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Objective:To analyze the symmetry of different reference planes in the surgical simulation design of patients with protrusive jaw deformity with high and low eyes.Methods:Fifteen patients with partial jaw deformity were selected from January 2019 to June 2020, including 3 males and 12 females, aged 18-26 years, with average 23.78 years. Inclusion criteria were that the patients, aged more than 18 years, were diagnosed as protrusive jaw deformity with maxillary occlusal plane tilt and high and low eyes by clinical and imaging analysis. Three different 3D reference plane systems were established by different modeling methods. The distance between the landmarks of soft and hard tissues and the median sagittal plane was measured. The symmetry of skull was qualitatively analyzed by mirror image technique. The difference of three reference planes in surgical simulation symmetry of patients with protrusion jaw and high and low eyes was evaluated by one-way ANOVA.Results:Qualitative analysis showed that in the three measurement planes, the symmetry of the third reference plane was the best, and the symmetry of the second and the first was poor. Quantitative analysis showed that in measurement index of hard tissue, there was statistical difference between the distance of each landmark in the reference plane established by Method 3 and Method 1, Method 2 [(1.65±1.19) mm; (3.37±1.58) mm; (3.26±2.36) mm, P<0.05], but there was no statistical difference between Method 1 and Method 2 (P > 0.05). The measurement result of soft tissue was consistent with that of hard tissue, and the distance of each landmark in Method 3 from the median sagittal plane was very small, and the mean error was less than 0.5 mm, which was consistent with the clinical results. Conclusions:Digital model surgery technology can assist orthognathic surgeons in the design and prediction of surgical scheme, especially for patients with special partial jaw deformity.
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Objective:To explore the effect of functional electrical stimulation on cognition and on the expression of the brain-derived neurotrophic factor (BDNF), synaptophysin (SYN) and microtubule-associated protein 2 (MAP2) using a rat model of vascular dementia.Methods:Ninety pathogen-free male Wistar rats were randomly divided into a sham operation group, a placebo stimulation group and an electrical stimulation group. Both the placebo and electrical stimulation groups underwent bilateral occlusion of the common carotid artery to establish a model of vascular dementia. In the sham operation group the arteries were exposed without occlusion. Each group was then sub-divided into 3, 7 and 14 days subgroups with 10 rats in each subgroup. Beginning seven days after the surgery, the rats in the electrical stimulation group were given 30-minutes of stimulation every day while those in the sham operation group and the placebo stimulation group were given false electrical stimulation. After 3, 7 or 14 days the rats′ cognitive functioning was quantified using the Morris water maze test. The rats were then sacrificed and the expression of BDNF mRNA was measured using in situ hybridization. MAP2 and SYN levels were quantified immunohistochemically.Results:After 14 days the average latency in the placebo stimulation group was significantly longer than in the other groups. On the sixth day the average time in the target zone among the placebo stimulation group was significantly shorter than the other two groups′ averages. After only 3 days of simulation, the average expression of BDNF mRNA in the CA1 area of the hippocampus was significantly lower in the placebo stimulation group than among the others. After 7 days of stimulation the placebo group′s average was significantly lower than that of the sham operation group. The average expression of MAP2 had decreased significantly in the placebo stimulation group compared with the other two groups after 7 and 14 days of simulation. After 7 days the average expression of SYN in the placebo stimulation group was significantly lower than in the sham operation group, and after 14 days it was significantly lower than in the other two groups.Conclusions:Functional electrical stimulation may improve learning and memory in rats modelling vascular dementia through increasing BDNF, SYN and MAP2 expression levels.
