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Sample records for experimental glaucoma filtration

  1. Cellular proliferation after experimental glaucoma filtration surgery

    SciTech Connect

    Jampel, H.D.; McGuigan, L.J.; Dunkelberger, G.R.; L'Hernault, N.L.; Quigley, H.A.

    1988-01-01

    We used light microscopic autoradiography to determine the time course of cellular incorporation of tritiated thymidine (a correlate of cell division) following glaucoma filtration surgery in seven eyes of four cynomolgus monkeys with experimental glaucoma. Incorporation of tritiated thymidine was detected as early as 24 hours postoperatively. Peak incorporation occurred five days postoperatively and had returned to baseline levels by day 11. Cells incorporating tritiated thymidine included keratocytes, episcleral cells, corneal and capillary endothelial cells, and conjunctival and corneal epithelial cells. Transmission electron microscopy was correlated with the autoradiographic results to demonstrate that fibroblasts were dividing on the corneoscleral margin. These findings have potential clinical implications for the use of antiproliferative agents after filtration surgery.

  2. Bevacizumab-Loaded Polyurethane Subconjunctival Implants: Effects on Experimental Glaucoma Filtration Surgery

    PubMed Central

    Ribeiro, Vanessa Raquel Coimbra; Chahud, Fernando; Cannellini, Roberta; Monteiro, Tassia Cristina; de Lima Gomes, Elionai Cassiana; Reinach, Peter Sol; Veronese Rodrigues, Maria de Lourdes; Silva-Cunha, Armando

    2013-01-01

    Abstract Purpose Vascular endothelial growth factor (VEGF) may contribute to the scarring process resulting from glaucoma filtration surgery, since this cytokine may stimulate fibroblast proliferation. The aim of this study was to describe a new bevacizumab-loaded polyurethane implant (BPUI) and to evaluate its effectiveness as a new drug delivery system of anti-VEGF antibody in a rabbit model of glaucoma filtration surgery. Methods An aqueous dispersion of polyurethane was obtained via the conventional process. Bevacizumab (1.5 mg) was then incorporated into the dispersion and was subsequently dried to form the polymeric films. Films with dimensions of 3×3×1 mm that either did (group BPUI, n=10) or did not contain bevacizumab (group PUI, n=10) were implanted in the subconjunctival space, at the surgical site in 1 eye of each rabbit. The in vitro bevacizumab release was evaluated using size-exclusion high-performance liquid chromatography (HPLC), and the in vivo effects of the drug were investigated in a rabbit experimental trabeculectomy model by examining the bleb characteristics and collagen accumulation, and by performing immunohistological analyses of VEGF expression. Results HPLC showed that only 10% of the bevacizumab in the implants had been released by postoperative day 5. In vivo studies demonstrated that the drug had no adverse effects; however, no significant differences in either the bleb area score or the collagen deposit intensity between the group PUI and the group that BPUI were observed. Moreover, the group BPUI presented a significantly lower proportion of VEGF-expressing fibroblasts than group PUI (0.17±0.03 vs. 0.35±0.05 cells/field, P=0.005). Conclusions This study demonstrated that bevacizumab release from the BPUIs only occurred for a short time probably from the surface of the films. Nevertheless, they were well tolerated in rabbit eyes and reduced the number of VEGF-expressing fibroblasts. PMID:23391327

  3. Topical infliximab for the suppression of wound healing following experimental glaucoma filtration surgery

    PubMed Central

    Turgut, Burak; Eren, Kenan; Akın, Mehmet Mustafa; Demir, Tamer; Kobat, Sabiha

    2014-01-01

    Background The purpose of this work was to look into the effects of infliximab on wound healing in experimental glaucoma filtration surgery and to compare the antifibrotic effects of this agent to that of mitomycin-C (MMC). Methods Twenty-eight male New Zealand White rabbits were randomly assigned to four groups, each including seven rabbits: control group, sham group, MMC group, and infliximab group. The rabbits in the control group were not operated on and did not receive any treatment. The rabbits in the sham group underwent trabeculectomy and had one drop of saline instilled four times a day for 14 days. The rabbits in the MMC treatment group underwent trabeculectomy, and a sponge soaked in 0.4 mg/mL MMC was applied intraoperatively to the scleral surgical site for three minutes. The rabbits in the infliximab treatment group underwent trabeculectomy and one drop of 10 mg/mL infliximab was instilled four times a day for 14 days after surgery. On day 14 of the experiment, the operated and control eyes were enucleated and histologically and immunohistochemically analyzed. Results The mean fibroblast and mononuclear cell (MNC) numbers and the mean immunostaining intensities of transforming growth factor-β (TGF-β), fibroblast growth factor-β (FGF-β), and platelet-derived growth factor (PDGF) in the sham group were higher than those of the control group (P<0.01). The mean fibroblast and MNC numbers and the mean immunostaining intensities of TGF-β, FGF-β, and PDGF in the MMC and infliximab groups were statistically significantly lower than those of the sham group (P<0.01). The mean fibroblast and MNC numbers and the mean TGF-β, FGF-β, and PDGF immunostaining intensities of the MMC and infliximab groups were similar (P>0.05). Conclusion Our study suggests that topical infliximab effectively suppresses the subconjunctival wound healing response after experimental glaucoma filtration surgery, reducing the MNC and fibroblast numbers and immunostaining intensities

  4. Safety of Using Matrix Metalloproteinase Inhibitor in Experimental Glaucoma Filtration Surgery

    PubMed Central

    2017-01-01

    We evaluated the safety of matrix metalloproteinase (MMP) inhibitor in experimental glaucoma filtration surgery in an animal model. Fifteen New Zealand white rabbits underwent an experimental trabeculectomy and were randomly allocated into 3 groups according to the adjuvant agent: no treatment group (n = 5), 0.02% mitomycin C (MMC) soaking group (n = 5), and MMP inhibitor (ilomastat) subconjunctival injection group (n = 5). Slit lamp examination with Seidel testing, pachymetry, and specular microscopy was performed preoperatively and postoperatively. The conjunctiva and ciliary body toxicity were evaluated with scores according to the pathologic grading systems. Electron microscopy was used to examine the structural changes in cornea, conjunctiva, and ciliary body. In the ilomastat-treated group, there was no statistically significant change in central corneal thickness preoperatively and at 28 days postoperatively (P = 0.655). There were also no significant changes in specular microscopy findings over the duration of the study in the ilomastat-treated group. The conjunctival toxicity score was 1 in the control group, 1.5 in the ilomastat-treated group, and 2 in the MMC-treated group. When assessing ciliary body toxicity scores, the ilomastat-treated group score was 0.5 and the MMC-treated group score was 1.5. Transmission electron microscopy did not show structural changes in the cornea and ciliary body whereas the structural changes were noticed in MMC group. A single subconjunctival injection of MMP inhibitor during the experimental trabeculectomy showed a less toxic affect in the rabbit cornea, conjunctiva, and ciliary body compared to MMC. PMID:28244295

  5. EX-PRESS Glaucoma Filtration Device: efficacy, safety, and predictability.

    PubMed

    Chan, Jessica E; Netland, Peter A

    2015-01-01

    Trabeculectomy has been the traditional primary surgical therapy for open-angle glaucoma. While trabeculectomy is effective in lowering intraocular pressure, complications associated with the procedure have motivated the development of alternative techniques and devices, including the EX-PRESS Glaucoma Filtration Device. This review describes the efficacy, safety, complication rates, and potential advantages and disadvantages of the EX-PRESS Glaucoma Filtration Device. EX-PRESS implantation is technically simpler compared with that of trabeculectomy, with fewer surgical steps. Vision recovery has been more rapid after EX-PRESS implantation compared with trabeculectomy. Intraocular pressure variation is lower during the early postoperative period, indicating a more predictable procedure. While efficacy of the EX-PRESS implant has been comparable to trabeculectomy, postoperative complications appear less common after EX-PRESS implantation compared with trabeculectomy. The EX-PRESS Glaucoma Filtration Device appears to be safe and effective in the surgical management of open-angle glaucoma.

  6. Evaluation of ExPress glaucoma filtration device in Indian patients with advanced glaucoma.

    PubMed

    Angmo, Dewang; Sharma, Reetika; Temkar, Shreyas; Dada, Tanuj

    2015-05-01

    ExPress glaucoma filtration device (GFD) has recently become available in India as a surgical option for glaucoma patients. We retrospectively evaluated the outcome of ExPress GFD in 12 eyes with advanced glaucoma with intraocular pressures (IOPs) not controlled on maximal tolerable medical therapy. The mean preoperative IOP of 29.58 ± 7.13 mmHg decreased to 17.0 ± 2.67 and 17.40 ± 0.89 mmHg at 6 and 12 months after surgery. Absolute success (IOP ≤ 18 mmHg, with no additional glaucoma medications) was achieved in eight cases (66.7%) and qualified success (IOP ≤ 18 mmHg, with additional glaucoma medications) in two cases (16.7%) at 1-year after surgery. Early intervention was needed in 4 patients; two underwent anterior chamber reformation while the other two required needling. Two patients required resurgery. There was no significant change in the best corrected visual acuity postoperatively (P = 0.37). ExPress GFD does not seem to offer a benefit over standard trabeculectomy in patients with advanced glaucomatous disease in terms of IOP control or complication rate. However, due to the small sample size with a heterogeneous mixture of primary and secondary glaucoma's, we await further studies with a larger sample size and long-term follow-up, to see how the device performs.

  7. Stab Incision Glaucoma Surgery: A Modified Guarded Filtration Procedure for Primary Open Angle Glaucoma

    PubMed Central

    Jacob, Soosan; Figus, Michele; Ashok Kumar, Dhivya; Areeckal Incy, Saijimol

    2016-01-01

    Purpose. To describe a modified guarded filtration surgery, stab incision glaucoma surgery (SIGS), for primary open angle glaucoma (POAG). Methods. This prospective, interventional case series included patients with POAG (IOP ≥21 mmHg with glaucomatous visual field defects). After sliding superior conjunctiva down over limbus, 2.8 mm bevel-up keratome was used to create conjunctival entry and superficial corneoscleral tunnel in a single step starting 1.5 mm behind limbus. Lamellar corneoscleral tunnel was carefully dissected 0.5–1 mm into cornea and anterior chamber (AC) was entered. Kelly Descemet's punch (1 mm) was slid along the tunnel into AC to punch internal lip of the tunnel, thereby compromising it. Patency of ostium was assessed by injecting fluid in AC and visualizing leakage from tunnel. Conjunctival incision alone was sutured. Results. Mean preoperative IOP was 27.41 ± 5.54 mmHg and mean postoperative IOP was 16.47 ± 4.81 mmHg (n = 17). Mean reduction in IOP was 38.81 ± 16.55%. There was significant reduction of IOP (p < 0.000). 64.7% had IOP at final follow-up of <18 mmHg without medication and 82.35% had IOP <18 mmHg with ≤2 medications. No sight threatening complications were encountered. Conclusion. Satisfactory IOP control was noted after SIGS in interim follow-up (14.18 ± 1.88 months). PMID:27144015

  8. Stab Incision Glaucoma Surgery: A Modified Guarded Filtration Procedure for Primary Open Angle Glaucoma.

    PubMed

    Jacob, Soosan; Figus, Michele; Ashok Kumar, Dhivya; Agarwal, Ashvin; Agarwal, Amar; Areeckal Incy, Saijimol

    2016-01-01

    Purpose. To describe a modified guarded filtration surgery, stab incision glaucoma surgery (SIGS), for primary open angle glaucoma (POAG). Methods. This prospective, interventional case series included patients with POAG (IOP ≥21 mmHg with glaucomatous visual field defects). After sliding superior conjunctiva down over limbus, 2.8 mm bevel-up keratome was used to create conjunctival entry and superficial corneoscleral tunnel in a single step starting 1.5 mm behind limbus. Lamellar corneoscleral tunnel was carefully dissected 0.5-1 mm into cornea and anterior chamber (AC) was entered. Kelly Descemet's punch (1 mm) was slid along the tunnel into AC to punch internal lip of the tunnel, thereby compromising it. Patency of ostium was assessed by injecting fluid in AC and visualizing leakage from tunnel. Conjunctival incision alone was sutured. Results. Mean preoperative IOP was 27.41 ± 5.54 mmHg and mean postoperative IOP was 16.47 ± 4.81 mmHg (n = 17). Mean reduction in IOP was 38.81 ± 16.55%. There was significant reduction of IOP (p < 0.000). 64.7% had IOP at final follow-up of <18 mmHg without medication and 82.35% had IOP <18 mmHg with ≤2 medications. No sight threatening complications were encountered. Conclusion. Satisfactory IOP control was noted after SIGS in interim follow-up (14.18 ± 1.88 months).

  9. Experimental Contact Lens to Prevent Glaucoma-Induced Blindness

    MedlinePlus

    ... Articles | Inside Life Science Home Page An Experimental Contact Lens to Prevent Glaucoma-Induced Blindness By Sharon Reynolds Posted January 23, 2014 An experimental contact lens design releases a glaucoma medicine at a ...

  10. Glaucoma

    MedlinePlus

    ... closure glaucoma; Acute glaucoma; Secondary glaucoma; Congenital glaucoma; Vision loss - glaucoma ... the optic nerve causes blind spots in your vision. Open-angle glaucoma tends to run in families. ...

  11. Glaucoma

    MedlinePlus

    ... version of this page please turn Javascript on. Glaucoma What is Glaucoma? Glaucoma is a group of diseases that can ... is much greater for people over 60. How Glaucoma Develops There are several different types of glaucoma. ...

  12. Experimentally Induced Mammalian Models of Glaucoma

    PubMed Central

    Yoshitomi, Takeshi; Zorumski, Charles F.; Izumi, Yukitoshi

    2015-01-01

    A wide variety of animal models have been used to study glaucoma. Although these models provide valuable information about the disease, there is still no ideal model for studying glaucoma due to its complex pathogenesis. Animal models for glaucoma are pivotal for clarifying glaucoma etiology and for developing novel therapeutic strategies to halt disease progression. In this review paper, we summarize some of the major findings obtained in various glaucoma models and examine the strengths and limitations of these models. PMID:26064891

  13. EX-PRESS glaucoma filtration device: Review of clinical experience and comparison with trabeculectomy.

    PubMed

    Shaarawy, Tarek; Goldberg, Ivan; Fechtner, Robert

    2015-01-01

    Glaucoma filtration surgery is performed to reduce intraocular pressure (IOP) in patients for whom maximal tolerable pharmacologic IOP-lowering therapy and/or laser surgery fail to lower IOP sufficiently and/or fail to prevent optic nerve damage or visual field deterioration. For decades, the most widely utilized procedure for glaucoma filtration surgery has been trabeculectomy. Although this approach reliably provides long-term IOP reduction in many patients, the postoperative complication rate is high. This has driven the development of alternative approaches to reduce IOP surgically. The EX-PRESS glaucoma filtration device was developed to mimic IOP control by trabeculectomy and to have a better safety profile. This non-valved, medical-grade stainless steel device diverts aqueous humor from the anterior chamber to an intrascleral space. Despite the widespread use of the EX-PRESS device, only a few studies compare its efficacy and safety with that of trabeculectomy. We analyze available data regarding the safety and efficacy of the EX-PRESS device, particularly in comparison with trabeculectomy.

  14. Scleral fibroblast response to experimental glaucoma in mice

    PubMed Central

    Tezel, Gülgün; Cone-Kimball, Elizabeth; Steinhart, Matthew R.; Jefferys, Joan; Pease, Mary E.; Quigley, Harry A.

    2016-01-01

    Purpose To study the detailed cellular and molecular changes in the mouse sclera subjected to experimental glaucoma. Methods Three strains of mice underwent experimental bead-injection glaucoma and were euthanized at 3 days and 1, 3, and 6 weeks. Scleral protein expression was analyzed with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) using 16O/18O labeling for quantification in 1- and 6-week tissues. Sclera protein samples were also analyzed with immunoblotting with specific antibodies to selected proteins. The proportion of proliferating scleral fibroblasts was quantified with Ki67 and 4’,6-diamidino-2-phenylindole (DAPI) labeling, and selected proteins were studied with immunohistochemistry. Results Proteomic analysis showed increases in molecules involved in integrin-linked kinase signaling and actin cytoskeleton signaling pathways at 1 and 6 weeks after experimental glaucoma. The peripapillary scleral region had more fibroblasts than equatorial sclera (p=0.001, n=217, multivariable regression models). There was a sixfold increase in proliferating fibroblasts in the experimental glaucoma sclera at 1 week and a threefold rise at 3 and 6 weeks (p=0.0005, univariate regression). Immunoblots confirmed increases for myosin, spectrin, and actinin at 1 week after glaucoma. Thrombospondin-1 (TSP-1), HINT1, vimentin, actinin, and α-smooth muscle actin were increased according to immunohistochemistry. Conclusions Scleral fibroblasts in experimental mouse glaucoma show increases in actin cytoskeleton and integrin-related signaling, increases in cell division, and features compatible with myofibroblast transition. PMID:26900327

  15. Glaucoma

    MedlinePlus

    ... with stress. Meditation and other techniques may help. Marijuana. Research shows that marijuana lowers eye pressure in people with glaucoma, but ... The American Academy of Ophthalmology doesn't recommend marijuana for treating glaucoma. When you receive a diagnosis ...

  16. Management of hypotony and flat anterior chamber associated with glaucoma filtration surgery

    PubMed Central

    Tunç, Yavuz; Tetikoglu, Mehmet; Kara, Necip; Sagdık, Haci Murat; Özarpaci, Selahattin; Elçioğlu, Mustafa Nuri

    2015-01-01

    AIM To determine the effectiveness of pharmacological and interventional treatment of hypotony and flat anterior chamber (FAC) resulting from glaucoma filtration surgery. METHODS We retrospectively examined the medical records of fifty-two trabeculectomy patients (52 eyes) who developed postoperative hypotony and FAC. The management and associated complications of hypotony, changing intraocular pressure (IOP) and best corrected visual acuity (BCVA) were evaluated. RESULT Of the 52 patients with hypotony, 29 (56%) had a grade 1 FAC, 21 (40%) had a grade 2 FAC, and only 2 had a grade 3 FAC. There was no significant difference between the mean preoperative IOP and the mean IOP at three and six months after surgery. Thirteen eyes (25%) required antiglaucomatous medication three months after surgery. The mean BCVA at 6mo after surgery was significantly reduced as compared with the mean preoperative BCVA. CONCLUSION Hypotonia and FAC following trabeculectomy are associated with troublesome complications that require pharmacological and/or surgical treatment. Thus, close follow-up is essential for affected patients. PMID:26558207

  17. [Glaucoma].

    PubMed

    Funk, Jens

    2009-03-01

    Glaucoma is one of the most frequent causes of blindness in the world. Although there are several different subforms of glaucoma, their final common pathway is an atrophy of the optic disc leading to progressive visual field defects and finally total blindness. The loss of function in glaucoma is irreversible, i.e. early detection of the disease is the most important part of its therapy. Early detection, however, requires improved knowledge about the disease in the general population and the active help of all general practitioners, explaining their patients the insidious nature of the disease.

  18. Glaucoma

    MedlinePlus

    ... Courier services use: Rockville, MD 20852) 301-451-2020 Research at NEI Office of the Scientific Director ... Eye Disease Education Program Glaucoma Education Program Low Vision Education Program Hispanic/Latino Program Vision and Aging ...

  19. Glaucoma

    MedlinePlus

    ... job openings visit HHS USAJobs Home > Glaucoma Healthy Vision Diabetes Diabetes Home How Much Do You Know? What You Should Know Protecting Against Vision Loss Staying on TRACK Diabetic Eye Disease FAQ ...

  20. Withaferin A Effectively Targets Soluble Vimentin in the Glaucoma Filtration Surgical Model of Fibrosis

    PubMed Central

    Bargagna-Mohan, Paola; Deokule, Sunil P.; Thompson, Kyle; Wizeman, John; Srinivasan, Cidambi; Vooturi, Sunil; Kompella, Uday B.; Mohan, Royce

    2013-01-01

    Withaferin A (WFA) is a natural product that binds to soluble forms of the type III intermediate filament (IF) vimentin. Currently, it is unknown under what pathophysiological contexts vimentin is druggable, as cytoskeltal vimentin-IFs are abundantly expressed. To investigate druggability of vimentin, we exploited rabbit Tenon's capsule fibroblast (RbTCF) cell cultures and the rabbit glaucoma filtration surgical (GFS) model of fibrosis. WFA potently caused G0/G1 cell cycle inhibition (IC50 25 nM) in RbTCFs, downregulating ubiquitin E3 ligase skp2 and inducing p27Kip1 expression. Transforming growth factor (TGF)-ß-induced myofibroblast transformation caused development of cell spheroids with numerous elongated invadopodia, which WFA blocked potently by downregulating soluble vimentin and α-smooth muscle actin (SMA) expression. In the pilot proof-of-concept study using the GFS model, subconjunctival injections of a low WFA dose reduced skp2 expression in Tenon's capsule and increased p27Kip1 expression without significant alteration to vimentin-IFs. This treatment maintains significant nanomolar WFA concentrations in anterior segment tissues that correspond to WFA's cell cycle targeting activity. A ten-fold higher WFA dose caused potent downregulation of soluble vimentin and skp2 expression, but as found in cell cultures, no further increase in p27Kip1 expression was observed. Instead, this high WFA dose potently induced vimentin-IF disruption and downregulated α-SMA expression that mimicked WFA activity in TGF-ß-treated RbTCFs that blocked cell contractile activity at submicromolar concentrations. These findings illuminate that localized WFA injection to ocular tissues exerts pharmacological control over the skp2-p27Kip1 pathway by targeting of soluble vimentin in a model of surgical fibrosis. PMID:23667686

  1. Glaucoma.

    PubMed

    Mantravadi, Anand V; Vadhar, Neil

    2015-09-01

    Glaucoma is a multifactorial degenerative optic neuropathy that can progress at variable rates and afflict all age groups. It is the second leading cause of blindness worldwide. The disease is commonly divided into 2 major subtypes, open angle and angle closure. Diagnosis of glaucoma is made by a combination of identifying characteristic changes of the optic nerve, functional testing such as visual fields, and structural imaging of the optic nerve. Management is aimed at reducing intraocular pressure (IOP). Patients with known risk factors should be referred to an ophthalmologist for complete evaluation.

  2. The Non-Human Primate Experimental Glaucoma Model

    PubMed Central

    Burgoyne, Claude F.

    2015-01-01

    The purpose of this report is to summarize the current strengths and weaknesses of the non-human primate (NHP) experimental glaucoma (EG) model through sections devoted to its history, methods, important findings, alternative optic neuropathy models and future directions. NHP EG has become well established for studying human glaucoma in part because the NHP optic nerve head (ONH) shares a close anatomic association with the human ONH and because it provides the only means of systematically studying the very earliest visual system responses to chronic IOP elevation, i.e. the conversion from ocular hypertension to glaucomatous damage. However, NHPs are impractical for studies that require large animal numbers, demonstrate spontaneous glaucoma only rarely, do not currently provide a model of the neuropathy at normal levels of IOP, and cannot easily be genetically manipulated, except through tissue-specific, viral vectors. The goal of this summary is to direct NHP EG and non-NHP EG investigators to the previous, current and future accomplishment of clinically relevant knowledge in this model. PMID:26070984

  3. Lamina Cribrosa Microarchitecture in Monkey Early Experimental Glaucoma: Global Change

    PubMed Central

    Reynaud, Juan; Lockwood, Howard; Gardiner, Stuart K.; Williams, Galen; Yang, Hongli; Burgoyne, Claude F.

    2016-01-01

    Purpose The purpose of this study was to characterize experimental glaucoma (EG) versus control eye differences in lamina cribrosa (LC), beam diameter (BD), pore diameter (PD), connective tissue volume fraction (CTVF), connective tissue volume (CTV), and LC volume (LV) in monkey early EG. Methods Optic nerve heads (ONHs) of 14 unilateral EG and 6 bilateral normal (BN) monkeys underwent three-dimensional reconstruction and LC beam segmentation. Each beam and pore voxel was assigned a diameter based on the largest sphere that contained it before transformation to a common cylinder with inner, middle, and outer layers. Full-thickness and layer averages for BD, PD, CTVF, CTV, and LV were calculated for each ONH. Beam diameter and PD distributions for each ONH were fit to a gamma distribution and summarized by scale and shape parameters. Experimental glaucoma and depth effects were assessed for each parameter by linear mixed-effects (LME) modeling. Animal-specific EG versus control eye differences that exceeded the maximum intereye difference among the six BN animals were considered significant. Results Overall EG eye mean PD was 12.8% larger (28.2 ± 5.6 vs. 25.0 ± 3.3 μm), CTV was 26.5% larger (100.06 ± 47.98 vs. 79.12 ± 28.35 × 106 μm3), and LV was 40% larger (229.29 ± 98.19 vs. 163.63 ± 39.87 × 106 μm3) than control eyes (P ≤ 0.05, LME). Experimental glaucoma effects were significantly different by layer for PD (P = 0.0097) and CTVF (P < 0.0001). Pore diameter expanded consistently across all PDs. Experimental glaucoma eye-specific parameter change was variable in magnitude and direction. Conclusions Pore diameter, CTV, and LV increase in monkey early EG; however, EG eye-specific change is variable and includes both increases and decreases in BD and CTVF. PMID:27362781

  4. Trabeculectomy Versus Ex-Press Glaucoma Filtration Device in Silicomacrophagocytic Open Angle Glaucoma Secondary to Silicone Oil Emulsification

    PubMed Central

    Errico, Donato; Scrimieri, Francesca Luigia; Riccardi, Roberta; Iarossi, Giancarlo

    2016-01-01

    Purpose: To compare the outcomes of Ex-PRESS device implantation versus trabeculectomy in patients with ocular hypertension after pars plana vitrectomy and silicone oil injection (SOI). Materials and Methods: Twenty-six consecutive eyes with ocular hypertension after pars plana vitrectomy and SOI were included in this study and randomized to one of two groups: A group treated with Ex-PRESS (model P50) placed under a scleral flap (Ex-PRESS group), and a group treated with trabeculectomy (trabeculectomy group). Complete success (intraocular pressure [IOP] <21 mmHg without medication) and qualified success rates (IOP <21 mmHg with one or two glaucoma medications) at 2 years postoperatively were analyzed. Between-groups comparison was performed with the Mann-Whitney U-test for continuous variables, and Fischer exact test for categorical data. Success rates between groups were compared using Kaplan-Meier life analysis and the log-rank test. P < 0.05 was considered statistically significant. Results: In the Ex-PRESS group, complete success was achieved in 73% eyes and qualified success in 81.8% of eyes. In the trabeculectomy group, complete success was achieved in 40% and qualified success was achieved in 60% of eyes. The difference in mean IOP between groups was statistically significant from the 3rd postoperative month onward (P = 0.007 at 3 months, P = 0.003 at 6 months, and P = 0.03 at 24 months). Conclusion: Ex-PRESS implantation was more effective than trabeculectomy in controlling IOP in ocular hypertensives after pars plana vitrectomy and SOI, but the surgical technique may require improvement. PMID:27162449

  5. Depot effect of bioactive components in experimental membrane filtrations

    NASA Astrophysics Data System (ADS)

    Mitev, D.; Peshev, D.; Peev, G.; Peeva, L.

