Mechanism of selective laser trabeculoplasty:a systemic review

Although selective laser trabeculoplasty(SLT)is a recognized method for the treatment of glaucoma,the exact changes in the target tissue and mechanism for its intraocular pressure lowing effect are still unclear.The purpose of this review is to summarize the potential mechanisms of SLT on trabecular meshwork both in vivo and in vitro,so as to reveal the potential mechanism of SLT.SLT may induce immune or inflammatory response in trabecular meshwork(TM)induced by possible oxidative damage etc,and remodel extracellular matrix.It may also induce monocytes to aggregate in TM tissue,increase Schlemm’s canal(SC)cell conductivity,disintegrate cell junction and promote permeability through autocrine and paracrine forms.This provides a theoretical basis for SLT treatment in glaucoma.

Global current research status and future hotspots in osteoporotic fracture based on bibliometric assessment and visualization techniques

BACKGROUND In the past decade,the evolution of themes in the field of osteoporotic fractures has changed from epidemiology and prediction of long-term morbidity,risk assessment of osteoporotic fractures,and zoledronic acid and denosumab in the treatment of osteoporosis to treatment guidelines for osteoporosis and the side effects caused by anti-osteoporotic drugs.AIM To understand the trends and hotspots in osteoporotic fracture research.METHODS Original articles were retrieved between January 1,2010,and December 31,2019,from the Web of Science Core Collection database.CiteSpace software facilitated the analysis and visualization of scientific productivity and emerging trends.RESULTS Nine studies were identified using bibliometric indices,including citation,centrality,and sigma value,which might indicate a growing trend.Through clustering,we identified six major hot subtopics.Using burst analysis,top-5 references with the strongest bursting strength after 2017 were identified,indicating a future hotspot in this field.CONCLUSION Current hot subtopics in osteoporotic fracture research include atypical femoral fractures,androgen deprivation therapy,denosumab discontinuation,hip fractures,trabecular bone score(TBS),and bone phenotype.Management and prevention of secondary fractures in patients with osteoporotic fractures,TBSs,and long-term administration strategy for zoledronic acid are expected to become research hotspots.

Understanding Osteoporosis: Pathophysiology, Risk Factors, Diagnosis, and Management

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and deterioration of bone architecture, resulting in reduced bone strength and, consequently, increased susceptibility to fractures which poses a significant public health concern worldwide, particularly in aging populations [1]. The health-economic impact of vertebral and hip fractures has been extensively explored and it is well known that these fractures are associated with morbidity/disability and increased mortality;they also account for a substantial portion of the direct fracture costs. This review aims to provide a comprehensive overview of osteoporosis, including its pathophysiology, risk factors, diagnostic approaches, and management strategies. By elucidating the multifaceted nature of this condition, healthcare providers can better identify individuals at risk, implement preventive measures, and optimize treatment to reduce the burden of osteoporotic fractures.

Convenient model of hard tissue simulation for dental radiographic research and instruction

BACKGROUND The authors describe a technique for building an alternative jawbone phantom using dental gypsum and rice for research and dental radiology instruction.AIM To investigate the potential of an alternative phantom to simulate the trabecular bone aspect of the human maxilla in periapical radiographs.METHODS Half-maxillary phantoms built from gypsum-ground rice were exposed to X-rays,and the resulting images(experimental group)were compared to standardized radiographic images produced from dry human maxillary bone(control group)(n=7).The images were blindly assessed according to strict criteria by three examiners for the usual trabecular aspects of the surrounding bone,and significant differences between groups and in assessment reliability were compared using Fisher’s exact and kappa tests(α=0.05).RESULTS The differences in the trabecular aspects between groups were not statistically significant.In addition,interobserver agreement among observers was 0.43 and 0.51 for the control and experimental groups,respectively,whereas intraobserver agreement was 0.71 and 0.73,respectively.CONCLUSION The tested phantom seemed to demonstrate potential for trabecular bone image Munhoz EA et al.Model of hard tissue simulation for dental radiography WJM https://www.wjgnet.com 2 March 20,2024 Volume 14 Issue 1 simulation on maxillary periapical radiographs.