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A 87-day-old female patient presented with patchy erythema on the right body and ipsilateral limb deformity after birth, and visited the hospital in January 2012. Skin examination showed obvious red plaques on the right lower abdomen, right buttock, right perineum, right leg and right foot, with yellow scales on the surface and clear boundaries, and there was no obvious exudation or odor; pale yellow verrucous hyperplasia was observed on the right lower jaw, right neck, right axilla, and on the back of the first to fourth fingers of the right hand; only 1 interphalangeal joint and no nail plate was observed on the second, third and fourth toes of the right foot. The X-ray of the right foot showed deformity and bone defects. The patient was diagnosed with CHILD syndrome, and treated with intermittent oral acitretin capsules, and topical vaseline ointment, tacalcitol ointment and weak-potency glucocorticoid ointment for more than 6 years. The skin lesions regressed during treatment, but occurred repeatedly after withdrawal. Thereafter, the patient was switched to simvastatin ointment for 2 years. The skin lesions increased proportionally with the increase of age, and the affected limb grew a little more rapidly than the healthy limb. By January 2020, the skin lesions on the right lower jaw, right neck, and the first to fourth fingers of the right hand had subsided, but new band-like hypertrophic verrucous plaques occurred on the fifth finger of the right hand; the skin lesions on the right leg were slightly improved, and no involvement of other systems was observed.
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Objective To investigate the etiology,clinical manifestations,diagnosis and outcomes of lichen scrofulosorum (LS).Methods Clinical data collected from 7 infants with LS,who visited Department of Dermatology,Tianjin Children's Hospital between 2010 and 2018,were analyzed retrospectively,and the etiology,clinical manifestations,diagnosis,development and outcomes of LS were investigated.Results All the 7 infants developed LS after bacillus Calmette-Guérin (BCG)vaccination,and the clinical manifestations of LS were reddish or hazel papules mainly distributed on the trunk with small scales attached to the surface.No abnormal laboratory examination results were observed.Histopathological examination showed granuloma in the dennis.Without any treatment,all rashes of the 7 patients disappeared within 6 months,and no scar or hyperpigmentation remained.Conclusions Infant LS usually appears 2-3 months after BCG vaccination,clinically presents as papules mostly on the trunk,pathologically characterized as granuloma in the dermis,and can heal spontaneously.
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0bjective@#To establish a three-dimensional finite element model of mandible and study the transverse displacement of proximal segment after Bilateral Sagittal Split Ramus Osteotomy (BSSRO) with different retrogression amounts during mastication.@*Methods@#DICOM data of a skull model were processed with MIMICS and ANSYS software, reconstructing the 3D model including the teeth and temporomandibular joint in order to simulate BSSRO and evaluate the transverse displacement of proximal segment with different retrogression amounts during mastication.@*Results@#The mean of proximal segment width change were 2.955 mm and 3.490 mm, when retrogression amounts of distal segmentwere 3 mm and 8 mm, respectively.No significant difference between the two groups were found (P=0.131). Meanwhile the displacement color scale of the 3D finite element models showed that the apparent transverse displacement distribution of the proximal segment was measured around the gonial area, decreased from the exterior to the interior.@*Conclusions@#The mandibular angle width was significantly expanded right after BSSRO. The masticatory muscle system and single cortical fixation system played an important role in expanding the width of proximal segment. However there was no correlation between the widening effect and retrogression amounts of distal segment of mandible.