    2017-01-01

    Depot effects were found to be accompanying phenomena of membrane separation processes. Accumulation of target species in the membrane matrix during feasibility tests can hamper proper conclusions or compromise the filtration results. Therefore, we investigated the effects of delayed membrane release of chlorogenic acid and caffeine, considered as key compounds of interest in spent coffee products’ recovery treatment. Permeate fluxes and key components release were studied in course of 24 hours via nanofiltration of pure solvent, both immediately after the mock solution filtration and after idle stay. Conclusions are drawn and recommendations advised for proper analysis of experimental data on membrane screening.

  6. Effect of CNTF on Retinal Ganglion Cell Survival in Experimental Glaucoma

    PubMed Central

    Pease, Mary Ellen; Zack, Donald J; Berlinicke, Cynthia; Bloom, Kristen; Cone, Frances; Wang, Yuxia; Klein, Ronald L.; Hauswirth, William W.; Quigley, Harry A.

    2009-01-01

    Purpose To assess the neuroprotective effect of virally-mediated over-expression of ciliary derived neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) in experimental rat glaucoma. Methods Laser-induced glaucoma was produced in one eye of 224 Wistar rats after injection of adeno-associated viral vectors (type 2) containing either CNTF, BDNF or both, using saline injected eyes and uninjected glaucoma eyes as controls. IOP was measured with the TonoLab and semi-automated optic nerve axon counts were performed by masked observers. IOP exposure over time was adjusted in multivariate regression analysis to calculate the effect of CNTF and BDNF. Results By multivariate regression, CNTF had a significant protective effect, with 15% less RGC axon death (p < 0.01). Both combined CNTF—BDNF and BDNF over-expression alone had no statistically significant improvement in RGC axon survival. By Western blot, there was a quantitative increase in CNTF and BDNF expression in retinas exposed to single viral vectors carrying each gene, but no increase with sequential injection of both vectors. Conclusion These data confirm that CNTF can exert a protective effect in experimental glaucoma. The reason for a lack of observed effect with the BDNF overexpression groups is unclear, but may be a function of the level of neurotrophin expression achieved. PMID:19060281

  7. Neuroprotective and antioxidant effects of ghrelin in an experimental glaucoma model

    PubMed Central

    Can, Nagehan; Catak, Onur; Turgut, Burak; Demir, Tamer; Ilhan, Nevin; Kuloglu, Tuncay; Ozercan, Ibrahim Hanifi

    2015-01-01

    Damage to retinal ganglion cells due to elevation of intraocular pressure (IOP) is responsible for vision loss in glaucoma. Given that loss of these cells is irreversible, neuroprotection is crucial in the treatment of glaucoma. In this study, we investigated the possible antioxidant and neuroprotective effects of ghrelin on the retina in an experimental glaucoma model. Twenty-one Sprague–Dawley rats were randomly assigned to three groups comprising seven rats each. The rats in the control group were not operated on and did not receive any treatment. In all rats in the other groups, IOP was increased by cauterization of the limbal veins. After creation of the IOP increase, saline 1 mL/kg or ghrelin 40 μg/kg was administered intraperitoneally every day for 14 days in the vehicle control group and ghrelin groups, respectively. On day 14 of the study, the eyes were enucleated. Levels of malondialdehyde (MDA), nitric oxide (NO), and nitric oxide synthase-2 (NOS2) in anterior chamber fluid were measured. The retinas were subjected to immunohistochemistry staining for glial fibrillary acidic protein (GFAP), S-100, and vimentin expression. Mean levels of MDA, NO, and NOS2 in the aqueous humor were higher in the vehicle control group than in the control group (P<0.05). Mean levels of MDA, NO, and NOS2 in the ghrelin group did not show a significant increase compared with levels in the control group (P>0.05). Retinal TUNEL and immunohistochemistry staining in the vehicle control group showed an increase in apoptosis and expression of GFAP, S-100, and vimentin compared with the control group (P<0.05). In the ghrelin group, apoptosis and expression of GFAP, S-100, and vimentin was significantly lower than in the vehicle control group (P<0.05). This study suggests that ghrelin has antioxidant and neuroprotective effects on the retina in an experimental glaucoma model. PMID:26082612

  8. Losartan Treatment Protects Retinal Ganglion Cells and Alters Scleral Remodeling in Experimental Glaucoma

    PubMed Central

    Pitha, Ian F.; Nguyen, Cathy; Steinhart, Matthew R.; Nguyen, Thao D.; Pease, Mary Ellen; Oglesby, Ericka N.; Berlinicke, Cynthia A.; Mitchell, Katherine L.; Kim, Jessica; Jefferys, Joan J.

    2015-01-01

    Purpose To determine if oral losartan treatment decreases the retinal ganglion cell (RGC) death caused by experimental intraocular pressure (IOP) elevation in mice. Methods We produced IOP increase in CD1 mice and performed unilateral optic nerve crush. Mice received oral losartan, spironolactone, enalapril, or no drug to test effects of inhibiting angiotensin receptors. IOP was monitored by Tonolab, and blood pressure was monitored by tail cuff device. RGC loss was measured in masked axon counts and RGC bodies by β-tubulin labeling. Scleral changes that could modulate RGC injury were measured including axial length, scleral thickness, and retinal layer thicknesses, pressure-strain behavior in inflation testing, and study of angiotensin receptors and pathways by reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry. Results Losartan treatment prevented significant RGC loss (median loss = 2.5%, p = 0.13), while median loss with water, spironolactone, and enalapril treatments were 26%, 28% and 43%; p < 0.0001). The lower RGC loss with losartan was significantly less than the loss with spironolactone or enalapril (regression model p = 0.001; drug treatment group term p = 0.01). Both losartan and enalapril significantly lowered blood pressure (p< 0.001), but losartan was protective, while enalapril led to worse than water-treated RGC loss. RGC loss after crush injury was unaffected by losartan treatment (difference from control p = 0.9). Survival of RGC in cell culture was not prolonged by sartan treatment. Axonal transport blockade after 3 day IOP elevations was less in losartan-treated than in control glaucoma eyes (p = 0.007). Losartan inhibited effects of glaucoma, including reduction in extracellular signal-related kinase activity and modification of glaucoma-related changes in scleral thickness and creep under controlled IOP. Conclusions The neuroprotective effect of losartan in mouse glaucoma is associated with adaptive changes

  9. Regional Choroidal Blood Flow and Multifocal Electroretinography in Experimental Glaucoma in Rhesus Macaques

    PubMed Central

    Nork, T. Michael; Kim, Charlene B. Y.; Munsey, Kaitlyn M.; Dashek, Ryan J.; Hoeve, James N. Ver

    2014-01-01

    Purpose. To test a hypothesis of regional variation in the effect of experimental glaucoma on choroidal blood flow (ChBF) and retinal function. Methods. Five rhesus macaques underwent laser trabecular destruction (LTD) to induce elevated intraocular pressure (IOP). Intraocular pressures were elevated for 56 to 57 weeks. Multifocal electroretinographic (mfERG) and multifocal visual evoked cortical potential (mfVEP) testing were performed at regular intervals before and during the period of IOP elevation. At euthanasia, the IOP was manometrically controlled at 35 (experimentally glaucomatous eye) and 15 (fellow control eye) mm Hg. Fluorescent microspheres were injected into the left ventricle. Regional ChBF was determined. Results. All of the experimentally glaucomatous eyes exhibited supranormal first-order kernel (K1) root mean square (RMS) early portions of the mfERG waveforms and decreased amplitudes of the late waveforms. The supranormality was somewhat greater in the central macula. Second-order kernel, first slice (K2.1) RMS mfVEP response was inversely correlated (R2 = 0.97) with axonal loss. Total ChBF was reduced in the experimentally glaucomatous eyes. The mean blood flow was 893 ± 123 and 481 ± 37 μL/min in the control and glaucomatous eyes, respectively. The ChBF showed regional variability with the greatest proportional decrement most often found in the central macula. Conclusions. This is the first demonstration of globally reduced ChBF in chronic experimental glaucoma in the nonhuman primate. Both the alteration of mfERG waveform components associated with outer retinal function and the reduction in ChBF were greatest in the macula, suggesting that there may be a spatial colocalization between ChBF and some outer retinal effects in glaucoma. PMID:25370515

  10. Assessment of Filtration Bleb and Endplate Positioning Using Magnetic Resonance Imaging in Eyes Implanted with Long-Tube Glaucoma Drainage Devices

    PubMed Central

    Sano, Ichiya; Tanito, Masaki; Uchida, Koji; Katsube, Takashi; Kitagaki, Hajime; Ohira, Akihiro

    2015-01-01

    Background To evaluate ocular fluid filtration and endplate positioning in glaucomatous eyes with long-tube glaucoma drainage devices (GDDs) using magnetic resonance imaging (MRI) and the effects of various factors on postoperative intraocular pressure (IOP). Methods This observational case series included 27 consecutive glaucomatous eyes (18 men, 7 women; mean age ± standard error, 63.0±2.0 years) who underwent GDD implantation (n = 8 Ahmed Glaucoma Valves [AGV] and n = 19 Baerveldt Glaucoma Implants [BGI]). Tubes were inserted into the pars plana in 23 eyes and anterior chamber in 4 eyes. Six months postoperatively, high-resolution orbital images were obtained using 3-Tesla MRI with head-array coils, and the filtering bleb volume, bleb height, and distances between the anterior endplate edge and corneal center or limbus or between the endplate and orbital wall were measured. Results In MR images obtained by three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences, the shunt endplate was identified as low-intensity signal, and the filtering bleb was identified as high-intensity signals above and below the endplate in all eyes. The 6-month-postoperative IOP level was correlated negatively with bleb volume (r = -0.4510, P = 0.0182) and bleb height (r = -0.3954, P = 0.0412). The postoperative IOP was significantly (P = 0.0026) lower in BGI-implanted eyes (12.2±0.7 mmHg) than AGV-implanted eyes (16.7±1.2 mmHg); bleb volume was significantly (P = 0.0093) larger in BGI-implanted eyes (478.8±84.2 mm3) than AGV-implanted eyes (161.1±52.3 mm3). Other parameters did not differ. Conclusions The presence of intraorbital/periocular accumulation of ocular fluid affects postoperative IOP levels in eyes implanted with long-tube GDDs. Larger filtering blebs after BGI than AGI implantations explain lower postoperative IOP levels achieved with BGI than AGV. The findings will contribute to better understanding of IOP reducing mechanism of long

  11. Pressure filtration of ceramic pastes. 4: Treatment of experimental data

    NASA Technical Reports Server (NTRS)

    Torrecillas, A. S.; Polo, J. F.; Perez, A. A.

    1984-01-01

    The use of data processing method based on the algorithm proposed by Kalman and its application to the filtration process at constant pressure are described, as well as the advantages of this method. This technique is compared to the least squares method. The operation allows the precise parameter adjustment of the equation in direct relationship to the specific resistance of the cake.

  12. In Vivo Detection of Laminar and Peripapillary Scleral Hypercompliance in Early Monkey Experimental Glaucoma

    PubMed Central

    Ivers, Kevin M.; Yang, Hongli; Gardiner, Stuart K.; Qin, Lirong; Reyes, Luke; Fortune, Brad; Burgoyne, Claude F.

    2016-01-01

    Purpose To compare optical coherence tomography (OCT) detected, optic nerve head (ONH) compliance within control and experimental glaucoma (EG) eyes of 15 monkeys at EG onset. Methods Intraocular pressure (IOP) was chronically elevated in one eye of each animal using a laser. Experimental glaucoma onset was identified using confocal scanning laser tomography (CSLT). Optical coherence tomography ONH imaging (40 radial B-scans) was performed at 10 mm Hg before and after laser. At EG onset, OCT scans were obtained at IOP 10 and 30 mm Hg. Optical coherence tomography landmarks within the IOP 10/30 images were delineated to quantify IOP 10/30 differences (compliance) for anterior lamina cribrosa surface depth (ALCSD) relative to Bruch's membrane opening (BMO) (ALCSD-BMO), ALCSD relative to peripheral BM (ALCSD-BM), and BMO depth relative to peripheral BM (BMOD-BM). A linear mixed effects model assessed for acute IOP elevation effects, control versus EG eye effects, and their interaction Results Effects of IOP elevation were greater in EG versus control eyes for ALCSD-BMO (−46 ± 45 vs. −8 ± 13 μm, P = 0.0042) and ALCSD-BM (−92 ± 64 vs. −42 ± 22 μm, P = 0.0075). Experimental glaucoma eye-specific ALCSD-BMO and ALCSD-BM compliance exceeded the range of control eye compliance in 9 and 8 of the 15 EG eyes, respectively. Post-laser peak IOP (R2 = 0.798, P < 0.0001) and post-laser mean IOP (R2 = 0.634, P < 0.0004) most strongly correlated to EG versus control eye differences in ALCSD-BMO compliance. Conclusions Laminar (ALCSD-BMO) and peripapillary scleral (ALCSD-BM) hypercompliance are present in most monkey eyes at the onset of EG. PMID:27409498

  13. Experimental study of head loss and filtration for LOCA debris

    SciTech Connect

    Rao, D.V.; Souto, F.J.

    1996-02-01

    A series of controlled experiments were conducted to obtain head loss and filtration characteristics of debris beds formed of NUKON{trademark} fibrous fragments, and obtain data to validate the semi-theoretical head loss model developed in NUREG/CR-6224. A thermally insulated closed-loop test set-up was used to conduct experiments using beds formed of fibers only and fibers intermixed with particulate debris. A total of three particulate mixes were used to simulate the particulate debris. The head loss data were obtained for theoretical fiber bed thicknesses of 0.125 inches to 4.0 inches; approach velocities of 0.15 to 1.5 ft/s; temperatures of 75 F and 125 F; and sludge-to-fiber nominal concentration ratios of 0 to 60. Concentration measurements obtained during the first flushing cycle were used to estimate the filtration efficiencies of the debris beds. For test conditions where the beds are fairly uniform, the head loss data were predictable within an acceptable accuracy range by the semi-theoretical model. The model was equally applicable for both pure fiber beds and the mixed beds. Typically the model over-predicted the head losses for very thin beds and for thin beds at high sludge-to-fiber mass ratios. This is attributable to the non-uniformity of such debris beds. In this range the correlation can be interpreted to provide upper bound estimates of head loss. This is pertinent for loss of coolant accidents in boiling water reactors.

  14. Experimental study on non-woven filamentous fibre micro-filter with high filtration speed.

    PubMed

    Niu, Siping; Park, Kisoo; Guerra, Heidi B; Kim, Youngchul

    2015-01-01

    A laboratory study was undertaken to pursue the filter performance of a micro-filter module employing highly porous fibre media under a high filtration rate (≥1,500 m/day), faster than that of any conventional filter process. The effects of filtration rate, head loss, raw water turbidity, and filter aid chemicals on filter performance were analysed. In spite of the extremely high filtration rate, the filter achieved an attractive efficiency, reducing the raw water turbidity by over 80%. As with other filter systems, the filter aid used ((polyaluminium chloride (PAC)) greatly affected the performance of this particular fibre filter. Long-term repetitive runs were additionally carried out to confirm the reproducibility of the filter performance. Also, a comparison was carried out with other high-rate filter systems which are either being tested for use in experimental studies, or are already commercially available. This study reveals that the filter performance under a high filtration speed is still attractive especially as PAC is used. Due to the high porosity of the fibre, the filter had small head loss even though the filtration rate was high. These results ascertain that it is possible to operate the filters with high filtration rate achieving reliable treatment performance.

  15. Scleral Permeability Varies by Mouse Strain and Is Decreased by Chronic Experimental Glaucoma

    PubMed Central

    Pease, Mary E.; Oglesby, Ericka N.; Cone-Kimball, Elizabeth; Jefferys, Joan L.; Steinhart, Matthew R.; Kim, Anthony J.; Hanes, Justin; Quigley, Harry A.

    2014-01-01

    Purpose. To determine differences in scleral permeability, as measured by diffusion of macromolecules, by using fluorescence recovery after photobleaching (FRAP), with reference to differences by mouse strain, scleral region, and the effect of experimental glaucoma. Methods. In three mouse strains (B6, CD1, and B6 mice with mutation in collagen 8α2 [Aca23]), we used FRAP to measure the diffusion of fluorescein isothiocyanate–dextran, molecular weight 40 kDa, into a photobleached zone of sclera. Scleral regions near the optic nerve head (peripapillary) and two successively more anterior regions were compared. Sclera from mouse eyes subjected to chronically elevated intraocular pressure after bead injection into the anterior chamber were compared to fellow eye controls. FRAP data were compared against estimated retinal ganglion cell axon loss in glaucomatous eyes. Results. Diffusion rates of dextran molecules in the sclera were significantly greater in Aca23 and B6 mice than in CD1 mice in a multivariate model adjusted for region and axial length (P < 0.0001). Dextran diffusion significantly decreased in glaucomatous eyes, and the decline increased with greater axon loss (P = 0.0003, multivariable model). Peripapillary scleral permeability was higher in CD1 than B6 and Aca23 mice (P < 0.05, multivariable model, adjusted by Bonferroni). Conclusions. Measurement of the diffusion rates of dextran molecules in the sclera showed that glaucoma leads to decreased scleral permeability in all three mouse strains tested. Among mouse strains tested, those that were more susceptible to glaucomatous loss of retinal ganglion cells had a lower scleral permeability at baseline. PMID:24557355

  16. Size exclusion deep bed filtration: Experimental and modelling uncertainties

    SciTech Connect

    Badalyan, Alexander You, Zhenjiang; Aji, Kaiser; Bedrikovetsky, Pavel; Carageorgos, Themis; Zeinijahromi, Abbas

    2014-01-15

    A detailed uncertainty analysis associated with carboxyl-modified latex particle capture in glass bead-formed porous media enabled verification of the two theoretical stochastic models for prediction of particle retention due to size exclusion. At the beginning of this analysis it is established that size exclusion is a dominant particle capture mechanism in the present study: calculated significant repulsive Derjaguin-Landau-Verwey-Overbeek potential between latex particles and glass beads is an indication of their mutual repulsion, thus, fulfilling the necessary condition for size exclusion. Applying linear uncertainty propagation method in the form of truncated Taylor's series expansion, combined standard uncertainties (CSUs) in normalised suspended particle concentrations are calculated using CSUs in experimentally determined parameters such as: an inlet volumetric flowrate of suspension, particle number in suspensions, particle concentrations in inlet and outlet streams, particle and pore throat size distributions. Weathering of glass beads in high alkaline solutions does not appreciably change particle size distribution, and, therefore, is not considered as an additional contributor to the weighted mean particle radius and corresponded weighted mean standard deviation. Weighted mean particle radius and LogNormal mean pore throat radius are characterised by the highest CSUs among all experimental parameters translating to high CSU in the jamming ratio factor (dimensionless particle size). Normalised suspended particle concentrations calculated via two theoretical models are characterised by higher CSUs than those for experimental data. The model accounting the fraction of inaccessible flow as a function of latex particle radius excellently predicts normalised suspended particle concentrations for the whole range of jamming ratios. The presented uncertainty analysis can be also used for comparison of intra- and inter-laboratory particle size exclusion data.

  17. Benzalkonium Chloride and Glaucoma

    PubMed Central

    Kaufman, Paul L.; Kiland, Julie A.

    2014-01-01

    Abstract Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology. PMID:24205938

  18. Benzalkonium chloride and glaucoma.

    PubMed

    Rasmussen, Carol A; Kaufman, Paul L; Kiland, Julie A

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology.

  19. Experimental prestorage filtration removes antibodies and decreases lipids in RBC supernatants mitigating TRALI in vivo.

    PubMed

    Silliman, Christopher C; Kelher, Marguerite R; Khan, Samina Y; LaSarre, Monica; West, F Bernadette; Land, Kevin J; Mish, Barbara; Ceriano, Linda; Sowemimo-Coker, Samuel

    2014-05-29

    Transfusion-related acute lung injury (TRALI) remains a significant cause of transfusion-related mortality with red cell transfusion. We hypothesize that prestorage filtration may reduce proinflammatory activity in the red blood cell (RBC) supernatant and prevent TRALI. Filters were manufactured for both small volumes and RBC units. Plasma containing antibodies to human lymphocyte antigen (HLA)-A2 or human neutrophil antigen (HNA)-3a was filtered, and immunoglobulins and specific HNA-3a and HLA-2a neutrophil (PMN) priming activity were measured. Antibodies to OX27 were added to plasma, and filtration was evaluated in a 2-event animal model of TRALI. RBC units from 31 donors known to have antibodies against HLA antigens and from 16 antibody-negative controls were filtered. Furthermore, 4 RBC units were drawn and underwent standard leukoreduction. Immunoglobulins, HLA antibodies, PMN priming activity, and the ability to induce TRALI in an animal model were measured. Small-volume filtration of plasma removed >96% of IgG, antibodies to HLA-A2 and HNA-3a, and their respective priming activity, as well as mitigating antibody-mediated in vivo TRALI. In RBC units, experimental filtration removed antibodies to HLA antigens and inhibited the accumulation of lipid priming activity and lipid-mediated TRALI. We conclude that filtration removes proinflammatory activity and the ability to induce TRALI from RBCs and may represent a TRALI mitigation step.

  20. Comparison of Modeling and Experimental Approaches for Improved Modeling of Filtration in Granular and Consolidated Media

    NASA Astrophysics Data System (ADS)

    Mirabolghasemi, M.; Prodanovic, M.; DiCarlo, D. A.

    2014-12-01

    Filtration is relevant to many disciplines from colloid transport in environmental engineering to formation damage in petroleum engineering. In this study we compare the results of the novel numerical modeling of filtration phenomenon on pore scale with the complementary experimental observations on laboratory scale and discuss how the results of comparison can be used to improve macroscale filtration models for different porous media. The water suspension contained glass beads of 200 micron diameter and flows through a packing of 1mm diameter glass beads, and thus the main filtration mechanism is straining and jamming of particles. The numerical model simulates the flow of suspension through a realistic 3D structure of an imaged, disordered sphere pack, which acts as the filter medium. Particle capture through size exclusion and jamming is modeled via a coupled Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) approach. The coupled CFD-DEM approach is capable of modeling the majority of particle-particle, particle-wall, and particle-fluid interactions. Note that most of traditional approaches require spherical particles both in suspension and the filtration medium. We adapted the interface between the pore space and the spherical grains to be represented as a triangulated surface and this allows extensions to any imaged media. The numerical and experimental results show that the filtration coefficient of the sphere pack is a function of the flow rate and concentration of the suspension, even for constant total particle flow rate. An increase in the suspension flow rate results in a decrease in the filtration coefficient, which suggests that the hydrodynamic drag force plays the key role in hindering the particle capture in random sphere packs. Further, similar simulations of suspension flow through a sandstone sample, which has a tighter pore space, show that filtration coefficient remains almost constant at different suspension flow rates. This

  1. [The structure of the optic nerve in experimental glaucoma and in the means for its treatment].

    PubMed

    Ivanova, V F; Mikheeva, E A; Karelina, V E; Alekseev, V N

    2000-01-01

    Using light and electron microscopy disorders of structure of the optic nerve were studied in rabbits with adrenaline induced glaucoma and after the action of antioxidants (Emoxipine, Erisode) used for preventive and medical purposes. Changes in glaucoma and after administration of drugs in axons and their myelinated sheath were similar but differently pronounced in right and left eye of the same animal. Positive effect of Erisode used for preventive and medical purposes was noted. Emoxipine enhanced the disturbances in optic nerve structure.

  2. Experimental study of the effect of polyanionic cellulose on process of filtrate loss of low-solids drilling fluid

    NASA Astrophysics Data System (ADS)

    yang, P.

    2013-12-01

    Experimental study of the effect of polyanionic cellulose on process of filtrate loss of low-solids drilling fluid Ping Yang 1,2, Min-hui Wu2, Xue-wen Zhu2, Tao Deng2, Xue-qing Sun2 1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092,China 2. Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China Abstract The process of filtrate loss of low-solids drilling fluid was tested by changing the polyanionic cellulose content in low-solids drilling fluid. The effect of polyanionic cellulose on process of filtrate loss of low-solids drilling fluid was analyzed. The test results showed that when time of filtration is same, the volume of filtrate loss decreases linearly with increasing polyanionic cellulose content. When polyanionic cellulose content is same, the rate of filtrate loss decreases nonlinearly with increasing time and the rate of filtrate loss will reach a stable value.The volume of filtrate loss in 7 to 8 minutes can reaches half of the total volume of filtrate loss. At the same time, the rate of filtrate loss of drilling fluid decreases nonlinearly with increasing viscosity.When the apparent viscosity is between 3.5~4.15 MPa.s, decrease speed of rate of filtrate loss of drilling fluid is quick. The results are helpful for characteristics evaluation of filtrate loss of drilling fluid and control of filtrate loss. Keyword Polyanionic Cellulose,Drilling Fluid,Process of Filtrate Loss Acknowledgments This investigation was supported by the National Natural Science Foundation of China (projects No. 41002093 and 41072205); the Fundamental Research Funds for the Central Universities; the Shanghai Leading Academic Discipline Project (project No. B308), Tongji University; and the Program for Young Excellent Talents, Tongji University. The authors are extremely grateful for the financial support from these five organizations.

