Analysis and improvement of dynamic range in a time-division-multiplexing interferometric fiber-optic sensor array.

Dynamic range, the ratio of maximum detectable amplitude, and the noise level, are of great importance in characterizing the performance of an interferometric fiber-optic sensor (IFOS). Here we analyze the dependence of dynamic range on carrier frequency and repetition frequency in a time-division-multiplexing (TDM) IFOS array using a heterodyne detection scheme. A novel, to the best of our knowledge, demodulation method with higher carrier frequency and an upgraded algorithm is proposed to improve the dynamic range. In the simulation and experiment, the carrier frequency was increased from 50 kHz to 20 MHz, and the demodulation method was adjusted correspondingly. The maximum detectable phase amplitude is elevated by more than 6 dB as the theoretical expectation, and the demodulated noise floor is proven to be barely influenced, holding at ∼-100 dB ref rad/H z. Experimental results demonstrate that the average dynamic range over 10 Hz to 20 kHz is enhanced by approximately 10.5 dB. The analysis and optimization presented here provide an effective solution to improve the dynamic range of TDM IFOS without any hardware change, which is promising in various applications.

Common-mode noise self-suppressed 3-component fiber optic accelerometer based on low-reflectivity Bragg gratings.

Common-mode noises (CMNs) are frequent in the fiber optic accelerometer, and their suppression is extremely important, particularly in the ultra-weak signal detection application, e.g., micro-seismic monitoring. This Letter proposes a 3-component (3C) low-reflectivity fiber Bragg gratings accelerometer for CMN self-suppression. When compared with the traditional CMN suppression method, the proposed 3C accelerometer is able to improve the CMN suppression effect by an average value larger than 4.5 dB in three axes, as well as double the effective signal amplitude due to the push-pull structure, which brings an enhanced signal-to-noise ratio. Besides, the proposed 3C accelerometer does not need an additional reference interferometer to achieve such a CMN suppression effect; hence, it largely reduces the volume and cost of the sensing system, which shows huge advantages, particularly in the large-scale quasi-distributed array. The proposed 3C accelerometer provides a promising candidate for the weak vector vibration detection.

On the phase fading effect in the dual-pulse heterodyne demodulated distributed acoustic sensing system.

Understanding signal fading effect is essential for the application of Rayleigh-scattering-based distributed acoustic fibre sensors (DASs) due to the nature of coherent beam interference within the pulse length. Statistical properties for the intensity of the Rayleigh backscattered light (i.e. intensity fading) and its impact on the sensitivity of DAS systems have been intensely studied over the last decades. Here we for the first time establish an analytical model for the phase signal retrieved from the dual-pulse heterodyne demodulated DAS system, which can be exploited to investigate the phase fading effect in this system. The developed model reveals that the phase fading phenomenon mainly originates from the randomness in the phase retardant of the Rayleigh scatters. The quantitatively resolved statistical features of the phase fading is confirmed by experimental results. Based on the analytical model, a noise figure is defined to characterize the global fading-induced noise level via taking into account contributions from all channels along the sensing fiber. The model also reproduces the anti-correlation relation between the power spectrum density of retrieved phase at the heterodyne frequency and the phase fading noise level. Following the analysis and the definition of the noise figure, an optimized real-time weighted-channel stack algorithm is developed to efficiently suppress the fading noise. Experimental results show that the algorithm can achieve a maximum noise figure reduction of 15.8 dB without increasing the system complexity.

Performance Improvement of Dual-Pulse Heterodyne Distributed Acoustic Sensor for Sound Detection.

