ObjectiveTo observe the effect of non-vitrectomy in the treatment of idiopathic macular epiretinal membranes (IMEM).MethodsThis study is a randomized controlled trial. From December 2017 to December 2018, 60 IMEM patients (60 eyes) diagnosed in Weifang Eye Hospital were included in the study. BCVA, intraocular pressure (IOP) and OCT were performed in all patients. The BCVA examination was performed using the international standard visual acuity chart, which was converted to logMAR. The CMT was measured by OCT. According to the surgical methods, the patients were divided into non-vitrectomy group and control group, 30 patients (30 eyes) in each group. The age (t=1.723), logMAR BCVA (t=1.703), CMT (t=-0.956), IOP (t=-1.434) were not significantly different between the two groups (P=0.090, 0.094, 0.343, 0.157). 23G vitreous cutting system was used in all eyes. The macular epiretinal membranes was removed by non-vitrectomy in the non-vitrectomy group and by vitrectomy in the control group. The relevant examination with the same equipment and methods before the operation at 1 week and 1, 3, 6 months after operation. The time of surgery, the changes of BCVA, CMT and postoperative complications in the two groups were observed comparatively. Variance analysis of repeated measurements was performed for the comparison of BCVA, CMT and IOP after surgery in the two groups. Wilcoxon rank sum test of two independent samples was performed for the degree of vision improvement. The incidence of postoperative complications was compared by χ2 test.ResultsAt 6 months after operation, BCVA increased in 24 eyes (80%) and unchanged in 6 eyes (20%) in the non-vitrectomy group. Compared with preoperative BCVA, the difference was statistically significant (P＜0.05). BCVA increased in 25 eyes (83.4%), unchanged in 4 eyes (13.3%) and decreased in 1 eye (3.3%) in the control group. Compared with preoperative BCVA, the difference was statistically significant (P＜0.05). There was no significant difference between the two groups in BCVA improvement degree after operation (Z=－0.26, P＞ 0.05). At 6 months after operation, the average logMAR BCVA was statistically significant compared with the preoperative in the non-vitrectomy group (P=0.002, 0.005) and control group (P=0.004, ＜0.001). Visual stability occurred 1 month after operation in the non-vitrectomy group and 3 months after operation in the control group. The effective operative time of the non-vitrectomy group and control group was 4.50±1.41 and 15.50±2.33 min, respectively. The difference of effective operation time between the two groups was statistically significant (t=－22.12, P＜0.05). After surgery, no significant complications were found in the non-vitrectomy group. In the control group, there were 3 eyes with low IOP and 1 eye with macular hole during operation.ConclusionsNon-vitrectomy and vitrectomy have similar effects on IMEM. Non-vitrectomy has short effective operation time, faster recovery after surgery and no obvious complications.
Objective To evaluate the effect of internal fixation on the stability of pedicled fascial flap and the osteogenesis of exceed critical size defect (ECSD) of bone so as to provide theory for the clinical application by the radiography and histology observation. Methods The ECSD model of the right ulnar midshaft bone and periosteum defect of 1 cm in length was established in 32 New Zealand white rabbits (aged 4-5 months), which were divided into group A and group B randomly (16 rabbits in each group). The composite tissue engineered bone was prepared by seeding autologous red bone marrow (ARBM) on osteoinductive absorbing material (OAM) containing bone morphogenetic protein and was used repair bone defect. A pedicled fascial flap being close to the bone defect area was prepared to wrap the bone defect in group A (control group). Titanium miniplate internal fixation was used after defect was repair with composite tissue engineered bone and pedicled fascial flap in group B (experimental group). At 2, 4, 6, and 8 weeks, the X-ray films examination, morphology observation, and histology examination were performed; and the imaging 4-score scoring method and the bone morphometry analysis was carried out. Results All rabbits survived at the end of experiment. By X-ray film observation, group B was superior to group A in the bone texture, the space between the bone ends, the radiographic changes of material absorption and degradation, osteogenesis, diaphysis structure formation, medullary cavity recanalization. The radiographic scores of group B were significantly higher than those of group A at different time points after operation (P lt; 0.05). By morphology and histology observation, group B was superior to group A in fascial flap stability, tissue engineered bone absorption and substitution rate, external callus formation, the quantity and distribution area of new cartilage cells and mature bone cells, and bone formation such as bone trabecula construction, mature lamellar bone formation, and marrow cavity recanalization. The quantitative ratio of bone morphometry analysis in the repair area of group B were significantly larger than those of group A at different time points after operation (P lt; 0.05). Conclusion The stability of the membrane structure and the bone defect area can be improved after the internal fixation, which can accelerate bone regeneration rate of the tissue engineered bone, shorten period of bone defect repair, and improve the bone quality.