Anisotropy of Trabecular Bone from Ultra-Distal Radius Digital X-Ray Imaging: Effects on Bone Mineral Density and Age

Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions parallel and perpendicular to the forearm. Methodology: Data from more than two hundred subjects were studied retrospectively. A DXA (GE Lunar Prodigy) scan of the forearm was performed on each subject to measure the bone mineral density (BMD) value at the location of ultra-distal radius, and an X-ray digital image of the same forearm was taken on the same day. The values of trabecular bone score along the direction perpendicular to the forearm, TBSx, and along the direction parallel to the forearm, TBSy, were calculated respectively. The statistics of TBSx and TBSy were calculated, and the anisotropy of the trabecular bone, which was defined as the ratio of TBSy to TBSx and changed with subjects’ BMD and age, was reported and analyzed. Results: The results show that the correlation coefficient between TBSx and TBSy was 0.72 (p BMD and age was reported. The results showed that decreased trabecular bone anisotropy was associated with deceased BMD and increased age in the subject group. Conclusions: This study shows that decreased trabecular bone anisotropy was associated with decreased BMD and increased age.

Ocular manifestations of central insulin resistance

Central insulin resistance, the diminished cellular sensitivity to insulin in the brain, has been implicated in diabetes mellitus, Alzheimer’s disease and other neurological disorders. However, whether and how central insulin resistance plays a role in the eye remains unclear. Here, we performed intracerebroventricular injection of S961, a potent and specific blocker of insulin receptor in adult Wistar rats to test if central insulin resistance leads to pathological changes in ocular structures. 80 mg of S961 was stereotaxically injected into the lateral ventricle of the experimental group twice at 7 days apart, whereas buffer solution was injected to the sham control group. Blood samples, intraocular pressure, trabecular meshwork morphology, ciliary body markers, retinal and optic nerve integrity, and whole genome expression patterns were then evaluated. While neither blood glucose nor serum insulin level was significantly altered in the experimental or control group, we found that injection of S961 but not buffer solution significantly increased intraocular pressure at 14 and 24 days after first injection, along with reduced porosity and aquaporin 4 expression in the trabecular meshwork, and increased tumor necrosis factor α and aquaporin 4 expression in the ciliary body. In the retina, cell density and insulin receptor expression decreased in the retinal ganglion cell layer upon S961 injection. Fundus photography revealed peripapillary atrophy with vascular dysregulation in the experimental group. These retinal changes were accompanied by upregulation of pro-inflammatory and pro-apoptotic genes, downregulation of anti-inflammatory, anti-apoptotic, and neurotrophic genes, as well as dysregulation of genes involved in insulin signaling. Optic nerve histology indicated microglial activation and changes in the expression of glial fibrillary acidic protein, tumor necrosis factor α, and aquaporin 4. Molecular pathway architecture of the retina revealed the three most significant pathways involved being inflammation/cell stress, insulin signaling, and extracellular matrix regulation relevant to neurodegeneration. There was also a multimodal crosstalk between insulin signaling derangement and inflammation-related genes. Taken together, our results indicate that blocking insulin receptor signaling in the central nervous system can lead to trabecular meshwork and ciliary body dysfunction, intraocular pressure elevation, as well as inflammation, glial activation, and apoptosis in the retina and optic nerve. Given that central insulin resistance my lead to neurodegenerative phenotype in the visual system, targeting insulin signaling may hold promise for vision disorders involving the retina and optic nerve.

Evaluation of trabecular meshwork-specific promoters in vitro and in vivo using scAAV2 vectors expressing C3 transferase