Phase fading is fatal to the performance of distributed acoustic sensors (DASs) influencing its capability of distributed measurement as well as its noise level. Here, we report the experimental observation of a strong negative correlation between the relative power spectrum density (PSD) at the heterodyne frequency and the noise floor of the detected phase for the heterodyne demodulated distributed acoustic sensor (HD-DAS) system. We further propose a weighted-channel stack algorithm (WCSA) to alleviate the phase fading noise via an enhancement of the relative PSD at the heterodyne frequency. Experimental results show that the phase noise of the demodulated signal can be suppressed by 13.7 dB under optimal condition. As a potential application, we exploited the improved HD-DAS system to retrieve a piece of music lasted for 205 s, demonstrating the reliability of detecting wideband sound signal without distortion.

Risk factors for flat anterior chamber after glaucoma filtration surgery.

AIM: To investigate the incidence rate and risk factors for grade III flat anterior chamber (FAC) after glaucoma filtration surgery based on 5-year data. METHODS: Patients who underwent glaucoma filtration surgery in Daping hospital from January 2009 to December 2013 were enrolled in this retrospective study. The incidence of grade III FAC following glaucoma filtration surgery was determined. Regression analysis was performed to investigate the influence of glaucoma type, surgical approach, age, and preoperative intraocular pressure (IOP) on the risk of postoperative FAC. RESULTS: A total of 2179 eyes receiving anti-glaucoma surgery were included. Ninety-one eyes suffered from postoperative FAC, with an overall incidence rate of 4.18%. Of 471 eyes with primary open angle glaucoma (POAG), grade III FAC occurred in only 3 eyes (0.64%). Primary angle-closure glaucoma (PACG) was diagnosed in 1076 eyes, 39 (3.62%) of which developed grade III FAC, including 12 eyes (12/300, 4%) with acute PACG (aPACG) and 27 eyes (27/776, 3.48%) with chronic PACG (cPACG). Six of 259 eyes (2.32%) with secondary glaucoma, 28 of 186 eyes (15.05%) with neovasular glaucoma, 1 of 66 eyes (1.52%) with congenital glaucoma, and 14 of 115 eyes (12.17%) with remnant glaucoma suffered from grade III FAC. Of 6 eyes with mixed glaucoma, none developed grade III FAC after surgery. When stratified by surgical approach, 24 of 766 eyes (3.13%) undergoing trabeculectomy, 21 of 924 eyes (2.27%) treated by trabeculectomy plus mitomycin C (MMC), 18 of 109 eyes (16.51%) undergoing Ahmed glaucoma valve implantation, 23 of 201 eyes (11.44%) managed by Ahmed implantation plus MMC, and 5 of 133 eyes (3.76%) treated by Ahmed implantation plus lens extraction or vitrectomy developed grade III FAC. Logistic regression analysis revealed that factors including neovasular glaucoma, remnant glaucoma, glaucoma valve implantation, glaucoma valve implantation+MMC, glaucoma valve implantation+vitrectomy, age>60y, and IOP at admission >50 mm Hg were significantly associated with an increased risk for grade III FAC. CONCLUSION: The overall incidence of grade III FAC after glaucoma filtration surgery is 4.18%. Patients with neovasular glaucoma and remnant glaucoma are at a higher risk of developing FAC. Ahmed glaucoma valve implantation is associated with a higher risk for grade III FAC compared with trabeculectomy. No significant correlation was observed between the use of MMC in glaucoma filtration surgery and the risk of postoperative FAC. Higher IOP at admission (>50 mm Hg) and old age (>60y) are risk factors for grade III FAC.

Distributed gas sensing with optical fibre photothermal interferometry.

We report the first distributed optical fibre trace-gas detection system based on photothermal interferometry (PTI) in a hollow-core photonic bandgap fibre (HC-PBF). Absorption of a modulated pump propagating in the gas-filled HC-PBF generates distributed phase modulation along the fibre, which is detected by a dual-pulse heterodyne phase-sensitive optical time-domain reflectometry (OTDR) system. Quasi-distributed sensing experiment with two 28-meter-long HC-PBF sensing sections connected by single-mode transmission fibres demonstrated a limit of detection (LOD) of ∼10 ppb acetylene with a pump power level of 55 mW and an effective noise bandwidth (ENBW) of 0.01 Hz, corresponding to a normalized detection limit of 5.5ppb⋅W/Hz. Distributed sensing experiment over a 200-meter-long sensing cable made of serially connected HC-PBFs demonstrated a LOD of ∼ 5 ppm with 62.5 mW peak pump power and 11.8 Hz ENBW, or a normalized detection limit of 312ppb⋅W/Hz. The spatial resolution of the current distributed detection system is limited to ∼ 30 m, but it is possible to reduce down to 1 meter or smaller by optimizing the phase detection system.

