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High myopia macular hole (MH) is a serious complication of high myopia. The main treatment method is surgery. Because of axial growth, posterior scleral staphyloma, choroidal atrophy and other factors, the operation is difficult, the anatomic reduction rate is low, and the visual prognosis is poor. How to improve the reduction rate of surgical dissection and the recovery of visual function is a hot topic. At present, the most popular surgeries include parsplanavitrectomy (PPV) and posterior scleral reinforcement (PSR). However, there are many controversies regarding the treatment of internal limiting membrane in PPV, the selection of vitreous gapfiller, the choice of reinforcement materials and reinforcement methods of PSR, and whether it is necessary to combine PPV and PSR, etc. In recent years, many new surgical methods or techniques have emerged, which significantly increase the success rate of MH.
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From international students' origin, composition, cultural background, with experience of teaching Australian students for 10 years, we put forward a set of teaching measures for the overseas students in ophthalmic optics, specifically overall planning, preparing good complete and detailed teaching plans be-fore teaching, adopting typical case teaching and question guiding teaching, making full use of multimedia media teaching and at the same time, using both constraints and guidance in the education management of international students.
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Objective To evaluate efficacy ,stability and safety after implantation of toric implantable collamer lens (TICL) to correct moderate to high myopic astigmatism .Methods This study evaluated 125 eyes of 71 patients with moderate to high myopic astigmatism who accepted TICL implantation .LogMAR uncorrected(UCVA) and best corrected(BCVA) visual acuity ,intraocular pressure ,cycloplegic refraction and manifest refraction examination were assessed preoperatively on 3 ,6 ,12 months postoperatively . The rotation of TICL axis were measured on 3 ,6 ,12 months postoperatively .Results 12 months postoperatively ,the logarithm of the minimum angle of resolution(LogMAR) UCVA were 0 .064 ± 0 .157 which were remarkably better than preoperative BCVA (P<0 .01) .119 eyes(95 .2% ) had postoperative UCVA better than or equal to preoperative BCVA .The manifest spherical refrac‐tion(absolute value) was (0 .36 ± 0 .41)D .105 (84 .0% ) eyes were within ± 0 .5 D .The mean manifest refractive cylinder was (-0 .63 ± 0 .61)D .109(87 .2% ) eyes had ≤ -1 .00 D .The mean rotation on 12 months postoperatively was (4 .76 ± 6 .14)° .The rotation of 101(80 .8% ) eyes were within 5 degrees .No vision threatening complications occurred during the observation period . Conclusion Implantation of TICL is safe and stable in the treatment of moderate to high myopic astigmatism .TICL is an ideal sur‐gical option to treat moderate to high myopic astigmatism .
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BACKGROUND: Structural characteristics of calcium phosphate cement (CPC) offer substantial mechanical integrity for fracture stabilization and fixation during the healing process, with particular applications in mechanically compromised osteoporotic bone.OBJECTIVE: To investigate the mechanism of the augmentation to fixation with CPC, comparing with screw fixation augmented by polymenthymethacrylate (PMMA) bone cement or with unaugmented screw fixation for femoral neck fractures in sheep by histological evaluation.DESIGN: Randomized controlled, duplicated observation and opening study.SETTING: Departments of Orthopeadics and General Surgery, the First Hospital of Jilin University; Department of Pathology, Basic Medical College of Jilin University; Department of Plastic Surgery, Aichi Medical University of Japan.MATERIALS: The experiment was completed in the Taonan Municipal Hospital of Jilin, Jilin University and Aichi Medical University of Japan from January 1999 to January 2004. A total of 45 adult sheep with mean age of 12.5 months were divided into three groups: unaugmentation group,CPC augmentation group and PMMA augmentation group with 15 in each group. Five sheep from each group were selected at 3, 6 and 12 weeks after operation. CPC was consisted of 75% α-tricalcium phosphate (α-TCP),18% tetracalcium phosphate (TeCP), 5% dicalcium phosphate dihydrate (DCPD) and 2% hydroxyapatite (HA). The solidify liquid was consisted of 5% sodium chondroitin sulphate, 12% sodium succinate and 83% water.The ratio between powder and water was 3:1. PMMA bone cement was combined with 97.4% methylmethacrylate, 2.6% N dimethyl-para-toluidine and hydroquinone.METHODS: ① Sheep from each group were anaesthetized by intravenous injection of pentobarbital sodium. The surgical steps were steotomy, drill,tap and fixation. An osteotomized bone at the base of right femoral neck of all groups was fixed by two cancellous bone screws of the diameter 4 mm through femoral neck at the site below great trochanter region. The cement material was filled into the screw hole before the screw insertion. ② CPC was injected into wells in CPC augmentation group, PMMA was injected into wells in PMMA augmentation group, but wells in unaugmentation group was not give any materials. ③After the maximum, compressive load was tested to detect intensity of healing bone, the specimens were fixed in 40%, 70%, 90% and 100% ethanol, dehydrated and stained, in the end embedded in PMMA resin. Serial histological specimens of 150-200 μm thickness were sliced along the long axis of the femoral neck with the microtom. The histological specimens also were taken for contact microradiography. The changes of the host bone and the new bone formation at the interface between cement and bone would be evaluated histologically until 3, 6 or 12 weeks after surgery.MAIN OUTCOME MEASURES: Changes of the host bone and the new bone formation in each group at various time points after operation.RESULTS: All 45 mature Chinese sheep were involved in the final analysis without any loss. Changes of the host bone and the new bone formation in each group at various time points after operation: ① Unaugmentation group: By 3 weeks after surgery, the thin fibrous tissue was found around the screw, and the host bone had micro-destruction. By 6 or 12 weeks after surgery, the micro-destruction of host bone was repaired. ② CPC augmentation group: By 3, 6 or 12 weeks after surgery, the most of gap between the screw and the host bone was occupied by this material, and the new bone connected directly to the material surface, and there was no intervening fibrous tissue between new bone and the material. Especially by 12weeks after surgery, a large quantity of the new bone was formed, and new bone was matured with many bone canals. ③ PMMA augmentation group:By 3 weeks after surgery, the thick fibrous tissue Between PMMA bone cement and the host bone, and the remarkable bone atrophy of host bone were found. By 6,12 weeks after surgery, the fibrous tissue and the bone atrophy were developed.CONCLUSION: CPC provide long-term beneficial augmentation of femoral neck fractures in sheep because of a good biocompatibility, good osteoconduction and capability of remodeling.