AIM:To evaluate the potential of two trabecular meshwork(TM)-specific promoters,Chitinase 3-like 1(Ch3L1)and matrix gla protein(MGP),for improving specificity and safety in glaucoma gene therapy based on self-complementary AAV2(scAAV2)vector technologies.METHODS:An scAAV2 vector with C3 transferase(C3)as the reporter gene(scAAV2-C3)was selected.The scAAV2-C3 vectors were driven by Ch3L1(scAAV2-Ch3L1-C3),MGP(scAAV2-MGP-C3),enhanced MGP(scAAV2-eMGP-C3)and cytomegalovirus(scAAV2-CMV-C3),respectively.The cultured primary human TM cells were treated with each vector at different multiplicities of infections.Changes in cell morphology were observed by phase contrast microscopy.Actin stress fibers and Rho GTPases/Rho-associated protein kinase pathway-related molecules were assessed by immunofluorescence staining,real-time quantitative polymerase chain reaction and Western blot.Each vector was injected intracamerally into the one eye of each rat at low and high doses respectively.In vivo green fluorescence was visualized by a Micron III Retinal Imaging Microscope.Intraocular pressure(IOP)was monitored using a rebound tonometer.Ocular responses were evaluated by slit-lamp microscopy.Ocular histopathology analysis was examined by hematoxylin and eosin staining.RESULTS:In TM cell culture studies,the vectormediated C3 expression induced morphologic changes,disruption of actin cytoskeleton and reduction of fibronectin expression in TM cells by inhibiting the Rho GTPases/Rhoassociated protein kinase signaling pathway.At the same dose,these changes were significant in TM cells treated with scAAV2-CMV-C3 or scAAV2-Ch3L1-C3,but not in cells treated with scAAV2-eMGP-C3 or scAAV2-MGP-C3.At lowinjected dose,the IOP was significantly decreased in the scAAV2-Ch3L1-C3-injected eyes but not in scAAV2-MGPC3-injected and scAAV2-eMGP-C3-injected eyes.At highinjected dose,significant IOP reduction was observed in the scAAV2-eMGP-C3-injected eyes but not in scAAV2-MGP-C3-injected eyes.Similar to scAAV2-CMV-C3,scAAV2-Ch3L1-C3 vector showed efficient transduction both in the TM and corneal endothelium.In anterior segment tissues of scAAV2-eMGP-C3-injected eyes,no obvious morphological changes were found except for the TM.Inflammation was absent.CONCLUSION:In scAAV2-transduced TM cells,the promoter-driven efficiency of Ch3L1 is close to that of cytomegalovirus,but obviously higher than that of MGP.In the anterior chamber of rat eye,the transgene expression pattern of scAAV2 vector is presumably affected by MGP promoter,but not by Ch3L1 promoter.These findings would provide a useful reference for improvement of specificity and safety in glaucoma gene therapy using scAAV2 vector.

Development and validation of a predictive model for spinal fracture risk in osteoporosis patients

BACKGROUND Spinal osteoporosis is a prevalent health condition characterized by the thinning of bone tissues in the spine,increasing the risk of fractures.Given its high incidence,especially among older populations,it is critical to have accurate and effective predictive models for fracture risk.Traditionally,clinicians have relied on a combination of factors such as demographics,clinical attributes,and radiological characteristics to predict fracture risk in these patients.However,these models often lack precision and fail to include all potential risk factors.There is a need for a more comprehensive,statistically robust prediction model that can better identify high-risk individuals for early intervention.AIM To construct and validate a model for forecasting fracture risk in patients with spinal osteoporosis.METHODS The medical records of 80 patients with spinal osteoporosis who were diagnosed and treated between 2019 and 2022 were retrospectively examined.The patients were selected according to strict criteria and categorized into two groups:Those with fractures(n=40)and those without fractures(n=40).Demographics,clinical attributes,biochemical indicators,bone mineral density(BMD),and radiological characteristics were collected and compared.A logistic regression analysis was employed to create an osteoporotic fracture risk-prediction model.The area under the receiver operating characteristic curve(AUROC)was used to evaluate the model’s performance.RESULTS Factors significantly associated with fracture risk included age,sex,body mass index(BMI),smoking history,BMD,vertebral trabecular alterations,and prior vertebral fractures.The final risk-prediction model was developed using the formula:(logit[P]=-3.75+0.04×age-1.15×sex+0.02×BMI+0.83×smoking history+2.25×BMD-1.12×vertebral trabecular alterations+1.83×previous vertebral fractures).The AUROC of the model was 0.93(95%CI:0.88-0.96,P<0.001),indicating strong discriminatory capabilities.CONCLUSION The fracture risk-prediction model,utilizing accessible clinical,biochemical,and radiological information,offered a precise tool for the evaluation of fracture risk in patients with spinal osteoporosis.The model has potential in the identification of high-risk individuals for early intervention and the guidance of appropriate preventive actions to reduce the impact of osteoporosis-related fractures.

Morphogenesis of Floating Bone Segments: A Legacy of Serial Tensile Cross-Strut Microdamage in Trabecular Disconnection “Crumple Zones”?