Thalidomide and its analogues: A review of the potential for immunomodulation of fibrosis diseases and opthalmopathy.

The US Food and Drug Administration approved thalidomide and its analogues for the treatment of erythema nodosum leprosum, in spite of the notoriety of reports of severe birth defects in the middle of the last century. As immunomodulatory drugs, thalidomide and its analogues have been used to effectively treat various diseases. In the present review, preclinical data about the effects of thalidomide and its analogues on the immune system are integrated, including the effects of cytokines on transdifferentiation, the anti-inflammatory effect, immune cell function regulation and angiogenesis. The present review also investigates the latest developments of thalidomide as a therapeutic option for the treatment of idiopathic pulmonary fibrosis, skin fibrosis, and ophthalmopathies.

Multi-event waveform-retrieved distributed optical fiber acoustic sensor using dual-pulse heterodyne phase-sensitive OTDR.

We demonstrate a novel type of distributed optical fiber acoustic sensor, with the ability to detect and retrieve actual temporal waveforms of multiple vibration events that occur simultaneously at different positions along the fiber. The system is realized via a dual-pulse phase-sensitive optical time-domain reflectometry, and the actual waveform is retrieved by heterodyne phase demodulation. Experimental results show that the system has a background noise level as low as 8.91×10-4 rad/√Hz with a demodulation signal-to-noise ratio of 49.17 dB at 1 kHz, and can achieve a dynamic range of ∼60 dB at 1 kHz (0.1 to 104 rad) for phase demodulation, as well as a detection frequency range from 20 Hz to 25 kHz.

[Randomized parallel group study of 0.0015% tafluprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension (comparison with 0.005% latanoprost ophthalmic solution)].

OBJECTIVE: To confirm the non-inferiority of the IOP-lowering effect of the 0.0015% Tafluprost ophthalmic solution to the 0.005% Latanoprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension.Safety was also compared between two groups. METHODS: This study was conducted from August 2008 to December 2009, at five clinical trial sites in China. Patients of this study population was diagnosed with primary open-angle glaucoma or ocular hypertension in both eyes.Subjects were randomized into 0.0015% Tafluprost group or 0.005% Latanoprost group.Intraocular pressure (IOP) measurement by Goldmann applanation tonometer, slit-lamp microscopy, Gonioscopy, Fundascopy, Visual acuity test, Perimetry, Blood pressure and pulse rate, Subjective symptoms were compered between two groups at Week 0, Week 2 and Week 4.For main effectiveness evaluation index adopt the bad effect evaluation, safety evaluation index by Fisher's exact test probability method. RESULTS: The 246 subjects/246 eyes were randomized (Tafluprost group:122 subjects/122 eyes, Latanoprost group:124 subjects/ 124 eyes). Change in the IOP at 17:00 of Week 2 is (8.8 ± 3.8) mmHg and (8.9 ± 4.4) mmHg (1 mmHg = 0.133 kPa) in Tafluprost group and Latanoprost group. Percent change in the IOP at 17:00 of Week 2 is (33.2 ± 12.8)% and (34.4 ± 14.1)% in Tafluprost group and Latanoprost group. Change in the IOP at 17:00 at the end of treatment is (9.8 ± 4.0) mmHg and (9.2 ± 4.1) mmHg in Tafluprost group and Latanoprost group. Percent change in the IOP at 17:00 at the end of treatment is 37.2% ± 13.4% group and 35.7% ± 13.0% in Tafluprost and Latanoprost group.In addition, distribution of subjects with percentage decrease of IOP > 30% was 72.5% in Tafluprost group higher than 63.8% in Latanoprost group. The major adverse reactions were conjunctival hyperemia, eye irritation, eye pain and foreign body sensation. The incidence of adverse reactions is 31.7% in Tafluprost group and 20.8% in Latanoprost group. The inter-group difference had no statistical significance. CONCLUSION: Efficacy and safety of Tafluprost ophthalmic solution are no less than Latanoprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension.

