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.
Purpose To observe the color motion perception of patients with diabetic retinopathy (DR) in very early stage and find a good way to diagnose early DR in time． Methods The motion perceptions of patients with early DR and normal subjects were tested by using equiluminant moving chromatic grating and moving luminance grating generated on VGA monitor in a PC compatible computer and the results were compared with those of electroretinogram(ERG),oscillatory potentials(OPs) and color perception． Results When the two gratings were of equal spatial frequency and equal time frequency,the normal subjects judged that chromatic grating moved faster than luminance grating．Very signifincant differences were detected between blue/yellow grating and black/white grating while the luminance contrast of was 80% and the velocity was 20.2 mm/s or 14.3mm/s(Plt;0.01).The abnormal ratio of color motion perception(69.2%)was higher than that of color vision(43.6%) and ERG OPs(48.9%) when the luminance contrast of black/white grating was 80% and the velocity was 20.2mm/s. Conclusion The test of color motion perception provides new method for diagnosing early DR. (Chin J Ocul Fundus Dis,1998,14:135-138)
Objective To investigate the causes of blindness and low vision of the people over 50 years old in Binhu Area of Wuxi City. Methods Cluster sampling was used in randomly selected individuals over 50 years old in 28 villages. The oculopathy related to blindness and low vision of the people over 50 years old were analyzed. The vision acuity lt;0.05 was defined as blindness, while 0.05-0.3 was defined as low vision. SPSS 17.0 software was used to analyze the data. Results Totally 6150 individuals were examined. The bilateral blindness and low vision was found in 47 and 84 individuals, unilateral blindness and low vision was found in 201 and 214 individuals. Among 201 unilateral blindness individuals, there were 55 individuals have low vision in the other eye. In the 295 blind eyes, there are 116 eyes (39.32%) with cataract, 31 eyes (10.51%) with high myopia macular degeneration, and 28 (9.49%) eyes with atrophy eyeballs. In the 437 low vision eyes, there are 223 eyes (51.03%) with cataract, 41 (9.38%) eyes with high myopia macular degeneration, and 41 (9.38%) eyes with age-related macular degeneration. Conclusion Cataract is the first cause leading to blindness and low vision, followed by age-related macular degeneration, high myopia macular degeneration and atrophy eyeballs.
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 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)
ObjectiveTo explore the light sensitivity and kinetic of the new optogenetics tools Channelrhodopsin-XXM2.0 (XXM2.0) and Channelrhodopsin-PsCatCh2.0 (PsCatCh2.0), and analyze whether they could be used to restore the visual function by optogenetics.MethodsMolecular biology techniques were used to link the gene fragments of XXM2.0 and PsCatCh2.0 to the vector pCIG(c)-msFoxn3 containing ampicillin resistant screening gene and reporter gene to form new plasmid pCIG(c)-msFoxn3-XXM2.0 and pCIG(c)-msFoxn3-PsCatCh2.0. The constructed plasmids were transfected into HEK 293T cells, and light responses were recorded in the whole cell mode with the HEKA patch clamp system. The photocurrent was recorded under three light intensity included 2.7×1016, 4.7×1015, and 6.4×1014 photons/(cm2·s). And then, XXM2.0 and PsCatCh2.0 were stimulated with 2.7×1016 photons/(cm2·s) and fully recovered. The opening and closing time constants were analyzed with Clampfit 10.6 software. At the same light intensity, photocurrents of XXM2.0 and PsCatCh2.0 were recorded by the light pulse stimulating of 2-32 Hz. The current attenuation was analyzed at long intervals of 4000 ms and short intervals of 200 ms after repeated stimulation. Comparisons between groups were performed by independent samples t test.ResultsRestriction endonuclease sites of EcoRⅠ and EcoRⅤ were successfully introduced at XXM2.0 and PsCatCh2.0 sequences. When the digestion was completed, they were ligated by T4 DNA ligase to construct new plasmids pCIG(c)-msFoxn3-XXM2.0 and pCIG (c)-msFoxn3-PsCatCh2.0, and then transfected on HEK 293T cells. The light intensity dependence was showed in XXM2.0 and PsCatCh2.0. The greater light intensity was accompanied by the greater photocurrent. Under the light intensity 6.4×1014 photons/(cm2·s) below the retinal safety threshold, large photocurrent was still generated in XXM2.0 and PsCatCh2.0 with 92.8±142.0 and 13.9±5.6 pA (t=1.24, 1.24; P=0.28, 0.29). The opening time constants of XXM2.0 and PsCatCh2.0 were 23.9±6.7 and 2.4±0.8 ms, and the closing time constants were 5803.0±568.2 and 219.9±25.6 ms. Compared with PsCatCh2.0, the opening and closing time constant of XXM2.0 were both larger than PsCatCh2.0. The differences were statistically significant (t=7.10, 31.60; P=0.00, 0.00). In terms of response frequency, XXM2.0 and PsCatCh2.0 could follow to 32 Hz high-frequency pulsed light stimulation, and all could respond to repeated light stimulation at a long (4000 ms) and a short time (200 ms) interval with the small current decay rate.ConclusionXXM2.0 and PsCatCh2.0 could be activated under light intensity with safety for the retina, and could respond to high frequency (at least 32 Hz) pulsed light stimuli with low current attenuation, which could meet the characteristics of opsins required to restore the visual function by optogenetics.