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Objective To investigate the value of standardized ultrasound screening in diagnosis of fetal congenital heart disease (CHD) during the first trimester. Methods This study retrospectively analyzed the clinical data of 8 383 fetuses who received ultrasound screening during the first trimester in the Dongguan Maternal and Child Health Hospital from September 2015 to December 2016. Standardized ultrasound was performed to observe fetal heart position, apical direction, apical four-chamber view, three vessels and trachea view and the thickness of nuchal translucency (NT). Fetuses with thickened NT or fetal CHD observed during the first and second trimester were followed up. Pregnancy outcomes and the growth of newborns within one year after birth were recorded and analyzed. Pathological results after the termination of pregnancy were compared with the results of routine karyotyping and chromosome microarray analysis (CMA). Results (1) A total of 27 cases of fetal CHD were identified during the first trimester giving a detection rate of 0.32% (27/8 383). These included ten (37.0%) of single atrium and/or single ventricle, seven (25.9%) of endocardial cushion defect (including two complicated by persistent arterial trunk), three (11.1%) of hypoplastic right heart syndrome, three (11.1%) of interventricular septal defect, two (7.4%) of hypoplastic left heart syndrome, one (3.7%) of mirror-image dextrocardia and one (3.7%) of right atrial enlargement and severe tricuspid regurgitation. Nineteen out of the 27 cases had NT thickening (NT≥3.0 mm) and 17 of them had a cystic hygroma (NT≥6.0 mm). Among the 27 cases, 22 were terminated in the first trimester which autopsy results were consistent with ultrasound and the other five were rescreened during the second trimester. Thirteen out of the 27 cases received chorionic villus sampling, and seven of them were found to have chromosomal abnormalities by karyotyping and CMA, among whom one was microdeletion of 22q11. (2) Twenty-one cases of CHD were detected in the second-trimester ultrasound screening, including five initially identified in the first trimester. These cases included four (19.0%) of complex cardiac malformations (with three or more malformations), four (19.0%) of interventricular septal defect, three (14.3%) of dextroaortic arch, left subclavian artery vagus and 'U' shaped vascular ring, three (14.3%) of hypoplastic right heart syndrome (including one complicated by coronary artery-right ventricular fistula and one by interventricular septal defect), two (9.5%) of transposition of the great arteries, two (9.5%) of tetralogy of Fallot, one (4.8%) of hypoplastic left heart syndrome, one (4.8%) of Taussig-Bing anomaly and one (4.8%) of coarctation of the aorta. Among the 16 cases first identified in the second trimester, eight had NT thickening, including one with cystic hygroma. Among the 21 cases, two were lost to follow-up after being transferred to another hospital; four with negative results in karyotype analysis and CMA were delivered vaginally at term (37-40 gestational weeks) with 1-min Apgar scores of ten points and postpartum ultrasound of the baby was consistent with the second-trimester ultrasound screening; 15 were terminated and the autopsy confirmed those findings in the second-trimester ultrasound screening. Eleven out of the 21 cases received amniocentesis and five of them were found to be abnormal according to karyotype analysis and CMA, including one of microdeletion of 22q11. Conclusions Standardized first-trimester ultrasound screening is important and of great clinical value in the diagnosis of fetal CHD. Increased NT thickness could be a key indicator of fetal CHD and chromosomal abnormalities in early pregnancy. CMA may facilitate detecting the abnormality of genetic material in fetuses with normal chromosome karyotype.
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Objective@#To evaluate the surgical prediction accuracy of Proplan CMF software for zygomatic reduction surgery using L-shaped osteotomy.@*Methods@#Pre-and-postoperative 1-year CBCT data of 26 patients with zygomatic arch hypertrophy were imported in Proplan CMF software during 2014 Jan. to 2016 Jun., the 3D models were reconstructed for simulation of L-shaped osteotomy, characteristic landmarks were selected and 3D point measurement system was established. The measurement result were analyzed by one-way ANOVA. Meanwhile, the overlap color grading charts of preoperative and simulated images were also observed.@*Results@#The facial width, bilateral zygomatic process angle and facial width index were [(128.56±2.72) mm, (106.87±2.53)°, (108.56±3.02)°and 1.41±0.03] in postoperative result, [(129.49±2.26) mm, (108.68±2.40)°, (108.85±3.02)°and 1.42±0.03]in simulated result and [(135.45±2.45) mm, (102.50±2.60)°, (103.41±2.56)°and 1.48±0.05] in preoperative result, with significant difference between preoperative and postoperative result, or between preoperative and simulated result (P<0.05), while no significance between postoperative and simulated result (P>0.05). The soft tissue zygomatic process distance was(153.25±2.58) mm in preoperative result, (150.23±2.76)mm in postoperative result , (149.36±3.27)mm in simulated result, with no significance between any of two groups result (P>0.05). The zygomatic process distance and bilateral zygomatic process tragal distance were (126.35±2.56) mm, (68.75±2.15) mm and(68.86±3.21) mm in postoperative result, showing significant differences compared with preoperative result [(120.16±3.18) mm, (74.58±3.19) mm and(76.14±3.15) mm] and simulated result [(118.86±3.45) mm, (73.85±3.57) mm and(76.87±2.58) mm] respectively(P<0.05), while zygomatic arch distance was not statistically different among the three groups(P>0.05). It indicated that predictive accuracy of facial width, facial width index, zygomatic process angle, soft tissue zygomatic arch distance was high but the soft tissue zygomatic process distance and zygomatic process tragal distance was relatively low. Meanwhile, the color overlay image showed that predictive accuracy was not good in the zygomatic region while the zygomatic arch area was high.@*Conclusions@#The predictive accuracy of Proplan CMF software for zygomatic arch hypertrophy is relatively high except for the zygomatic region. Further improvement of the CMF software is needed.
