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find Keyword "视觉" 109 results
  • 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
  • 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
  • Magnetic resonance diffusion tensor imaging for optic nerves and optic radiation in blind patients

      Objective To observe the characteristics of magnetic resonance diffusion tensor imaging(MR-DTI)for optic nerves and optic radiation in blind patients.Methods The optic nerves and optic radiation of 20 blind patients(blind group)and 20 controls(control group) were scanned by MR-DTI. Fractional anisotropy (FA) and directional encoded color (DEC) maps were acquired through postprocessing with the aid of volumeone 1.72 software. The signal intensity of optic nerves and optic radiation were then observed. The FA, mean diffusivity (MD), lambda;∥ and lambda;perp; value of bilateral optic nerves and optic radiation in two groups were measured in the DEC maps.Results While the high signal intensity was found in bilateral optic nerves in FA and DEC maps in control group,the signal decreased markedly in the blind group. The FA and lambda;∥ value of optic nerves in the blind group were declined obviously compared to that in the control group. The difference was statistically significant (t=16.294, 14.660;P=0.000). The MD and lambda;perp; value of optic nerves in the blind group were increased obviously compared to that in the control group, the difference was also statistically significant (t=8.096, 8.538; P=0.000). The high signal intensity was found in bilateral optic radiation in FA and DEC maps in both the blind and control groups. There were no statistic differences in FA and MD value in bilateral optic radiation between the blind and control groups (Left:t=1.456,1.811;P=0.152,0.076. Right:t=0.779,0.073;P=0.440,0.942). Conclusion A low signal intensity of bilateral optic nerves and a high signal intensity of bilateral optic radiation were found in blind patients.

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
  • 二价锰离子增强磁共振视神经活体示踪的实验研究

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
  • 非器质性视力下降的临床特征分析

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
  • 矫正视力异常的正常眼底青少年患者视觉电生理检查结果分析

    Release date:2016-09-02 05:43 Export PDF Favorites Scan
  • 扫描视觉诱发电位对视功能的评估

    扫描视觉诱发电位(sVEP)是在稳态视觉诱发电位基础上发展起来的一种视功能检测技术,具有一定的测定可重复性,可以对视力和对比敏感度等视功能进行快速、客观的有效测定和评价。在未来的研究中,应着重提高sVEP 测定技巧,选择最佳的技术参数;明确该技术与其他视觉检查的关系;以深入理解sVEP 产生机制和所蕴含的视觉信息为基础,进一步揭示其与视功能、视觉系统发育及疾病的关系。

    Release date:2016-09-02 05:43 Export PDF Favorites Scan
  • Characteristics of electroretinograms in preterm infants

    Objective To investigate the degree of retinal developmen t in pret erm infants and compare the electroretinograms between preterm and fullterm in fants. Methods Flash electroretinogram (ERG) were obtained wit h contact lens el ectrodes in one eye from ten preterm infants (10 eyes) and twenty full-term inf a nts (20 eyes) in seven days after birth. The rod cell, cone cell, maximal combi nation, oscillatory potentials, and 30 Hz flicker responses were recorded. Results Compared with the full-term infants, the implicit time of rod cell respon s e (t=3.216,P=0.003) was longer and the amplitudes were lower (t=6.0 50,P=0.000) in the preterm infants; the difference of implicit time of maximal response was not significant (t=0.465,P=0.650; t=1.068,P=0.295), while th e amplitudes dec reased (t=6.584, P=0.000; t=6.649, P=0.000). The a- and b-wav e implicit time of cone response was not differed much between the two groups (t=0.077, P=0.939; t=0.935,P=0.358); the amplitudes was obvious lower in preterm group (t =3 .417,P=0.002;t=6.310,P=0.000); the difference of implicit t ime of 30 Hz flic ker betw een the two groups was not significant (t=3.745,P=0.001). The difference of b/a value of maximal combination response was not obvious between the two groups ( t=0.215, P=0.831). Conclusions The development of retinal function is slower in preterm infants than that in full-term ones.

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Mini visual evoked optential in infants during their sensitive period of visual development

    Objective To observe the changes of amplitude and latency of mini visual evoked optential (mini VEP) examinations in infants at different age.Methods A total of 84 healthy infants and adults (168 eyes) were randomly selected to underwent mini VEP. According to the age, all the individuals were divided into seven groups: A, 0-3 months; B, 4-6 months; C: 7-12 months; D: 1-3 years; E: 4-6 years; F: 7-12 years; G: adults (control). There were 12 individuals (24 eyes) in each group. By using the stimulater of mini VEP, the flash VEP was performed and the changes of amplitude and latency of P100 wave were recorded and analyzed.Results The average value of amplitude in group A was(7.39plusmn;1.79)mu;V which was the lowest, and the average latency was (137.45plusmn;7.64)ms which was the largest.At the same time, the average amplitude of P100 increased from group A to E (F=359.56); the average latency decreased from Group A to D(F=326.64); the difference was significant (P<0.01). The amplitude in group E, F, and G was high and no significant difference was found (F=2.39,P>0.05);the latency in group D,E,F,and G was short with no significant difference (F=2.64,P>0.05).Conclusions With the growth of the infants' age, the amplitude of miniVEP increases and latency decreases; moreover, the latency reaches the normal adult level in advance of the amplitude of miniVEP.

    Release date:2016-09-02 05:43 Export PDF Favorites Scan
  • Multifocal electroretinogram of the fellow eye in patients with unilateral retinal vein occlusion

    Objective To measure the macular function of the fellow eye in patients with unilateral retinal vein occlusion (RVO). Methods A total of 24 cases of unilateral RVO were diagnosed by fundus fluorescein angiography (FFA), and multifocal ERG (mfERG) was recorded by RETI scan. The mfERG data of 24 fellow eyes of those RVO patients, and 18 normal control eyes were analyzed and compared. The parameters included the amplitude density, latency of the P1 and N1 wave in 6 concentric circles and 4 quadrants of the mfERG graphics. Results The amplitude densities of P1 and N1 wave in first and second concentric circles of RVO fellow eyes were significantly lower than normal eyes (t=4.520, 2.147; P<0.05). There was no significant difference (P>0.05) of P1/N1 latency in any concentric circles or quadrants between RVO fellow eyes and normal eyes. Conclusion The central fovea of the RVO fellow eyes was functionally impaired.

    Release date:2016-09-02 05:43 Export PDF Favorites Scan
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