063,P=0.027). Conclusions NMO are characterized by recurrent ON and myelitis. Visual loss, sensory disability, dyskinesia and vesicorectal disorder are the main clinical features. With recurrence rate increasing, the blindness rate, abnormalities the optic nerve and the abnormity rate of VEP increase. Seropositive recurrent NMO patients have higher bilateral blindness rate than seronegative patients.

          Release date:2016-09-02 05:22 Export PDF Favorites Scan
        • Metamorphopsia and vision-related quality of life and its influencing factor after surgical treatment of idiopathic macular hole

          Objective To evaluate metamorphopsia and vision-related quality of life (VRQoL) and its influencing factor after vitrectomy for idiopathic macular hole (IMH). Methods This is a prospective and non-randomized clinical cohort study. Thirty eyes of 30 IMH patients who received vitrectomy and inner limited membrane (ILM) peeling were included. The best-corrected visual acuity (BCVA), medical refraction test and optical coherence tomography (OCT) were performed. BCVA was recorded as logarithm of the minimum angle of resolution (logMAR). The macular hole index (MHI) was measured using OCT. The average logMAR BCVA and MHI in suffering eyes at baseline were 1.02±0.07 and 0.47±0.02, respectively. The uncorrected visual acuity of the fellow eyes was less than 0.1. Follow-up period was longer than 6 months. At 6 months after surgery, the central retinal thickness (CRT) was measured by OCT; vertical and horizontal metamorphopsia were measured by metamorphopsia charts; VRQoL was evaluated by Chinese VRQoL-25. Spearman correlation analysis was performed to analyze the relationship of VRQoL and postoperative BCVA, metamorphopsia and preoperative MHI. Results At 6 months after surgery, macular hole closure was confirmed by OCT in all patients. The vertical and horizontal metamorphopsia were (0.17±0.03)° and (0.11±0.03)°, respectively. The VRQoL-25 composite score was 79.81±1.29. The average BCVA was 0.59±0.05. The average CRT was (155.10±6.27) μm. The postoperative VRQoL was positive correlated with preoperative MHI (r=0.491,P=0.002), and negative correlated with preoperative BCVA (r=?0.445,P=0.014), postoperative BCVA (r=?0.530,P=0.003) and postoperative metamorphopsia (r=?0.532,P=0.006), but not correlated with the postoperative CRT (r=0.231,P>0.05). Conclusions IMH patients improved their visual acuity after surgery, but still have metamorphopsia. VRQoL was negative correlated with metamorphopsia, positive correlated with preoperative MHI.

          Release date:2017-04-01 08:56 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
        • Effects of local foveal photoreceptor defect on visual acuity

          Objective To observe the effects of local macular foveal photoreceptor defects on visual acuity.Methods Thirty-one patients (31 eyes) with photoreceptor defect in macular fovea (case group) diagnosed by spectral domain optical coherence tomography (SD-OCT) and 30 patients (30 eyes) age- and diopter- matched normal subjects (control group) were enrolled in this study. There were 22 eyes with full photoreceptor defects and 9 eyes with outer segment defects in case group. All subjects were examined for best corrected visual acuity (BCVA), slit-lamp microscopy, direct ophthalmoscope and SD-OCT. Independent sample t-test was used to compare central foveal thickness (CFT) between case group and control group. Difference of logMAR BCVA, CFT, maximum width and height of photoreceptor defects, defected area and residual retinal thickness in macular between patients with full photoreceptor defects and outer segment defects were also compared.Results The CFT of case group and control group were (225.32plusmn;19.70),(240.02plusmn;10.70) mu;m, the difference was not statistically significant (t=-1.96, P>0.05). In full photoreceptor defects and outer segment defects patients, the mean logMAR BCVA were 0.22plusmn;0.31, 0.32plusmn;0.43; the mean CFT were (224.09plusmn;20.57), (228.33plusmn;18.17) mu;m; the maximum width of photoreceptor defects were (131.32plusmn;108.18), (143.22plusmn;66.93) mu;m; the mean defected area were (0.022plusmn;0.054), (0.019plusmn;0.019) mm2; the mean maximum height of photoreceptor defects were (77.41plusmn;6.62), (44.89plusmn;4.26) mu;m; the mean residual retinal thickness were (87.00plusmn;20.31), (128.33plusmn;23.54) mu;m respectively. There was no statistical significance between full photoreceptor defects and outer segment defects patients in the mean logMAR BCVA, CFT, maximum width of photoreceptor defects and defected area (t=-0.76, -0.538, -0.305, 0.166; P>0.05), but there were significant difference in mean maximum width of photoreceptor defects and residual retinal thickness (t=12.72, -4.91;P<0.05). Conclusions The local photoreceptor defects in macular fovea can lead to decrease of visual acuity. The wider the photoreceptor defects, the worse the visual acuity.