  3. Cataract Surgery in the Glaucoma Patient

    PubMed Central

    Kung, Jennifer S.; Choi, Daniel Y.; Cheema, Anjum S.; Singh, Kuldev

    2015-01-01

    To summarize the role of cataract surgery in the glaucoma patient, in terms of the effect on intraocular pressure (IOP) as well as diagnostic and therapeutic considerations for those with both conditions. Recent evidence suggests that cataract extraction may produce a significant and sustained IOP reduction in individuals with open-angle glaucoma, ocular hypertension, and angle-closure glaucoma. Cataract removal may improve the practitioner's ability to interpret perimetric testing, and re-establishing perimetric and optic nerve imaging baselines is recommended after cataract surgery. The sequence of cataract surgery relative to glaucoma surgery impacts the likelihood of complications and surgical success. There are multiple benefits to perform cataract surgery prior to glaucoma surgery while cataract surgery after trabeculectomy increases the risk of subsequent filtration failure. As “minimally invasive glaucoma surgeries” continue to improve in terms of efficacy, there is an evolving role for combined cataract and glaucoma surgery in patients with early to moderate stages of glaucoma. PMID:25624668

  4. The Role of the Immune System in Glaucoma: Bridging the Divide Between Immune Mechanisms in Experimental Glaucoma and the Human Disease.

    PubMed

    Kamat, Shivani S; Gregory, Meredith S; Pasquale, Louis R

    2016-01-01

    Glaucoma is one of the leading causes of visual impairment worldwide. Classically, clinicians have evaluated patients through a full ophthalmological examination including gonioscopy, measurement of intraocular pressure (IOP), and assessment of the optic nerve. New imaging modalities have further enhanced our ability to evaluate glaucoma; however, our treatments have not evolved as much. Whether one uses medical treatment with topical ocular antihypertensives, laser trabeculoplasty, or filtering surgery, the mainstay of treatment is to lower IOP. However, as our understanding of the disease evolves, mechanisms other than elevated IOP have been implicated in glaucoma pathogenesis. Recent animal model studies have shown a possible role of the immune system in the pathophysiology of glaucoma. This article explores the current understanding of immune reactions in glaucoma, which could lead to a new paradigm of treatment for human disease.

  5. Experimental study of two-phase filtration regimes of methane-n-pentane mixture

    NASA Astrophysics Data System (ADS)

    Zaichenko, V. M.; Molchanov, D. A.; Torchinskiy, V. M.

    2016-11-01

    The results of experimental studies of methane-n-pentane mixture filtration in a porous medium under isothermal conditions in pressure range typical for gas-condensate reservoirs are presented. Interest in the filtration problem of such mixtures is aroused by the need to intensify production of heavy fractions of gas-condensate-valuable hydrocarbons, consisting of methane and its higher homologues. Different flow regimes including oscillatory one are observed during gas-condensate extraction under natural conditions. Our studies have shown that there are multiple flow regimes including self-oscillating one under isothermal conditions for this type of mixtures depending on the initial pressure, the kind of the mixture's phase diagram and the permeability coefficients of the liquid and gas phases in the porous medium.

  6. Colloid filtration in surface dense vegetation: experimental results and theoretical predictions.

    PubMed

    Wu, Lei; Muñoz-Carpena, Rafael; Gao, Bin; Yang, Wen; Pachepsky, Yakov A

    2014-04-01

    Understanding colloid and colloid-facilitated contaminant transport in overland flow through dense vegetation is important to protect water quality in the environment, especially for water bodies receiving agricultural and urban runoff. In previous studies, a single-stem efficiency theory for rigid and clean stem systems was developed to predict colloid filtration by plant stems of vegetation in laminar overland flow. Hence, in order to improve the accuracy of the single-stem efficiency theory to real dense vegetation system, we incorporated the effect of natural organic matter (NOM) on the filtration of colloids by stems. Laboratory dense vegetation flow chamber experiments and model simulations were used to determine the kinetic deposition (filtration) rate of colloids under various conditions. The results show that, in addition to flow hydrodynamics and solution chemistry, steric repulsion afforded by NOM layer on the plants stem surface also plays a significant role in controlling colloid deposition on vegetation in overland flow. For the first time, a refined single-stem efficiency theory with considerations of the NOM effect is developed that describes the experimental data with good accuracy. This theory can be used to not only help construct and refine mathematical models of colloid transport in real vegetation systems in overland flow, but also inform the development of theories of colloid deposition on NOM-coated surfaces in natural, engineered, and biomedical systems.

  7. Glaucoma (image)

    MedlinePlus

    Glaucoma is a condition of increased fluid pressure inside the eye. The increased pressure causes compression of ... nerve which can eventually lead to nerve damage. Glaucoma can cause partial vision loss, with blindness as ...

  8. Delivery of antifibroblast agents as adjuncts to filtration surgery. Part I--Periocular clearance of cobalt-57 bleomycin in experimental drug delivery: pilot study in the rabbit

    SciTech Connect

    Kay, J.S.; Litin, B.S.; Woolfenden, J.M.; Chvapil, M.; Herschler, J.

    1986-10-01

    Antitumor and antifibroblast agents show promise as adjuncts after glaucoma filtration surgery in reducing postoperative scarring and failure. We used nuclear imaging in rabbits to investigate periocular clearance of one such agent (/sup 57/Co-bleomycin). Sub-Tenon injection was compared to other delivery techniques. Our results showed that a collagen sponge and a silastic disc implant with a microhole prolonged drug delivery when compared to sub-Tenon injection alone or injection with a viscosity enhancing agent (0.5% sodium hyaluronate). We theorize that if an antifibroblast agent can be delivered in small and sustained amounts after filtration surgery, this may prolong bleb longevity and avoid unnecessary drug toxicity.

  9. Neuroprotection in Glaucoma

    PubMed Central

    Doozandeh, Azadeh; Yazdani, Shahin

    2016-01-01

    Glaucoma is a degenerative optic neuropathy characterized by retinal ganglion cell (RGC) loss and visual field defects. It is known that in some glaucoma patients, death of RGCs continues despite intraocular pressure (IOP) reduction. Neuroprotection in the field of glaucoma is defined as any treatment, independent of IOP reduction, which prevents RGC death. Glutamate antagonists, ginkgo biloba extract, neurotrophic factors, antioxidants, calcium channel blockers, brimonidine, glaucoma medications with blood regulatory effect and nitric oxide synthase inhibitors are among compounds with possible neuroprotective activity in preclinical studies. A few agents (such as brimonidine or memantine) with neuroprotective effects in experimental studies have advanced to clinical trials; however the results of clinical trials for these agents have not been conclusive. Nevertheless, lack of compelling clinical evidence has not prevented the off-label use of some of these compounds in glaucoma practice. Stem cell transplantation has been reported to halt experimental neurodegenerative disease processes in the absence of cell replacement. It has been hypothesized that transplantation of some types of stem cells activates multiple neuroprotective pathways via secretion of various factors. The advantage of this approach is a prolonged and targeted effect. Important concerns in this field include the secretion of unwanted harmful mediators, graft survival issues and tumorigenesis. Neuroprotection in glaucoma, pharmacologically or by stem cell transplantation, is an interesting subject waiting for broad and multidisciplinary collaborative studies to better clarify its role in clinical practice. PMID:27413504

  10. Elevated intraocular pressure decreases response sensitivity of inner retinal neurons in experimental glaucoma mice

    PubMed Central

    Pang, Ji-Jie; Frankfort, Benjamin J.; Gross, Ronald L.; Wu, Samuel M.

    2015-01-01

    Glaucoma is the second leading cause of blindness in the United States and the world, characterized by progressive degeneration of the optic nerve and retinal ganglion cells (RGCs). Glaucoma patients exhibit an early diffuse loss of retinal sensitivity followed by focal loss of RGCs in sectored patterns. Recent evidence has suggested that this early sensitivity loss may be associated with dysfunctions in the inner retina, but detailed cellular and synaptic mechanisms underlying such sensitivity changes are largely unknown. In this study, we use whole-cell voltage-clamp techniques to analyze light responses of individual bipolar cells (BCs), AII amacrine cells (AIIACs), and ON and sustained OFF alpha-ganglion cells (ONαGCs and sOFFαGCs) in dark-adapted mouse retinas with elevated intraocular pressure (IOP). We present evidence showing that elevated IOP suppresses the rod ON BC inputs to AIIACs, resulting in less sensitive AIIACs, which alter AIIAC inputs to ONαGCs via the AIIAC→cone ON BC→ONαGC pathway, resulting in lower ONαGC sensitivity. The altered AIIAC response also reduces sOFFαGC sensitivity via the AIIAC→sOFFαGC chemical synapses. These sensitivity decreases in αGCs and AIIACs were found in mice with elevated IOP for 3–7 wk, a stage when little RGC or optic nerve degeneration was observed. Our finding that elevated IOP alters neuronal function in the inner retina before irreversible structural damage occurs provides useful information for developing new diagnostic tools and treatments for glaucoma in human patients. PMID:25675503

  11. The Connective Tissue Components of Optic Nerve Head Cupping in Monkey Experimental Glaucoma Part 1: Global Change

    PubMed Central

    Yang, Hongli; Ren, Ruojin; Lockwood, Howard; Williams, Galen; Libertiaux, Vincent; Downs, Crawford; Gardiner, Stuart K.; Burgoyne, Claude F.

    2015-01-01

    Purpose To characterize optic nerve head (ONH) connective tissue change within 21 monkey experimental glaucoma (EG) eyes, so as to identify its principal components. Methods Animals were imaged three to five times at baseline then every 2 weeks following chronic unilateral IOP elevation, and euthanized early through end-stage confocal scanning laser tomographic change. Optic nerve heads were serial-sectioned, three-dimensionally (3D) reconstructed, delineated, and quantified. Overall EG versus control eye differences were assessed by general estimating equations (GEE). Significant, animal-specific, EG eye change was required to exceed the maximum physiologic intereye differences in six healthy animals. Results Overall EG eye change was significant (P < 0.0026) and animal-specific EG eye change most frequent, for five phenomena (number of EG eyes and range of animal-specific change): posterior laminar deformation (21, −29 to −437 μm), laminar thickening (11, 20–73 μm) and thinning (3, −23 to −31 μm), scleral canal expansion (17, 20–139 μm), outward anterior (16, −16 to −124 μm) and posterior (17, −22 to −279 μm) laminar insertion migration, and peripapillary scleral bowing (11, 21–77 μm). Experimental glaucoma versus control eye laminar thickness differences were bimodal in behavior, being thickened in most EG eyes demonstrating the least deformation and less thickened or thinned in most EG eyes demonstrating the greatest deformation. Conclusions Our postmortem studies retrospectively identify five connective tissue components of ONH “cupping” in monkey EG which serve as targets for longitudinally staging and phenotyping ONH connective tissue alteration within all forms of monkey and human optic neuropathy. PMID:26641545

  12. Towards axonal regeneration and neuroprotection in glaucoma: Rho kinase inhibitors as promising therapeutics.

    PubMed

    Van de Velde, Sarah; De Groef, Lies; Stalmans, Ingeborg; Moons, Lieve; Van Hove, Inge

    2015-08-01

    Due to a prolonged life expectancy worldwide, the incidence of age-related neurodegenerative disorders such as glaucoma is increasing. Glaucoma is the second cause of blindness, resulting from a slow and progressive loss of retinal ganglion cells (RGCs) and their axons. Up to now, intraocular pressure (IOP) reduction is the only treatment modality by which ophthalmologists attempt to control disease progression. However, not all patients benefit from this therapy, and the pathophysiology of glaucoma is not always associated with an elevated IOP. These limitations, together with the multifactorial etiology of glaucoma, urge the pressing medical need for novel and alternative treatment strategies. Such new therapies should focus on preventing or retarding RGC death, but also on repair of injured axons, to ultimately preserve or improve structural and functional connectivity. In this respect, Rho-associated coiled-coil forming protein kinase (ROCK) inhibitors hold a promising potential to become very prominent drugs for future glaucoma treatment. Their field of action in the eye does not seem to be restricted to IOP reduction by targeting the trabecular meshwork or improving filtration surgery outcome. Indeed, over the past years, important progress has been made in elucidating their ability to improve ocular blood flow, to prevent RGC death/increase RGC survival and to retard axonal degeneration or induce proper axonal regeneration. Within this review, we aim to highlight the currently known capacity of ROCK inhibition to promote neuroprotection and regeneration in several in vitro, ex vivo and in vivo experimental glaucoma models.

  13. Inflammatory glaucoma

    PubMed Central

    Bodh, Sonam A.; Kumar, Vasu; Raina, Usha K.; Ghosh, B.; Thakar, Meenakshi

    2011-01-01

    Glaucoma is seen in about 20% of the patients with uveitis. Anterior uveitis may be acute, subacute, or chronic. The mechanisms by which iridocyclitis leads to obstruction of aqueous outflow include acute, usually reversible forms (e.g., accumulation of inflammatory elements in the intertrabecular spaces, edema of the trabecular lamellae, or angle closure due to ciliary body swelling) and chronic forms (e.g., scar formation or membrane overgrowth in the anterior chamber angle). Careful history and follow-up helps distinguish steroid-induced glaucoma from uveitic glaucoma. Treatment of combined iridocyclitis and glaucoma involves steroidal and nonsteroidal antiinflammatory agents and antiglaucoma drugs. However, glaucoma drugs can often have an unpredictable effect on intraocular pressure (IOP) in the setting of uveitis. Surgical intervention is required in case of medical failure. Method of Literature Search: Literature on the Medline database was searched using the PubMed interface. PMID:21713239

  14. Experimental investigation of air pressure affecting filtration performance of fibrous filter sheet.

    PubMed

    Xu, Bin; Yu, Xiao; Wu, Ya; Lin, Zhongping

    2017-03-01

    Understanding the effect of air pressure on their filtration performance is important for assessing the effectiveness of fibrous filters under different practical circumstances. The effectiveness of three classes of air filter sheets were investigated in laboratory-based measurements at a wide range of air pressures (60-130 KPa). The filtration efficiency was found most sensitive to the air pressure change at smaller particle sizes. As the air pressure increased from 60 to 130 KPa, significant decrease in filtration efficiency (up to 15%) and increase in pressure drop (up to 90 Pa) were observed. The filtration efficiency of the filter sheet with largest fiber diameter and smallest solid volume fraction was affected most, while the pressure drop of the filter sheet with smallest fiber diameter and largest solid volume fraction was affected most. The effect of air pressure on the filtration efficiency was slightly larger at greater filter face air velocity. However, the effect of air pressure on the pressure drop was negligible. The filtration efficiency and pressure drop were explicitly expressed as functions of the air pressure. Two coefficients were empirically derived and successfully accounted for the effects of air pressure on filtration efficiency and pressure drop.

  15. Feline Glaucoma.

    PubMed

    McLellan, Gillian J; Teixeira, Leandro B C

    2015-11-01

    Feline glaucoma is often insidious in onset and slowly progressive with very subtle clinical signs. As a consequence, it is likely that the disease in cats is underdiagnosed. As cats typically present late in the course of disease, prognosis for long-term maintenance of vision is poor. Patient and owner compliance with frequent application of topical medications can be a limiting factor, and represents a serious clinical challenge. This review outlines the clinical features, classification, and pathophysiology of the feline glaucomas and provides current evidence on which to base the selection of appropriate treatment strategies for cats with glaucoma.

  16. Long-term glial reactivity in rat retinas ipsilateral and contralateral to experimental glaucoma.

    PubMed

    Kanamori, Akiyasu; Nakamura, Makoto; Nakanishi, Yoriko; Yamada, Yuko; Negi, Akira

    2005-07-01

    Although glaucoma is known to alter glial reactivity, the long-term effect of elevated intraocular pressure (IOP) on glial change has not been fully elucidated. This study aimed to examine how chronically elevated IOP induced by episcleral vein cauterization (EVC) in unilateral eyes affect reactivities of astrocytes and Müller cells of rats in the treated as well as contralateral eyes over time. EVC in unilateral eyes of Sprague-Dawley rats were performed to produce chronically elevated IOP. Flat mounted retina preparations were made at several points until 6 months, which were subjected to immunostaining for glial fibrillary acidic protein (GFAP). Retinal homogenates were one- or two-dimensionally electrophoresed, followed by GFAP immunoblotting. EVC significantly increased IOPs up to 27.8 from 13.1 mmHg, which gradually decreased over time. In flat mounted retinas, astrocytes lost but Müller cells gained GFAP immunoreactivity at 3 days after cauterization. The glial changes were partially reversed over time but last even after IOP normalization. In the contralateral eyes, similar glial changes gradually appeared at 1 month after EVC and thereafter. Immunoblotting demonstrated not only molecular size shifts but also alteration of isoelectric focusing of GFAP both in treated and contralateral retina as compared with age-matched control retina. EVC led to opposite reactions in astrocytes and Müller cells in terms of GFAP immunoreactivity. Late-onset glial reactivity also occurred in the contralateral retina.

  17. Glaucoma medications.

    PubMed

    Chae, Bora; Cakiner-Egilmez, Tulay; Desai, Manishi

    2013-01-01

    Glaucoma is a common eye condition that affects millions of individuals worldwide, making it the second-leading cause of blindness. Because glaucoma is associated with increased IOP level, the primary goal in treatment of glaucoma includes lowering IOP to prevent further progression of the disease. While various surgical interventions exist, medical therapy is currently the first line of treatment. Medical treatment of glaucoma includes topical beta-blockers, alpha-2 agonists, prostaglandins, parasympathomimetics and CAIs. Anti-glaucoma agents help reduce IOP by affecting the production of aqueous humor or increasing the outflow of aqueous through the trabecular or uveoscleral pathway. Choosing an appropriate medical regimen can be challenging and various factors such as efficacy, safety, cost and patient compliance must be considered. First-line treatment is often topical beta-blockers or prostaglandin analogs. However, beta-blocking agents can be associated with systemic side effects and need to be used cautiously in patients with serious concomitant cardiopulmonary disease. Alpha-2 agonists and parasympathomimetics are often considered second- or third-line treatment options but good adjunctive agents. Oral CAIs are often indicated for patients with elevated IOP in an acute setting or for patients resistant to other glaucoma medications and patients who are not good surgical candidates.

  18. Experimental development of advanced air filtration media based on electrospun polymer fibers

    NASA Astrophysics Data System (ADS)

    Ghochaghi, Negar

    Electrospinning is a process by which polymer fibers can be produced using an electrostatically driven fluid jet. Electrospun fibers can be produced at the micro- or nano-scale and are, therefore, very promising for air filtration applications. However, because electrospun fibers are electrically charged, it is difficult to control the morphology of filtration media. Fiber size, alignment and uniformity are very important factors that affect filter performance. The focus of this project is to understand the relationship between filter morphology and performance and to develop new methods to create filtration media with optimum morphology. This study is divided into three focus areas: unimodal and bimodal microscale fibrous media with aligned, orthogonal and random fiber orientations; unimodal and bimodal nanoscale fibers in random orientations; bimodal micrometer and nanometer fiber media with orthogonally aligned orientations. The results indicate that the most efficient filters, which are those with the highest ratio of particle collection efficiency divided by pressure drop, can be obtained through fabricating filters in orthogonal layers of aligned fibers with two different fiber diameters. Moreover, our results show that increasing the number of layers increases the performance of orthogonally layered fibers. Also, controlling fiber spacing in orthogonally layered micrometer fiber media can be an alternative way to study the filtration performance. Finally, such coatings presented throughout this research study can be designed and placed up-stream, down-stream, and/or in between conventional filters.

  19. Colloid filtration in surface dense vegetation: Experimental results and theoretical predictions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding colloid and colloid-facilitated contaminant transport in overland flow through dense vegetation is essential to protect water quality for the environment. In previous studies, a single-stem efficiency theory for rigid and clean stem systems has been developed to predict colloid filtrat...

  20. African Americans and Glaucoma

    MedlinePlus

    ... Involved News About Us Donate In This Section African Americans and Glaucoma email Send this article to a ... glaucoma is the leading cause of blindness in African Americans. Half of those with glaucoma don't know ...

  1. The dark phase intraocular pressure elevation and retinal ganglion cell degeneration in a rat model of experimental glaucoma.

    PubMed

    Kwong, Jacky M K; Vo, Nancy; Quan, Ann; Nam, Michael; Kyung, Haksu; Yu, Fei; Piri, Natik; Caprioli, Joseph

    2013-07-01

    analysis showed statistical significance for the relationships between the total cumulative IOP elevation and RGC body loss (P = 0.009), and axonal injury (P = 0.016). To examine the role of light and dark IOP elevation in RGC body loss and axonal injury, analyses for the association between different light/dark IOP factors and percentage of RGC body loss/axonal injury grading were performed and only the association between the cumulative dark IOP elevation and axonal injury showed statistical significance (P = 0.033). The findings demonstrated that the cumulative total (light and dark) IOP elevation is a risk factor to RGC degeneration in a rat model of experimental glaucoma using modified partial laser photocoagulation at 330° trabecular meshwork. Further investigations are required to understand the role of longer term light and dark phase IOP elevation contributing to the progression of degeneration in different compartments of RGCs.

  2. Experimental Glaucoma Causes Optic Nerve Head Neural Rim Tissue Compression: A Potentially Important Mechanism of Axon Injury

    PubMed Central

    Fortune, Brad; Reynaud, Juan; Hardin, Christy; Wang, Lin; Sigal, Ian A.; Burgoyne, Claude F.

    2016-01-01

    Purpose We tested the hypothesis that experimental glaucoma (EG) results in greater thinning of the optic nerve head (ONH) neural rim tissue than the peripapillary retinal nerve fiber layer (RNFL) tissue. Methods Longitudinal spectral-domain optical coherence tomography (SDOCT) imaging of the ONH and peripapillary RNFL was performed every other week under manometric IOP control (10 mm Hg) in 51 nonhuman primates (NHP) during baseline and after induction of unilateral EG. The ONH parameter minimum rim area (MRA) was derived from 80 radial B-scans centered on the ONH; RNFL cross-sectional area (RNFLA) from a peripapillary circular B-scan with 12° diameter. Results In control eyes, MRA was 1.00 ± 0.19 mm2 at baseline and 1.00 ± 0.19 mm2 at the final session (P = 0.77), while RNFLA was 0.95 ± 0.09 and 0.95 ± 0.10 mm2, respectively (P = 0.96). In EG eyes, MRA decreased from 1.00 ± 0.19 mm2 at baseline to 0.63 ± 0.21 mm2 at the final session (P < 0.0001), while RNFLA decreased from 0.95 ± 0.09 to 0.74 ± 0.19 mm2, respectively (P < 0.0001). Thus, MRA decreased by 36.4 ± 20.6% in EG eyes, significantly more than the decrease in RNFLA (21.7 ± 19.4%, P < 0.0001). Other significant changes in EG eyes included increased Bruch's membrane opening (BMO) nonplanarity (P < 0.05), decreased BMO aspect ratio (P < 0.0001), and decreased MRA angle (P < 0.001). Bruch's membrane opening area did not change from baseline in either control or EG eyes (P = 0.27, P = 0.15, respectively). Conclusions Optic nerve head neural rim tissue thinning exceeded peripapillary RNFL thinning in NHP EG. These results support the hypothesis that axon bundles are compressed transversely within the ONH rim along with glaucomatous deformation of connective tissues. PMID:27564522

  3. Experimental and Numerical Investigations on Flue Gas Purification during Hot Gas Filtration

    SciTech Connect

    Thulfaut, C.; Renz, U.

    2002-09-19

    The aim of the actual investigations is to integrate the catalytic reduction of carbon monoxide and particularly nitric oxides into the hot gas filtration process with ceramic filter elements of fluidized bed combustors which mainly represent an important N2O-source. According to Klein (Klein 1994) worldwide approx. 260 coal-fired power plants with fluidized bed combustors in the power range > 50 MWel existed in 1994, to which approx. 1% of the global coal dissipation corresponds. These emitted dinitrogen oxide with 70 kt/a, however, 20% of the entire N2O amounts from stationary firing plants. After Kleins calculations an increase of coal-fired fluidized bed combustors only by 10% triples the N2O emission.

  4. Filtration of triazine herbicides by polymer-clay sorbents: coupling an experimental mechanistic approach with empirical modeling.

    PubMed

    Gardi, Ido; Nir, Shlomo; Mishael, Yael G

    2015-03-01

    Triazine herbicides detected in surface and groundwater pose environmental and health risks. Removal of triazine herbicides (simazine, atrazine and terbuthylazine) by polymer-clay composites was studied and modeled. Their binding by a poly 4-vinyl pyridine co styrene-montmorillonite (HPVP-CoS-MMT) composite was especially high due to specific interactions between the herbicides and polymer, mainly hydrogen bonds and π-π stacking. The binding kinetics to the composite was in the order of simazine > atrazine > terbuthylazine, which was in accord with their equilibrium Langmuir binding coefficients; 44,000, 17,500 and 16,500 M(-1), respectively, which correlated with herbicide accessibility to form specific interaction with the polymer. Simazine binding kinetics to the composite was significantly faster than to granulated activated carbon (GAC), reaching 93% vs 38% of the maximal adsorption within 10 min, respectively. Herbicide filtration by composite columns was adequately fitted by a model which considers convection and employs Langmuir formalism for kinetics of adsorption/desorption. Filtration of simazine (10 μg L(-1)) by composite columns (40 cm long, which included 26 g composite mixed with sand 1:40 (weight ratio)), was well predicted by the model with nearly 120 L purified, i.e., effluent concentrations were below regulation limit (3 μg L(-1)). Effluent concentrations from GAC columns exceeded the limit after filtering 5 L. Experimental results and model predictions suggest that while GAC has a high capacity for simazine binding, the composite has higher affinity towards the herbicide and its adsorption is faster, which yields more efficient filtration by composite columns.

  5. [Iridoschisis and glaucoma].

    PubMed

    Radian, A B; Alupei, A

    1999-01-01

    Three patients with unilateral iridoschisis and glaucoma (1 with bilateral open-angle glaucoma, 1 with unilateral glaucoma) were observed for 3 to 15 years. In none of these patients did iridoschisis progress and a good control of the glaucoma was achieved. The mechanism of this rare condition is yet not clear.

