Amblyopia is a visual development deficit caused by abnormal visual experience in early life, mainly manifesting as defected visual acuity and binocular visual impairment, which is considered to reflect abnormal development of the brain rather than organic lesions of the eye. Previous studies have reported abnormal spontaneous brain activity in patients with amblyopia. However, the location of abnormal spontaneous activity in patients with amblyopia and the association between abnormal brain function activity and clinical deficits remain unclear. The purpose of this study is to analyze spontaneous brain functional activity abnormalities in patients with amblyopia and their associations with clinical defects using resting-state functional magnetic resonance imaging (fMRI) data. In this study, 31 patients with amblyopia and 31 healthy controls were enrolled for resting-state fMRI scanning. The results showed that spontaneous activity in the right angular gyrus, left posterior cerebellum, and left cingulate gyrus were significantly lower in patients with amblyopia than in controls, and spontaneous activity in the right middle temporal gyrus was significantly higher in patients with amblyopia. In addition, the spontaneous activity of the left cerebellum in patients with amblyopia was negatively associated with the best-corrected visual acuity of the amblyopic eye, and the spontaneous activity of the right middle temporal gyrus was positively associated with the stereoacuity. This study found that adult patients with amblyopia showed abnormal spontaneous activity in the angular gyrus, cerebellum, middle temporal gyrus, and cingulate gyrus. Furthermore, the functional abnormalities in the cerebellum and middle temporal gyrus may be associated with visual acuity defects and stereopsis deficiency in patients with amblyopia. These findings help explain the neural mechanism of amblyopia, thus promoting the improvement of the treatment strategy for amblyopia.
Objective To investigate the characteristic of the multifocal visual evoked potentials(MVEP)and the visual function across the visual field in anisometropic amblyopes and isometropic amblyopes. Methods MVEP from 32 anisometropic amblyopic eyes and 31 control eyes were tested. Results In anisometropic amblyopic eyes,the latencies of MVEP were significantly prolonged．The amplitudes of MVEP were significantly attenuated in the central region of the visual field,and these phenomena gradually reduced with the increase of the eccentricity． Conclusion The visual function of anisometropic amblyopic eyes is reduced more significantly in the central region than in the peripheral region of the visual field. (Chin J Ocul Fundus Dis,20000,16:27-29)
【摘要】 目的 观察综合疗法治疗大龄儿童弱视的疗效。 方法 回顾分析2008年1月-2010年10月在我院初诊并经综合治疗的8～13岁弱视儿童62例85只眼的临床资料。治疗前最佳矫正视力0.1~0.7，平均0.46±0.17。观察患者经弱视综合治疗后视力、空间对比敏感度及立体视提升效果。 结果 治疗后视力正常22例31只眼（36.5%），进步29例39只眼（45.9%），无效11例15只眼（17.6%）；总有效率82.4%，与治疗前相比，差异有统计学意义（Plt;0.001）。空间对比敏感度基本正常11例16只眼（18.8%），进步43例58只眼（68.2%），无效8例11只眼（12.9%）。弱视眼在1.5、3、6三个低空间频率的对比敏感度值与治疗前相比提升有统计学意义（Plt;0.001）；在12和18两个高空间频率，对比敏感度值与治疗前相比提升无统计学意义（Pgt;0.05）。立体视锐度正常12例（19.4%），进步26例（41.9%），无效24例（38.7%），立体视锐度与治疗前相比提升具有统计学意义（Plt;0.001）。 结论 综合疗法治疗大龄儿童弱视能取得令人较为满意的疗效，患儿视力显著提升，低到中等频率空间对比敏感度及立体视锐度也有较大提升。【Abstract】 Objective To explore the therapeutic effect of comprehensive therapy on elder children with amblyopia. Methods The clinical data of 62 patients (85 eyes) with amblyopia who underwent the comprehensive therapy between January 2008 and October 2010 were retrospectively analyzed. The best-corrected visual acuity was 0.1-0.7 (mean 0.46±0.17) before the treatment. The visual acuity, spatial contrast sensitivity and stereoacuity of the patients after the treatment were observed. Results After the comprehensive therapy, the visual acuity was normal in 22 patients (31 eyes, 36.5%), improved in 29 patients (39 eyes, 45.9%), invalid in 11 patients (15 eyes, 17.6%). The total effective rate was 82.4% which was differed significantly from that before the treatment (Plt;0.001). The spatial contrast sensitivity was almost normal in 11 patients (16 eyes, 18.8%), improved in 43 patients (58 eyes, 68.2%), and invalid in 8 patients (11 eyes, 12.9%). The examination of spatial contrast sensitivity showed that the improvement was only statistically significant when frequency equates 1.5, 3, or 6 (Plt;0.001) compared with those before the treatment; while no statistically significant improvement was observed in higher frequencies of 12, 18 (Pgt;0.05). The stereoacuity was normal in 12 patients (19.4%), improved in 26 (41.9%), and invalid in 24 (38.7%); the difference in stereoacuity before and after the treatment was significant (Plt;0.001). Conclusion The therapeutic effect of comprehensive therapy is good: the visual acuity of the patients improves obviously, and the low to middle spatial contrast sensitivity and stereoacuity improve apparently.
Purpose To identify the expression of alternatively spliced mRNA isoforms of the NMDA-R1 in the visual cortex of strabismic cats. Methods Two pai rs of normal and strabismic cats were used．The amblyopic cats had been made monocularly esotropic (by tenotomy) at the age of weeks，resulting in behavioral am blyopia．Animals were sacrificed about 6 months by intraperitoneal administration of Nembutal．Cryostat sections of fresh，frozen central visual cortex of the ats were cut to 20 micron thickness．A series of digoxygenin-labelled oligonucle otide probes basing on the human gene sequence were used for ISH．Control probes included sense oligonucleotides and short segment probes which were adjacent to ，but did not，span the splice junctions．A computer-assisted systematic morphometric ounting procedure was used to enumerate hybridising cells． Results The number of positive cells expressing NMDA-R1 mRNA in t he strabismic amblyopic cats was decreased，notably in layer IV of visual cortex (P＜0．0001)．The pattern of isoform expression varied between normal and strabismic amblyopic cats with decreased numbers of 1-a，1- b and 1-1 isoforms and apparently increased expression of 1-3 P ＜0．0001)，whereas no significant difference was found for the 1-2 and 1-4 isoforms (P＞0．05)． Conclusion Transcriptional inhibition of NMDA-R1 mRNA and of specifie isoforms may underlie the change in receptor expression．Alternatively，preferentialloss of neurones bearing particular NMDA-R1 isoforms and compensation with a proportional increase in cells expressing other isoforms may occurr during the critical period of visual plasticity． (Chin J Ocul Fundus Dis，2000，16：71-138)