Trabecular bone disconnection “hotspots” of real termini (ReTm) previously mapped as loci of weakness in the female aging spine and hip may be a source of free-floating cancellous segments found in the medullary space using a bespoke, thick slice histological method for identifying ReTm. A factor in their origin is apparently microdamage proliferation (differentiated by en bloc silver staining) with occasional callus moderation. Validation of similar “floating segments” (FS) in the ex-breeder rat suggested a pilot model for a potentially common phenomenon. Following marrow elution and density fractionation of the isolated floating segments from the whole proximal rat femora, scanning electron microscopy (SEM) and elemental microanalysis (EDS) was performed. The eluent contained numbers of vertically truncated, laterally branched floating segments (acute severance of sequential tensile cross-struts, causing chronic compression overload of axial-struts, with ii) inadequate stabilising callus, facilitating ReTm stacking into predetermined, substructural “crumple zones” of force containment, spheroidal attrition and particulate dissociation. As a catabolic outcome of altered tensile and hormonal influence, FS number may add a novel variable to cancellous bone kinetics particularly in women of relevance to fracture predisposition.

青光眼微创手术进展

青光眼超微手术以其手术切口单一、创伤小、降眼压效果良好、安全性高以及术后恢复快的特点成为目前青光眼治疗研究和发展的热点之一,本文就近5 a来的青光眼微创手术的进展作一综述。

Bone three-dimensional microstructural features of the common osteoporotic fracture sites

Osteoporosis is a common metabolic skeletal disorder characterized by decreased bone mass and deteriorated bone structure, leading to increased susceptibility to fractures. With aging population, osteoporotic fractures are of global health and socioeconomic importance. The three-dimensional microstructural information of the common osteoporosis-related fracture sites, including vertebra, femoral neck and distal radius, is a key for fully understanding osteoporosis pathogenesis and predicting the fracture risk. Low vertebral bone mineral density(BMD) is correlated with increased fracture of the spine. Vertebral BMD decreases from cervical to lumbar spine, with the lowest BMD at the third lumbar vertebra. Trabecular bone mass of the vertebrae is much lower than that of the peripheral bone. Cancellous bone of the vertebral body has a complex heterogeneous three-dimensional microstructure, with lower bone volume in the central and anterior superior regions. Trabecular bone quality is a key element to maintain the vertebral strength. The increased fragility of osteoporotic femoral neck is attributed to low cancellous bone volume and high compact porosity. Compared with age-matched controls, increased cortical porosity is observed at the femoral neck in osteoporoticfracture patients. Distal radius demonstrates spatial inhomogeneous characteristic in cortical microstructure. The medial region of the distal radius displays the highest cortical porosity compared with the lateral, anterior and posterior regions. Bone strength of the distal radius is mainly determined by cortical porosity, which deteriorates with advancing age.

Effect of Dexamethasone and Aquaporin-1 Antisense Oligonucleotides on the Aquaporin-1 Expression in Cultured Human Trabecular Meshwork Cells

The changes in the expression of aquaporin-1 （AQP1） mRNA and protein in cultured human trabecular meshwork （HTM） cells treated with dexamethasone and transfected with antisense oligonucleotides （AS-ODN） were studied, and the implication of AQP1 regulation in corticosteroid-glaucoma and the possibility of AS-ODN inhibiting the AQP1 expression were evaluated. The cultured HTM cells in vitro were treated with different concentrations of dexamethasone and transfected with oligonucleotides for 5 days respectively. Then, total RNA and protein of HTM cells were extracted. The changes of AQP1 mRNA and protein were demonstrated qualitatively and quantitatively by RT-PCR and Western blot. Band intensities were detected by imaging analysis. There was a parallel relationship between the results of RT-PCR and those of Western blot. The expression levels of AQP1 mRNA and protein in dexamethasone-treated groups were increased initially and decreased later as dexamethasone concentration was stepped up. In the 0.04 μg/mL and 0.4 μg/mL groups, the levels of AQP1 were higher than in control group （0 μg/mL）. In the 4 μg/ mL and 40 μg/mL groups, the AQP1 expression levels were lower than in control group. AS-ODN could down-regulate the expression of AQP1 mRNA and protein in a dose-dependent manner. At 5 μg/mL, down-regulation efficiency reached the maximum. There was no statistically significant difference in the expression of AQP1 mRNA and protein between all sense oligonucleotides groups and control group. It was suggested that dexamethasone may induce the changes of the AQP1 expression in HTM cells to be involved in the occurrence of corticosteroid-glaucoma. AS-ODN can down-regulate the AQP1 expression in HTM cells to some extent.

Managing osteoporosis in ulcerative colitis: Something new?