  6. Simultaneous Complement Response via Lectin Pathway in Retina and Optic Nerve in an Experimental Autoimmune Glaucoma Model

    PubMed Central

    Reinehr, Sabrina; Reinhard, Jacqueline; Gandej, Marcel; Kuehn, Sandra; Noristani, Rozina; Faissner, Andreas; Burkhard Dick, H.; Joachim, Stephanie C.

    2016-01-01

    Glaucoma is a multifactorial disease and especially mechanisms occurring independently from an elevated intraocular pressure (IOP) are still unknown. Likely, the immune system contributes to the glaucoma pathogenesis. Previously, IgG antibody depositions and retinal ganglion cell (RGC) loss were found in an IOP-independent autoimmune glaucoma model. Therefore, we investigated the possible participation of the complement system in this model. Here, rats were immunized with bovine optic nerve homogenate antigen (ONA), while controls (Co) received sodium chloride (n = 5–6/group). After 14 days, RGC density was quantified on flatmounts. No changes in the number of RGCs could be observed at this point in time. Longitudinal optic nerve sections were stained against the myelin basic protein (MBP). We could note few signs of degeneration processes. In order to detect distinct complement components, retinas and optic nerves were labeled with complement markers at 3, 7, 14, and 28 days and analyzed. Significantly more C3 and MAC depositions were found in retinas and optic nerves of the ONA group. These were already present at day 7, before RGC loss and demyelination occurred. Additionally, an upregulation of C3 protein was noted via Western Blot at this time. After 14 days, quantitative real-time PCR revealed significantly more C3 mRNA in the ONA retinas. An upregulation of the lectin pathway-associated mannose-serine-protease-2 (MASP2) was observed in the retinas as well as in the optic nerves of the ONA group after 7 days. Significantly more MASP2 in retinas could also be observed via Western Blot analyses at this point in time. No effect was noted in regard to C1q. Therefore, we assume that the immunization led to an activation of the complement system via the lectin pathway in retinas and optic nerves at an early stage in this glaucoma model. This activation seems to be an early response, which then triggers degeneration. These findings can help to develop novel

  7. The prediction of filter belt press dewatering efficiency for activated sludge by experimentation on filtration compression cells.

    PubMed

    Olivier, J; Vaxelaire, J

    2004-12-01

    The filter belt press is commonly used to dewater activated sludge. However, little research has been done on this process and the prediction of its efficiency. Experimentation has been carried out in a filtration compression cell (FCC) and in a pilot scale filter belt press. It offers a way of determining filter belt press efficiency thanks to simple laboratory research. The pressure distribution around the pressing roller was measured inside the pilot scale filter belt press. It showed progressive increase (up to a certain maximum value: plateau), which was followed by a rapid decrease. The impact of the progressive increase of applied pressure onto the dry solid sludge content was observed in FCC. Similar dry solid contents were obtained from both the above laboratory devices when the application of the pressure is comparable (in time and increasing rate).

  8. An experimental model of affinity filtration for the isolation of egg white Lysozyme using Cibacron Blue immobilized to yeast cells.

    PubMed

    Ferraris, María del Pilar; Gonzalez, Ulises A; Aguilar, Carlos F; Rodríguez, Jorge A

    2016-05-01

    An experimental model of affinity filtration process was designed using a macroligand composed by Cibacron Blue F3GA immobilized to yeast cells. Its performance was evaluated, at bench scale, through the recovery of egg white Lysozyme. The selective and reversible binding between the Cibacron ligand molecule and the enzyme is described. The separation of Lysozyme from the protein mixture included the application of stages such as affinity adsorption, concentration, diafiltration and elution. A tangential microfiltration system with an inorganic membrane was designed. The main finding was the development of the diafiltration operation, key stage in the enzyme isolation. The macroligand particle kept its integrity along the whole process and the degree of purity of the isolated Lysozyme was significant.

  9. IOP induces upregulation of GFAP and MHC-II and microglia reactivity in mice retina contralateral to experimental glaucoma

    PubMed Central

    2012-01-01

    Background Ocular hypertension is a major risk factor for glaucoma, a neurodegenerative disease characterized by an irreversible decrease in ganglion cells and their axons. Macroglial and microglial cells appear to play an important role in the pathogenic mechanisms of the disease. Here, we study the effects of laser-induced ocular hypertension (OHT) in the macroglia, microglia and retinal ganglion cells (RGCs) of eyes with OHT (OHT-eyes) and contralateral eyes two weeks after lasering. Methods Two groups of adult Swiss mice were used: age-matched control (naïve, n = 9); and lasered (n = 9). In the lasered animals, both OHT-eyes and contralateral eyes were analyzed. Retinal whole-mounts were immunostained with antibodies against glial fibrillary acid protein (GFAP), neurofilament of 200kD (NF-200), ionized calcium binding adaptor molecule (Iba-1) and major histocompatibility complex class II molecule (MHC-II). The GFAP-labeled retinal area (GFAP-RA), the intensity of GFAP immunoreaction (GFAP-IR), and the number of astrocytes and NF-200 + RGCs were quantified. Results In comparison with naïve: i) astrocytes were more robust in contralateral eyes. In OHT-eyes, the astrocyte population was not homogeneous, given that astrocytes displaying only primary processes coexisted with astrocytes in which primary and secondary processes could be recognized, the former having less intense GFAP-IR (P < 0.001); ii) GFAP-RA was increased in contralateral (P <0.05) and decreased in OHT-eyes (P <0.001); iii) the mean intensity of GFAP-IR was higher in OHT-eyes (P < 0.01), and the percentage of the retinal area occupied by GFAP+ cells with higher intensity levels was increased in contralateral (P = 0.05) and in OHT-eyes (P < 0.01); iv) both in contralateral and in OHT-eyes, GFAP was upregulated in Müller cells and microglia was activated; v) MHC-II was upregulated on macroglia and microglia. In microglia, it was similarly expressed in contralateral

  10. Filtration Fundamentals.

    ERIC Educational Resources Information Center

    Ward, Ken; Hunsaker, Scot

    1997-01-01

    Examines how choice of commercial swimming-pool filtration systems is driven by the project-specific needs of the pools. Also highlighted are definitions of specific terms used when discussing filtration systems. Questions that pool designers can answer to make filtration-system purchasing decisions are listed. (GR)

  11. Water Filtration

    ERIC Educational Resources Information Center

    Jacobsen, Erica K.

    2004-01-01

    A water filtration column is devised by students using a two-liter plastic bottle containing gravel, sand, and activated charcoal, to test the filtration potential of the column. Results indicate that the filtration column eliminates many of the contaminating materials, but does not kill bacteria.

  12. Minimally invasive glaucoma surgery: current status and future prospects

    PubMed Central

    Richter, Grace M; Coleman, Anne L

    2016-01-01

    Minimally invasive glaucoma surgery aims to provide a medication-sparing, conjunctival-sparing, ab interno approach to intraocular pressure reduction for patients with mild-to-moderate glaucoma that is safer than traditional incisional glaucoma surgery. The current approaches include: increasing trabecular outflow (Trabectome, iStent, Hydrus stent, gonioscopy-assisted transluminal trabeculotomy, excimer laser trabeculotomy); suprachoroidal shunts (Cypass micro-stent); reducing aqueous production (endocyclophotocoagulation); and subconjunctival filtration (XEN gel stent). The data on each surgical procedure for each of these approaches are reviewed in this article, patient selection pearls learned to date are discussed, and expectations for the future are examined. PMID:26869753

  13. Daily Life with Glaucoma

    MedlinePlus

    ... Size Small Text Medium Text Large Text Contrast Dark on Light Light on Dark Donate Search Menu Donate What is Glaucoma? Care ... Low Vision Resources Medication Guide Resources on the Web » See All Articles Help the Cause Glaucoma affects ...

  14. Glaucoma in Asian Populations

    MedlinePlus

    ... Us Donate In This Section Glaucoma In Asian Populations email Send this article to a friend by ... an even more serious problem as the world population and longevity increases. The other major glaucoma type ...

  15. Screening for Glaucoma

    MedlinePlus

    ... enough evidence to determine the potential benefits and harms of glaucoma screening for adults who do not ... Glaucoma is a group of diseases that can harm the eye’s optic nerve. The optic nerve carries ...

  16. Types of Glaucoma

    MedlinePlus

    ... Support Groups For more information about area support groups, please click here . NEWSWORTHY WORLD GLAUCOMA WEEK - GET INVOLVED! click for info © Copyright 2017 The Glaucoma Foundation. All Rights Reserved. | Site Map Web design by Integra Strategic Technologies

  17. Get Tested for Glaucoma!

    MedlinePlus

    ... Glaucoma! Past Issues / Fall 2009 Table of Contents Taylor Klose continues to battle the effects of glaucoma. ... The one on the wall." "What wall?" For Taylor Klose, 72, those questions are no joke. Klose ...

  18. Magnetic-seeding filtration

    SciTech Connect

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab.

  19. Experimental investigation of the formaldehyde removal mechanisms in a dynamic botanical filtration system for indoor air purification.

    PubMed

    Wang, Zhiqiang; Pei, Jingjing; Zhang, Jensen S

    2014-09-15

    Botanical filtration has been proved to be effective for indoor gas pollutant removal. To understand the roles of different transport, storage and removal mechanism by a dynamic botanical air filter, a series of experimental investigations were designed and conducted in this paper. Golden Pothos (Epipremnum aureum) plants was selected for test, and its original soil or activated/pebbles root bed was used in different test cases. It was found that flowing air through the root bed with microbes dynamically was essential to obtain meaningful formaldehyde removal efficiency. For static potted plant as normally place in rooms, the clean air delivery rate (CADR), which is often used to quantify the air cleaning ability of portable air cleaners, was only ∼ 5.1m(3)/h per m(2) bed, while when dynamically with air flow through the bed, the CADR increased to ∼ 233 m(3)/h per m(2) bed. The calculated CADR due to microbial activity is ∼ 108 m(3)/h per m(2) bed. Moisture in the root bed also played an important role, both for maintaining a favorable living condition for microbes and for absorbing water-soluble compounds such as formaldehyde. The role of the plant was to introduce and maintain a favorable microbe community which effectively degraded the volatile organic compounds adsorbed or absorbed by the root bed. The presence of the plant increased the removal efficiency by a factor of two based on the results from the bench-scale root bed experiments.

  20. Pediatric Glaucoma: Pharmacotherapeutic Options.

    PubMed

    Samant, Monica; Medsinge, Anagha; Nischal, Ken K

    2016-06-01

    Childhood glaucoma is a major therapeutic challenge for pediatric ophthalmologists and glaucoma specialists worldwide. Management depends on the etiology and age at presentation. A variety of drugs are available for the control of intraocular pressure in children; however, none of these drugs have been licensed by the regulatory agencies for use in children. Furthermore, evidence gained from randomized controlled trials in the pediatric population is sparse, and little is known regarding the use of newer anti-glaucoma preparations. This evidence-based review aims to discuss the available pharmacotherapeutic options for glaucoma in children. Topical adrenoceptor blockers, topical and systemic carbonic anhydrase inhibitors, prostaglandin (PG) analogs, adrenoceptor agonists, parasympathomimetics, and combined preparations are available for use in children, but usually as an off-label indication. Therefore, it is important to recognize that serious side effects have been reported, even with topical drops, and measures to reduce systemic absorption should be taken. Most drugs have been shown to have comparable ocular hypotensive effects, with the lowest occurrence of systemic side effects with PG analogs. Whereas a newly introduced prostaglandin analog, tafluprost, and some other preservative-free preparations have shown promising results in adult glaucoma patients, no pediatric reports are available as yet. Future studies may describe their role in treating pediatric glaucoma. This review also shares some suggested treatment pathways for primary congenital glaucoma (PCG), juvenile open angle glaucoma (JOAG), developmental glaucoma, aphakic/pseudophakic glaucoma, and uveitic glaucoma.

  1. Does Marijuana Help Treat Glaucoma?

    MedlinePlus

    ... Ophthalmologist Patient Stories Español Eye Health / Tips & Prevention Marijuana Sections Does Marijuana Help Treat Glaucoma? Why Eye ... Don't Recommend Marijuana for Glaucoma Infographic Does Marijuana Help Treat Glaucoma? Written by: David Turbert , contributing ...

  2. Electromagnetically Modified Filtration of Aluminum Melts—Part I: Electromagnetic Theory and 30 PPI Ceramic Foam Filter Experimental Results

    NASA Astrophysics Data System (ADS)

    Kennedy, Mark William; Akhtar, Shahid; Bakken, Jon Arne; Aune, Ragnhild E.

    2013-06-01

    In the present work, laboratory-scale continuous filtration tests of liquid A356 aluminum alloy have been performed. The tests were conducted using standard 30 PPI (pores per inch) ceramic foam filters combined with magnetic flux densities (~0.1 and 0.2 T), produced using two different induction coils operated at 50 Hz AC. A reference filtration test was also carried out under gravity conditions, i.e., without an applied magnetic field. The obtained results clearly prove that the magnetic field has a significant affect on the distribution of SiC particles. The influence of the electromagnetic Lorentz forces and induced bulk metal flow on the obtained filtration efficiencies and on the wetting behavior of the filter media by liquid aluminum is discussed. The magnitudes of the Lorentz forces produced by the induction coils are quantified based on analytical and COMSOL 4.2® finite element modeling.

  3. Closed angle glaucoma detection in RetCam images.

    PubMed

    Cheng, Jun; Liu, Jiang; Lee, Beng Hai; Wong, Damon Wing Kee; Yin, Fengshou; Aung, Tin; Baskaran, Mani; Shamira, Perera; Wong, Tien Yin

    2010-01-01

    Closed/Open angle glaucoma classification is important for glaucoma diagnosis. RetCam is a new imaging modality that captures the image of iridocorneal angle for the classification. However, manual grading and analysis of the RetCam image is subjective and time consuming. In this paper, we propose a system for intelligent analysis of iridocorneal angle images, which can differentiate closed angle glaucoma from open angle glaucoma automatically. Two approaches are proposed for the classification and their performances are compared. The experimental results show promising results.

  4. Experimental study on filtration and continuous regeneration of a particulate filter system for heavy-duty diesel engines.

    PubMed

    Tang, Tao; Zhang, Jun; Cao, Dongxiao; Shuai, Shijin; Zhao, Yanguang

    2014-12-01

    This study investigated the filtration and continuous regeneration of a particulate filter system on an engine test bench, consisting of a diesel oxidation catalyst (DOC) and a catalyzed diesel particulate filter (CDPF). Both the DOC and the CDPF led to a high conversion of NO to NO2 for continuous regeneration. The filtration efficiency on solid particle number (SPN) was close to 100%. The post-CDPF particles were mainly in accumulation mode. The downstream SPN was sensitively influenced by the variation of the soot loading. This phenomenon provides a method for determining the balance point temperature by measuring the trend of SPN concentration.

  5. The Suprachoroidal Route in Glaucoma Surgery

    PubMed Central

    Shaarawy, Tarek

    2016-01-01

    ABSTRACT Glaucoma surgeries targeting the uveoscleral drainage pathways have been drawing more attention lately. Among all the available techniques, procedures focusing on the supra-choroidal space seem particularly promising, by making use of a presumably efficient and secure outflow route and avoiding subconjunctival filtration blebs. The purpose of this review is to assess the efficacy and the security of the different suprachoroidal drainage implants, namely the CyPass Micro-Stent, the iStent Supra, the SOLX Gold Shunt, the Aquashunt, and the STARflo Glaucoma Implant. Most clinical studies seem to currently point toward the direction that there are actual benefits in suprachoroidal surgeries by avoiding bleb-related complications. Nevertheless, even suprachoroidal implants may be subject to scarring and failure. More data are still needed, especially concerning long-term effects, although the approach does seem appealing. How to cite this article: Gigon A, Shaarawy T. The Suprachoroidal Route in Glaucoma Surgery. J Curr Glaucoma Pract 2016;10(1): 13-20. PMID:27231415

  6. [Music and Glaucoma].

    PubMed

    Plange, N

    2017-02-01

    Music may have multiple influences on the human organism. A possible therapeutic effect for patients with glaucoma has been postulated, aside from the known impact of music on the cardiovascular system, psychogenic effects and a short-term improvement in mental performance (Mozart effect). The higher level of mental stress in patients with glaucoma and type-A personality behaviour may be related to higher intraocular pressure in patients with glaucoma. Relaxing music may have a positive impact in these patients, related to a reduction in intraocular pressure or its fluctuations. However, only limited data exist on the effects of music on intraocular pressure. No clinical studies have yet been performed to investigate the effect of music or music therapy on glaucoma progression. The music of Mozart may influence visual field examinations, possibly due to a positive short term effect on mental performance. This factor needs to be addressed in studies dealing with the effect of music in glaucoma. The relevance of intraocular pressure increases in professional wind instrument players is controversial. An increased level of care might be advisable in patients with advanced glaucoma. The influences of music on humans, altered personality profiles in patients with glaucoma and the studies showing some effect of stress on intraocular pressure stress the relevance of psychological support for glaucoma patients, who are confronted with a disease with a high longterm risk of blindness.

  7. [Vascular factors in glaucoma].

    PubMed

    Mottet, B; Aptel, F; Geiser, M; Romanet, J P; Chiquet, C

    2015-12-01

    The exact pathophysiology of glaucoma is not fully understood. Understanding of the vascular pathophysiology of glaucoma requires: knowing the techniques for measuring ocular blood flow and characterizing the topography of vascular disease and the mechanisms involved in this neuropathy. A decreased mean ocular perfusion pressure and a loss of vascular autoregulation are implicated in glaucomatous disease. Early decrease in ocular blood flow has been identified in primary open-angle glaucoma and normal pressure glaucoma, contributing to the progression of optic neuropathy. The vascular damage associated with glaucoma is present in various vascular territories within the eye (from the ophthalmic artery to the retina) and is characterized by a decrease in basal blood flow associated with a dysfunction of vasoregulation.

  8. Nanotechnology Applications for Glaucoma.

    PubMed

    Cetinel, Sibel; Montemagno, Carlo

    2016-01-01

    Glaucoma is the second leading cause of blindness worldwide, and the antiglaucoma treatments currently available suffer from various complications. Nanotechnology-based treatments show a great deal of promise in overcoming these complications and form the basis for next-generation glaucoma treatment strategies, with the help of applications such as controlled release, targeted delivery, increased bioavailability, diffusion limitations, and biocompatibility. Significant progress has been made in nanomedicine in the efficiency of antiglaucoma medications, nanofabrication systems such as microelectromechanical systems that remove the limitations of nanodevices, and tissue regeneration vesicles for developing glaucoma treatments not based on intraocular pressure. With the use of these advanced technologies, the prevention of glaucoma-induced blindness will be possible in the near future. Herein, we reviewed the recent advances in nanotechnology-based treatment strategies for glaucoma.

  9. Filtration by eyelashes

    NASA Astrophysics Data System (ADS)

    Vistarakula, Krishna; Bergin, Mike; Hu, David

    2010-11-01

    Nearly every mammalian and avian eye is rimmed with lashes. We investigate experimentally the ability of lashes to reduce airborne particle deposition in the eye. We hypothesize that there is an optimum eyelash length that maximizes both filtration ability and extent of peripheral vision. This hypothesis is tested using a dual approach. Using preserved heads from 36 species of animals at the American Museum of Natural History, we determine the relationship between eye size and eyelash geometry (length and spacing). We test the filtration efficacy of these geometries by deploying outdoor manikins and measuring particle deposition rate as a function of eyelash length.

  10. A Period of Controlled Elevation of IOP (CEI) Produces the Specific Gene Expression Responses and Focal Injury Pattern of Experimental Rat Glaucoma

    PubMed Central

    Morrison, John C.; Cepurna, William O.; Tehrani, Shandiz; Choe, Tiffany E.; Jayaram, Hari; Lozano, Diana C.; Fortune, Brad; Johnson, Elaine C.

    2016-01-01

    Purpose We determine if several hours of controlled elevation of IOP (CEI) will produce the optic nerve head (ONH) gene expression changes and optic nerve (ON) damage pattern associated with early experimental glaucoma in rats. Methods The anterior chambers of anesthetized rats were cannulated and connected to a reservoir to elevate IOP. Physiologic parameters were monitored. Following CEI at various recovery times, ON cross-sections were graded for axonal injury. Anterior ONHs were collected at 0 hours to 10 days following CEI and RNA extracted for quantitative PCR measurement of selected messages. The functional impact of CEI was assessed by electroretinography (ERG). Results During CEI, mean arterial pressure (99 ± 6 mm Hg) and other physiologic parameters remained stable. An 8-hour CEI at 60 mm Hg produced significant focal axonal degeneration 10 days after exposure, with superior lesions in 83% of ON. Message analysis in CEI ONH demonstrated expression responses previously identified in minimally injured ONH following chronic IOP elevation, as well as their sequential patterns. Anesthesia with cannulation at 20 mm Hg did not alter these message levels. Electroretinographic A- and B-waves, following a significant reduction at 2 days after CEI, were fully recovered at 2 weeks, while peak scotopic threshold response (pSTR) remained mildly but significantly depressed. Conclusions A single CEI reproduces ONH message changes and patterns of ON injury previously observed with chronic IOP elevation. Controlled elevation of IOP can allow detailed determination of ONH cellular and functional responses to an injurious IOP insult and provide a platform for developing future therapeutic interventions. PMID:27942722

  11. Comparing Optic Nerve Head Rim Width, Rim Area, and Peripapillary Retinal Nerve Fiber Layer Thickness to Axon Count in Experimental Glaucoma

    PubMed Central

    Fortune, Brad; Hardin, Christy; Reynaud, Juan; Cull, Grant; Yang, Hongli; Wang, Lin; Burgoyne, Claude F.

    2016-01-01

    Purpose We compare spectral-domain optical coherence tomography (SDOCT) measurements of minimum rim width (MRW), minimum rim area (MRA), and peripapillary retinal nerve fiber layer thickness (RNFLT) to complete orbital optic nerve axon counts in nonhuman primates (NHP) with unilateral experimental glaucoma (EG). Methods Biweekly SDOCT measurements of MRW, MRA, and RNFLT were acquired under manometric IOP control (10 mm Hg) in 51 NHP during baseline (mean ± SD, 5.0 ± 1.6 sessions) and after laser photocoagulation was applied to the trabecular meshwork of one eye to induce chronic IOP elevation. At the study endpoint (predefined for each NHP), 100% axon counts were obtained from each optic nerve. Results For SDOCT parameters at baseline, the correlation between the two eyes of each animal was strongest for RNFLT (R = 0.97) and MRW (R = 0.97), but lower for MRA (R = 0.85). At the final time point, average values in EG eyes relative to control eyes were: −22% for RNFLT, −38% for MRW, −36% for MRA, and −36% for optic nerve axons. The correlation with axon counts was strongest for RNFLT (R = 0.81), compared to MRW (R = 0.72, P = 0.001) or MRA (R = 0.70, P = 0.001). Diagnostic sensitivity was 75% for RNFLT, 90% for MRW, and 88% for MRA; all had 100% specificity. Conclusions Peripapillary RNFLT was correlated more closely with total orbital optic nerve axon count than were the ONH parameters MRW or MRA. This is likely because glaucomatous deformation (beyond axon loss alone) has a greater influence on the ONH parameters MRW and MRA than on RNFLT. PMID:27409499

  12. Ahmed glaucoma valve implant: surgical technique and complications

    PubMed Central

    Riva, Ivano; Roberti, Gloria; Oddone, Francesco; Konstas, Anastasios GP; Quaranta, Luciano

    2017-01-01

    Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications. PMID:28255226

  13. Effectiveness of Membrane Filtration to Improve Drinking Water: A Quasi-Experimental Study from Rural Southern India

    PubMed Central

    Francis, Mark Rohit; Sarkar, Rajiv; Roy, Sheela; Jaffar, Shabbar; Mohan, Venkata Raghava; Kang, Gagandeep; Balraj, Vinohar

    2016-01-01

    Since point-of-use methods of water filtration have shown limited acceptance in Vellore, southern India, this study evaluated the effectiveness of decentralized membrane filtration 1) with safe storage, 2) without safe storage, versus 3) no intervention, consisting of central chlorination as per government guidelines, in improving the microbiological quality of drinking water and preventing childhood diarrhea. Periodic testing of water sources, pre-/postfiltration samples, and household water, and a biweekly follow up of children less than 2 years of age was done for 1 year. The membrane filters achieved a log reduction of 0.86 (0.69–1.06), 1.14 (0.99–1.30), and 0.79 (0.67–0.94) for total coliforms, fecal coliforms, and Escherichia coli, respectively, in field conditions. A 24% (incidence rate ratio, IRR [95% confidence interval, CI] = 0.76 [0.51–1.13]; P = 0.178) reduction in diarrheal incidence in the intervention village with safe storage and a 14% (IRR [95% CI] = 1.14 [0.75–1.77]; P = 0.530) increase in incidence for the intervention village without safe storage versus no intervention village was observed, although not statistically significant. Microbiologically, the membrane filters decreased fecal contamination; however, provision of decentralized membrane-filtered water with or without safe storage was not protective against childhood diarrhea. PMID:27601525

  14. Detection of rare circulating breast cancer cells by filtration cytometry and identification by DNA content: sensitivity in an experimental model.

    PubMed

    Rostagno, P; Moll, J L; Bisconte, J C; Caldani, C

    1997-01-01

    Current methods of detecting micrometastases in breast cancer fail in a large proportion of patients. Therefore an improved method for detection of metastases in blood samples could be of great clinical interest both for prognosis and selection of patients for adjuvant systemic therapy. We have developed a new non-invasive method which associates immuno-magnetic separation and filtration cytometry. The sensitivity of our procedure was evaluated in a model system using a mixture from a human breast cancer cell line (MCF-7) and a normal human blood sample. The identification of tumoral cells was achieved by measuring DNA content in comparison with standard cells. The lowest concentration of MCF-7 detected was 1 tumoral cell in 500,000 white blood cells. In addition, filtration cytometry provides a visual control of nuclei permitting the elimination of all doubtful cases and an automatic count of tumoral cells directly per ml of blood, which may be an independent predictor of early relapse. This new method may avoid unnecessary axillary lymph node dissection in patients with negative nodes. Our procedure seems suitable for the detection of rare circulating cells in routine laboratory testing and could be used in other applications.