Clinical relevance of the glucocorticoid receptor gene polymorphisms in glucocorticoid-induced ocular hypertension and primary open angle glaucoma.

AIM: To avoid the side effects of ocular hypertension of glucocorticoid (GC) usage in eye, we must identify susceptible individuals, which exists in about one-third of all population. Further, the majority of all primary open angle glaucoma (POAG) patients show this phenotype. Glucocorticoid receptor (GR) regulates C responsiveness in trabecular meshwork (TM) cells. In this study, single nucleotide polymorphism (SNP) genotyping was used to determine whether there are differences in the BclI (rs41423247) and N363S (rs6195) polymorphisms of the GR gene in healthy and POAG patients, and glucocorticoid-induced ocular hypertension (GIOH) populations. METHODS: Three hundred and twenty-seven unrelated Chinese adults, including 111 normal controls, 117 GIOH subjects and 99 POAG patients, were recruited. DNA samples were prepared and the BclI and N363S polymorphisms were screened using real-time polymerase chain reaction (RT-PCR)-restriction fragment length polymorphism (RFLP) analysis. Frequencies of the BclI and N363S polymorphisms were determined and compared using Fisher's exact test and the Chi-squared test. RESULTS: Only the BclI polymorphism was identified in the Chinese Han population. The frequency of the G allele was 21.6 % in normal controls, 18.3% in GIOH patients, and 13.64% in the POAG patients. There was no significant difference in polymorphism or allele frequency in the 3 groups. Furthermore, no N363S polymorphism was found in the study subjects. CONCLUSION: The BclI polymorphisms in GR gene had no association with GIOH and POAG patients, and N363S polymorphism might not exist in the Chinese Han population. Therefore, the BclI polymorphism might not be responsible for the development of GC-induced ocular hypertension or POAG.

Family-based analysis identified CD2 as a susceptibility gene for primary open angle glaucoma in Chinese Han population.

Primary open angle glaucoma (POAG) is characterized by optic disc cupping and irreversible loss of retinal ganglion cells. Few genes have been detected that influence POAG susceptibility and little is known about its genetic architecture. In this study, we employed exome sequencing on three members from a high frequency POAG family to identify the risk factors of POAG in Chinese population. Text-mining method was applied to identify genes associated with glaucoma in literature, and protein-protein interaction networks were constructed. Furthermore, reverse transcription PCR and Western blot were performed to confirm the differential gene expression. Six genes, baculoviral inhibitors of apoptosis protein repeat containing 6 (BIRC6), CD2, luteinizing hormone/choriogonadotropin receptor (LHCGR), polycystic kidney and hepatic disease gene 1 (PKHD1), phenylalanine hydroxylase (PAH) and fucosyltransferase 7 (FUT7), which might be associated with POAG, were identified. Both the mRNA expression levels and protein expression levels of HSP27 were increased in astrocytes from POAG patients compared with those from normal control, suggesting that mutation in CD2 might pose a risk for POAG in Chinese population. In conclusion, novel rare variants detected by exome sequencing may hold the key to unravelling the remaining contribution of genetics to complex diseases such as POAG.

Prevalence of open-angle glaucoma in southwestern China: the Yongchuan Glaucoma study.