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BACKGROUND:The repairing of bone defect near joint in long bone resulting from complicated comminuted fracture or excision of bone tumor is very difficult. It is a much studied issue to find a feasible solution to this problem.OBJECTIVE: To explore a feasible treatment to bone defect near joint in long bone through comparative observation of 3 reconstruction methods.DESIGN: A completely randomized experiment with self-control and mutual control.SETTING: Laboratory for Experimental Animals, First Hospital of Jilin University.MATERIALS: Twelve healthy adult hybrid dogs, 5 males and 7 females weighing 12 to 18 kg, were recruited.METHODS: The bone defects near joints were established in upper femoral condyle in the 12 dogs, which were reconstructed by 3 operation styles: only filling with bone cement, filling with bone cement + autogenous ilium bone graft, and filling with bone cement + autogenous ilium bone graft + fixation with L-trapezoid compression plate. There was one dog in each method. The specimens were harvested at the end of weeks 3, 6, 12and 24, respectively, after operation. One week before specimens were harvested the fluorescent labeling was prepared; we conducted vascular perfusion of disulphine blue before the animals were executed.MAIN OUTCOME MEASURES: A series of examinations were carried out, including X-ray film, biomechanical test, intravascular perfusion and tetracycline fluorescent labeling. The bone healing, blood supply recovery and biomechanics were observed in the three groups.RESULTS: The 12 dogs all entered the result analysis. ① Results of Xray examination: Two cases of fracture occurred in experimental side at 6and 12 weeks in group Ⅰ; one case of fracture occurred in experimental side at 6 weeks in group Ⅱ. No fracture happened in group Ⅲ. ② Bone stiffness assayed with biomechanics: It decreased in experimental side as compared to control side by 67% and 70% in group Ⅰ; 66%, 76% and 46% in group Ⅱ; and 8% in group Ⅲ. ③ Specimen observation after operation: Bone formation, callus, and blood supply recovery were significantly better in group Ⅲ than in groups Ⅰ and Ⅱ at all stages.CONCLUSION: The third operation, filling with bone cement + autogenous ilium bone graft + fixation with L-trapezoid compression plate, is an ideal method of bone reconstruction. It can recover bone function, and prevent complications such as refracture and bone nonunion.
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BACKGROUND:Bone morphogenetic protein (BMP) has strong osteoinductibility. At present, it becomes a hot topic to find a proper carrier for BMP. Calcium phosphate cement (CPC) may become a favorable carrier for BMP for its many merits. OBJECTIVE: To evaluate using the CPC/BMP composite as well as only CPC to repair experimental avascular necrosis of femoral head (ANFH).DESIGN: A randomized controlled experimental study SETTING: Experimental Animal Laboratory of the 208 hospital of Chinese PLAMATERIALS: The subjects were 24 healthy adult rabbits of either sex,weighing 2.5-3.0 kg. BMP was provided by Research Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University of Chinese PLA. CPC was developed together by Department of Orthopaedics, First hospital of Jilin University and Department of Orthopaedics, Aichi Medical University, Japan and Mitsubishi Material Corporation, Japan)METHODS: This experiment was conducted in the Animal Laboratory,the 208 Hospital of Chinese PLA between April 2003 and April 2004.The CPC/BMP composite was constructed by combining calcium phosphate cement (CPC) with bone morphogenetic protein (BMP). The 24 rabbits were randomly divided into two groups: CPC group and CPC/BMP group, 12 rabbits in each group. The models of experimental avascular necrosis of femoral head (ANFH) were made. Then the CPC or CPC/BMP composite were filled into the bone defects. The specimens were harvested separately at the end of 3 and 12 weeks after operation. A series of examinations were carried out including radiograph, histomorphology, and observation under transmission electron microscope (LEM).MAIN OUTCOME MEASURES: Bone formation, degradation of materials and repairing of bone defects in each group.RESULTS:Totally 24 rabbits were examined and analyzed. ① The results of general observation and X-ray examination on the bone defect regions in two groups: at week 12 in CPC group much new bone formed, the volume of CPC decreased. In CPC/BMP group more new bone formed. The phenomena of degradation and absorption were evident and the volume of the material decreased evidently. ② The results of histology observation and transmission electron microscope (TEM) observation in femoral heads in two groups: at week 12 in CPC group CPC decreased and there were some interspaces between CPC and new bone. New bone trabecula enlarged. Juvenile osteocytes could be found with round nucleus, chromatin deviating to one side, rough endoplasmic reticulum (rER) swelling and there were the phenomena of mitochondrion vacuolated and mitochondrial cristaes broken. In CPC/BMP group, CPC was dispersed with new bone intruded into the material and enwrapping each other. Osteoblasts contacted with CPC granules tightly whose rER and mitochondrion in cytoplasm increased and swelled. Many capillaries invaded the material and were encircled by many osteoblasts.CONCLUSION: CPC is an ideal carrier to BMP. The CPC/BMP composite has stronger steoconductibility and osteoinductibility in ANFH repairing than CPC, and is effective in repairing experimental avascular necrosis of femoral head.