  15. Effectiveness of Membrane Filtration to Improve Drinking Water: A Quasi-Experimental Study from Rural Southern India.

    PubMed

    Francis, Mark Rohit; Sarkar, Rajiv; Roy, Sheela; Jaffar, Shabbar; Mohan, Venkata Raghava; Kang, Gagandeep; Balraj, Vinohar

    2016-11-02

    Since point-of-use methods of water filtration have shown limited acceptance in Vellore, southern India, this study evaluated the effectiveness of decentralized membrane filtration 1) with safe storage, 2) without safe storage, versus 3) no intervention, consisting of central chlorination as per government guidelines, in improving the microbiological quality of drinking water and preventing childhood diarrhea. Periodic testing of water sources, pre-/postfiltration samples, and household water, and a biweekly follow up of children less than 2 years of age was done for 1 year. The membrane filters achieved a log reduction of 0.86 (0.69-1.06), 1.14 (0.99-1.30), and 0.79 (0.67-0.94) for total coliforms, fecal coliforms, and Escherichia coli, respectively, in field conditions. A 24% (incidence rate ratio, IRR [95% confidence interval, CI] = 0.76 [0.51-1.13]; P = 0.178) reduction in diarrheal incidence in the intervention village with safe storage and a 14% (IRR [95% CI] = 1.14 [0.75-1.77]; P = 0.530) increase in incidence for the intervention village without safe storage versus no intervention village was observed, although not statistically significant. Microbiologically, the membrane filters decreased fecal contamination; however, provision of decentralized membrane-filtered water with or without safe storage was not protective against childhood diarrhea.

  16. Facts about Glaucoma

    MedlinePlus

    ... several evenly spaced burns that stretch the drainage holes in the meshwork. This allows the fluid to ... who may be at high risk for glaucoma-African Americans over age 40; everyone over age 60, especially ...

  17. Five Common Glaucoma Tests

    MedlinePlus

    ... pressure Tonometry The shape and color of the optic nerve Ophthalmoscopy (dilated eye exam) The complete field ... This diagnostic procedure helps the doctor examine your optic nerve for glaucoma damage. Eye drops are used ...

  18. Glaucoma Research Foundation

    MedlinePlus

    ... find a cure for glaucoma. The Biomarker Initiative Catalyst for a Cure Applying for a Grant Photos ... Gala The Annual Gala showcases the visionaries and catalysts who believe in our mission. The Gala took ...

  19. Glaucoma, Open-Angle

    MedlinePlus

    ... Courier services use: Rockville, MD 20852) 301-451-2020 Research at NEI Office of the Scientific Director ... Eye Disease Education Program Glaucoma Education Program Low Vision Education Program Hispanic/Latino Program Vision and Aging ...

  20. Surgical Treatment of Canine Glaucoma: Filtering and End-Stage Glaucoma Procedures.

    PubMed

    Maggio, Federica; Bras, Dineli

    2015-11-01

    Canine glaucoma is a common cause of vision loss associated with raised intraocular pressure, and leads to damage of the retina and optic nerve head. In most cases, medical treatment alone cannot provide long-term management of intraocular pressure control and preservation of vision. Surgical intervention is usually recommended to either decrease aqueous humor production, or increase its outflow. Among the current available procedures, filtering techniques are aimed at increasing aqueous humor outflow. Proper surgical timing and a combination of cyclodestructive and filtering procedures have been recently suggested to improve the long-term success of surgical treatment in dogs. Bleb fibrosis and surgical failure are still common occurrences in filtration surgery with relapse of glaucoma and vision loss. End stage procedures, such as enucleation, evisceration with intrascleral prosthesis, and chemical ablation of the ciliary bodies are then recommended to address chronic discomfort in buphthalmic and blind eyes.

  1. New Tool to Predict Glaucoma

    MedlinePlus

    ... News About Us Donate In This Section A New Tool to Predict Glaucoma email Send this article ... determine if a patient has glaucoma. Recently, a new tool has become available to eye care specialists ...

  2. Does Your Child Have Glaucoma?

    MedlinePlus

    ... Donate In This Section Does Your Child Have Glaucoma? email Send this article to a friend by ... a pediatric ophthalmologist. Signs and Symptoms of Childhood Glaucoma What to watch for in children under the ...

  3. Effect of filtration by activated charcoal on the toxicological activity of cigarette mainstream smoke from experimental cigarettes.

    PubMed

    Gaworski, Charles L; Schramke, Heike; Diekmann, Joerg; Meisgen, Thomas J; Tewes, Franz J; Veltel, Detlef J; Vanscheeuwijck, Patrick M; Rajendran, Narayanan; Muzzio, Miguel; Haussmann, Hans-Juergen

    2009-07-01

    Activated charcoal (AC) filtration reportedly decreases the yields of smoke vapor phase constituents including some identified as human carcinogens and respiratory irritants. Non-clinical studies including chemical smoke analysis, in vitro cytotoxicity and mutagenicity (bacterial and mammalian cells), and in vivo subchronic rat inhalation studies were carried out using machine smoking at ISO conditions with lit-end research cigarettes containing AC filters. The objective was to assess whether AC filter technology would alter the established toxicity profile of mainstream smoke by increasing or decreasing any known toxicological properties, or elicit new ones. The reduced yield of vapor phase irritants from AC filter cigarettes correlated with markedly decreased in vitro cytotoxicity and in vivo morphology of the nose and lower respiratory tract. Increased yields of particulate phase constituents (e.g. polycyclic aromatic hydrocarbons) in AC filtered smoke were noted in comparison to controls in some studies. The in vitro bacterial mutagenicity of AC filtered smoke particulate preparations was occasionally increased over control levels. Laryngeal epithelial thickness was increased in some rats inhaling AC filtered smoke in comparison to controls, an effect perhaps related to higher inspiratory flow. When tested under more intense Massachusetts Department of Public Health smoking conditions, AC filter associated reductions in vapor phase constituent yields were smaller than those seen with ISO conditions, but the effect on in vitro cytotoxicity remained.

  4. Cake Filtration in Viscoelastic Polymer Solutions

    NASA Astrophysics Data System (ADS)

    Surý, Alexander; Machač, Ivan

    2009-07-01

    In this contribution, the filtration equations for a cake filtration in viscoelastic fluids are presented. They are based on a capillary hybrid model for the flow of a power law fluid. In order to express the elastic pressure drop excess in the flow of viscoelastic filtrate through the filter cake and filter screen, modified Deborah number correction functions are included into these equations. Their validity was examined experimentally. Filtration experiments with suspensions of hardened polystyrene particles (Krasten) in viscoelastic aqueous solutions of polyacryl amides (0.4% and 0.6%wt. Kerafloc) were carried out at a constant pressure on a cylindrical filtration unit using filter screens of different resistance.

  5. [Perspectives in glaucoma surgery].

    PubMed

    Dietlein, T S

    2002-02-01

    Trabeculectomy is still considered to be the gold standard in the surgical treatment of the open-angle glaucomas. The additional application of local antimetabolites has reduced the rate of early filtering bled fibrosis, but increased the rate of essential late-postoperative complications. Growth factor inhibition and photodynamic therapy may be an alternative local treatment to enhance the results in filtering surgery. Non-penetrating glaucoma surgery and ab-interno trabecular surgery have several conceptual advantages, e.g. the lack of overfiltration or the untouched conjunctiva in the ab-interno approach. Clinical studies of these and other new procedures including antiglaucomatous retinectomy and subchoroidal shunt systems are currently performed in order to evaluate their potential and limits in the clinical management of glaucoma.

  6. Exciting Directions in Glaucoma

    PubMed Central

    Rasmussen, Carol A; Kaufman, Paul L

    2014-01-01

    Glaucoma is a complex, life-long disease that requires an individualized, multifaceted approach to treatment. Most patients will be started on topical ocular hypotensive eyedrop therapy and over time, multiple classes of drugs will be needed to control their intraocular pressure (IOP). The search for drugs with novel mechanisms of action, to treat those who do not achieve adequate IOP control with, or become refractory to, current therapeutics, is ongoing, as is the search for more efficient, targeted drug delivery methods. Gene transfer and stem cell applications for glaucoma therapeutics are moving forward. Advances in imaging technologies improve our understanding of glaucoma pathophysiology and enable more refined patient evaluation and monitoring, improving patient outcomes. PMID:25433744

  7. Selective laser trabeculoplasty (SLT): 1-year results in early and advanced open angle glaucoma.

    PubMed

    Schlote, Torsten; Kynigopoulos, Myron

    2016-02-01

    The purpose of this study was to examine the efficacy of selective laser trabeculoplasty (SLT) in eyes with early and more advanced stages of open angle glaucoma within 1 year of follow-up. Retrospective chart review in a consecutive series of patients treated by SLT to reduce intraocular pressure (IOP) or decrease number of topical medications in cases of discomfort and allergy. The cup-to-disc ratio of the optic nerve and the GSS 2 (glaucoma staging system 2) was used to differentiate between early (group 1) and more advanced (group 2) stages of glaucoma. At the time of SLT treatment, no new signs of glaucoma progression were seen. Only the first treated eye of every patient was included in the analysis. In group 1 (early glaucoma), 27 eyes were included. IOP reduction <21 mmHg/>20 % of the preoperative IOP-value and reduction of medication were achieved in 17 eyes (62.96 %). Successful re-treatment was necessary in 2 eyes (7.4 %). In group 2 (advanced glaucoma), 44 eyes underwent SLT. In eight eyes (18.18 %), filtrating surgery was necessary after initial SLT. In the remaining 36 eyes, IOP reduction <21 mmHg/>20 % of the baseline IOP was achieved in 26 eyes (59.09 % of 44 eyes) and IOP reduction <18 mmHg/> 30 % of the baseline IOP in 22 eyes (50 % of 44 eyes). SLT was safe and effective in nearly 2/3 of early glaucoma patients and also in 50 % of advanced glaucoma patients using stronger criteria of success. Failure of SLT in advanced glaucoma should lead to immediate filtrating surgery, which seems not to be associated with higher risk of fibrosis.

  8. A New Safety Concern for Glaucoma Treatment Demonstrated by Mass Spectrometry Imaging of Benzalkonium Chloride Distribution in the Eye, an Experimental Study in Rabbits

    PubMed Central

    Brignole-Baudouin, Françoise; Desbenoit, Nicolas; Hamm, Gregory; Liang, Hong; Both, Jean-Pierre; Brunelle, Alain; Fournier, Isabelle; Guerineau, Vincent; Legouffe, Raphael; Stauber, Jonathan; Touboul, David; Wisztorski, Maxence; Salzet, Michel; Laprevote, Olivier; Baudouin, Christophe

    2012-01-01

    We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for

  9. A new safety concern for glaucoma treatment demonstrated by mass spectrometry imaging of benzalkonium chloride distribution in the eye, an experimental study in rabbits.

    PubMed

    Brignole-Baudouin, Françoise; Desbenoit, Nicolas; Hamm, Gregory; Liang, Hong; Both, Jean-Pierre; Brunelle, Alain; Fournier, Isabelle; Guerineau, Vincent; Legouffe, Raphael; Stauber, Jonathan; Touboul, David; Wisztorski, Maxence; Salzet, Michel; Laprevote, Olivier; Baudouin, Christophe

    2012-01-01

    We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for

  10. Pars plana vitrectomy for malignant glaucoma in nonglaucomatous and in filtered glaucomatous eyes

    PubMed Central

    Matlach, Juliane; Slobodda, Joerg; Grehn, Franz; Klink, Thomas

    2012-01-01

    Purpose To assess the outcomes of pars plana vitrectomy for the treatment of malignant glaucoma in patients with and without previous filtration surgery. Patients and methods Data of 15 patients developing malignant glaucoma after trabeculectomy (60%) or following ophthalmic interventions other than filtration surgery (40%) were recorded retrospectively. Pars plana vitrectomy was performed in case of failed medical or laser treatment recreating the normal pathway of aqueous humor. The main outcome measures were the postoperative intraocular pressure (IOP), the frequency of complications, and success rate based on the following criteria: IOP reduction by ≥20% and to ≤21 mmHg (definition one) or an IOP < 18 mmHg (definition two) with (qualified success) and without (complete success) glaucoma medication. Results Vitrectomy reduced IOP from baseline in eyes with and without previous trabeculectomy during a median follow-up of 16.4 months (range 7 days to 58 months); although the majority of patients required glaucoma medication to reach desired IOP. The complete success rates were 11% (both definitions) for patients with filtering blebs and none of the patients without previous trabeculectomy had complete success at the 12-month visit. Complications were few and included transient shallowing of the anterior chamber, choroidal detachment, corneal decompensation, filtering bleb failure, and need for further IOP-lowering procedures. Conclusion Pars plana vitrectomy is equally effective for malignant glaucoma caused by trabeculectomy or interventions other than filtration surgery, although IOP-lowering medication is necessary in nearly all cases to maintain target IOP. PMID:23226000

  11. Pharmacotherapy of Glaucoma

    PubMed Central

    Schmidl, Doreen; Garhöfer, Gerhard; Popa-Cherecheanu, Alina

    2015-01-01

    Abstract Glaucoma is a group of diseases involving the optic nerve and associated structures, which is characterized by progressive visual field loss and typical changes of the optic nerve head (ONH). The only known treatment of the disease is reduction of intraocular pressure (IOP), which has been shown to reduce glaucoma progression in a variety of large-scale clinical trials. Nowadays, a relatively wide array of topical antiglaucoma drugs is available, including prostaglandin analogues, carbonic anhydrase inhibitors, beta-receptor antagonists, adrenergic agonists, and parasympathomimetics. In clinical routine, this allows for individualized treatment taking risk factors, efficacy, and safety into account. A major challenge is related to adherence to therapy. Sustained release devices may help minimize this problem but are not yet available for clinical routine use. Another hope arises from non-IOP-related treatment concepts. In recent years, much knowledge has been gained regarding the molecular mechanisms that underlie the disease process in glaucoma. This also strengthens the hope that glaucoma therapy beyond IOP lowering will become available. Implementing this concept with clinical trials remains, however, a challenge. PMID:25587905

  12. OCT Imaging in Glaucoma

    NASA Astrophysics Data System (ADS)

    Nevins, Jessica E.; Wollstein, Gadi; Schuman, Joel S.

    The precise micron scale quantification of ocular structures provided by OCT turn this technology to be a valuable tool in clinical evaluation of glaucoma patients. This chapter describes the clinical utility of OCT from choosing the scan pattern and scan location to the interpretation of the test outcome.

  13. Evaluation of post-treatment filter, Part I: Experimental study of DMMP and DIMP filtration at high temperature and high dew point using activated carbon. Final report, November 1994-September 1995

    SciTech Connect

    Mahle, J.J.; Buettner, L.C.; Mauer, S.

    1996-08-01

    A series of experimental results are reported for breakthrough of the agent simulants DMMP and DIMP on coconut carbon. This adsorbent is used in filters for the Chemical Demiliterization program. The conditions were appropriate for a post treatment stack gas filter. Results indicate that high capacity and long filtration times are achievable under moderate humidity conditions up to 180 degrees F.

  14. Gene therapy for retinal ganglion cell neuroprotection in glaucoma.

    PubMed

    Wilson, A M; Di Polo, A

    2012-02-01

    Glaucoma is the leading cause of irreversible blindness worldwide. The primary cause of glaucoma is not known, but several risk factors have been identified, including elevated intraocular pressure and age. Loss of vision in glaucoma is caused by the death of retinal ganglion cells (RGCs), the neurons that convey visual information from the retina to the brain. Therapeutic strategies aimed at delaying or halting RGC loss, known as neuroprotection, would be valuable to save vision in glaucoma. In this review, we discuss the significant progress that has been made in the use of gene therapy to understand mechanisms underlying RGC degeneration and to promote the survival of these neurons in experimental models of optic nerve injury.

  15. Ganglion cell death in glaucoma: from mice to men.

    PubMed

    Nickells, Robert W

    2007-01-01

    Glaucoma results from the degeneration of retinal ganglion cells and their axons. Over the last 20 years several important advancements have been made in our understanding of the molecular pathology of this disease, particularly through the development of rat models of experimental glaucoma and the characterization of a spontaneous secondary form of glaucoma in DBA/2 substrains of inbred mice. One of these advances is the observation that ganglion cells die by apoptosis, an intrinsic molecular pathway of programmed cell death. An important aspect of this cell death process is the concept that these cells actually undergo compartmentalized self-destruction. Importantly, genetic evidence now suggests that axons die independently of the apoptotic program that executes the cell body or soma. This review briefly summarizes some of the most significant developments in glaucoma research, with respect to the process of ganglion cell degeneration.

  16. Glaucoma: Symptoms, Diagnosis, Treatment and Latest Research

    MedlinePlus

    ... Feature: Glaucoma Glaucoma: Symptoms, Diagnosis, Treatment and Latest Research Past Issues / Fall 2009 Table of Contents Symptoms ... patients may need to keep taking drugs. Latest Research Researchers are studying the causes of glaucoma, looking ...

  17. The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery

    PubMed Central

    Bikbov, Mukharram Mukhtaramovich

    2015-01-01

    ABSTRACT The treatment of refractory glaucoma (RG) is challenging. The commonly adopted strategy in RG treatment is a glaucoma drainage device (GDD) implantation, which despite its radical nature may not always provide the desired intraocular pressure (IOP) levels for a long term. This review is based on the scientific literature on Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. The technique of AGV implantation is described and data for both the types, FP7 and FP8 performance are presented. The outcome with adjunct antimetabolite and anti-VEGF drugs are also highlighted. An insight is given about experimental and histological examinations of the filtering bleb encapsulation. The article also describes various complications and measures to prevent them. How to cite this article: Bikbov MM, Khusnitdinov II. The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery. J Curr Glaucoma Pract 2015;9(3):86-91. PMID:26997843

  18. Bacterial, viral and turbidity removal by intermittent slow sand filtration for household use in developing countries: experimental investigation and modeling.

    PubMed

    Jenkins, Marion W; Tiwari, Sangam K; Darby, Jeannie

    2011-11-15

    A two-factor three-block experimental design was developed to permit rigorous evaluation and modeling of the main effects and interactions of sand size (d(10) of 0.17 and 0.52 mm) and hydraulic head (10, 20, and 30 cm) on removal of fecal coliform (FC) bacteria, MS2 bacteriophage virus, and turbidity, under two batch operating modes ('long' and 'short') in intermittent slow sand filters (ISSFs). Long operation involved an overnight pause time between feeding of two successive 20 L batches (16 h average batch residence time (RT)). Short operation involved no pause between two 20 L batch feeds (5h average batch RT). Conditions tested were representative of those encountered in developing country field settings. Over a ten week period, the 18 experimental filters were fed river water augmented with wastewater (influent turbidity of 5.4-58.6 NTU) and maintained with the wet harrowing method. Linear mixed modeling allowed systematic estimates of the independent marginal effects of each independent variable on each performance outcome of interest while controlling for the effects of variations in a batch's actual residence time, days since maintenance, and influent turbidity. This is the first study in which simultaneous measurement of bacteria, viruses and turbidity removal at the batch level over an extended duration has been undertaken with a large number of replicate units to permit rigorous modeling of ISSF performance variability within and across a range of likely filter design configurations and operating conditions. On average, the experimental filters removed 1.40 log fecal coliform CFU (SD 0.40 log, N=249), 0.54 log MS2 PFU (SD 0.42 log, N=245) and 89.0 percent turbidity (SD 6.9 percent, N=263). Effluent turbidity averaged 1.24 NTU (SD 0.53 NTU, N=263) and always remained below 3 NTU. Under the best performing design configuration and operating mode (fine sand, 10 cm head, long operation, initial HLR of 0.01-0.03 m/h), mean 1.82 log removal of bacteria (98

  19. Nonwoven filtration mat production by electrospinning method

    NASA Astrophysics Data System (ADS)

    Lackowski, M.; Krupa, A.; Jaworek, A.

    2011-06-01

    The filtration of nanoparticles and submicron particles is an important problem in industry and health protection. One of the methods which can be used to solve this problem is to use nonwoven nanofibrous filters. The process of producing filtration mats of different thickness by electrospinning is presented in the paper. The experimental results on filtration properties of nanofibrous filter mat, including the efficiency of removal of cigarette smoke particles from a gas are also presented.

  20. The management of complicated glaucoma

    PubMed Central

    Clement, C I; Goldberg, Ivan

    2011-01-01

    Complicated glaucomas present considerable diagnostic and management challenges. Response to treatment can be unpredictable or reduced compared with other glaucomas. However, target intraocular pressure and preservation of vision may be achieved with selected medical, laser and surgical treatment. The evidence for such treatment is expanding and consequently affords clinicians a better understanding of established and novel techniques. Herein we review the mechanisms involved in the development of complicated glaucoma and the current evidence supporting its management. PMID:21150026

  1. Vérification expérimentale de la relation de réciprocité d'Onsager pour l'électro-osmose et l'électro-filtration dans une argile naturelleExperimental verification of the Onsager's reciprocal relations for electro-osmosis and electro-filtration phenomena on a saturated clay

    NASA Astrophysics Data System (ADS)

    Beddiar, Karim; Berthaud, Yves; Dupas, André

    2002-12-01

    This Note is devoted to the experimental verification of the Onsager's reciprocal relations in the particular case of electro-osmosis and electro-filtration. A special set up has been designed to carry out the measurements of both the electro-osmotic permeability and the streaming potential. This has been performed by using a natural material i.e., saturated kaolinite. To cite this article: K. Beddiar et al., C. R. Mecanique 330 (2002) 893-898.

  2. Glaucoma history and risk factors.

    PubMed

    McMonnies, Charles W

    Apart from the risk of developing glaucoma there is also the risk that it is not detected and irreversible loss of vision ensues. Some studies of methods of glaucoma diagnosis have examined the results of instrument-based examinations with great if not complete reliance on objective findings in arriving at a diagnosis. The very valuable advances in glaucoma detection instrument technologies, and apparent increasing dependence on them, may have led to reduced consideration of information available from a patient history in those studies. Dependence on objective evidence of glaucomatous pathology may reduce the possibility of detecting glaucoma suspects or patients at risk for becoming glaucoma suspects. A valid positive family history of glaucoma is very valuable information. However, negative family histories can often be unreliable due to large numbers of glaucoma cases being undiagnosed. No evidence of family history is appropriate rather than no family history. In addition the unreliability of a negative family history is increased when patients with glaucoma fail to inform their family members. A finding of no family history can only be stated as no known family history. In examining the potential diagnostic contribution from a patient history, this review considers, age, frailty, race, type and degree of refractive error, systemic hyper- and hypotension, vasospasm, migraine, pigmentary dispersion syndrome, pseudoexfoliation syndrome, obstructive sleep apnea syndrome, diabetes, medication interactions and side effects, the degree of exposure to intraocular and intracranial pressure elevations and fluctuations, smoking, and symptoms in addition to genetics and family history of the disease.

  3. Glomerular filtration rate

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/007305.htm Glomerular filtration rate To use the sharing features on this page, please enable JavaScript. Glomerular filtration rate (GFR) is a test used to check ...

  4. Glaucoma in atomic bomb survivors.

    PubMed

    Kiuchi, Yoshiaki; Yokoyama, Tomoko; Takamatsu, Michiya; Tsuiki, Eiko; Uematsu, Masafumi; Kinoshita, Hirofumi; Kumagami, Takeshi; Kitaoka, Takashi; Minamoto, Atsushi; Neriishi, Kazuo; Nakashima, Eiji; Khattree, Ravindra; Hida, Ayumi; Fujiwara, Saeko; Akahoshi, Masazumi

    2013-10-01

    Radiation has been associated with increases in noncancerous diseases. An effect of low-dose radiation on the prevalence of clinically detected glaucoma has not been previously reported. We therefore investigated the prevalence of glaucoma in A-bomb survivors and its possible association with radiation dose. A total of 1,589 people who participated in the clinical examination program for A-bomb survivors at the Radiation Effects Research Foundation (RERF) between October 2006 and September 2008 and who had reconstructed radiation doses, were recruited into this cross-sectional screening study. The prevalence of glaucoma and its dose-response relationship to A-bomb radiation were measured. Each subject underwent an initial screening consisting of an interview and ophthalmological examination. Questionable cases with any indication of ocular disease, including glaucoma, were referred to local hospitals for more comprehensive evaluation. A diagnosis of glaucoma was made based on specific optic disc appearance, perimetric results and other ocular findings. Of 1,589 eligible people, we detected 284 (17.9%) cases of glaucoma overall, including 36 (2.3%) cases of primary open-angle glaucoma with intraocular pressure levels greater than 21 mmHg, 226 (14.2%) cases of normal-tension glaucoma and 25 (1.6%) cases of primary angle-closure glaucoma. Seven glaucoma risk factors were examined as potential confounders but only two needed to be included in the final model. Binary regression using a generalized estimating equation method, with adjustment for gender, age, city, cataract surgery or diabetes mellitus, revealed an odds ratio at 1 Gy of 1.31 (95% confidence interval 1.11-1.53, P = 0.001) in the case of normal-tension glaucoma, but no association for other types of glaucoma. The prevalence of normal-tension glaucoma may increase with A-bomb radiation dose, but uncertainties associated with nonparticipation (59% participation) suggest caution in the interpretation of these

  5. Neuroprotective therapies for glaucoma

    PubMed Central

    Song, Wei; Huang, Ping; Zhang, Chun

    2015-01-01

    Glaucoma is the second leading cause for blindness worldwide. It is mainly caused by glaucomatous optic neuropathy (GON) characterized by retinal ganglion cell loss, which leads to visual field defect and blindness. Up to now, the main purpose of antiglaucomatous therapies has been to lower intraocular pressure (IOP) through surgeries and medications. However, it has been found that progressive GON is still present in some patients with effective IOP decrease. Therefore, risk factors other than IOP elevation, like neurotrophin deprivation and excitotoxicity, contribute to progressive GON. Novel approaches of neuroprotection may be more effective for preserving the function of the optic nerve. PMID:25792807

  6. Rotary filtration system

    DOEpatents

    Herman, David T.; Maxwell, David N.

