Objective To explore the role of activated macrophage in the repair of traumatic optic nerve injury in an animal model of incomplete traumatic optic nerve injury with lens damage.Methods One hundred and twelve healthy New Zealand big ear white rabbits were divided into two groups (experimental and control groups) randomly. According to the different time points (one, four, seven, ten, 14, 21 and 28 days), each group was further divided into seven subgroups, each subgroup had eight rabbits. Traumatic optic neuropathy and lens damage were induced in one eye of each rabbit by fluid percussion brain injury device (FPI); those eyes were the experimental group. The eyes of control group only had traumatic optic neuropathy. The functional and morphological changes of retina and optic nerve were evaluated by histopathology and flashvisual evoked potential (FVEP).Results FVEP P100 latency was (42.74plusmn; 5.83) ms, P100 amplitude was (7.98 plusmn; 2.15) mu;V before optic nerve injury was induced. One day after the injury, the P100latency increased and the P100amplitude reduced significantly. The P100 latency reached the longest at ten days after injury, and then recovered gradually. The P100 amplitude reached the lowest at seven days after injury, and then recovered gradually. The histopathological examination showed activated macrophages were not detected in the retina and optic nerve at day one after the injury, then they increased gradually and reached their peak (91.25plusmn;6.91) at day ten, and decreased after that, the difference was statistically significant (F=21.277, P=0.000); retinal ganglion cell axon regeneration began at day seven after the injury with an average of (6.38plusmn;1.85). The axons increased gradually and reached their peak (49.63plusmn;2.50) at day 28, and the changes were significant (F=7.711, P=0.000). Conclusions Incomplete optic nerve injury can recover gradually if there is lens damage at the same time. Activated macrophage may play an important role in this recovery process.
Objective To evaluate the influence of the location of retinal vessel trunk on neuroretinal rim width of inferior and superior sectors of optic disc, and explore its role in the diagnosis of glaucomatous optic nerve lesion. Methods The photographs of ocular fundus from 459 patients with clear location of retinal vessel trunk, including large disc in 131, medium disc in 145, horizontally oval disc in 75, and small disc in 108 were evaluated. Independent-sample t test was used to compare the difference of the superior and inferior rim widths between the higher-vessel group and the lower-vessel group, and to compare the difference of superior and inferior vessel distances between the narrow-superior-rim-width group and the narrow inferior-rim-width group. Results In most of the patients, or the ones with large and small disc, the ratio of superior rim width to summation of superior and inferior rim widths in the higher-vessel group（0.467plusmn;0.051，0.445plusmn;0.040，0.508plusmn;0.056）were less than which in the lowervessel group（0.500plusmn;0.066，0.474plusmn;0.062，0.546plusmn;0.048）, and the differences were significant（P=0.000, 0.045, 0.018）; the ratio of superior vessel distance to summation of superior and inferior vessel distance in the narrow-superior-rim-width group（0.510plusmn;0.051，0.508plusmn;0.055，0.512plusmn;0.036）were less than which in the narrow-inferior-rim-width group（0.528plusmn;0.045，0.533plusmn;0.048，0.534plusmn;0.045）, and the differences were significant（P=0.000, 0.046, 0.022）. Conclusions The position of optic disc vessel trunk influences its superior and inferior rim width. The rim closer to vessel trunk position has narrower width than which comparatively far away from the position. In patients with large, medium, horizontally oval optic disc, glaucoma optic nerve lesion would be considered if the optic disc has the shape of narrower inferior rim, broader superior rim, and vessel location in the superior half of the disc. In the ones with small disc, the optic disc with the shape of narrower superior rim, broader inferior rim, and vessel location in the inferior half of the disc may suggest glaucoma optic nerve lesion. (Chin J Ocul Fundus Dis, 2007, 23: 118-121)
ObjectiveTo observe the early ultrastructural changes of the optic nerves after the brain impact injury.MethodsEighteen 15-week-old Wistar rats were used in the air-pressure brain impact injury examination. All of the rats underwent the procedures of right-parietal-bone fenestration after abdominal cavity anesthesia with 1% sodium pentolbarbital (45 mg/kg), and then they were divided randomly into 3 groups, i.e., mild injury group (8 rats) underwent with 7 kg of air pressure in distance of 11 cm; severe injury group (8 rats) with 7 kg of airpressure in distance of 8 cm; and control group (2 rats) underwent with the parietalbone fenestration but without impact injury.The ultrastructural changes of the optic nerves were observed 1, 6, 24, and 72 hours after the injury by electron microscopy.ResultsThe difference of ultrastructural changes of optic nerve was not obvious in wild injury group and the control group, and the lanthanum nitrate was only found in the blood vessels in optic nerve. The lanthanum nitrate entered the nerve stroma 1 hour after severe and increased as time goes on. Simultaneously, displayed dilatation of endoplasmic reticulum, cavitation and tumefaction of mitochondrion, vacuolation of nerve stroma, and vacuolation of some axis-cylinder were seen in the glial cells.ConclusionThe brain impact injury may cause ultrastructural changes of the optic nerve and increase of permeability of blood vessels. (Chin J Ocul Fundus Dis, 2005,21:41-43)
