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.
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 investigate the effects of form deprivation on the morphology of different types of RGC in mice.MethodsSixty B6.Cg-Tg (Thy1-YFP) HJrs/J transgenic mice were randomly assigned to form-deprived group (n=28) and control group (n=32). The right eyes of mice in the form-deprived group were covered by an occluder for 2 weeks as experimental eyes. The right eyes of mice in the control group were taken as control eyes. Before and 2 weeks after form deprivation, the refraction and ocular biometrics were measured; RGC were stained with Bra3a antibody and counted; the morphology of RGC was reconstructed with Neuroexplore software after immunohistochemical staining. The data was compared among experimental eyes, fellow eyes and control eyes by one-way analysis of variance.ResultsTwo weeks after form deprivation, the axial myopia was observed in the experimental eyes (refraction: F=15.009, P＜0.001; vitreous chamber depth: F=3.360, P=0047; ocluar axial length: F=5.011, P=0013). The number of RGC in central retina of the experimental eyes was decreased compared with the fellow eyes and the control eyes (F=4.769, P=0.035). The reconstructed RGC were classified into 4 types according to their dendritic morphology. Form deprivation affected all 4 types of RGC but in a different way. Among them, 3 types of RGC were likely contribute to form vision perception. Form deprivation increased the dendrite branches in these types of ganglion cells. However, form deprivation decreasd dendrite segment numbers in both eyes and the intersection and length insholl analyse type 4 ganglion cells which were morphologically identified as ipRGC.ConclusionForm deprivation distinguishingly affects the morphology of different types of RGC, indicating that form vision and non-form vision play different role in myopia development.
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 fullterm 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 fullterm 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.
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.
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.
Objective To observe the clinical characteristics of patients with macular branch retinal vein occlusion (MBRVO) and the changes of the area of foveal avascular zone (FAZ).Methods The data of 69 eyes of 69 patients with MBRVO, who had been diagnosed by ophthalmoscopy, slit-lamp examination and fluoresce in angiography, were retrospectively studied. The relationship of locations between artery and vein on the obstructive site, and the characteristics of fundus pictures, retinal vasculature changes and the complications were analyzed. In 69 patients with MBRVO, 36 had the course of disease for more than 3-6 months, of whom the area of FAZ was compared with that of 30 healthy people.Results In 69 patients, superior MBRVO occurred in 45 eyes (65.22%), and inferior MBRVO occurred in 24 eyes (34.78%). Most of the arteries were anterior to the veins at the obstructive site. Four clinical types of MBRVO were found, and the main complication was macular edema. There was a significant difference in area of FAZ between patients with MBRVO and healthy people (P＜0.05). Conclusion There are several clinical characteristics of MBRVO with different manifestations. The area of FAZ of patients with MBRVO is obviously lager than that of the healthy people. (Chin J Ocul Fundus Dis，2003，19：269-332)
Macular edema (ME) secondary to central retinal vein occlusion（CRVO) often cause severe visual impairment. Intravitreal anti-vascular endothelial growth factor agents and steroids can effectively eliminate ME and improve visual function, but the visual outcome is affected by multiple factors. Retinal blood flow, especially the macular microcirculation, has significant correlation with visual outcome. Ischemic CRVO, especially patients with severe damage in the deep and superficial vascular layer of the macular zone, usually have poor visual outcome. In addition, the integrity of the multi-layer retinal structure closely correlates with the visual outcome. Patients with intact ellipsoid zone, external limit membrane beneath the fovea have good visual recovery. Additionally, good baseline visual acuity, positive response to treatment in early phase, young age and timely treatment usually brings about better visual outcome.