          Release date:2016-09-02 05:26 Export PDF Favorites Scan
        • Etiologies and vision outcomes of 367 inpatients with no light perception

          Objective To observe the etiologies and vision outcomes of inpatients with no light perception (NLP). Methods A total of 367 inpatients (430 eyes) with NLP in Zhongshan Ophthalmic Center were enrolled in this study. The visual acuity examination followed the international standard methods. NLP was detected by torch light in a dark room and the pupil light reflection state was also considered. The patients included 208 males (235 eyes) and 159 females (195 eyes). Sixtythree patients (126 eyes) were bilateral and 304 patients (304 eyes) were unilateral cases including 159 right eyes and 145 left eyes. The patients' ages ranged from 2.5 to 86.0 years, with a mean age of (40.85plusmn;18.03) years. All the patients were treated according to their diseases. The ratio of different eye disease and visual outcome were recorded and analyzed. Results Among 430 eyes, there were 157 eyes (36.5%) with optic neuritis, 68 eyes (15.8%) with uveitis, 54 eyes (12.6%) with retinal vascular disease, 35 eyes (8.1%) with ischemic optic neuropathy, 29 eyes (6.7%) with traumatic optic neuropathy, 28 eyes (6.5%) with optic atrophy, 18 eyes (4.2%) with trauma, 17 eyes (4.0%) with radiation optic neuropathy, 10 eyes (23%) with glaucoma, five eyes (1.2%) with retinal detachment, four eyes (0.9%) with compressive optic neuropathy, two eyes (0.5%) with orbital apex syndrome, two eyes (0.5%) with hysteria, and one eye (0.2%) with orbital cellulitis. After active treatment, 269 eyes (62.6%) remained NLP, 161 eyes (37.4%) got improved visual acuity, including light perception- 0.02 in 74 eyes (17.2%), ge;0.02-<0.05 in 25 eyes (5.8%), ge;0.05 -<0.1 in 14 eyes (3.3%), ge;0.1 -<0.3 in 11 eyes (2.6%) and ge;0.3 in 37 eyes (8.6%). Conclusions The main causes of nonsurgical and non-trauma NLP are retinal disease and optic neuropathy. Some patients with NLP may restore useful vision if they received prompt referral and active intervention.

          Release date:2016-09-02 05:26 Export PDF Favorites Scan
        • Correlation of choroidal thickness and visual function in retinitis pigmentosa patients

          ObjectiveTo analyze the subfoveal choroidal thickness in retinitis pigmentosa (RP) patients and to evaluate the correlation between the subfoveal choroidal thickness (SCT) and visual function. MethodsTotally 42 RP patients (84 eyes) and 49 age and diopter-matched normal controls (98 eyes) were enrolled in this study. All the patients were taken the enhanced depth imaging technique of optical coherence tomography (EDI-OCT) examination for the measurement of the SCT. The covariate analysis was used to analyze the interaction effect between age and group. Then the SCT was amended. The RP patients were examined by 30°visual field test (T32 or LVC program) and electroretinogram (ERG) test. 32 eyes examined by T32 program, 52 eyes examined by LVC program. The waveform of ERG, mean sensitivity (MS) and mean defect (MD) were recorded. The relationship of SCT, MS and MD were analyzed by Pearson correlation analysis. ResultsThe SCT of RP patients and controls were (223.12±69.59), (288.29±52.36) μm. The covariate analysis of covariance with different age group interaction was not statistically significant (F=1.619, P=0.205), as amended SCT of RP patients and controls were (217.34±6.60), (293.20±6.00) μm, respectively. The SCT was decreased in RP patients (t=7.042, P < 0.001). Among 84 eyes, bright cone response weaken in 35 eyes, scotopic rod response weaken in 31 eyes. The difference of SCT in different ERG waveform was not significant (t=-0.976, -1.584; P=0.332, 0.117). The MS and MD of 32 eyes using T32 program were (9.05±6.42), (18.84±6.30) dB, the SCT was (209.83±71.48) μm; the MS and SCT of 52 eyes using LVC program were (7.14±5.03) dB and (228.32±66.32) μm. The SCT was related to MS (r=0.494, P=0.003) and MD (r=-0.448, P=0.009) in eyes using T32 program. There was no correlation between SCT and MD in eyes using LVC program (r=-0.232, P=0.095). ConclusionsThe SCT of RP patients is thinner than that of normal controls. The SCT of RP patients is related to MS and MD of T32 program, but not correlated to ERG waveform and MS of LVC program.

          Release date: 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
        5 pages Previous 1 2 3 4 5 Next

        Format

        Content

      3. <xmp id="1ykh9"><source id="1ykh9"><mark id="1ykh9"></mark></source></xmp>
          <b id="1ykh9"><small id="1ykh9"></small></b>
        1. <b id="1ykh9"></b>

          1. <button id="1ykh9"></button>
            <video id="1ykh9"></video>
          2. 射丝袜