ObjectiveTo investigate the effect of nerve growth factor (NGF) on recuperate of optic nerve after contusion by clamping in adult rabbits. MethodsSixteen adult rabbits were randomly divided into NGF and the control group with 8 rabbits in each group. After the optic nerve of the right eyes was clamped，tissue engineering nerve containing 0.06 ml NGF（concentration: 5×10-4 g/L, NGF group） and 0.06 ml of PBS (control group) was immediately transplanted into the injured eyes respectively, and 0.02 ml NGF（concentration: 5×10-4 g/L, NGF group）and 0.02 ml of PBS (control group) were injected into the vitreous of right eyes respectively. Flash visual evoked potential (FVEP) test was performed on the eyes 1 day, 2 weeks and 8 weeks after the injury. The number of retinal ganglion cells (RGCs) and changes of optic nerves were observed by light microscopy and electron microscopy at the 8th week after contusion,and a computer-image-analysis system was used to count the optic nerve axons.ResultsThe ratio of amplitude of FVEP of the injured and healthy eyes was 0.765±0.150 in NGF group and 0.494±0.108 in the control at the 2th week after injury with a significant difference between the two groups (Plt;0.05); and was 0.581±0.138 and 0.409±0.119 respectively at the 8th week after contusion with statistical difference between the two groups (Plt;0.05). The results of light microscopy and electron microscopy showed that degeneration of RGCs and optic nerves in the NGF group was lighter than that in the control group 8 weeks after injury, while the amount of optic nerve axons was (10 955±608.7) axons/ mm2 in the NGF group and (7 898±608.8) axons/mm2 in the control with statistical difference between the two groups (Plt;0.05). ConclusionNGF may redound to the survival of RGCs and regeneration of the axons in some degree, which can promote the recuperation of optic nerve and visual function. (Chin J Ocul Fundus Dis, 2005,21:253-257)
ObjectiveTo investigate the gene expression spectrum of retina and optic nerve after partial injury of optic nerve.MethodsSixty SD rats were randomly divided into 4 groups. The optic nerves of the right eyes were clipped for 6 seconds with a pair of crossaction forceps. The retinae and optic nerves in the operation eye and contralateral sham operation eye were removed 3, 7, 14, and 21 days after the injury to detect gene expression patterns with high-density DNA microarrays.ResultsChanges of a mass of gene expressions were found after the optic nerve injury, and the positive rate of gene expression was 2.35%, 6.48%, 3.82% and 4.09% after 3, 7, 14, 21 days, respectively, and the total positive rate was 11.77%. The functions of positive expression of the gene involved cell survival, cytoskeleton, extracellular matrix and cell adhesion, free radicals and oxidative damage, energy and metabolism, inflammation, neurotransmission and ion transport, signal transduction, structural protein, transcription and translation. Up-or down-regulation of repaired genes was the main part of the changes of gene expression, while the alteredexpression destroy genes was the minor part in the whole gene expression spectrum, in which the up- and down-regulation of expression of repaired genes accounted for 13.98% and 24.73% respectively 7 days after the injury, and the downregulation of expression of repaired genes accounted for 17.20% 14 days after the injury.ConclusionsA mass of gene expression changes occurs after the optic nerve injury, and the comprehensive view on the gene expression pattern following the optic nerve injury is crucial to discover the mechanism of post-injury reaction and regeneration.(Chin J Ocul Fundus Dis, 2005,21:163-166)