The authors revise the latest evidence in the literature regarding managing of osteoporosis in ulcerative colitis (UC), paying particular attention to the latest tendency of the research concerning the management of bone damage in the patient affected by UC. It is wise to assess vitamin D status in ulcerative colitis patients to recognize who is predisposed to low levels of vitamin D, whose deficiency has to be treated with oral or parenteral vitamin D supplementation. An adequate dietary calcium intake or supplementation and physical activity, if possible, should be guaranteed. Osteoporotic risk factors, such as smoking and excessive alcohol intake, must be avoided. Steroid has to be prescribed at the lowest possible dosage and for the shortest possible time. Moreover, conditions favoring falling have to been minimized, like carpets, low illumination, sedatives assumption, vitamin D deficiency. It is advisable to assess the fracture risk in all UC patient by the fracture assessment risk tool (FRAX® tool), that calculates the ten years risk of fracture for the population aged from 40 to 90 years in many countries of the world. A high risk value could indicate the necessity of treatment, whereas a low risk value suggests a follow-up only. An intermediate risk supports the decision to prescribe bone mineral density (BMD) assessment and a subsequent patient revaluation for treatment. Dual energy X-ray absorptiometry bone densitometry can be used not only for BMD measurement, but also to collect data about bone quality by the means of trabecular bone score and hip structural analysis assessment. These two indices could represent a method of interesting perspectives in evaluating bone status in patients affected by diseases like UC, which may present an impairment of bone quality as well as of bone quantity. In literature there is no strong evidence for instituting pharmacological therapy of bone impairment in UC patients for clinical indications other than those that are also applied to the patients with osteoporosis. Therefore, a reasonable advice is to consider pharmacological treatment for osteoporosis in those UC patients who already present fragility fractures, which bring a high risk of subsequent fractures. Therapy has also to be considered in patients with a high risk of fracture even if it did not yet happen, and particularly when they had long periods of corticosteroid therapy or cumulative high dosages. In patients without fragility fractures or steroid treatment, a medical decision about treatment could be guided by the FRAX tool to determine the intervention threshold. Among drugs for osteoporosis treatment, the bisphosphonates are the most studied ones, with the best and longest evidence of efficacy and safety. Despite this, several questions are still open, such as the duration of treatment, the necessity to discontinue it, the indication of therapy in young patients, particularly in those without previous fractures. Further, it has to be mentioned that a long-term bisphosphonates use in primary osteoporosis has been associated with an increased incidence of dramatic side-effects, even if uncommon, like osteonecrosis of the jaw and atypical sub-trochanteric and diaphyseal femoral fractures. UC is a long-lasting disease and the majority of patients is relatively young. In this scenario primary prevention of fragility fracture is the best cost-effective strategy. Vitamin D supplementation, adequate calcium intake, suitable physical activity (when possible), removing of risk factors for osteoporosis like smoking, and avoiding falling are the best medical acts.

Fluid-Structure Interaction Simulation of Aqueous Outflow System in Response to Juxtacanalicular Meshwork Permeability Changes with a Two-Way Coupled Method

Elevated intraocular pressure appears to have a broader impact on increased resistance to aqueous humor outflow through the conventional aqueous outflow system(AOS).However,there is still no consensus about exact location of the increased outflow resistance of aqueous humor,and the mechanism is not perfect.In addition,it is difficult to accurately obtain hydrodynamic parameters of aqueous humor within the trabecular meshwork outflow pathways based on the current technology.In this paper,a two-way fluid-structure interaction simulation was performed to study the pressure difference and velocity in the superficial trabecular meshwork,juxtacanalicular meshwork(JCM)and Schlemm’s canal in response to JCM permeability changes.We obtained the JCM permeability of normal intraocular pressure varied between 1×10?15 m2 and 10×10?15 m2 while permeability of the JCM ranged from 2×10?16 m2 and 3×10?16 m2 under conditions of high intraocular pressure.The study indicated that the fluid dynamics parameters in trabecular meshwork and Schlemm’s canal are most significantly affected by the changes of JCM permeability.Moreover,the study demonstrates that the finite element modeling of AOS provides a practical means for studying the outflow dynamics and the biomechanical environment of the AOS.