    2011-04-19

    A rotary filtration apparatus for filtering a feed fluid into permeate is provided. The rotary filtration apparatus includes a container that has a feed fluid inlet. A shaft is at least partially disposed in the container and has a passageway for the transport of permeate. A disk stack made of a plurality of filtration disks is mounted onto the shaft so that rotation of the shaft causes rotation of the filtration disks. The filtration disks may be made of steel components and may be welded together. The shaft may penetrate a filtering section of the container at a single location. The rotary filtration apparatus may also incorporate a bellows seal to prevent leakage along the shaft, and an around the shaft union rotary joint to allow for removal of permeate. Various components of the rotary filtration apparatus may be removed as a single assembly.

  7. ITP Filtrate Benzene Removal Alternatives

    SciTech Connect

    Dworjanyn, L.O.

    1993-05-21

    Existing ITP filtrate hold tanks may provide sufficient capacity and residence time to strip dissolved benzene from the incoming filtrate using nitrogen sparging in the bottom of the old tanks. This is based on equilibrium supported by late Wash test data using aged washed slurry. Theoretical considerations indicate that benzene stripping will be more difficult from the ITP unwashed high salt filtrates due to reduced mass transfer. Therefore experimental sparging data is needed to quantify the theoretical effects.Foaming limits which dictate allowable sparging rate will also have to be established. Sparging in the hold tanks will require installation of sintered metal spargers, and possibly stirrers and foam monitoring/disengagement equipment. The most critical sparging needs are at the start of the precipitation/concentration cycle, when the filtrate flux rate is the highest,and at the end of wash cycle where Henry`s equilibrium constant falls off,requiring more gas to sparge the dissolved benzene. With adequate recycle (for proper distribution) or sparging in the old tanks, the 30 inch column could be used for the complete ITP process. A courser packing would reduce back pressure while enabling benzene stripping. The Late Wash Tests indicate adequate benzene stripping even at reduced gas flow. This will require experimental verification under ITP conditions. Using the 30 in. column vs 18 in. during the wash cycle will enhance stripping without need for additional sparging provided the minimum flow requirements are met.

  8. Glaucoma Surgery: Taking the Sub-Conjunctival Route

    PubMed Central

    Shaarawy, Tarek

    2015-01-01

    We are currently in the midst of a surge in interest in glaucoma surgery. Novel pathways for reducing intraocular pressure (IOP) have been tried with various levels of success over the last few years. While the trabecular bypass and suprachoroidal approaches have captured much of the attention, filtering aqueous into the sub-conjunctival space remains the gold standard for lowering IOP. This review attempts to focus on current research in surgical methods to enhance filtration by potentially improving on tried and tested methods like the trabeculectomy, deep sclerectomy, and tube surgeries. PMID:25624674

  9. Acupuncture for glaucoma

    PubMed Central

    Law, Simon K; Li, Tianjing

    2013-01-01

    Background Glaucoma is a multifactorial optic neuropathy in which there is an acquired loss of retinal ganglion cells at levels beyond normal age-related loss and corresponding atrophy of the optic nerve. Although there are many existing treatments, glaucoma is a chronic condition. Some patients may seek complementary or alternative medicine such as acupuncture to supplement their regular treatment. The underlying plausibility of acupuncture is that disorders related to the flow of Chi (the traditional Chinese concept translated as vital force or energy) can be prevented or treated by stimulating the relevant points on the body surface. Objectives The objective of this review was to assess the effectiveness and safety of acupuncture in people with glaucoma. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2010, Issue 3), MEDLINE (January 1950 to March 2010), EMBASE (January 1980 to March 2010), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2010), ZETOC (January 1993 to March 2010), Allied and Complementary Medicine Database (AMED) (January 1985 to March 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the National Center for Complementary and Alternative Medicine web site (NCCAM) (http://nccam.nih.gov). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 23 March 2010 with the exception of NCCAM which was last searched on 14 July 2010. We also handsearched Chinese medical journals at Peking Union Medical College Library in April 2007. Although the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Chinese Acupuncture Trials Register, the Traditional Chinese Medical Literature Analysis and Retrieval System (TCMLARS), and the Chinese

  10. PDF-based heterogeneous multiscale filtration model.

    PubMed

    Gong, Jian; Rutland, Christopher J

    2015-04-21

    Motivated by modeling of gasoline particulate filters (GPFs), a probability density function (PDF) based heterogeneous multiscale filtration (HMF) model is developed to calculate filtration efficiency of clean particulate filters. A new methodology based on statistical theory and classic filtration theory is developed in the HMF model. Based on the analysis of experimental porosimetry data, a pore size probability density function is introduced to represent heterogeneity and multiscale characteristics of the porous wall. The filtration efficiency of a filter can be calculated as the sum of the contributions of individual collectors. The resulting HMF model overcomes the limitations of classic mean filtration models which rely on tuning of the mean collector size. Sensitivity analysis shows that the HMF model recovers the classical mean model when the pore size variance is very small. The HMF model is validated by fundamental filtration experimental data from different scales of filter samples. The model shows a good agreement with experimental data at various operating conditions. The effects of the microstructure of filters on filtration efficiency as well as the most penetrating particle size are correctly predicted by the model.

  11. Managing advanced unilateral pseudoexfoliative glaucoma.

    PubMed

    Marques, André

    2014-05-21

    The only proven therapy for glaucoma is intraocular pressure (IOP) reduction, which can be accomplished by different means. Each should be properly discussed with patients in order to best preserve visual function and quality of life. We report a case of unilateral pseudoexfoliative glaucoma, treated for years with triple topical IOP-lowering drugs. The patient presented with advanced optic neuropathy and important ocular side effects secondary to the treatment. Having discussed his options and prognosis, laser trabeculoplasty was performed while maintaining the remaining therapy considering the advanced stage of glaucoma. His IOP was effectively reduced and no progression was noted after 1-year follow-up. Although medical therapy is the mainstream in glaucoma management, its side effects should not be ignored, especially in unilateral cases. Surgery might have been a better solution, but we chose to perform laser trabeculoplasty, an effective and safer alternative, considering the unlikely but serious risk of the "wipe-out phenomenon" in this case.

  12. Implants for draining neovascular glaucoma.

    PubMed Central

    Molteno, A C; Van Rooyen, M M; Bartholomew, R S

    1977-01-01

    The implant design, surgical technique, and pharmacological methods of controlling bleb fibrosis, used to treat neovascular glaucoma, are described, together with the results of 14 operations performed on 12 eyes. Images PMID:843508

  13. Scanning laser polarimetry in glaucoma.

    PubMed

    Dada, Tanuj; Sharma, Reetika; Angmo, Dewang; Sinha, Gautam; Bhartiya, Shibal; Mishra, Sanjay K; Panda, Anita; Sihota, Ramanjit

    2014-11-01

    Glaucoma is an acquired progressive optic neuropathy which is characterized by changes in the optic nerve head and retinal nerve fiber layer (RNFL). White-on-white perimetry is the gold standard for the diagnosis of glaucoma. However, it can detect defects in the visual field only after the loss of as many as 40% of the ganglion cells. Hence, the measurement of RNFL thickness has come up. Optical coherence tomography and scanning laser polarimetry (SLP) are the techniques that utilize the evaluation of RNFL for the evaluation of glaucoma. SLP provides RNFL thickness measurements based upon the birefringence of the retinal ganglion cell axons. We have reviewed the published literature on the use of SLP in glaucoma. This review elucidates the technological principles, recent developments and the role of SLP in the diagnosis and monitoring of glaucomatous optic neuropathy, in the light of scientific evidence so far.

  14. Primary open-angle glaucoma.

    PubMed

    Weinreb, Robert N; Khaw, Peng Tee

    2004-05-22

    Primary open-angle glaucoma is a progressive optic neuropathy and, perhaps, the most common form of glaucoma. Because the disease is treatable, and because the visual impairment caused by glaucoma is irreversible, early detection is essential. Early diagnosis depends on examination of the optic disc, retinal nerve fibre layer, and visual field. New imaging and psychophysical tests can improve both detection and monitoring of the progression of the disease. Recently completed long-term clinical trials provide convincing evidence that lowering intraocular pressure prevents progression at both the early and late stages of the disease. The degree of protection is related to the degree to which intraocular pressure is lowered. Improvements in therapy consist of more effective and better-tolerated drugs to lower intraocular pressure, and more effective surgical procedures. New treatments to directly treat and protect the retinal ganglion cells that are damaged in glaucoma are also in development.

  15. Smoking and incidence of glaucoma

    PubMed Central

    Pérez-de-Arcelus, Mónica; Toledo, Estefanía; Martínez-González, Miguel Á.; Martín-Calvo, Nerea; Fernández-Montero, Alejandro; Moreno-Montañés, Javier

    2017-01-01

    Abstract Smoking is a serious global public health concern that has been related to many chronic diseases. However, the effect of smoking on eye disorders has been less studied. The aim of this cohort study was to assess the association between current tobacco smokers and the risk of developing glaucoma and furthermore to evaluate the relationship between passive or former smokers and glaucoma. In this prospective and dynamic cohort, 16,797 participants initially who were found not to have glaucoma were followed up for a median of 8.5 years. Validated data on lifestyle, including tobacco consumption, were assessed at baseline. Information about new diagnosis of glaucoma was collected by follow-up questionnaires every 2 years. The outcome was the incidence of self-reported glaucoma during the follow-up. A subsample was used to validate the glaucoma diagnosis. During the 8.5 years of follow-up, 184 new glaucoma cases were identified. Current smokers had a significantly higher risk of glaucoma compared to participants who had never smoked after controlling for potential confounders (Hazard ratio [HR] 1.88 [95% coefficient interval (CI): 1.26–2.81]; P = 0.002). A nonsignificant increased risk was found among former smokers (HR 1.27 [95% CI: 0.88–1.82]; P = 0.198). When we assessed the exposure as per the number of cigarette pack-years, a dose–response relationship between pack-years and the risk of glaucoma was found (HR for the 5th quintile versus the 1st quintile: 1.70 [95% IC: 1.10–2.64], P for trend, 0.009). However, no relationship was found between passive smokers and glaucoma. (HR 0.67 [95% CI: 0.37–1.21]; P = 0.189). Our results suggest a direct association between current smokers and the incidence of glaucoma. In particular, this association was related to the number of pack-years, which was not found in the case of former smokers nor in the case of passive smokers. PMID:28072720

  16. Glaucoma: Screening Can Save Your Sight!

    MedlinePlus

    ... turn Javascript on. Feature: Glaucoma Glaucoma: Screening Can Save Your Sight! Past Issues / Fall 2009 Table of ... be restored. However, there are treatments that may save remaining sight. That is why early diagnosis is ...

  17. 7. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHEAST, SHOWING PUMP NO. 1 AND METERING EQUIPMENT - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  18. 8. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING SOUTHWEST, SHOWING MEZZANINE WITH FILTER TANKS AT REAR - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  19. Glaucoma - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Glaucoma (Arabic) الجلوآوما - العربية Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Glaucoma 青光眼 - 简体中文 (Chinese - Simplified) Bilingual PDF Health Information Translations Glaucoma English 青光眼 - 简体中文 (Chinese - Simplified) PDF Chinese ...

  20. Differential Gene Expression in Glaucoma

    PubMed Central

    Jakobs, Tatjana C.

    2014-01-01

    In glaucoma, regardless of its etiology, retinal ganglion cells degenerate and eventually die. Although age and elevated intraocular pressure (IOP) are the main risk factors, there are still many mysteries in the pathogenesis of glaucoma. The advent of genome-wide microarray expression screening together with the availability of animal models of the disease has allowed analysis of differential gene expression in all parts of the eye in glaucoma. This review will outline the findings of recent genome-wide expression studies and discuss their commonalities and differences. A common finding was the differential regulation of genes involved in inflammation and immunity, including the complement system and the cytokines transforming growth factor β (TGFβ) and tumor necrosis factor α (TNFα). Other genes of interest have roles in the extracellular matrix, cell–matrix interactions and adhesion, the cell cycle, and the endothelin system. PMID:24985133

  1. Differential gene expression in glaucoma.

    PubMed

    Jakobs, Tatjana C

    2014-07-01

    In glaucoma, regardless of its etiology, retinal ganglion cells degenerate and eventually die. Although age and elevated intraocular pressure (IOP) are the main risk factors, there are still many mysteries in the pathogenesis of glaucoma. The advent of genome-wide microarray expression screening together with the availability of animal models of the disease has allowed analysis of differential gene expression in all parts of the eye in glaucoma. This review will outline the findings of recent genome-wide expression studies and discuss their commonalities and differences. A common finding was the differential regulation of genes involved in inflammation and immunity, including the complement system and the cytokines transforming growth factor β (TGFβ) and tumor necrosis factor α (TNFα). Other genes of interest have roles in the extracellular matrix, cell-matrix interactions and adhesion, the cell cycle, and the endothelin system.

  2. Clinical Management of Malignant Glaucoma

    PubMed Central

    Foreman-Larkin, Julie; Netland, Peter A.; Salim, Sarwat

    2015-01-01

    Malignant glaucoma remains one of the most challenging complications of ocular surgery. Although it has been reported to occur spontaneously or after any ophthalmic procedure, it is most commonly encountered after glaucoma surgery in eyes with prior chronic angle closure. The clinical diagnosis is made in the setting of a patent peripheral iridotomy and axial flattening of the anterior chamber. Intraocular pressure is usually elevated, but it may be normal in some cases. Although the exact etiology of this condition is not fully understood, several mechanisms have been proposed and it is thought to result from posterior misdirection of aqueous humor into or behind the vitreous. This review discusses pathophysiology, differential diagnosis, imaging modalities, and current treatment strategies for this rare form of secondary glaucoma. PMID:26819754

  3. A retrospective survey of childhood glaucoma prevalence according to Childhood Glaucoma Research Network classification

    PubMed Central

    Hoguet, Ambika; Grajewski, Alana; Hodapp, Elizabeth; Chang, Ta Chen Peter

    2016-01-01

    Purpose: To evaluate the Childhood Glaucoma Research Network (CGRN) classification system and describe the prevalence of each subtype according to this classification. Materials and Methods: Retrospectively, the medical records of 205 consecutive childhood glaucoma and glaucoma suspect patients at an urban tertiary care center were reviewed. The initial diagnosis and new diagnosis according to CGRN classification were recorded. Results: All patients fit one of the seven categories of the new classification. Seventy-one percent of diagnoses were changed upon reclassification. Twenty-three percent of patients had primary glaucoma (juvenile open-angle glaucoma and primary congenital glaucoma [PCG]); 36% had secondary glaucoma (glaucoma associated with nonacquired ocular anomalies; glaucoma associated with nonacquired systemic disease or syndrome; glaucoma associated with acquired condition; and glaucoma following cataract surgery); and 39% were glaucoma suspect. Of the patients diagnosed with glaucoma, PCG was the most common diagnosis, seen in 32% of patients. Conclusion: The CGRN classification provides a useful method of classifying childhood glaucoma. PMID:27050345

  4. Water sample filtration unit

    USGS Publications Warehouse

    Skougstad, M.W.; Scarbro, G.F.

    1968-01-01

    A readily portable, all plastic, pressure filtration unit is described which greatly facilitates rapid micropore membrane field filtration of up to several liters of water with a minimum risk of inorganic chemical alteration or contamination of the sample. The unit accommodates standard 10.2-cm. (4-inch) diameter filters. The storage and carrying case serves as a convenient filter stand for both field and laboratory use.

  5. Water Filtration Products

    NASA Technical Reports Server (NTRS)

    1986-01-01

    American Water Corporation manufactures water filtration products which incorporate technology originally developed for manned space operations. The formula involves granular activated charcoal and other ingredients, and removes substances by catalytic reactions, mechanical filtration, and absorption. Details are proprietary. A NASA literature search contributed to development of the compound. The technology is being extended to a deodorizing compound called Biofresh which traps gas and moisture inside the unit. Further applications are anticipated.

  6. Experimental proof of contamination of blood components by (1-->3)-beta-D-glucan caused by filtration with cellulose filters in the manufacturing process.

    PubMed

    Nagasawa, Koichi; Yano, Tatsuyuki; Kitabayashi, Go; Morimoto, Hiroaki; Yamada, Yuji; Ohata, Atsushi; Usami, Makoto; Horiuchi, Takashi

    2003-01-01

    The level of (1-->3)-beta-D-glucan in blood is a diagnostic index of fungal infection because it is released from the fungal cell wall. However, high levels of plasma (1-->3)-beta-D-glucan in patients administered blood components may give false positive results. High levels of (1-->3)-beta-D-glucan have been detected in blood components. We suspected that (1-->3)-beta-D-glucan from cellulose filters had been eluted into blood components by filtration in the manufacturing process. To investigate the contamination of blood components by (1-->3)-beta-D-glucan from cellulose filters, in vitro experiments were performed by using six cellulose filters and a nylon filter. Human serum albumin (HSA) solution (100 ml) was flowed through each filter after rinsing with 100 ml of distilled water, and (1-->3)-beta-D-glucan in each fraction was determined by Fungitec G test MK. The concentration of (1-->3)-beta-D-glucan eluted from cellulose filters in 100-ml distilled water fractions ranged from 6 to 207 pg/ml, and that of HSA fractions ranged from 33 to 20,784 pg/ml. These data showed that remarkably higher (1-->3)-beta-D-glucan levels were detected in HSA fractions flowed through cellulose filters in spite of advance rinsing with 100 ml of distilled water. In the case of a nylon filter, (1-->3)-beta-D-glucan was not eluted in either fraction. These results indicate that (1-->3)-beta-D-glucan contamination in blood components is caused by filtration with cellulose filters in the manufacturing process.

  7. Visualization of water flow during filtration using flat filtration materials

    NASA Astrophysics Data System (ADS)

    Bílek, Petr; Šidlof, Petr; Hrůza, Jakub

    2012-04-01

    Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  8. Functional analysis of glaucoma data.

    PubMed

    Hosseini-Nasab, Mohammad; Mirzaei K, Zahra

    2014-05-30

    We refer glaucoma to a category of eye disorders often associated with a dangerous buildup of intraocular pressure (IOP), which can damage the eyes' optic nerve that transmits visual information to the brain. Because IOP changes over time, it is a function of time, and it is an advantage that we analyze the phenomenon using functional data analysis. In this paper, we treat the data related to the IOP of 35 patients with right eye glaucoma, collected in Rasul-e-Akram Hospital at Tehran, Iran, over the years 2007–2011. We shall explore the structure of the data in search of the features that describe them, and find the characteristics that give a comprehensible presentation of the structure of the variability in the data.We extract patterns of variation in the data by using a generalization of the smoothed functional principal component analysis to obtain the main factors causing glaucoma and then determine their importance. We also explore the correlation patterns between the IOP of right and left eyes, and then model the left eye IOP of the glaucoma patients at each time on the basis of their right eye IOP in a previous interval of time.We can use the model to predict the values of the former variable by using the latter one in a previous time interval.

  9. Optical Coherence Tomography in Glaucoma

    NASA Astrophysics Data System (ADS)

    Berisha, Fatmire; Hoffmann, Esther M.; Pfeiffer, Norbert

    Retinal nerve fiber layer (RNFL) thinning and optic nerve head cupping are key diagnostic features of glaucomatous optic neuropathy. The higher resolution of the recently introduced SD-OCT offers enhanced visualization and improved segmentation of the retinal layers, providing a higher accuracy in identification of subtle changes of the optic disc and RNFL thinning associated with glaucoma.

  10. Managing advanced unilateral pseudoexfoliative glaucoma

    PubMed Central

    Marques, André

    2014-01-01

    The only proven therapy for glaucoma is intraocular pressure (IOP) reduction, which can be accomplished by different means. Each should be properly discussed with patients in order to best preserve visual function and quality of life. We report a case of unilateral pseudoexfoliative glaucoma, treated for years with triple topical IOP-lowering drugs. The patient presented with advanced optic neuropathy and important ocular side effects secondary to the treatment. Having discussed his options and prognosis, laser trabeculoplasty was performed while maintaining the remaining therapy considering the advanced stage of glaucoma. His IOP was effectively reduced and no progression was noted after 1-year follow-up. Although medical therapy is the mainstream in glaucoma management, its side effects should not be ignored, especially in unilateral cases. Surgery might have been a better solution, but we chose to perform laser trabeculoplasty, an effective and safer alternative, considering the unlikely but serious risk of the “wipe-out phenomenon” in this case. PMID:24850557

  11. Prevention of Blindness: Chronic Glaucoma

    ERIC Educational Resources Information Center

    Richardson, Kenneth T.

    1970-01-01

    An evaluation of present screening procedures for chronic open-angle glaucoma includes suggestions for improvement: greater distribution of screening and education, conversion from monophasic to multiphasic screen, and examination of visual fields, optic nerve, and medical history in addition to the tonometry currently done. (KW)

  12. Peripapillary Retinoschisis in Glaucoma Patients

    PubMed Central

    Bayraktar, Serife; Cebeci, Zafer; Kabaalioglu, Melis; Ciloglu, Serife; Kir, Nur; Izgi, Belgin

    2016-01-01

    Purpose. To investigate peripapillary retinoschisis and its effect on retinal nerve fiber layer (RNFL) thickness measurements by using spectral-domain optical coherence tomography (SD-OCT) in glaucomatous eyes. Methods. Circumpapillary RNFL (cpRNFL) B-scan images of 940 glaucoma patients (Group 1) and 801 glaucoma-suspect patients (Group 2) obtained by SD-OCT were reviewed. The structural and clinical characteristics of the retinoschisis were investigated. The RNFL thickness measurements taken at the time of retinoschisis diagnosis and at the follow-up visits were also compared. Results. Twenty-nine retinoschisis areas were found in 26 of the 940 glaucoma patients (3.1%) in Group 1 and seven areas were found in 801 patients (0.87%) in Group 2. In glaucomatous eyes, the retinoschisis was attached to the optic disc and overlapped with the RNFL defect. At the time of retinoschisis, the RNFL thickness was statistically greater in the inferior temporal quadrant when compared with the follow-up scans (p < 0.001). No macular involvement or retinal detachment was observed. Conclusion. The present study investigated 33 peripapillary retinoschisis patients. Increase in RNFL thickness measurements was observed at the time of retinoschisis. It is important to examine the cpRNFL B-scan images of glaucoma patients so that the RNFL thickness is not overestimated. PMID:27069674

  13. Corneal hysteresis and its relevance to glaucoma

    PubMed Central

    Deol, Madhvi; Taylor, David A.; Radcliffe, Nathan M.

    2015-01-01

    Purpose of review Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that roughly 60.5 million people had glaucoma in 2010 and that this number is increasing. Many patients continue to lose vision despite apparent disease control according to traditional risk factors. The purpose of this review is to discuss the recent findings with regard to corneal hysteresis, a variable that is thought to be associated with the risk and progression of glaucoma. Recent findings Low corneal hysteresis is associated with optic nerve and visual field damage in glaucoma and the risk of structural and functional glaucoma progression. In addition, hysteresis may enhance intraocular pressure (IOP) interpretation: low corneal hysteresis is associated with a larger magnitude of IOP reduction following various glaucoma therapies. Corneal hysteresis is dynamic and may increase in eyes after IOP-lowering interventions are implemented. Summary It is widely accepted that central corneal thickness is a predictive factor for the risk of glaucoma progression. Recent evidence shows that corneal hysteresis also provides valuable information for several aspects of glaucoma management. In fact, corneal hysteresis may be more strongly associated with glaucoma presence, risk of progression, and effectiveness of glaucoma treatments than central corneal thickness. PMID:25611166

  14. Altered aquaporin expression in glaucoma eyes.

    PubMed

    Tran, Thuy Linh; Bek, Toke; la Cour, Morten; Nielsen, Søren; Prause, Jan Ulrik; Hamann, Steffen; Heegaard, Steffen

    2014-09-01

    Aquaporins (AQP) are channels in the cell membrane that mainly facilitate a passive transport of water. In the eye, AQPs are expressed in the ciliary body and retina and may contribute to the pathogenesis of glaucoma and optic neuropathy. We investigated the expression of AQP1, AQP3, AQP4, AQP5, AQP7 and AQP9 in human glaucoma eyes compared with normal eyes. Nine glaucoma eyes were examined. Of these, three eyes were diagnosed with primary open angle glaucoma; three eyes had neovascular glaucoma; and three eyes had chronic angle-closure glaucoma. Six eyes with normal intraocular pressure and without glaucoma were used as control. Immunohistochemistry was performed using antibodies against AQP1, AQP3, AQP4, AQP5, AQP7 and AQP9. For each specimen, optical densities of immunoprecipitates were measured using Photoshop and the staining intensities were calculated. Immunostaining showed labelling of AQP7 and AQP9 in the nonpigmented ciliary epithelium and the staining intensities were significantly decreased in glaucoma eyes (p = 0.003; p = 0.018). AQP7 expression in the Müller cell endfeet was increased (p = 0.046), and AQP9 labelling of the retinal ganglion cells (RGC) showed decreased intensity (p = 0.037). No difference in AQP1, AQP4 and AQP9 expression was found in the optic nerve fibres. This study is the first investigating AQPs in human glaucoma eyes. We found a reduced expression of AQP9 in the retinal ganglion cells of glaucoma eyes. Glaucoma also induced increased AQP7 expression in the Müller cell endfeet. In the ciliary body of glaucoma eyes, the expression of AQP7 and AQP9 was reduced. Therefore, the expression of AQPs seems to play a role in glaucoma.

  15. Microfluidic colloid filtration

    NASA Astrophysics Data System (ADS)

    Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J. C.; Wessling, Matthias

    2016-03-01

    Filtration of natural and colloidal matter is an essential process in today’s water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a “cake layer” – often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level.

  16. CENTRIFUGAL MEMBRANE FILTRATION

    SciTech Connect

    Daniel J. Stepan; Bradley G. Stevens; Melanie D. Hetland

    1999-10-01

    The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc).

  17. Magnetic-seeding filtration

    SciTech Connect

    Depaoli, D.

    1996-10-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes.

  18. Preliminary results of CO2 laser-assisted sclerectomy surgery (CLASS) in the treatment of advanced glaucoma in a Chinese population

    PubMed Central

    Yick, Doris W.F.; Lee, Jacky W.Y.; Tsang, Susanna; Yeung, Barry Y.M.; Yuen, Can Y.F.