Objective To observe the influences of depolarized arrest and hyperpolarized arrest on alternation of fluidity of myocardial cell membrane during cardiopulmonary bypass (CPB) and evaluate the protective effects on myocardium of hyperpolarized arrest. Methods Seventy-two felines were randomized into three groups, each group 24. Control group: 180 minutes of CPB was conducted without aortic and vena caval cross-clamping. Depolarized arrest group: hearts underwent 60 minutes of global ischemia after aortic cross-clamping (ACC) followed by 90 minutes of reperfusion. The cardioplegic solution consisted of St. Thomas solution (K+16mmol/L). Hyperpolarized arrest group: the protocol was the same as that in depolarized arrest group except that the cardioplegic solution consisted of St.Thomas solution with pinacidil (50 mmol/L,K+5mmol/L). Microviscosity, the reciprocal of fluidity of myocardial membrane was measured in all groups by using fluorescence polarization technique. (Results )Microvis cosity of myocardial cell in depolarized arrest group during ACC period was significantly higher than that before ACC and kept on rising during reperfusion period. Microviscosity of myocardial cell in hyperpolarized arrest group during ACC was trending up and reperfusion periods as well, but markedly lower compared to that in depolarized arrest group at corresponding time points(Plt;0.01). Conclusion Hyperpolarized arrest is more effective in protecting myocardial cells from ischemia-reperfusion injury than depolarized arrest during CPB by maintaining better fluidity of myocardial membrane.
OBJECTIVE To confirm membrane-guided tissue regeneration in the healing course of segmental bone defects and study the mechanism. METHODS Segmental, 1 cm osteoperiosteal defects were produced in both radii of 12 rabbits. One side was covered with hydroxyapatite/polylactic acid(HA/PLA) membrane encapsulated as a tube. The contralateral side served as an untreated control. Healing courses were detected by radiographic and histologic examinations. RESULTS All control sides showed nonunion, whereas there were consistent healing pattern in test sides. CONCLUSION Membrane technique can promote bone regeneration.
Objective To investigate the effect of repairing bone defect with tissue engineered bone seeded with the autologous red bone marrow (ARBM) and wrapped by the pedicled fascial flap and provide experimental foundation for cl inicalappl ication. Methods Thirty-two New Zealand white rabbits (male and/or female) aged 4-5 months old and weighing2.0-2.5 kg were used to make the experimental model of bilateral 2 cm defect of the long bone and the periosteum in the radius. The tissue engineered bone was prepared by seeding the ARBM obtained from the rabbits on the osteoinductive absorbing material containing BMP. The left side of the experimental model underwent the implantation of autologous tissue engineered bone serving as the control group (group A). While the right side was designed as the experimental group (group B), one 5 cm × 3 cm fascial flap pedicled on the nameless blood vessel along with its capillary network adjacent to the bone defect was prepared using microsurgical technology, and the autologous tissue engineered bone wrapped by the fascial flap was used to fill the bone defect. At 4, 8, 12, and 16 weeks after operation, X-ray exam, absorbance (A) value test, gross morphology and histology observation, morphology quantitative analysis of bone in the reparative area, vascular image analysis on the boundary area were conducted. Results X-ray films, gross morphology observation, and histology observation: group B was superior to group A in terms of the growth of blood vessel into the implant, the quantity and the speed of the bone trabecula and the cartilage tissue formation, the development of mature bone structure, the remolding of shaft structure, the reopen of marrow cavity, and the absorbance and degradation of the implant. A value: there was significant difference between two groups 8, 12, and 16 weeks after operation (P lt; 0.05), and there were significant differences among those three time points in groups A and B (P lt; 0.05). For the ratio of neonatal trabecula area to the total reparative area, there were significant differences between two groups 4, 8, 12, and 16 weeks after operation (P lt; 0.05), and there were significant differences among those four time points in group B (P lt; 0.05).For the vascular regenerative area in per unit area of the junctional zone, group B was superior to group A 4, 8, 12, and 16 weeks after operation (P lt; 0.05). Conclusion Tissue engineered bone, seeded with the ARBM and wrapped by the pedicled fascial flap, has a sound reparative effect on bone defect due to its dual role of constructing vascularization and inducing membrane guided tissue regeneration.