This study examined the prevalence of primary open-angle glaucoma (POAG) among residents aged ≥50 years living in Yongchuan district of Chongqing. Stratified cluster sampling was employed in random selection to estimate the prevalence of glaucoma from April to June, 2005. Twenty-nine villages or neighborhood communities were randomly selected in urban area (Zhongshan Road), suburban area (Shanjiao Town) and exurban area (Zhutuo Town) of this district. All the respondents underwent detailed ophthalmic examinations. The examinations included questionnaire investigation, visual acuity test, naked-eye examination, measurement of peripheral anterior chamber depth (Van Herrick's technique), detection of intraocluar pressure (IOP) with a Perkins hand-held applanation tonometer (HA-2) and examination of the optic disc by using a 78 diopters (D) lens (including the cup-disc ratio, cup/disc ratio asymmetries, horizontal and vertical diameter, notching and optic disc hemorrhages). A total of 5938 residents were actually examined, and the response rate was 85.19%. The crude prevalence of POAG was 0.86% (n=51/5938, 95% CI 0.64%-1.11%). There were 24 males and 27 females in the glaucoma group. The glaucoma prevalence was not significant different in case number between the male and female subjects (P=0.4900). Furthermore, no association between age or schooling and POAG was noted (P=0.8030, 0.0734). Out of 51 subjects with POAG, unilateral glaucoma-related blindness occurred in 38 subjects (74.5%) and bilateral glaucoma-related blindness was found in 7 subjects (13.7%). This study exhibited that the prevalence of POAG was 0.86% among residents aged ≥50 years living in Yongchuan District of Chongqing. The vision loss caused by POAG in this population was obviously higher than that previously reported in other studies. Glaucoma management, detection of affected persons and handling of the burden of glaucoma should be the priorities of the agenda of local health authorities of Western China.

Progress in the pathogenesis of pterygium.

Pterygium is a type of benign uncontrolled growth of the conjunctive tissue that lays over the sclera. It can significantly alter visual function in advanced cases and become inflamed, leading to redness and irritation in the area. Although the exact etiology of pterygium remains uncertain, recent advances have provided important insight into the pathogenesis of pterygium. These studies indicate that tumor suppressor gene p53 and other genes associated with DNA repair, cell proliferation, migration and angiogenesis are critical for the development of pterygium. In addition, Human papillomavirus infection has been shown to be a risk factor in some populations. In this article, the current understanding of the pathogenesis of pterygium is reviewed.

Screening of candidate genes for primary open angle glaucoma.

PURPOSE: Primary open-angle glaucoma (POAG) is one of the leading causes of irreversible blindness in the world. To make progress in understanding POAG, it is necessary to identify more POAG-causing genes. METHODS: Using haplotype analysis, we found that mutational region is located on chromosome 2 in two families. Furthermore, we screened 11 candidate genes on chromosome 2 by protein-protein interaction (PPI) analysis, including mutS homolog 6 (MSH6), mutS homolog 2 (MSH2), v-rel reticuloendotheliosis viral oncogene homolog (REL), endothelial PAS domain protein 1 (EPAS1), vaccinia related kinase 2 (VRK2), F-box protein 11 (FBXO11), EGF containing fibulin-like extracellular matrix protein 1 (EFEMP1), reticulon 4 (RTN4), RAB1A, member RAS oncogene family (RAB1A), ARP2 actin-related protein 2 homolog (ACTR2), and calmodulin 2 (phosphorylase kinase, delta; CALM2). These 11 genes are all predicted to be related to trabecular meshwork changes and progressive loss of retinal ganglion cells in POAG patients. RESULTS: According to our study, FBXO11 and VRK2 may interact with tumor protein p53 to regulate mitochondrial membrane permeability, mitochondrial membrane organization, and apoptosis. MSH2 is responsible for repairing DNA mismatches and RTN4 is for neuronal regeneration. Therefore, they are supposed to play a negative role in cellular process in POAG. CALM2 may be involved in retinal ganglion cell death and oxidative damage to cell communication. CONCLUSIONS: The results demonstrate that the genes above may be associated with pathogenesis of POAG.