Effect of persistent high intraocular pressure on microstructure and hydraulic permeability of trabecular meshwork

As the aqueous humor leaves the eye, it first passes through the trabecular meshwork （TM）. Increased flow resistance in this region causes elevation of intraocular pressure （IOP）, which leads to the occurrence of glaucoma. To quantitatively evaluate the effect of high IOP on the configuration and hydraulic permeability of the TM, second harmonic generation （SHG） microscopy was used to image the microstructures of the TM and adjacent tissues in control （normal） and high IOP conditions. Enucleated rabbit eyes were perfused at a pressure of 60 mmHg to achieve the high lOP. Through the anterior chamber of the eye, in situ images were obtained from different depths beneath the surface of the TM. Porosity and specific surface area of the TM in control and high IOP conditions were then calculated to estimate the effect of the high pressure on the permeability of tissue in different depths. We further photographed the histological sections of the TM and compared the in situ images. The following results were obtained in the control condition, where the region of depth was less than 55 μm with crossed branching beams and large pores in the superficial TM. The deeper meshwork is a silk-like tissue with abundant fluorescence separating the small size of pores. The total thickness of pathway tissues composed of TM and juxtacanalicular （JCT） is more than 100 p.m. After putting a high pressure on the inner wall of the eye, the TM region progressively collapses and decreases to be less than 40 μm. Fibers of the TM became dense, and the porosity at 34 μm in the high IOP condition is comparable to that at 105 μm in the control condition. As a consequent result, the permeability of the superficial TM decreases rapidly from 120 μm2 to 49.6 μm2 and that of deeper TM decreases from 1.66 μm2 to 0.57 μm2. Heterogeneity reflected by descent in permeability reduces from 12.4 μm of the control condition to 3.74 μm of the high IOP condition. The persistently high IOP makes the TM region collapse from its normal state, in which the collagen fibers of the TM are arranged in regular to maintain the physiological permeability of the outflow pathway. In the scope of pathologically high IOP, the microstructure of the TM is sensitive to pressure and hydraulic permeability can be significantly affected by IOP.

Meta Analysis of Non-penetrating Trabecular Surgery versus Trabeculectomy for the Treatment of Open Angle Glaucoma

This study compared the efficacy of non-penetrating trabecular surgery and trabeculectomy for the treatment of open angle glaucoma. We searched the Cochrane Library, PUBMED （1966 to 2009）, Embase （1980 to 2009） and CMB-disk （1979 to 2009） for the randomized clinical trials （RCT） concerning the two treatment strategies. The reports, including the papers listed in bibliographies, were evaluated against a set of quality criteria and the RCTs that satisfied the criteria were selected and subjected to Meta analysis by employing the Cochrane Collaboration＇s RevMan 4.5 software package. A total of nine RCTs were included in the study. The analyses of the reports showed that, 12 months after surgery, there was significant difference in the reduction of interocular pressure （IOP） between non-penetrating trabecular surgery and trabeculectomy （Z=6.05 P0.00001）. There also existed statistically significant difference in the reduction of IOP at the censored time between the two procedures （Z=4.92, P0.00001）. Difference in the success rate was also found between the two surgeries （Z=3.82, P=0.0001）. It is concluded that, compared with the non-penetrating trabeculectomy, the traditional trabeculectomy could reduce IOP more and had higher success rate while the non-penetrating trabecular surgery is associated with lower postoperative complications.

Apoptosis in the iris and trabecular meshwork of medically treated and untreated primary open angle glaucoma patients

AIM:To compare the trabecular meshwork(TM)and iris apoptosis of treated and untreated primary open angle glaucoma(POAG)patients.METHODS:Eight treatment-naive,newly diagnosed(group 1)and 11 medlcaiy treated(group 2)patients with POAG were included in the study.Each patient underwent a limbus-based trabeculectomy.The TM and peripheral iris specimens were dissected out and were snap-frozen in liquid nitrogen and stored at-80t until they were assayed.Apoptosis in each group was assesed by TUNEL method.RESULTS:The mean patient age was 60.6±5.8 years(53-68 years)vs 58.9±8.9 years(47-70 years)in group 1and group 2(P=0.859).The mean treatment time in group 2 was 22.2±7.3 months(12-34 months).Apoptotic indexes in TM and iris were significantly higher in POAG patients using medication(group 2)compared to treatment-naive POAG patients(group 1)(P=0.004,0.015;respectively).CONCLUSION:Long term administration of topical antiglaucoma medications causes additional toxic effects on TM.