Objective To investigate the mRNA expression of ciliary neurotrophic factor on the retina during injury and repair of optic nerves in rats. Methods Thirty-five healthy SD rats were randomly divided into 3 groups: 5 in the control group, 15 in the simply transected optic nerve group and 15 in the optic nerve-sciatic nerve anastomosis group. The simply transected and optic nerve-sciatic nerve anastomosed models were set up, and the retinal tissues of all of the rats were taken out after 3, 7 and 14 days, respectively; and the mRNA expression of CNTF in the 3 groups were observed by semiquantitative reversal transcription-polymerase chain reaction method. Results A minimum expression of CNTF mRNA was found in the retinae of the control group, and the increased rates of expression were found in the retinae of the simple transection of optic nerve group with the increase rate of 100%, 594%, and 485% on the 3rd, 7th, and 14th day respectively after the operation, while in optic nerve-sciatic nerve anastomosis group, the increase rates were found to be 258%, 752% and 515% on the 3rd, 7th, and 14th day respectively after the operation. Conclusion Retinal neurons can respond to axonal reaction of retinal ganglion cells by up-regulate endogenous CNTF after the injury of the optic nerves, which may provide a theoretic base for the application of the exogenous CNTF. (Chin J Ocul Fundus Dis，2004，20：355-357)
Objective To observe the content of thromboxane (TXA2 ) and prostacyclin (PGI2) in optic nerves after forehead impact injury.Methods The right forehead zones of 32 rabbits were struck by biology impact machine. Tweenty-four rabbits that had afferent papillary defect after injury were chosen, and randomly divided into four groups: 1 day, 2, 4, and 7 days group. Right eyes were in the experimental group and left eyes were in the control group. Flash visual evoked potentials were examined before and after the traumatic injury. The rabbits ′eyes were removed, the optic nerves were pathologically examined, and the content of TXB2 and 6-Keto-PGF1αwhich were the products of TXA2 and PGI2 were assayed 1, 2, 4, and 7 days after traumatic injury respectively.Results Histopath ological examination revealed the findings of injuries of optic nerves of all the 24 rabbits. The latency of wave P1 was significantly delayed after traum atic injury (Plt;0.01), and amplitude of wave P1 was significantly decreased after traumatic injury (Plt;0.01). The content of TXB2 ［(172.35±26.52) pg/mg ］and 6-Keto-PGF1α［(161.78±24.83) pg/mg］were significantly higher in the injured optic nerves than in the uninjured ones 1 day after the traumatic injury (Plt;0.01). The rate of TXB2 /6-Keto-PGF1α (1.077±0.18) was significantly increased compared to the control group (Plt;0.05), and lasted to the 7th day.Conclusions The content of TXA2 and PGI2 significantly increases and the ratio of them is lopsided after forehead impact injury in rabbits. (Chin J Ocul Fundus Dis，2003，19：49-51)
Purpose To evaluate differences in the pattern of optic disc and retinal nerve fiber layer (RNFL) damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) patients. Methods We enrolled 49 eyes of 49 patients:30 NTG (IOP≤21 mm Hg,1 mm Hg=0.133 kPa), 19 HTG(IOP≥25 mm Hg). Mean age was 59.2±12.3 (range, 36-75) for HTG patients, and 59.6±8.6(range, 39-71) for NTG patients. All patients underwent complete ophthalmic examination, achromatic automated perimetry (AAP), scanning laser ophthalmoscopy (SLO), scanning laser polarimetry (SLP), optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT). All patients had glaucomatous optic nerve damage and abnormal AAP. Results There were no differences in mean deviation on AAP between NTG and HTG eyes (P=0.37), while the corrected pattern standard deviation was larger in NTG than in HTG eyes (P=0.014). Cup∶disc area ratios in global (P=0.03) and three sectors (Plt;0.05) except nasal sector were significantly larger in the NTG group, whereas rim area in global (P=0.03) and three sectors (Plt;0.05) except nasal quadrant obtained by SLO were smaller in NTG than in HTG eyes. The other numerical parameters obtained by three imaging technologies could not detect differences in the optic disc or RNFL anatomy between the two groups. Conclusions Cup∶disc area ratio was larger in patients with NTG than in those with HTG, whereas significant thinning of rim was associated with NTG eyes. The measurement of retinal nerve layer thickness in global and each quadrant was similar between two groups. More focal or segmental analysis of the data contained within SLO, SLP and OCT images are needed to detect localized differences in eyes with varying levels of IOP. (Chin J Ocul Fundus Dis, 2002, 18: 109-112)
Objective To evaluate the relevant factors affecting prognosis of traumatic optic neuropathy. Methods Sixty-nine patients with traumatic optic neuropathy were enrolled. Multiple variable analysis was done to filter the risk factors to prognosis in traumatic optic neuropathy. Results At 3 months or more of followup,no light perception was found in 32 cases (46.4%); visual acuity were increased by≥1 lines in 33 cases (47.8%). The outcome of visual acuity was poorer in patients with the following conditions:no light perception after trauma （P=0.0031）, loss of consciousness （P=0.0262）, no pretreated common-dosage corticosteroids （P=0.0184）, and absence of VEP （P=0.0001）. Conclusion The initial visual acuity of no light perception, loss of consciousness, and no pretreated common-dosage corticosteroids were the risk factors to prognosis in traumatic optic neuropathy,and result of VEP was an effective prognosis indicator in traumatic optic neuropathy. (Chin J Ocul Fundus Dis, 2002, 18: 98-100)