A multicenter, randomized, parallel-group, clinical trial comparing the safety and efficacy of loteprednol etabonate 0.5%/tobramycin 0.3% with dexamethasone 0.1%/tobramycin 0.3% in the treatment of Chinese patients with blepharokeratoconjunctivitis.

OBJECTIVE: To compare the efficacy and safety of loteprednol etabonate 0.5%/tobramycin 0.3% (LE/T) and dexamethasone 0.1%/tobramycin 0.3% (DM/T) ophthalmic suspensions in a Chinese population with ocular inflammation associated with blepharokeratoconjunctivitis (BKC). RESEARCH DESIGN AND METHODS: This study was a multicenter, randomized, investigator-masked, parallel-group clinical trial. Patients aged ≥18 years with a clinical diagnosis of BKC in at least one eye received LE/T or DM/T administered 4 times daily for 2 weeks. At baseline and on days 3, 8, and 15 (visits 2, 3, and 4), clinical assessments of ocular signs and symptoms, visual acuity (VA), biomicroscopy, and intraocular pressure (IOP) were performed in both eyes. MAIN OUTCOME MEASURES: The primary efficacy endpoint was the change from baseline (CFB) to visit 4 in the signs and symptoms composite score in designated study eyes using a non-inferiority metric to compare LE/T to DM/T. Safety evaluation included adverse events, biomicroscopy findings, and changes in VA and IOP. CLINICAL TRIAL REGISTRATION: NCT number, NCT01028027. RESULTS: A total of 308 patients were included in the per protocol population (n = 156 LE/T, n = 152 DM/T). A significant CFB in composite signs and symptoms was seen with both treatments at each follow-up visit (p < 0.0001). The mean (SD) CFB at visit 4 was -11.63 (4.56) and -12.41 (4.71) in the LE/T and DM/T groups, respectively, and the upper bound of the 90% confidence interval for the difference was less than the prespecified non-inferiority margin. Comparable results were found for secondary efficacy outcomes. Patients treated with DM/T experienced a significantly greater increase in mean CFB in IOP compared to those treated with LE/T at all follow-up visits (p ≤ 0.0186) and nearly twice as many IOP elevations ≥5 mmHg (p = 0.0020). CONCLUSION: Treatment with LE/T was at least as effective as DM/T in Chinese patients with BKC and had a better safety profile with respect to change in IOP.

[Challenge and treatment strategy for ocular surface damage in patients with long term use of antiglaucoma drugs].

Long term use of topical anti-glaucoma drugs has been shown to induce chronic conjunctivitis, superficial punctate keratitis (SPK) and dry eye symptom. Under these conditions, a loss of goblet cells in conjunctiva, epithelial squamous metaplasia and apoptosis were morphologically revealed. Benzalkonium Chloride (BKC), a most frequently used preservative in eye drops, has been found to be an important factor causing ocular surface damage. Furthermore, a big challenge for ophthalmologists is that toxic damage of medication to ocular surface tissues is mild, poor specificity, and delayed manifestation in patients, especially when coexisting with other ocular surface diseases. Impairment of ocular surface tissues greatly impacts the life quality of patients and subsequently influences compliance with glaucoma therapy. This paper emphasizes to take measures to prevent ocular surface tissue damage resulted from chronic use of topical anti-glaucoma drugs and further discusses the treatment strategy. Effective and long-lasting action drugs should always be selected for glaucomatous patients in order to decrease the frequency of topical instillation or at a more expensive medication, a fixed combination formula can be considered for glaucoma therapy. An early surgery or laser treatment is also proposed for the patients who require an IOP reduction with an existing ocular surface impairment. Future investigation and development of new medications with long-term efficacy and appropriate BKC are suggested and preservative-free or drugs with new preservative materials recommended.

Gene expression profile determination in rat retinal tissue after ocular hypertension through oligo microarray.