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Objective To evaluate the clinical application value of reflectance confocal microscopy(RCM) in the diagnosis of several common diseases manifesting as papules in children, including lichen nitidus, verruca planae, lichen striatus, milium, molluscum contagiosum and lichen pilaris. Methods A total of 579 children clinically characterized by papules were recruited into this study. RCM was used to observe lesions and perilesional normal skin. The RCM features of 6 diseases manifesting as papules were analyzed and compared. Results Based on RCM images, 236 patients were diagnosed with lichen nitidus, 70 with verruca planae, 123 with lichen striatus, 40 with milium, 53 with molluscum contagiosum and 57 with lichen pilaris. All the 6 diseases had typical RCM features. Concretely speaking, RCM images of lichen nitidus lesions showed infiltration of dense inflammatory cells and melanophages in enlarged dermal papillae. In RCM images of verruca planae lesions, cells in the granular and spinous layers were arranged in concentric circles, giving a rose cluster?like appearance. RCM images of lichen striatus lesions revealed focal swelling of stratum spinosum, absent or local liquifaction degeneration of basal cells, and clustering of a moderate number of inflammatory cells in the superficial dermis. In RCM images of milium lesions, well?circumscribed round or oval structures containing highly but nonuniformly refractive materials could be seen in the dermis. RCM images of molluscum contagiosum lesions showed intact cystoid structures containing highly refractive molluscum bodies. Lowly to moderately refractive cutin ? like materials were observed along with the dilation of hair follicle infundibula in RCM images of lichen pilaris lesions. In RCM images, the 6 diseases were distinguished mainly based on structural features(patterns and refractivity)of skin lesions shown by continuous vertical scanning. Conclusion RCM is of great value to the diagnosis of diseases manifesting as papules in children.
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Objective To evaluate the clinical effects of ultrasonography for structural examination in the diagnosis of fetal brain malformation and neural tube defects ( NTDs ) in early pregnancy . Methods A retrospective study was conducted to analyse 6 630 cases taking obstetric examination in Dongguan Maternal and Child Health Hospital from February 2014 to June 2015. The examination included a standardized ultrasound structural examination at 11-13 plus 6 weeks of pregnancy. The autopsied results of the induced fetus in early pregnancy from craniocerebral and neural tube structure malformation were investigated. All the cases were followed up concerning the outcomes and the malformation detection rate was calculated for analysis. Results The detection rates of exencephalus and anencephalus, holoprosencephaly, aphylly-holoprosencephaly, rachischisis, open spina bifida, and meningocele were 100%, 80%, 100%, 42.9%, 50% and 100%, respectively. The malformations which was missed in the early pregnancy but detected in the later gestational ages included:Dandy-Walker Syndrome, most of the non-open spina bifida, hypoplasia of the corpus callosum, foliaceous-holoprosencephaly and ventriculomegaly. Conclusions The structural examination using ultrasonography at early pregnancy is effective in the detection of severe open-neural tube defects. It′s worth generalizing in the cliical diagnosis but part of fetal malformations still need a further ultrasound examination in the mid-gestation or the later gestation.