Objective To evaluate the effects of surgical treatment for severe ocular rupture with blood staining of cornea and non-light perception , and analyze the relative factors. Methods Seven severely rup tured eyes of 7 patients with blood staining of cornea and non-light perception underwent second-stage penetrating keratoplasty combined with vitrectomy using temporary keratoprosthesis. All injured eyes had blood staining of cornea, hemorrhage in anterior chamber and vitreous, and choroidal and retinal detachment before the second-stage surgery. The average interval of the two surgical stages was 18 days (12-21 days). The preoperative visual acuity was non-light percept ion in all injured eyes with the mean intraocular pressure of 3 mm Hg (1 mm Hg =0.133 kPa) (2-5 mm Hg).The mean follow-up period was 12 months (6-30 months). Results The postoperative visual acuity was better than light perception in 5 eyes with the best corrected visual acuity of light perception to 0.06. The retina was attached in 5 eyes (5/7). The mean postoperative intraocular pressure was 12 mm Hg(5-15 mm Hg)which was significantly higher than the preoperative one (Plt;0.05). Postoperative complications mainly included temporary intraocular hypertension (1 eye), corneal neovasculariza tion (4 eyes), cornea rejection (4 eyes), and ocular atrophy (2 eyes). Conclusion Penetrating keratoplasty combined with vitrectomy using temporary keratoprosthesis is a safe and effective method in treating severe ocular rupture with blood staining of cornea and non-light perception. (Chin J Ocul Fundus Dis，2004，20：212-214)
Objective To evaluate the effect of 27G pars plana vitrectomy (PPV) and 25G PPV on idiopathic epiretinal membrane (IMEM). Methods Thirty-eight eyes of 38 patients with IMEM were enrolled into this retrospective and comparative study. Eighteen eyes were treated with 27G PPV (group A), 20 eyes underwent 25G PPV (group B) voluntarily. The best corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp microscope, indirect ophthalmoscopy, fundus color photograph, ocular coherence tomography (OCT) and counting of corneal endothelial cells (CEC) were examined before the surgery. BCVA results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. There was no statistically significant difference between two groups in terms of BCVA, IOP, foveal macular thickness (FMT), the counting of CEC and CEC hexagon rate before the surgery (t=1.627, 0.860, 0.293, 1.238, 0.697;P＞0.05). All operations were performed by the same doctor. Operation time for vitrectomy and peeling membrane was recorded. BCVA, IOP, OCT, FMT, counting of CEC and the improvement of metamorphopsia were observed on 1, 7 days and 1, 3 months after PPV. Results The mean operation time for vitrectomy in group A and B were (6.7±2.8), (10.5±3.3) min, respectively. The mean operation time for vitrectomy in group A was significantly longer than that in group B (t=3.084,P＜0.05). The mean operation time for peeling membrane in group A and B were (10.2±5.2), (11.0±5.9) min, respectively. There was no statistically significant difference between two groups in terms of the time for peeling membrane (t=1.970,P=0.187). On 1, 7 days and 1, 3 months after PPV, the difference of BCVA (t=1.463, 0.683, 0.961, 1.226;P=0.833, 0.509, 0.699, 0.744) and IOP (t=1.314, 1.262, 0.699, 1.116;P=0.763, 0.721, 0.534, 0.712) between two groups were not statistically significant. On 1 day after PPV, there were 2 eyes and 5 eyes with ＜9 mmHg (1 mmHg=0.133 kPa) IOP in group A and B. On 7 days and 1, 3 months after PPV, the difference of FMT between two groups were not statistically significant (t=1.257, 1.368, 1.437;P=0.735, 0.745, 0.869). On 3 months after PPV, the difference of CEC between two groups were statistically significant (t=2.276,P＜0.05); the difference of hexagon rate between two groups were not statistically significant (t=1.473,P=0.889). Conclusion The efficacy of 27G PPV for IMEM appears similar to 25G PPV. But 27G PPV has a shorter operating time for vitrectomy, a more stable IOP and a minimal damage to CEC.