Increased intraocular pressure is the main cause of glaucoma development. However, the systemic information of genes related to ocular hypertension has not yet been clarified. In the present study, oligomicroarray determined the profile of gene expression in the retina after ocular hypertension. A rat ocular hypertension model was constructed through photocoagulation by diode lasers. On postoperative days 7, 35, 60, 90, 180 and 360, the intraocular pressure and the gene expression profile were determined using an ophthalmotonometer and an Oligochip containing 35,000 oligonucleotides, respectively. Oligochip reliability was verified by real-time PCR, and the Oligochip data were analyzed through functional distribution analysis. In our study, we found that the intraocular pressure was significantly increased in a time-dependent manner but returned to the normal level on postoperative day 360. We also found that 1,692 genes were differentially expressed, including 719 upregulated and 973 downregulated genes. The χ² value of gene clusters related to transport function is significantly higher than that of other gene clusters as determined through function distribution analysis, suggesting that this group of genes plays an important role in the repair process of the optical nerve. In conclusion, the gene expression pattern at different time points of ocular hypertension was determined, which may contribute to clarify the molecular mechanism of glaucoma and to establish better therapeutic strategies to treat glaucoma.

[Effect of Nogo-66 on retinal microglia in chronic ocular hypertension rats].

OBJECTIVE: To study the effect of protein Nogo-66 on the expression of CD11b and MHC-II in retinal microglia of chronic ocular hypertension SD rats and the effects of protein Nogo-66 on the immunogenicity of injured retinal tissues. METHODS: It was a control experimental study. Chronic ocular hypertension rat model was established by laser photocoagulation on the anterior chamber angle and superficial vein of the sclera. One ml of Nogo-66 (0.01%) in PBS was injected subcutaneously on the day of laser treatment and 0.005% Nogo-66 PBS solution was injected into the vitreous 7 days and 1 month latter. PBS without Nogo-66 was injected in the control group. The expression of cell surface antigen CD11b and MHC-II were detected by immunohistochemistry 1 month and 1 day after the establishment of hypertension model. The difference of average IOP among groups was analyzed by variance analysis. The difference of expression of CD11b and MHC-II between the experimental and control groups was analyzed by t-test. RESULTS: The intraocular pressure (IOP) of experimental groups rised from the seventh day after model-building and the highest IOP was (24.16 ± 2.70) mm Hg (1 mm Hg = 0.133 kPa) 1 month later while that in the control groups was (15.93 ± 3.28) mm Hg. The difference between them was statistically significant (F = 2.10, P < 0.05). Expression of CD11b was (1.78 ± 0.63)% and MHC-II was (3.92 ± 1.03)% in Nogo-66 with hypertension groups, these results was significantly lower than those in Nogo-66 with normal intraocular pressure groups in which the expression of CD11b was (8.15 ± 1.97)% (t = 2.35, P < 0.05) and MHC-II was (11.45 ± 1.97)% (t = 2.14, P < 0.05). CONCLUSIONS: Protein Nogo-66 activated the cell surface antigen CD11b in nerve fiber layer of retina and induced antigen presenting molecules (MHC-II). This indicates that Nogo has the center immunogenicity and this protein could activate antigen-presenting cells to present injury antigen.

[Efficacy and safety in treatment of ocular neovascularization by Bevacizumab versus Ranibizumab: a meta-analysis].