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Objective To valuate the applicability of multiplex ligation‐dependent probe amplication (MLPA ) for detection of chromosomal unbalance .Methods Aneuploid and subtelomeric MLPA technology were used to analyze 6 samples with chromosom‐al unbalances ,confirmed by karyotype analysis .Results All samples were identified to have abnormal signal of corresponding probes .The extent of unbalances contained subtelomeric region .Conclusion MLPA technology could have important role in diag‐nosis of chromosomal unbalance ,which could complement conventional karyotype analysis .
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Objective To study the effects of different types of exercise training on learning and memory, as well as on the expression of synaptophysin (SYP) and on postsynaptic density protein 95 (PSD-95) in rats in which a model of vascular dementia had been created.Methods Forty male Wistar rats were divided randomly into a voluntary exercise group (V-EX) , a forced exercise group (F-EX) , an involuntary exercise group (I-EX) , a vascular dementia group (VD) and a sham-operation group (Sham) , with 8 rats in each group.Two-vessel occlusion (2-VO) of the arteria carotis communis was used to create a model of vascular dementia in all of the rats except those in the sham-operation group.Beginning one week after the surgery, the V-Ex rats were free to run in a running wheel.The F-EX rats were forced to run 270 m a day in an electric wheel.The I-EX rats were stimulated to imitate the gait pattern of their forelimbs running at 9 m/min three times a day for l0 minutes each time.No special training was given to the rats in the other 2 groups.Three weeks after the surgery, their learning and memory were tested using a novel object recognition test.Immediately after the test, their prefrontal cortex was sampled and the expression of SYP and PSD-95 was detected using western blotting.Results The average novel object recognition indices of the rats in the V-EX, F-EX and I-EX groups were all significantly higher than that of the VD group.Average PSD-95 expression was also significandy higher than in the VD group.Conclusion Exercise, whether voluntary, forced or induced by functional electrical stimulation can improve learning and memory in vascular dementia, at least in rats.The mechanism is possibly that the training can increase the expression of PSD-95 in the prefrontal cortex, though not SYP.
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Objective To investigate whether functional electrical stimulation (FES) can improve the expression of proteins in the NMDAR1-pGLuR1 pathway so as to promote the recovery of motor function and sensation after stroke.Methods Eighty-one Wistar rats were used to make a photochemical brain model of local ischemia.Rats were randomly assigned into a sham, placebo stimulation or FES group.Rats in the placebo and FES groups had local ischemia induced in the M1 zone of the brain using the photosensitive dye Bengal rose.It was administered intravenously and a laser beam was then stereotactically positioned on the skull.The rats in the FES groups were stimulated for 30 minutes (10 minutes on, 10 minutes off, then 10 minutes on).The placebo group's treatment was similar, but without the electric current.The rats in the sham group received no intervention.The cylinder test and the adhesive-removal test were used to test the rats' motor function and sensation before the operation and before they were sacrificed.Cohorts were sacrificed after 3, 7 and 14 days of intervention.NMDA receptor and AMPA receptor were detected in the peri-ischemic cortex using western blotting.Results After 7 and 14 days the index of forelimb motor function in the cylinder test of the FES group was significantly better than that of the placebo group.The average adhesive-removal time of the FES group was also significantly faster compared with the placebo group.After 7 days the average expression of NMDAR1 in the FES group was significantly higher than in the placebo group.The average expression of GluR1 and pGluR1 in the FES group was significantly higher than in the placebo group after 14 days.Conclusion Functional electrical stimulation can improve motor function after ischemia through the NMDARAMPAR signal pathway, at least in rats.