    2016-01-01

    Abstract To evaluate the efficacy and safety of CO2 laser-assisted sclerectomy surgery (CLASS) in Chinese patients with advanced glaucoma. Patients with advanced glaucoma who were candidates for glaucoma filtration surgery were included. The intraocular pressure (IOP) and number of antiglaucoma medications were documented before surgery and at all postoperative clinic visits. All intra- and postoperative complications were documented. The primary outcome measures were the changes in IOP and medication use before and after the procedure as well as complications from the procedure. The secondary outcome measure included the CLASS success rate. Twenty patients (23 eyes) underwent CLASS between November 2014 and September 2015. Nineteen eyes had primary open-angle glaucoma, 2 eyes had primary angle-closure glaucoma, and 2 eyes had uveitic glaucoma. One patient was lost to follow-up. The mean age of subjects was 68.1 ± 11.9 years. IOP was significantly reduced at 1 day and 1 week after CLASS. At 6 months, the IOP and number of medications were significantly reduced by 19.0% and 38.2%, respectively (both P < 0.0001). One patient had intraoperative trabeculo-Descemet membrane perforation. Two patients required laser goniopuncture and 2 required needling between 3 and 6 months postoperatively. The overall success rate was 81.8% at 6 months. CLASS achieved a modest IOP reduction in the early postoperative period and was overall a safe procedure for advanced glaucoma. PMID:27828849

  19. Preliminary results of CO2 laser-assisted sclerectomy surgery (CLASS) in the treatment of advanced glaucoma in a Chinese population.

    PubMed

    Yick, Doris W F; Lee, Jacky W Y; Tsang, Susanna; Yeung, Barry Y M; Yuen, Can Y F

    2016-11-01

    To evaluate the efficacy and safety of CO2 laser-assisted sclerectomy surgery (CLASS) in Chinese patients with advanced glaucoma.Patients with advanced glaucoma who were candidates for glaucoma filtration surgery were included. The intraocular pressure (IOP) and number of antiglaucoma medications were documented before surgery and at all postoperative clinic visits. All intra- and postoperative complications were documented. The primary outcome measures were the changes in IOP and medication use before and after the procedure as well as complications from the procedure. The secondary outcome measure included the CLASS success rate.Twenty patients (23 eyes) underwent CLASS between November 2014 and September 2015. Nineteen eyes had primary open-angle glaucoma, 2 eyes had primary angle-closure glaucoma, and 2 eyes had uveitic glaucoma. One patient was lost to follow-up. The mean age of subjects was 68.1 ± 11.9 years. IOP was significantly reduced at 1 day and 1 week after CLASS. At 6 months, the IOP and number of medications were significantly reduced by 19.0% and 38.2%, respectively (both P < 0.0001). One patient had intraoperative trabeculo-Descemet membrane perforation. Two patients required laser goniopuncture and 2 required needling between 3 and 6 months postoperatively. The overall success rate was 81.8% at 6 months.CLASS achieved a modest IOP reduction in the early postoperative period and was overall a safe procedure for advanced glaucoma.

  20. Non-steroidal drug-induced glaucoma

    PubMed Central

    Razeghinejad, M R; Pro, M J; Katz, L J

    2011-01-01

    Numerous systemically used drugs are involved in drug-induced glaucoma. Most reported cases of non-steroidal drug-induced glaucoma are closed-angle glaucoma (CAG). Indeed, many routinely used drugs that have sympathomimetic or parasympatholytic properties can cause pupillary block CAG in individuals with narrow iridocorneal angle. The resulting acute glaucoma occurs much more commonly unilaterally and only rarely bilaterally. CAG secondary to sulfa drugs is a bilateral non-pupillary block type and is due to forward movement of iris–lens diaphragm, which occurs in individuals with narrow or open iridocorneal angle. A few agents, including antineoplastics, may induce open-angle glaucoma. In conclusion, the majority of cases with glaucoma secondary to non-steroidal medications are of the pupillary block closed-angle type and preventable if the at-risk patients are recognized and treated prophylactically. PMID:21637303

  1. [Neovascular glaucoma--etipathogeny and diagnosis].

    PubMed

    Călugăru, D; Călugăru, M

    2012-01-01

    Neovascular glaucoma is defined as an iris and/or anterior chamber angle neovascularization associated with increased intraocular presure. It is a secondary glaucoma most frequently determined by a severe retinal ischemia. The most common diseases responsible for the development of neovascular glaucoma are diabetic retinopathy, ischemic central retinal vein occlusion and ocular ischemic syndrome; the uncommon causes include ocular radiation, ocular tumors, uveitis and other miscellaneous conditions. Vascular endothelial growth factor is an important and probably predominant agent in the pathogenesis of both intraocular neovascularization and neovascular glaucoma. The evolution of clinical and histopathological changes from predisposing conditions to the occurrence of rubeosis iridis as well as neovacular glaucoma is divided into four grades that is prerubeotic, preglaucomatous, open-angle and angle closure glaucoma stages.

  2. Laser-induced primate glaucoma. II. Histopathology.

    PubMed

    Radius, R L; Pederson, J E

    1984-11-01

    A sustained, moderate pressure elevation was produced in 15 nonhuman primate eyes by application of laser energy to the trabecular meshwork. By light and electron microscopy, the trabecular beams were blunted, and scattered synechiae were present. Backward bowing of the lamina cribrosa, partial loss of the myelin sheath surrounding axonal segments just posterior to the lamina, and diffuse axonal loss involving the entire nerve cross section were noted. A quantitative analysis of this axonal loss revealed that eyes with moderate nerve head damage (cup-disc ratio, 0.6 to 0.8) had only 38% to 69% of the expected normal axonal count. The eyes with nearly total cupping (cup-disc ratio, 0.9 to 1.0) maintained between 10% and 36% of the normal axonal count. The disc changes in these experimental eyes are similar to those previously described in human eyes with glaucoma.

  3. Congenital glaucoma in cutis marmorata teleangiectatica congenita.

    PubMed

    Mayatepek, E; Krastel, H; Völcker, H E; Pfau, B; Almasan, K

    1991-01-01

    A case of congenital glaucoma in cutis marmorata teleangiectatica congenita (CMTC, van Lohuizen syndrome) is described. The cutaneous anomaly and heterochromia iridium were noticed at birth. Brown discoloration of one iris was due to iris anterior layer dysplasia, resulting in unilateral glaucoma. Two trabeculotomies were performed until persistent normalization of intraocular pressure could be achieved. The possibility of a genetic basis and hereditary condition of CMTC and its association with congenital glaucoma is discussed. Patients with CMTC should regularly undergo ophthalmological follow-up to rule out development of glaucoma.

  4. Simulation on combined rapid gravity filtration and backwash models.

    PubMed

    Han, S J; Fitzpatrick, C S B; Wetherill, A

    2009-01-01

    Combined rapid gravity filtration and backwash models have been applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that an optimum air flow rate exists to maximise particle removal efficiency in the backwash operation for a certain backwash system. The simulation of combined rapid gravity filtration and backwash models suggests that the filter should not be completely cleaned up in the backwash and a certain amount of particles retained on filter grains after backwash can be beneficial for subsequent filtration runs. This is consistent with the experimental results in the literature.

  5. Water Treatment Technology - Filtration.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on filtration provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purposes of sedimentation basins and flocculation…

  6. An adaptive threshold based image processing technique for improved glaucoma detection and classification.

    PubMed

    Issac, Ashish; Partha Sarathi, M; Dutta, Malay Kishore

    2015-11-01

    Glaucoma is an optic neuropathy which is one of the main causes of permanent blindness worldwide. This paper presents an automatic image processing based method for detection of glaucoma from the digital fundus images. In this proposed work, the discriminatory parameters of glaucoma infection, such as cup to disc ratio (CDR), neuro retinal rim (NRR) area and blood vessels in different regions of the optic disc has been used as features and fed as inputs to learning algorithms for glaucoma diagnosis. These features which have discriminatory changes with the occurrence of glaucoma are strategically used for training the classifiers to improve the accuracy of identification. The segmentation of optic disc and cup based on adaptive threshold of the pixel intensities lying in the optic nerve head region. Unlike existing methods the proposed algorithm is based on an adaptive threshold that uses local features from the fundus image for segmentation of optic cup and optic disc making it invariant to the quality of the image and noise content which may find wider acceptability. The experimental results indicate that such features are more significant in comparison to the statistical or textural features as considered in existing works. The proposed work achieves an accuracy of 94.11% with a sensitivity of 100%. A comparison of the proposed work with the existing methods indicates that the proposed approach has improved accuracy of classification glaucoma from a digital fundus which may be considered clinically significant.

  7. Glaucoma detection using novel optic disc localization, hybrid feature set and classification techniques.

    PubMed

    Akram, M Usman; Tariq, Anam; Khalid, Shehzad; Javed, M Younus; Abbas, Sarmad; Yasin, Ubaid Ullah

    2015-12-01

    Glaucoma is a chronic and irreversible neuro-degenerative disease in which the neuro-retinal nerve that connects the eye to the brain (optic nerve) is progressively damaged and patients suffer from vision loss and blindness. The timely detection and treatment of glaucoma is very crucial to save patient's vision. Computer aided diagnostic systems are used for automated detection of glaucoma that calculate cup to disc ratio from colored retinal images. In this article, we present a novel method for early and accurate detection of glaucoma. The proposed system consists of preprocessing, optic disc segmentation, extraction of features from optic disc region of interest and classification for detection of glaucoma. The main novelty of the proposed method lies in the formation of a feature vector which consists of spatial and spectral features along with cup to disc ratio, rim to disc ratio and modeling of a novel mediods based classier for accurate detection of glaucoma. The performance of the proposed system is tested using publicly available fundus image databases along with one locally gathered database. Experimental results using a variety of publicly available and local databases demonstrate the superiority of the proposed approach as compared to the competitors.

  8. Internal filtration, filtration fraction, and blood flow resistance in high- and low-flux dialyzers.

    PubMed

    Schneditz, Daniel; Zierler, Edda; Vanholder, Raymond; Eloot, Sunny

    2014-01-01

    It was the aim to examine the fluid flow in blood and dialysate compartments of highly permeable hollow fiber dialyzers where internal filtration contributes to solute removal but where excessive filtration bears a risk of cell activation and damage. Flow characteristics of high- (HF) and low-flux (LF) dialyzers were studied in lab-bench experiments using whole bovine blood. Measurements obtained under different operating conditions and under zero net ultrafiltration were compared to theoretical calculations obtained from a mathematical model. Experimental resistances in the blood compartment were within ±2% of those calculated from the model when dialysate was used as a test fluid. With whole blood, the experimental resistances in the blood compartment were only 81.8 ± 2.8% and 83.7 ± 4.3% of those calculated for the LF and HF dialyzer, respectively. Surprisingly, measured blood flow resistance slightly but significantly decreased with increasing flow rate (p < 0.001). Mathematical modeling confirmed this decrease both in LF and HF dialyzers which was accompanied by a concomitant decrease in internal filtration fraction, while overall internal filtration increased. The increase in internal filtration when increasing blood flow is associated with a beneficial reduction in internal filtration fraction. Concerns of increased hemoconcentration when increasing blood flow therefore appear to be unwarranted.

  9. Update on Normal Tension Glaucoma

    PubMed Central

    Mallick, Jyotiranjan; Devi, Lily; Malik, Pradeep K.; Mallick, Jogamaya

    2016-01-01

    Normal tension glaucoma (NTG) is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP) constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud's phenomenon, migraine, nocturnal systemic hypotension and over-treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre-existing levels to 12-14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases), systemic calcium channel blockers (such as nifedipine) and 24-hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG. PMID:27413503

  10. Bilateral angle closure glaucoma following general anaesthesia.

    PubMed

    Raj, K Mohan; Reddy, P Arun Subhash; Kumar, Vikram Chella

    2015-04-01

    Angle closure glaucoma is one of the ophthalmic emergencies and treatment has to be given at the earliest. It is a rare complication of general anesthesia. A female patient underwent Hysterectomy under general anesthesia. Following this, patient developed bilateral angle closure glaucoma. This patient was treated with antiglaucoma medications followed by YAG laser iridotomy and patient regained vision.

  11. Glaucoma Genetics: Recent Advances and Future Directions.

    PubMed

    Aung, Tin; Khor, Chiea Chuen

    2016-01-01

    Once considered primarily a disease of aging caused by unknown environmental influences, the notion that heritable factors could significantly contribute to the pathogenesis of sporadic glaucoma has rapidly gained traction. In part, this is due to the rapid and definitive identification of genes with strong effects on familial, earlier onset forms of glaucoma. Although the endpoint of glaucoma is irreversible optic nerve damage accompanied by blindness, the initial inciting trigger could differ. To this end, well-powered genome-wide association studies have each been conducted for primary open-angle glaucoma, primary angle-closure glaucoma, along with exfoliation syndrome and glaucoma. Each of these studies has revealed sets of significantly associated genetic loci implicating biological pathways that do not overlap between the forms of glaucoma. Although substantial biological insight has been gained from their identification, much further work remains to definitively link the implicated genetic variants with glaucoma causation. It is also hoped that the genetic findings could point us to potential routes of therapy beyond that of intraocular pressure-lowering medications or surgery.

  12. Animal models of glucocorticoid-induced glaucoma.

    PubMed

    Overby, Darryl R; Clark, Abbot F

    2015-12-01

    Glucocorticoid (GC) therapy is widely used to treat a variety of inflammatory diseases and conditions. While unmatched in their anti-inflammatory and immunosuppressive activities, GC therapy is often associated with the significant ocular side effect of GC-induced ocular hypertension (OHT) and iatrogenic open-angle glaucoma. Investigators have generated GC-induced OHT and glaucoma in at least 8 different species besides man. These models mimic many features of this condition in man and provide morphologic and molecular insights into the pathogenesis of GC-OHT. In addition, there are many clinical, morphological, and molecular similarities between GC-induced glaucoma and primary open-angle glaucoma (POAG), making animals models of GC-induced OHT and glaucoma attractive models in which to study specific aspects of POAG.

  13. Animal Models of Glucocorticoid-Induced Glaucoma

    PubMed Central

    Overby, Darryl R.; Clark, Abbot F.

    2015-01-01

    Glucocorticoid (GC) therapy is widely used to treat a variety of inflammatory diseases and conditions. While unmatched in their anti-inflammatory and immunosuppressive activities, GC therapy is often associated with the significant ocular side effect of GC-induced ocular hypertension (OHT) and iatrogenic open-angle glaucoma. Investigators have generated GC-induced OHT and glaucoma in at least 8 different species besides man. These models mimic many features of this condition in man and provide morphologic and molecular insights into the pathogenesis of GC-OHT. In addition, there are many clinical, morphological, and molecular similarities between GC-induced glaucoma and primary open-angle glaucoma (POAG), making animals models of GC-induced OHT and glaucoma attractive models in which to study specific aspects of POAG. PMID:26051991

  14. Peripheral iridotomy for pigmentary glaucoma

    PubMed Central

    Michelessi, Manuele; Lindsley, Kristina

    2016-01-01

    Background Glaucoma is a chronic optic neuropathy characterized by retinal ganglion cell death resulting in damage to the optic nerve head and the retinal nerve fiber layer. Pigment dispersion syndrome is characterized by a structural disturbance in the iris pigment epithelium (the densely pigmented posterior surface of the iris) that leads to dispersion of the pigment and its deposition on various structures within the eye. Pigmentary glaucoma is a specific form of open-angle glaucoma found in patients with pigment dispersion syndrome. Topcial medical therapy is usually the first-line treatment; however, peripheral laser iridotomy has been proposed as an alternate treatment. Peripheral laser iridotomy involves creating an opening in the iris tissue to allow drainage of fluid from the posterior chamber to the anterior chamber and vice versa. Equalizing the pressure within the eye may help to alleviate the friction that leads to pigment dispersion and prevent visual field deterioration. However, the effectiveness of peripheral laser iridotomy in reducing the development or progression of pigmentary glaucoma is unknown. Objectives The objective of this review was to assess the effects of peripheral laser iridotomy compared with other interventions, including medication, trabeculoplasty, and trabeculectomy, or no treatment, for pigment dispersion syndrome and pigmentary glaucoma. Search methods We searched a number of electronic databases including CENTRAL, MEDLINE and EMBASE and clinical trials websites such as (mRCT) and ClinicalTrials.gov. We last searched the electronic databases on 2 November 2015. Selection criteria We included randomized controlled trials (RCTs) that had compared peripheral laser iridotomy versus no treatment or other treatments for pigment dispersion syndrome and pigmentary glaucoma. Data collection and analysis We used standard methodological procedures for systematic reviews. Two review authors independently screened articles for eligibility

  15. Recent advances in pharmacotherapy of glaucoma

    PubMed Central

    Gupta, S. K.; Niranjan D., Galpalli; Agrawal, S. S.; Srivastava, Sushma; Saxena, Rohit

    2008-01-01

    Glaucoma is a slow progressive degeneration of the retinal ganglion cells (RGCs) and the optic nerve axons, leading to irreversible blindness if left undiagnosed and untreated. Although increased intraocular pressure is a major risk factor of glaucoma, other factors include increased glutamate levels, alterations in nitric oxide (NO) metabolism, vascular alterations and oxidative damage caused by reactive oxygen species. Glaucoma is the second leading cause of blindness globally, accounting for 12.3% of the total blindness. Glaucoma has been broadly classified as primary or secondary open-angle or angle-closure glaucoma. The primary goal in management of glaucoma is to prevent the risk factor, especially elevated intraocular pressure (IOP), using medications, laser therapy or conventional surgery. The first-line treatment of glaucoma usually begins with the use of a topical selective or nonselective blocker or a prostaglandin analog. Second-line drugs of choice include alpha-agonists and topical carbonic anhydrase inhibitors. Cholinergic agonists are considered third-line treatment options. When a single therapy is not sufficient to lower the IOP, a combination therapy is indicated. To enhance the patient compliance, drug delivery systems like electronic devices, ocular inserts, tansdermal and mechanical drug delivery systems have been developed. Use of viscoelastic agents in ophthalmic formulations, emulsions and soluble ophthalmic drug inserts (SODI) enhance patience compliance and ocular drug delivery in patients in long-term glaucoma therapy. For patients who do not respond to antiglaucoma medications, laser trabeculoplasty and incisional surgery are recommended. Several nutrients and botanicals hold promise for the treatment of glaucoma, but most studies are preliminary, and larger, controlled studies are required. Future directions for the development of a novel therapy glaucoma may target glutamate inhibition, NMDA receptor blockade, exogenously applied

  16. Quadrant Field Pupillometry Detects Melanopsin Dysfunction in Glaucoma Suspects and Early Glaucoma

    PubMed Central

    Adhikari, Prakash; Zele, Andrew J.; Thomas, Ravi; Feigl, Beatrix

    2016-01-01

    It is difficult to detect visual function deficits in patients at risk for glaucoma (glaucoma suspects) and at early disease stages with conventional ophthalmic tests such as perimetry. To this end, we introduce a novel quadrant field measure of the melanopsin retinal ganglion cell mediated pupil light response corresponding with typical glaucomatous arcuate visual field defects. The melanopsin-mediated post-illumination pupil response (PIPR) was measured in 46 patients with different stages of glaucoma including glaucoma suspects and compared to a healthy group of 21 participants with no disease. We demonstrate that the superonasal quadrant PIPR differentiated glaucoma suspects and early glaucoma patients from controls with fair (AUC = 0.74) and excellent (AUC = 0.94) diagnostic accuracy, respectively. The superonasal PIPR provides a linear functional correlate of structural retinal nerve fibre thinning in glaucoma suspects and early glaucoma patients. This first report that quadrant PIPR stimulation detects melanopsin dysfunction in patients with early glaucoma and at pre-perimetric stages may have future implications in treatment decisions of glaucoma suspects. PMID:27622679

  17. Prevalence of glaucoma in Eastern India: The Hooghly River Glaucoma Study

    PubMed Central

    Paul, Chandrima; Sengupta, Subhrangshu; Choudhury, Sumit; Banerjee, Souvik; Sleath, Betsy L

    2016-01-01

    Context: Glaucoma is the leading cause of global irreversible blindness. No recent study with adequate sample size has been carried out to estimate glaucoma prevalence in Eastern India. Aims: The aim of this study was to assess and compare the prevalence and types of glaucoma in a rural and urban East Indian population. Settings and Design: The Hooghly River Glaucoma Study (HRGS) is a population-based cross-sectional study from West Bengal. A tertiary hospital in Kolkata was our urban study center. Our rural study area included 28 contiguous villages from the district of Hooghly surrounding the rural base hospital located at Dhobapara in village Bakulia. Individuals aged 40 years and above were included in this study. Subjects and Methods: All subjects underwent a detailed ophthalmic examination at our base hospitals including applanation tonometry, ultrasound pachymetry, gonioscopy, and frequency doubling technology perimetry. Glaucoma was defined using modified International Society of Geographical and Epidemiological Ophthalmology criteria. Statistical Analysis Used: Analysis was performed using Chi-square test and multiple logistic regression using SPSS. Results: Totally, 14,092 individuals participated; 2.7% were detected to have glaucoma in rural arm and 3.23% in urban arm (P < 0.001). In urban population, 2.10% had primary open angle glaucoma (POAG), 0.97% had primary angle closure glaucoma (PACG), and 0.15% had secondary glaucoma. In rural population, 1.45% had POAG, 1.15% had ACG, and 0.10% had secondary glaucoma. Conclusions: HRGS is the largest population-based glaucoma study in India to date with glaucoma prevalence comparable to other landmark Indian studies. POAG was the most common form of glaucoma in our study population as well. PACG was more common in this region than previously thought. PMID:27688279

  18. The contribution of the sclera and lamina cribrosa to the pathogenesis of glaucoma: Diagnostic and treatment implications.

    PubMed

    Quigley, Harry A

    2015-01-01

    Glaucoma, the second most common cause of world blindness, results from loss of retinal ganglion cells (RGC). RGC die as a consequence of injury to their axons, as they pass through the transition between the environment within the eye and that of the retrobulbar optic nerve, as they course to central visual centers. At the optic nerve head (ONH), axonal transport becomes abnormal, at least in part due to the effect of strain induced by intraocular pressure (IOP) on the sclera and ONH. Animal glaucoma models provide the ability to study how alterations in ocular connective tissues affect this pathological process. New therapeutic interventions are being investigated to mitigate glaucoma blindness by modifying the remodeling of ocular tissues in glaucoma. Some genetically altered mice are resistant to glaucoma damage, while treatment of the sclera with cross-linking agents makes experimental mouse glaucoma damage worse. Inhibition of transforming growth factor β activity is strikingly protective. Treatments that alter the response of ocular connective tissues to IOP may be effective in protecting those with glaucoma from vision loss.

  19. Solute partitioning and filtration by extracellular matrices

    PubMed Central

    Hofmann, Christina L.; Ferrell, Nicholas; Schnell, Lisa; Dubnisheva, Anna; Zydney, Andrew L.; Yurchenco, Peter D.; Roy, Shuvo

    2009-01-01

    The physiology of glomerular filtration remains mechanistically obscure despite its importance in disease. The correspondence between proteinuria and foot process effacement suggests podocytes as the locus of the filtration barrier. If so, retained macromolecules ought to accumulate at the filtration barrier, an effect called concentration polarization. Literature data indicate macromolecule concentrations decrease from subendothelial to subepithelial glomerular basement membrane (GBM), as would be expected if the GBM were itself the filter. The objective of this study was to obtain insights into the possible role of the GBM in protein retention by performing fundamental experimental and theoretical studies on the properties of three model gels. Solute partitioning and filtration through thin gels of a commercially available laminin-rich extracellular matrix, Matrigel, were measured using a polydisperse polysaccharide tracer molecule, Ficoll 70. Solute partitioning into laminin gels and lens basement membrane (LBM) were measured using Ficoll 70. A novel model of a laminin gel was numerically simulated, as well as a mixed structure-random-fiber model for LBM. Experimental partitioning was predicted by numerical simulations. Sieving coefficients through thin gels of Matrigel were size dependent and strongly flux dependent. The observed flux dependence arose from compression of the gel in response to the applied pressure. Gel compression may alter solute partitioning into extracellular matrix at physiologic pressures present in the glomerular capillary. This suggests a physical mechanism coupling podocyte structure to permeability characteristics of the GBM. PMID:19587146

  20. [The denominations cataract and glaucoma].

    PubMed

    Tornquist, R

    1997-01-01

    Since ancient times a grey or white pupil in an nearly blind eye was thought to be caused by a mucous substance in front of the lens. It was called "hypochysis" or "hypochyma" in Greece and "suffusio" in Rome. Later the term "cataract" (=waterfall) was the most popular denomination. A surgical method was tried very early with usually good effect, when with a thin needle, introduced into the eye, the opaque material was removed from the pupillary area. In the middle of the 17th century more careful investigations showed that there was no membrane in front of the lens, but the lens itself was opaque. The final proof was delivered when an extraction of the lens was performed with good effect. In ancient times incurable blindness, which was called glaucoma, was thought to be located to the lens, which probably had a very important role in the seeing process. The name (of Greek orgin) is translated "green" or "blue-green", which was sometimes notified to be the color of the lens, seen through the pupil, in these cases. A period of great confusion followed when the removal of this very important part of the eye did not lead to blindness but rather an improved vision. As there were significant difficulties in identifying the specific color of the pupil the name glaucoma seemed to be very inadequate. In the beginning of the 19th century a disease entity (which is to-day called acute closed-angle glaucoma) seemed to eventually fullfill the demand of a greenlooking pupil. The most characteristic symptoms are pain and a high intraocular pressure causing a corneal edema and a change of the blackness of the pupil to hazy grey (and maybe a little green?).