OBJECTIVE: To evaluate the efficacy and safety in treatment of ocular neovascularization by Bevacizumab versus Ranibizumab. METHODS: It was a systematic review and meta-analysis. According to evaluation guidelines of Cochrane collaboration, clinical controlled trials (CCTs) comparing Bevacizumab and Ranibizumab in treatment of ocular neovascularization were searched using Medline, EMbase, the Cochrane Library and CBM. Methodology qualities of literatures were performed by experienced researchers according to the Jadad Score. RevMan 4.2 offered by Cochrane was used to do the meta-analysis. The differences of efficacy and safety in treatment of ocular neovascularization by Bevacizumab versus Ranibizumab were analyzed through statistical test for incorporative effect (the test results were shown by Z value). RESULTS: Only 7 literatures came into meta-analysis (1620 eyes). The result of analysis showed that Bevacizumab could improve the BCVA and cut down the CFT in treatment of ocular neovascularization, and that Bevacizumab did not display any statistically difference in improving best-corrected visual acuity (converted to logMAR, Bevacizumab group, from -0.9031 + or - 0.0323 to -0.7635 + or - 0.0214, improving by 0.1396 + or - 0.0225; Ranibizumab group, from -0.9345 + or - 0.0194 to -0.8050 + or - 0.0221, improving by 0.1295 + or - 0.0203, Z = 0.56, P = 0.57), and cutting down the central foveal thickness [Bevacizumab group, from (325.4 + or - 52.3) microm to (269.1 + or - 21.3) microm, cutting down by (56.3 + or - 18.5) microm; Ranibizumab group, from (342.0 + or - 45.1) microm to (277.2 + or - 35.5) microm, cutting down by (67.8 + or - 23.2) microm, Z = 1.13, P = 0.26] and safety [inflammation at injection site, Bevacizumab group, 4.1% (34/823 eyes); Ranibizumab group, 3.8% (30/797 eyes), Z = 0.74, P = 0.46; subconjunctival hemorrhage, Bevacizumab group, 3.3% (27/823 eyes); Ranibizumab group, 3.4% (27/797 eyes), Z = 0.98, P = 0.33; total complications, Bevacizumab group, 10.2% (84/823 eyes); Ranibizumab group, 9.5% (76/797 eyes), chi(2) = 0.21, P = 0.65] compared with Ranibizumab. CONCLUSIONS: Meta-analysis shows that Bevacizumab has equal efficacy and safety to Ranibizumab in treatment of ocular neovascularization. However, a high quality perspective study is still required for further analysis.

[Expression of CD11b in the retinal microglia in chronic hypertension rat].

OBJECTIVE: To study the expression of CD11b in the retinal microglia in laser induced ocular hypertension (OHT) SD rat. METHODS: It was an experimental study. OHT was induced by the coagulation of trabecular meshwork using 532-laser in sixty SD rats. Intraocular pressure (IOP) was measured by Tonopen-XL, the expression of CD11b in retinal microglia detected by immunohistochemistry, and retinal ganglion cells (RGCs) were labeled with Dextran Tetramethyl Rhodamine (DTR) and counted by Image-Pro Plus Version 6.0 image analysis software at 2 weeks, 1, 2, 3, 4, 5, and 6 months, respectively. All the numerical data were statistically analyzed by SPSS 13.0 software. RESULTS: Although the IOP of experimental groups are still the similar level at 2w after coagulation (t = 1.124, P = 0.287), Compared to control eyes, IOP in lasered eyes was significantly (t = 2.487, P = 0.036) increased at 1 month, lasting for 3 months and returned to normal from 5 to 6 months (t = 1.103, P = 0.290). The expression of CD11b in the retinal microglia in the lasered eyes was significantly more intensive than that in control eyes at 1 month (t = 3.333, P = 0.008) and faded after 5 months, a similar pattern to IOP response, that two group data shows significant dependability (r = 0.891, P = 0.014). The number of RGC was significantly reduced from 1 month to 6 months (t = 3.316, P = 0.009), the velocity of reducing seems dependability to the advancing of IOP (r = 0.757, P = 0.021). CONCLUSIONS: The expression of CD11b in retinal microglia is fluctuated with chronic OHT pattern and RGCs injury level indicating that the injury antigens by microglia are presented in the retina with the increase of IOP and activate the immunologic process leading to glaucomatous RGCs damage. It suggests that it is important to effectively control the IOP in order to reduce the risk of immune induced retinal damage by microglia.