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Objective To observe the effects of low-dose ultra-shortwaves radiationon the expression of apoptosis-related genes Bcl-2 and Bax in lens epithelial cells(LECs) of rats.Methods Thirty-six Wistar rats were divided into a normal group(n=8 eyes),a control group(n=32 eyes) and an experiment group(n=32 eyes) randomly.Both eyes of each rat in the experiment group were exposed to a low-dose ultra-shortwave radiation for 7min,once a day until the end of experiment,while the control groups were not.Rats were executed after 1 w,3w,6w and 9w.Both eyes were resected,and lens were separated under a microscope and sectioned in paraffin.After Streptavidin-Biotin Complex (SABC) staining,Bcl-2 and Bax expression in the LECs were detected using an image analysis technique,and the data were analyzed using the software of SPSS 13.0.Results The average integral optical density (AIOD) of Bcl-2 expression in the experiment group was (0.391 ± 0.014) after 1 week,(0.4470.006) after2,(0.417 ±0.011) after3 and (0.275 ±0.007) after4 weeks.The corresponding AIODs for Bax expression were (0.180 ±0.015),(0.155 ± 0.007),(0.167 ± 0.003) and (0.251 ± 0.016) respectively.After l w of daily radiation,no significant difference was found in the expressions of Bcl-2 and Bax protein between the experimental and the other 2 groups(P ＞ 0.05).Three weeks after the radiation,however,the expression of Bcl-2 protein in the experimental group was significantly higher than the control groups(P＜0.001),with that of Bax being significantly lower(P＜0.001).However,the expressions of Bcl-2 protein was significantly down-regulated and the expression of Bax protein was significantly up-regulated 6w later compared with those after3 w of exposure in the experiment group(P＜0.001) After9w,in the experimental group,the expressions of Bcl-2 protein was obviously down-regulated and significantly lower than the control group.Moreover,the expression of Bax protein increased significantly compared to the control group (P＜0.01).And there was no significant difference between the control and normal group(P＞0.05) in the expression of Bcl-2 and Bax.Conclusions Low doses of ultra-shortwave radiation may protect LECs against apoptosis for a few days,but they may cause damage with repeated exposure.
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Objective To observe the effect of electroacupuncture(EA) on the hippocampal expression of GluA1,pGluA1,CaMK Ⅱ and pCaMK Ⅱ in rats with vascular dementia(VD),so as to find out the underlying mo lecular mechanisms of EA in treating VD.Methods Thirty-two Wistar rats were randomly divided into a shamoperation group,a model group,a sham-acupuncture group,and an EA group (8 in each group).Permanent bilateral common carotid artery occlusion was performed to model vascular dementia in the model group,the shamacupuncture group and the EA group,while exposure but no occlusion of the bilateral common carotid were performed in the sham-operating group.Novel object recognition test was adopted to prove the establishment of VD rat model.All the rats were kept in an immobilization apparatus while receiving treatments.EA was applied ontoBaihui (GV20) and Zusanli (ST36) in EA group for 30 min,once daily for 7 days.Sham-acupuncture group were treated with needles inserted 0.5 mm superficially.And the sham-operation group and the model group were only immobilized.The protein expression of GluA1,pGluA1,CaMK Ⅱ and pCaMK Ⅱ in hippocampal tissue was detected by western blotting.Results The expression of GluA1 in the model group (1.216 ± 0.102) was significantly less than in the sham-operating group (1.918 ± 0.137) (P ＜ 0.05).The expression of GluA1 in the EA group (1.653 ± 0.169) was significantly higher than in the model group (1.216 ± 0.102) and in sham-acupuncture group (1.231 ±0.188) (P＜0.05).The expression of CaMKⅡ in the model group (1.516±0.392) was less than in the sham-operating group (2.187 ± 0.231) (P ＜ 0.05).The expression of CaMK Ⅱ in the EA group (2.733 ±0.387) was significantly higher than in the model group (1.516 ±0.392) and sham-acupuncture group (1.493 ±0.205) (P＜0.05).The expression ofpGluA1 in the model group (1.502 ±0.419) was less than in the sham-operating group (2.253 ± 0.244) (P ＜ 0.05).The expression of pGluA1 in the EA group (2.382 ± 0.308) was significantly higher than in the model group (1.502 ± 0.419) and the sham-acupuncture group (1.498 ± 0.223) (P ＜ 0.05).The expression of pCaMK Ⅱ in the model group (0.394 ± 0.227) was less than in the sham-operating group (0.667 ±0.175) (P＜0.05).The expression ofpCaMKⅡ in the EA group (1.189± 0.346) was significantly higher than in the model group (0.394 ± 0.227) and the sham-acupuncture group (0.408 ± 0.231) (P ＜ 0.05).Conclusion EA can enhance the protein expression and phosporylation of GluA1 and CaMK Ⅱ,causing silent synapses transforming into functional synapses,and consequently,long term potentiation was facilitated and cognitive impairment was improved by EA.