Objective To assess the change of the motion perception of cones in patients with AMD. Methods Motion perceptions of B、G and R cones of 20 eyes with dry type AMD were isolated by blue,green and red random dots stimulus displayed on the yellow,purple and blue-green background respectively,and keeping equiluminance between stimulus and background. Results The detecting displacement threshold and identifying threshold of motion perception from B,G and R cones were all damaged in eyes with dry type AMD compared with the normal group. Conclusion The abnormal changes of motion perception may reveal preclinical damage of visual function damage in dry type AMD. (Chin J Ocul Fundus Dis, 1999, 15: 219-221)
ObjectiveTo observe the changes of multifocal electroretinogram(mfERG)and central visual field before and after surgery in patients with rhegmatogenous retinal detachment (RRD) involving the macular area. MethodsThis is a retrospective study. Sixteen patients (16 eyes) with RRD involving the macular area (RRD group) and age-matched normal 20 cases (20 eyes, normal control group) were enrolled in the study. All patients in RRD group underwent scleral buckling surgery. Before surgery and 1, 3, 6 months after surgery, RRD eyes and normal eyes were checked by using mfERG and central visual field examination, and macular reaction wave amplitude density, incubation period and 4° visual field mean sensitivity (MS) were observed. The correlation between amplitude density, incubation period and MS in RRD group and the consistency between mfERG and central visual field examination in normal control group and RRD group were analyzed. ResultsCompared with the normal control group, in RRD group before surgery the macular reaction wave N1 and P1 amplitude density reduced, the incubation period prolonged, the differences were statistically significant (P < 0.05). Postoperative 1, 3, 6 months, in RRD group macular reaction wave amplitude density improved, the incubation period reduced than before surgery, the differences were statistically significant (P < 0.05). Postoperative 1, 3, 6 months, in RRD group macular reaction wave amplitude density reduced, the incubation period prolonged compared with the normal control group, the differences were statistically significant (P < 0.05). Compared with the normal control group, 4° visual field MS significantly reduced in RRD group before surgery reduced, the differences were statistically significant (t=49.752, P < 0.05). Postoperative 1, 3, 6 months, 4° visual field MS significantly increased compared with the preoperative value, the differences were statistically significant (t=-9.580, -16.533, -19.580; P < 0.05); but were lower than that of the normal control group, the differences were statistically significant (t=-6.286, -7.493, -6.366; P < 0.05). Postoperative 1, 3, 6 months, macular reaction wave amplitude density and MS in RRD group showed positive correlation (P < 0.05), and there was no correlation between incubation period and MS (P > 0.05). mfERG and vision consistency in normal control group and RRD group showed good agreement(K=0.886, P < 0.05). ConclusionsCompared with normal control eyes, in RRD eyes involving the macula area before and after surgery, macular reaction wave amplitude density reduced, the incubation period prolonged and MS values reduced; compared with the preoperative mfERG and central visual field, macular reaction wave amplitude density improved, the incubation period reduced and MS values increased.
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)
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.