The hallmark lesions of age-related macular degeneration (AMD) are drusen and basal linear deposit which are lipid substances deposited in Bruch membrane or the compartment on the Bruch membrane. There is a prevailing hypothesis that lipid and its oxidized derivant deposited in retina may have important roles in the pathogenesis of AMD. Lipid oxidation products are toxic, may affect the adjacent cells, induce inflammation, and trigger neovascularization.7-ketocholestoral (7KCh), a naturally occurring oxidized form of cholesterol, had been found to be toxic to retinal cells and able to induce chronic inflammation, which may play a critical role in the development of AMD. However the precise mechanism remains to be elucidated. Thus we will make a brief review of 7KCh and its association with AMD.
Objective To analyze the correlation of visual acuity and metamorphopsia with foveal morphology before and after vitrectomy with internal limiting membrane peeling (ILMP) in idiopathic macular epiretinal membrane (IMEM) eyes. Methods This is a retrospective case series of 47 IMEM patients (49 eyes). All the patients underwent 25G pars plana vitrectomy with IMEM removal and ILMP. The best corrected visual acuity (BCVA) was measured using the international standard visual acuity chart, and the results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. The severity of metamorphopsia was measured using M-charts. The central macular thickness (CMT), inner nuclear layer thickness (INT), inner retinal layer thickness (IRT), outer retinal layer thickness (ORT), the status of ellipsoid zone (EZ) were assessed with spectral-domain optical coherence tomography at baseline and each month postoperatively. The differences in BCVA, CMT, INT, IRT, ORT and status of EZ before and after surgery were analyzed, so did the correlations between these indexes at the same time. Results Compared with baseline, the postoperative BCVA was significantly increased (F=6.133, P＜0.001), but the M value, CMT, INT, IRT, ORT were significantly decreased (F=12.481, 10.565, 15.739, 6.046, 10.569; P＜0.001);the integrity of EZ was improved significantly (χ2=12.309, P＜0.001). Preoperative BCVA was positively related to the CMT (r=0.720) and ORT (r=0.720, 0.887; P＜0.05), while negatively related to preoperative integrity of EZ (r=?0.295, P＜0.05). The postoperative BCVA was positively related to the preoperative BCVA and postoperative CMT, ORT (r=0.774, 0.754, 0.842; P＜0.05), while negatively related to postoperative integrity of EZ (r=?0.676, P＜0.05). The preoperative M value was positively related to the preoperative CMT, INT, IRT, and ORT (r=0.931, 0.668, 0.840, 0.637; P＜0.05). The postoperative M value was positively related to the preoperative M value and postoperative CMT, INT, IRT, and ORT (r=0.723, 0.722, 0.767, 0.825, 0.387; P＜0.05). Conclusions Vitrectomy with ILMP for IMEM can improve the visual acuity, metamorphopsia and foveal morphology. Both visual acuity and metamorphopsia correlate with foveal morphology.
OBJECTIVE To repair long bone segmental defects using biodegradable poly epsilon-caprolactone (PCL) and polylactic acid(PLA) co-polymer membranes, and explore its role and mechanism in guided bone regeneration (GBR). METHODS Rabbit radial segmental defects (1.2 cm in length, retain the periosteum) were created in this study, 24 animals were divided into 2 groups. The membranes were used to enclose the defects in experimental group, and no treatment in control group. After 3, 6, and 12 weeks of operation, X-ray, gross and histological examinations were observed. RESULTS The bone regeneration of experimental group was better than that of control group. Three weeks after operation, obvious external callus along the membrane were found in experimental group, and bony linking composed of external callus bridge were found in 6 weeks after operation. After 12 weeks of operation, callus bridge outside the membrane and bony reunion inside the membrane were achieved in experimental group. While in control group, typical nonunion was observed after 6 weeks of operation. CONCLUSION Guided bone regeneration can be achieved by using biodegradable membrane. The defects are repaired by the means of outside membrane callus and relatively late inside membrane callus. The membrane can prevent the ingrowth of fibrous tissue into defect area, thus nonunion are avoid, and keep a high concentration of nutritive elements, also serve as a frame for osteocyte growth to enhance bone healing.