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Objective To investigate the effects of intra-articular hyaluronan(HA)injection on the expression of cartilage oligomeric matrix protein(COMP)in synovium of strenuous running rats,and investigate the possibility of predicting the effectiveness of HA based on COMP in synovium.Methods 36 healthy male Wistar rats were randomly divided into control group,strenuous running group and strenuous running group and HA injection group.Strenuous running group and HA injection group were intra- articularly injected with HA once a week for 5 consecutive weeks.The histological changes of synovium of knee joint was examined by H.E.staining and immunohistochemical expression of COMP in three groups after 6 weeks' strenuous running.Results Synovial inflammation was less severe in strenuous running and HA injection group than strenuous running group(t =7.15,P ＜0.01).The immunohistochemical expression of COMP in rats'synovium of knee joint in strenuous running and HA injection group was significantly lower than that in rats'synovium in strenuous running group(t = 6.30,P ＜ 0.01).Conclusions Intra- articular HA injection suppressed synovitis,and the expression of COMP in synovium could be used to predict the effectiveness of HA.
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Objective To determine whether or not 810 nm low power Ga-Al-As laser treatment can stimulate the regeneration of damaged optic nerves by measuring the expression of growth associated protein 43 ( GAP-43 )and flash-visual evoked potential (F-VEP). Methods Eighty-eight Wistar rats weighing (180-220) g were randomly divided into a laser therapy group with 40 rats,an injury group with 32 rats,and a normal control group with 16 rats.Each group was subdivided into 1st,3rd,6th and 9th week subgroups.A standardized crushing of the optic nerve was applied to make the model.After this,the laser therapy group was treated for 3 minutes daily at 60 mW applied transcutaneously to a 5 mm diameter spot on the injured optic nerve.The injury and normal control groups received the same treatment with no laser output.The expression of GAP-43 was detected by immunohistochemistry and RT-PCR after 1,3,6 and 9 weeks of treatment.F-VEP was measured pre-injury,immediately after injury and 1,3,6 and 9 weeks post injury. Results After the optic nerve was injured,obvious changes in F-VEP were detected,including significantly prolonged latencies of N1,P1 and N2 waves.The latency increased immediately after the optic nerve injured,and then recovered,but after 1 and 3 weeks the latency was still prolonged.There was significant recovery from the 3rd to the 9th week.In the laser therapy group,the peak latencies of the N1,P1 and N2 waves were also prolonged,but the changes were less than those in the injury group.Expression of GAP-43 was hardly detectable in normal retinas and optic nerves.GAP-43 had its highest expression level at 1 week post-injury,and then decreased.At the 1st,3rd and 6th week post-injury,the expression of GAP-43 in the laser therapy group was significantly higher than in the injury group.GAP-43 mRNA content in the retina showed the same tendency as GAP-43 protein. Conclusion A 810 nm low power Ga-Al-As laser can promote neural repair and axonal regeneration after optic nerve injury.