Fractal lacunarity of trabecular bone and magnetic resonance imaging:New perspectives for osteoporotic fracture risk assessment

Osteoporosis represents one major health condition for our growing elderly population. It accounts for severe morbidity and increased mortality in postmenopausal women and it is becoming an emerging health concern even in aging men. Screening of the population at risk for bone degeneration and treatment assessment of osteoporotic patients to prevent bone fragility fractures represent useful tools to improve quality of life in the elderly and to lighten the related socio-economic impact. Bone mineral density(BMD) estimate by means of dual-energy X-ray absorptiometry is normally used in clinical practice for osteoporosis diagnosis. Nevertheless, BMD alone does not represent a good predictor of fracture risk. From a clinical point of view, bone microarchitecture seems to be an intriguing aspect to characterize bone alteration patterns in aging and pathology. The widening into clinical practice of medical imaging techniques and the impressive advances in information technologies together with enhanced capacity of power calculation have promoted proliferation of new methods to assess changes of trabecular bone architecture(TBA) during aging and osteoporosis. Magnetic resonance imaging(MRI) has recently arisen as a useful tool to measure bone structure in vivo. In particular, high-resolution MRI techniques have introduced new perspectives for TBA characterization by non-invasive non-ionizing methods. However, texture analysis methods have not found favor with clinicians as they produce quite a few parameters whose interpretation is difficult. The introduction in biomedical field of paradigms, such as theory of complexity, chaos, and fractals, suggests new approaches and provides innovative tools to develop computerized methods that, by producing a limited number of parameters sensitive to pathology onset and progression, would speed up their application into clinical practice. Complexity of living beings and fractality of several physio-anatomic structures suggest fractal analysis as a promising approach to quantify morphofunctional changes in both aging and pathology. In this particular context, fractal lacunarity seems to be the proper tool to characterize TBA texture as it is able to describe both discontinuity of bone network and sizes of bone marrow spaces, whose changes are an index of bone fracture risk. In this paper, an original method of MRI texture analysis, based on TBA fractal lacunarity is described and discussed in the light of new perspectives for early diagnosis of osteoporotic fractures.

Implantation of trabecular micro-bypass stent using a novel “landing strip” technique

AIM：To describe a novel technique of creating a landing strip within the trabecular meshwork to guide trabecular micro-bypass stent（iStent） implantation in patients who underwent phacoemulsification.METHODS：Thirty-four eyes from 30 patients who underwent i Stent implantation after phacoemulsification from May 2014 to February 2015 were included in our retrospective study. All iStents were implanted via the ＂landing strip＂ technique. A 25-gauge microvitreoretinal blade was used to bisect the trabecular meshwork to less than 1 clock-hour, effectively creating a landing strip. The iStent applicator was pressed along the landing strip and then the stent was released into the trabecular meshwork. RESULTS：Of the 34 eyes with iStent implantation, 27（79.4%） eyes had primary open-angle glaucoma, 6（17.6%） eyes had pseudoexfoliation glaucoma, and 1（2.9%） eye had ocular hypertension. At 6-month follow-up（n=17）, the mean number of hypotensive medications decreased from 2.2±1.2 at baseline to 0.8±1.3（P=0.05） and mean intraocular pressure decreased from 19.7±4.1 mm Hg at baseline to 16.7±2.1 mm Hg（P=0.58）. Two eyes（5.9%） required subsequent trabeculectomy. CONCLUSION：The ＂landing strip＂ technique appears to be an effective way to assist with iS tent implantation.

Effect of CD44 Suppression by Antisense Oligonucleotide on Attachment of Human Trabecular Meshwork Cells to HA

The effects of suppression of CD44 by CD44-specific antisense oligonucleotide on attachment of human trabecular meshwork cells to hyaluronic acid (HA) were observed and the possible relationship between CD44 and primary open-angle glaucoma (POAG) investigated. CD44-specific antisense oligonucleotide was delivered with cationic lipid to cultured human trabecular meshwork cells. The expression of CD44 suppressed by CD44-specific antisense oligonucleotide was detected by RT-PCR and Western blotting. The effect of CD44 suppression by specific antisense oligonucleotide on attachment of trabecular meshwork cells to HA was measured by MTT assay. Results showed that expression of CD44 was suppressed by CD44-specific antisense oligonucleotide. Antisense oligonucleotide also suppressed the adhesion of human trabecular meshwork cells to HA in a concentration dependent manner. It was concluded that attachment of human trabecular meshwork cells to HA was decreased when CD44 was suppressed by specific antisense oligonucleotide. CD44 might play a role in pathogenesis of POAG by affecting the adhesion of trabecular meshwork cells to HA.