  1. Sympathectomy for glaucoma: Its rise and fall (1898-1910).

    PubMed

    Feibel, Robert M

    2015-01-01

    The influence of the sympathetic nervous system upon intraocular pressure (IOP) has been a subject of great interest since 1727, when the first experimental ocular sympathetic paralysis was produced in dogs. By the middle of the 19th century, it was known that excision of the superior cervical sympathetic ganglion lowered, and that electrical stimulation of the sympathetic nerve trunk raised IOP in various animals. From these observations, it was thought that excision of this ganglion could replace or supplement the available operations for glaucoma of which iridectomy was the most popular. Iridectomy was acknowledged to be of great value in acute and subacute glaucoma, but less useful in chronic glaucoma. Iridectomy, however, was associated with major surgical complications and long-term failure, so that there was considerable appeal of an extraocular operation that avoided the risks of intraocular surgery. Beginning in 1898, cervical sympathectomy became a widely performed operation around the world, with most surgeons enthusiastic about its results, at least initially, and many publications from 1898 to 1905 claimed excellent results for various types of glaucoma. Opponents of the procedure emphasized that the effect on IOP was transient, and that the published reports of successful results were poorly documented. The popularity of sympathectomy gradually diminished and by 1910 it was abandoned. I discuss the reasons why cervical sympathectomy received such initial enthusiasm but was then questioned and discarded. These included bias from the surgeons promoting this surgery; the placebo effect; short follow-up; inaccurate, subjective, and variable measures of the surgical results; and the development of more effective procedures such as filtering surgery and cyclodialysis.

  2. Structural basis for misfolding in myocilin-associated glaucoma

    PubMed Central

    Donegan, Rebecca K.; Hill, Shannon E.; Freeman, Dana M.; Nguyen, Elaine; Orwig, Susan D.; Turnage, Katherine C.; Lieberman, Raquel L.

    2015-01-01

    Olfactomedin (OLF) domain-containing proteins play roles in fundamental cellular processes and have been implicated in disorders ranging from glaucoma, cancers and inflammatory bowel disorder, to attention deficit disorder and childhood obesity. We solved crystal structures of the OLF domain of myocilin (myoc-OLF), the best studied such domain to date. Mutations in myoc-OLF are causative in the autosomal dominant inherited form of the prevalent ocular disorder glaucoma. The structures reveal a new addition to the small family of five-bladed β-propellers. Propellers are most well known for their ability to act as hubs for protein–protein interactions, a function that seems most likely for myoc-OLF, but they can also act as enzymes. A calcium ion, sodium ion and glycerol molecule were identified within a central hydrophilic cavity that is accessible via movements of surface loop residues. By mapping familial glaucoma-associated lesions onto the myoc-OLF structure, three regions sensitive to aggregation have been identified, with direct applicability to differentiating between neutral and disease-causing non-synonymous mutations documented in the human population worldwide. Evolutionary analysis mapped onto the myoc-OLF structure reveals conserved and divergent regions for possible overlapping and distinctive functional protein–protein or protein–ligand interactions across the broader OLF domain family. While deciphering the specific normal biological functions, ligands and binding partners for OLF domains will likely continue to be a challenging long-term experimental pursuit, atomic detail structural knowledge of myoc-OLF is a valuable guide for understanding the implications of glaucoma-associated mutations and will help focus future studies of this biomedically important domain family. PMID:25524706

  3. Dynamic optical filtration

    NASA Technical Reports Server (NTRS)

    Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

    2005-01-01

    A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

  4. Dynamic Optical Filtration

    NASA Technical Reports Server (NTRS)

    Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

    2005-01-01

    A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

  5. Melt Purification via Filtration

    DTIC Science & Technology

    1981-06-01

    4 ) c. re: " exp((|)n) + exp -i e ^ ( 6 - n) ’m - 7 - - 1 t where the subscript i refers to the inlet condition...temperature model system studies. 4 . PROGRESS TO DATE The phase of the work investigating the filtration of the aluminum- titanium diboride system through...CO 4 -1 3 O >, 3 6 ^ -H 4 -1 O B 3 SH 3 _^ u r-i a O 3 O CU SO rH 3 M w -H ca E l e c t r o l

  6. Neuroinflammation in glaucoma: A new opportunity.

    PubMed

    Williams, Pete A; Marsh-Armstrong, Nick; Howell, Gareth R

    2017-02-24

    Mounting evidence suggests neuroinflammation is a key process in glaucoma, yet the precise roles are not known. Understanding these complex processes, which may also be a key in other common neurodegenerations such as Alzheimer's disease, will lead to targeted therapeutics for a disease that affects as many as 80 million people worldwide. Here, we define neuroinflammation as any immune-relevant response by a variety of cell types including astrocytes, microglia, and peripherally derived cells occurring in the optic nerve head and/or retina. In this review article, we first discuss clinical evidence for neuroinflammation in glaucoma and define neuroinflammation in glaucoma. We then review the inflammatory pathways that have been associated with glaucoma. Finally, we set out key research directions that we believe will greatly advance our understanding of the role of neuroinflammation in glaucoma. This review arose from a discussion of neuroinflammation in glaucoma at the 2015 meeting of the The Lasker/IRRF Initiative for Innovation in Vision Science. This manuscript sets out to summarize one of these sessions; "Inflammation and Glaucomatous Neurodegeneration", as well as to review the current state of the literature surrounding neuroinflammation in glaucoma.

  7. Oral Microbiome Link to Neurodegeneration in Glaucoma

    PubMed Central

    Astafurov, Konstantin; Elhawy, Eman; Ren, Lizhen; Dong, Cecilia Q.; Igboin, Christina; Hyman, Leslie; Griffen, Ann; Mittag, Thomas; Danias, John

    2014-01-01

    Background Glaucoma is a progressive optic nerve degenerative disease that often leads to blindness. Local inflammatory responses are implicated in the pathology of glaucoma. Although inflammatory episodes outside the CNS, such as those due to acute systemic infections, have been linked to central neurodegeneration, they do not appear to be relevant to glaucoma. Based on clinical observations, we hypothesized that chronic subclinical peripheral inflammation contributes to neurodegeneration in glaucoma. Methods Mouthwash specimens from patients with glaucoma and control subjects were analyzed for the amount of bacteria. To determine a possible pathogenic mechanism, low-dose subcutaneous lipopolysaccharide (LPS) was administered in two separate animal models of glaucoma. Glaucomatous neurodegeneration was assessed in the retina and optic nerve two months later. Changes in gene expression of toll-like receptor 4 (TLR4) signaling pathway and complement as well as changes in microglial numbers and morphology were analyzed in the retina and optic nerve. The effect of pharmacologic blockade of TLR4 with naloxone was determined. Findings Patients with glaucoma had higher bacterial oral counts compared to control subjects (p<0.017). Low-dose LPS administration in glaucoma animal models resulted in enhancement of axonal degeneration and neuronal loss. Microglial activation in the optic nerve and retina as well as upregulation of TLR4 signaling and complement system were observed. Pharmacologic blockade of TLR4 partially ameliorated the enhanced damage. Conclusions The above findings suggest that the oral microbiome contributes to glaucoma pathophysiology. A plausible mechanism by which increased bacterial loads can lead to neurodegeneration is provided by experiments in animal models of the disease and involves activation of microglia in the retina and optic nerve, mediated through TLR4 signaling and complement upregulation. The finding that commensal bacteria may play a

  8. Abrasive Particle Trajectories and Material Removal Non-Uniformity during CMP and Filtration Characteristics of CMP Slurries - A Simulation and Experimental Study

    NASA Astrophysics Data System (ADS)

    Rastegar, Vahid

    Nanoscale finishing and planarization are integral process steps in multilevel metallization designs for integrated circuit (IC) manufacturing since it is necessary to ensure local and global surface planarization at each metal layer before depositing the next layer. Chemical mechanical planarization (CMP) has been widely recognized as the most promising technology to eliminate topographic variation and has allowed the construction of multilevel interconnection structures with a more regularly stacked sequence, resulting in better device performance [1]. Understanding fundamental of the CMP mechanisms can offer guidance to the control and optimization of the polishing processes. CMP kinematics based on slurry distribution and particle trajectories have a significant impact on MRR profiles. In this work a mathematical model to describe particle trajectories during chemical mechanical polishing was developed and extended to account for the effect of larger particles, particle location changes due to slurry dispensing and in-situ conditioning. Material removal rate (MRR) and within wafer non-uniformity (WIWNU) were determined based on the calculated particle trajectory densities. Rotary dynamics and reciprocating motion were optimized to obtain best MRR uniformity. Edge-fast MRR profile was discussed based on mechanical aspect of CMP. Using the model, we also investigated the effect of variable rotational speeds of wafer and pad, and of large particles on WIWNU and scratch growth. It was shown that the presence of even a small portion of large particles can deteriorate the WIWNU significantly and also lead to more scratches. Furthermore, it was shown that the in-situ conditioning improves the uniformity of the polished wafers. Furthermore, a combined experimental and computational study of fibrous filters for removal of larger abrasive particles from aqueous dispersions, essential to minimize defects during chemical mechanical polishing, was performed. Dilute aqueous

  9. [Steroid induced ocular hypertension and glaucoma].

    PubMed

    Călugăru, D; Călugăru, M

    2009-01-01

    Steroid induced ocular hypertension and glaucoma represent iatrogenic changes of pharmacogenic nature. They are mainly due to exogenous steroids following ocular periocular, intravitreal and systemic administration. Elevated ocular pressure is brought about by structural trabecular changes as well as obstruction of the outflow ways of the aqueous humor localized within the trabecular juxtacanalicular area. Although mostly raised ocular pressure spontaneously descends to basal values after ceasing the steroid therapy, progressive optic nerve damages and glaucomatous visual field defects may occur. Therapy of steroid induced ocular hypertension and glaucoma is similar to that of ocular hypertension and primary open-angle glaucoma.

  10. Management of complications in glaucoma surgery

    PubMed Central

    Vijaya, Lingam; Manish, Panday; Ronnie, George; Shantha, B

    2011-01-01

    Surgical option for glaucoma is considered when other modalities are not working out to keep the intraocular pressure under control. Since the surgical procedures for glaucoma disrupt the integrity of the globe, they are known to produce various complications. Some of those complications can be vision-threatening. To minimize the morbidity, it is very important that one should know how to prevent them, recognize them and treat them. The objective of this article is to provide insight into some of those complications that will help the ophthalmologists in treating glaucoma patients in their clinical practice. PMID:21150025

  11. Magnetic-seeding filtration

    SciTech Connect

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  12. Myocilin and glaucoma: facts and ideas.

    PubMed

    Tamm, Ernst R

    2002-07-01

    Mutations in the MYOC gene that encodes for myocilin are causative for some forms of juvenile and adult-onset primary open-angle glaucoma (POAG). Myocilin is a secreted 55-57kDa glycoprotein that forms dimers and multimers. Characteristic structural motifs include a myosin-like domain, a leucine zipper region and an olfactomedin domain. Most of the mutations that have been identified in patients with POAG are localized in the olfactomedin domain, which is highly conserved among species. In the eye, myocilin is expressed in high amounts in the trabecular meshwork (TM), sclera, ciliary body and iris, and at considerable lower amounts in retina and optic nerve head. Secreted myocilin is present in the aqueous humor. In the TM, myocilin is found within the cytoplasm of TM cells and in the juxtacanalicular region in association with fibrillar extracellular matrix components. Since patients with mutations in myocilin may have high intraocular pressures, the role of myocilin for aqueous humor outflow has been investigated and conflicting results have been obtained. Recombinant myocilin increases outflow resistance in perfused anterior segment organ cultures, while overexpression of myocilin after viral gene transfer appears to reduce outflow resistance. In TM cells, the expression of myocilin is induced upon treatment with dexamethasone at a time course similar to that observed in steroid-induced glaucoma. Other factors that induce myocilin expression are transforming growth factor-beta and mechanical stretch. Promoter elements that are important for the glucocorticoid induction have not been identified, but it has been shown that upstream stimulatory factor is critical for the basal promoter activity of MYOC. Mice with a targeted disruption of the myocilin gene do not express a phenotype, indicating that the glaucomatous phenotype in humans is not because of a loss-of-function effect. Experimental studies show that mutated myocilin is not secreted, but appears to

  13. Autophagy in glaucoma: Crosstalk with apoptosis and its implications.

    PubMed

    Wang, Yao; Huang, Changquan; Zhang, Hongbing; Wu, Renyi

    2015-08-01

    Glaucoma is characterized by elevated intraocular pressure that causes progressive loss of retinal ganglion cells (RGCs). Autophagy is a lysosomal degradative process that updates the cellular components and plays an important role in cellular homeostasis. Recent studies have shown that autophagy is involved in the pathophysiological process of glaucoma. The role played by autophagy in glaucoma is complex, and conflicting evidence shows that autophagy promotes both RGC survival and death. The understanding of the major pattern of RGC loss and the crosstalk between autophagy and apoptosis remains limited in glaucoma. This review focuses on the relationship between autophagy and glaucoma, particularly on the influence of autophagy on apoptosis in glaucoma. Further research on autophagy in glaucoma may provide a novel understanding of the glaucoma pathology and novel treatment targets for glaucoma in the future.

  14. Design parameters for rotating cylindrical filtration

    NASA Technical Reports Server (NTRS)

    Schwille, John A.; Mitra, Deepanjan; Lueptow, Richard M.

    2002-01-01

    Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions. c2002 Elsevier Science B.V. All rights reserved.

  15. Glaucoma classification using Regional Wavelet Features of the ONH and its surroundings.

    PubMed

    Haleem, Muhammad Salman; Han, Liangxiu; van Hemert, Jano; Fleming, Alan

    2015-08-01

    Glaucoma is one of the leading cause of blindness but the detection at its earliest stage and subsequent treatment can aid patients to preserve blindness. The existing work has been focusing on global features such as texture, grayscale and wavelet energy of the Optic Nerve Head (ONH) and its surrounding to differentiate between normal and glaucoma images. In contrast to previous approaches which focus on global information only, this work proposes a new approach to automatically classify between the normal and glaucoma images based on Regional Wavelet Features of the ONH and different regions around it. These regions are usually used for diagnosis of glaucoma by clinicians through visual observation only. Our method automatically determines different clinically observed regions around the ONH and performs classification on the basis of wavelet energy at different frequency subbands. We have conducted experiments based on different global features and regional features respectively and applied it to RIMONE (An Open Retinal Image Database for Optic Nerve Evaluation) database with 158 images. The experimental evaluation demonstrated that the classification accuracy of normal and glaucoma images using Regional Wavelet Features of different regions with 93% outperforms all other feature sets.

  16. Design, Fabrication, and In Vitro Testing of an Anti-biofouling Glaucoma Micro-shunt.

    PubMed

    Harake, Ryan S; Ding, Yuzhe; Brown, J David; Pan, Tingrui

    2015-10-01

    Glaucoma, one of the leading causes of irreversible blindness, is a progressive neurodegenerative disease. Chronic elevated intraocular pressure (IOP), a prime risk factor for glaucoma, can be treated by aqueous shunts, implantable devices, which reduce IOP in glaucoma patients by providing alternative aqueous outflow pathways. Although initially effective at delaying glaucoma progression, contemporary aqueous shunts often lead to numerous complications and only 50% of implanted devices remain functional after 5 years. In this work, we introduce a novel micro-device which provides an innovative platform for IOP reduction in glaucoma patients. The device design features an array of parallel micro-channels to provide precision aqueous outflow resistance control. Additionally, the device's microfluidic channels are composed of a unique combination of polyethylene glycol materials in order to provide enhanced biocompatibility and resistance to problematic channel clogging from biofouling of aqueous proteins. The microfabrication process employed to produce the devices results in additional advantages such as enhanced device uniformity and increased manufacturing throughput. Surface characterization experimental results show the device's surfaces exhibit significantly less non-specific protein adsorption compared to traditional implant materials. Results of in vitro flow experiments verify the device's ability to provide aqueous resistance control, continuous long-term stability through 10-day protein flow testing, and safety from risk of infection due to bacterial ingression.

  17. CENTRIFUGAL MEMBRANE FILTRATION

    SciTech Connect

    William A. Greene; Patricia A. Kirk; Richard Hayes; Joshua Riley

    2005-10-28

    SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, has engineered and developed a system for use within the U.S. Department of Energy (DOE) Environmental Management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. SpinTek II High Shear Rotary Membrane Filtration System is a unique compact crossflow membrane system that has large, demonstrable advantages in performance and cost compared to currently available systems: (1) High fluid shear prevents membrane fouling even with very high solids content; hazardous and radioactive components can be concentrated to the consistency of a pasty slurry without fouling. (2) Induced turbulence and shear across the membrane increases membrane flux by a factor of ten over existing systems and allows operation on fluids not otherwise treatable. (3) Innovative ceramic membrane and mechanical sealing technology eliminates compatibility problems with aggressive DOE waste streams. (4) System design allows rapid, simple disassembly for inspection or complete decontamination. (5) Produces colloidal- and suspended-solids-free filtrate without the addition of chemicals. The first phase of this project (PRDA maturity stage 5) completed the physical scale-up of the SpinTek unit and verified successful scale-up with surrogate materials. Given successful scale-up and DOE concurrence, the second phase of this project (PRDA maturity stage 6) will provide for the installation and

  18. Linkage analysis excludes the glaucoma locus on 1q from involvement in autosomal dominant glaucoma with iris hypoplasia

    SciTech Connect

    Heon, E.; Sheth, B.P.; Kalenak, J.W.

    1994-09-01

    Genetic factors have been implicated in a variety of types of glaucoma including primary open-angle glaucoma, infantile glaucoma, pigmentary glaucoma, and juvenile open-angle glaucoma. We previously mapped the disease-causing gene for one type of juvenile open angle glaucoma to chromosome 1q21-31. Weatherill and Hart (1969) and Pearce (1983) each noted the association of iris hypoplasia and early-onset autosomal dominant glaucoma. We recently had the opportunity to study a large family (12 affected members) with this phenotype. Affected individuals developed glaucoma at an average age of 30 years. These patients also have a strikingly underdeveloped iris stroma which causes a peculiar eye color. Linkage analysis was able to completely exclude the 1q glaucoma locus from involvement in the disorder that affects this family. A complete clinical description of the family and linkage results at additional candidate loci will be presented.

  19. Management of exfoliative glaucoma: challenges and solutions.

    PubMed

    Holló, Gábor; Katsanos, Andreas; Konstas, Anastasios Gp

    2015-01-01

    Exfoliative glaucoma is the most common type of secondary open-angle glaucoma worldwide. It is characterized by high intraocular pressure (IOP) and worse 24-hour IOP characteristics. In order to minimize progression, treatment of exfoliative glaucoma has to provide a low long-term mean IOP and good 24-hour IOP control. To achieve these goals, fixed-dose combination eye drops, argon and selective laser trabeculoplasty, and various forms of surgery (trabeculectomy, deep sclerectomy, viscocanalostomy, ab interno trabeculotomy, trabecular aspiration, and cataract surgery) all need to be considered during the long-term management of the disease. Since exfoliative glaucoma is a disease of the elderly, and is frequently associated with systemic vascular disease, interdisciplinary consultations are of great clinical importance. These management aspects and the current medical, laser, and surgical results are covered in this review, with a special focus on the needs of the general ophthalmologist.

  20. Management of exfoliative glaucoma: challenges and solutions

    PubMed Central

    Holló, Gábor; Katsanos, Andreas; Konstas, Anastasios GP

    2015-01-01

    Exfoliative glaucoma is the most common type of secondary open-angle glaucoma worldwide. It is characterized by high intraocular pressure (IOP) and worse 24-hour IOP characteristics. In order to minimize progression, treatment of exfoliative glaucoma has to provide a low long-term mean IOP and good 24-hour IOP control. To achieve these goals, fixed-dose combination eye drops, argon and selective laser trabeculoplasty, and various forms of surgery (trabeculectomy, deep sclerectomy, viscocanalostomy, ab interno trabeculotomy, trabecular aspiration, and cataract surgery) all need to be considered during the long-term management of the disease. Since exfoliative glaucoma is a disease of the elderly, and is frequently associated with systemic vascular disease, interdisciplinary consultations are of great clinical importance. These management aspects and the current medical, laser, and surgical results are covered in this review, with a special focus on the needs of the general ophthalmologist. PMID:26045655

  1. Genetics Home Reference: early-onset glaucoma

    MedlinePlus

    ... of eye disorders in which the optic nerves connecting the eyes and the brain are progressively damaged. ... pressure (hypertension) and diabetes mellitus, as well as family history. The risk of early-onset glaucoma depends ...

  2. Methylphenidate (Ritalin)-associated cataract and glaucoma.

    PubMed

    Lu, Chao-Kung; Kuang, Tung-Mei; Chou, Joe Ching-Kuang

    2006-12-01

    Methylphenidate hydrochloride (Ritalin) is the drug of choice for attention deficit hyperactivity disorder (ADHD). However, an association of Ritalin with glaucoma has been reported. We report a case of Ritalin-associated cataract and glaucoma. A 10-year-old boy was diagnosed with ADHD and had received methylphenidate hydrochloride, 60 mg/day for 2 years. He presented with blurred vision. Best-corrected visual acuity was 6/60 in both eyes. Ocular examinations revealed intraocular pressure (IOP) of 30 mmHg under medication, dense posterior subcapsular opacity of lens, pale disc with advanced cupping, and marked constriction of visual field. Despite maximal anti-glaucomatous medication, IOP still could not be controlled. The patient then received combined cataract and glaucoma surgery. Visual acuity improved and IOP was within normal limits in both eyes postoperatively. Large dose of methylphenidate may cause cataract and glaucoma. The mechanism remains unclear. Doctors should be aware of the possible ocular side effects of methylphenidate.

  3. Current perspective of neuroprotection and glaucoma

    PubMed Central

    Tian, Kailin; Shibata-Germanos, Shannon; Pahlitzsch, Milena; Cordeiro, M Francesca

    2015-01-01

    Glaucoma is the second leading cause of blindness worldwide and is most notably characterized by progressive optic nerve atrophy and advancing loss of retinal ganglion cells (RGCs). The main concomitant factor is the elevated intraocular pressure (IOP). Existing treatments are focused generally on lowering IOP. However, both RGC loss and optic nerve atrophy can independently occur with IOP at normal levels. In recent years, there has been substantial progress in the development of neuroprotective therapies for glaucoma in order to restore vital visual function. The present review intends to offer a brief insight into conventional glaucoma treatments and discuss exciting current developments of mostly preclinical data in novel neuroprotective strategies for glaucoma that include recent advances in noninvasive diagnostics going beyond IOP maintenance for an enhanced global view. Such strategies now target RGC loss and optic nerve damage, opening a critical therapeutic window for preventative monitoring and treatment. PMID:26635467

  4. Glaucoma Disparities in the Hispanic Population.

    PubMed

    Nathan, Niraj; Joos, Karen M

    2016-01-01

    The Hispanic population is the United States' largest minority and one of the fastest growing as well. In the next 30 to 40 years, the proportion of open-angle glaucoma patients represented by Hispanics is expected to dramatically rise. Here we examine the unique considerations and challenges of glaucoma care in this population, from demographics to risk factors to treatments and outcomes. Currently, access to care and the under-diagnosis of glaucoma in this population are significant issues that look only to grow in significance as the glaucoma burden continues to grow. Additionally, utilization of medical and surgical therapy remains lower in Hispanics than in many other ethnic groups. Understanding and proactively addressing the unique challenges in the screening and treatment of Hispanics will be of utmost importance to providing effective care to this population.

  5. Dry Eyes and Glaucoma: Double Trouble

    MedlinePlus

    ... News About Us Donate In This Section Dry Eyes and Glaucoma: Double Trouble email Send this article ... disease bothers the patient more. What Causes Dry Eye Syndrome? Dry eye can be caused by many ...

  6. Acquired color vision loss and a possible mechanism of ganglion cell death in glaucoma.

    PubMed Central

    Nork, T M

    2000-01-01

    PURPOSE: First, to study the cellular mechanisms of acquired color vision loss in retinal detachment and diabetic retinopathy. Second, to learn why, in glaucoma, the type of color vision deficit that is observed is more characteristic of a retinal injury than it is of an optic neuropathy. Third, to test a hypothesis of photoreceptor-induced, ganglion cell death in glaucoma. METHODS: Various histologic techniques were employed to distinguish the L/M-cones (long/medium wavelength-sensitive cones, or red/green sensitive cones) from the S-cones (short wavelength-sensitive cones, or blue sensitive cones) in humans and monkeys with retinal detachment, humans with diabetic retinopathy, and both humans and monkeys with glaucoma. To test if the photoreceptors were contributing to ganglion cell death, laser photocoagulation was used in a experimental model of glaucoma to focally eliminate the photoreceptors. As a control, optic nerve transection was done following retinal laser photocoagulation in one animal. RESULTS: Selective and widespread loss of the S-cones was found in retinal detachment as well as diabetic retinopathy. By contrast, in human as well as experimental glaucoma, marked swelling of the L/M-cones was the predominant histopathologic feature. Retinal laser photocoagulation followed by experimental glaucoma resulted in selective protection of ganglion cells overlying the laser spots. This was not seen with retinal laser photocoagulation by optic nerve transection. CONCLUSIONS: In retinal detachment and diabetic retinopathy, acquired tritan-like color vision loss could be caused, or contributed to, by selective loss of the S-cones. Both L- and M-cones are affected in glaucoma, which is also consistent with a tritan-like deficit. Although not a therapeutic option, protection of ganglion cells by retinal laser in experimental glaucoma is consistent with an hypothesis of anterograde, photoreceptor-induced, ganglion cell death. Images FIGURE 1 FIGURE 2 FIGURE 3

  7. Glaucoma Associated with Boston Type 1 Keratoprosthesis

    PubMed Central

    Kamyar, Roheena; Weizer, Jennifer S.; de Paula, Fernando Heitor; Stein, Joshua D.; Moroi, Sayoko E.; John, Denise; Musch, David C.; Mian, Shahzad I.

    2012-01-01

    Purpose To evaluate outcomes of the Boston Type 1 keratoprosthesis (KPro) and associated incidence of glaucoma. Design Retrospective cohort study. Participants All patients who underwent KPro surgery at one institution from 2003-2009 with at least 3 months follow-up. Methods Preoperative visual acuity, diagnosis, history of glaucoma, intraoperative and postoperative parameters were recorded. Statistical analysis was performed to identify factors that may influence increase in intraocular pressure (IOP) and glaucoma development or progression after surgery. Main Outcome Measures Best corrected visual acuity (BCVA), IOP, postoperative medical and surgical treatments for glaucoma, and KPro retention and complications. Results Thirty-six KPro procedures were performed in 30 eyes of 29 patients with mean (± SD) follow-up of 17±19 months (range 3-67 months). The main indication for KPro implantation was corneal graft failure (77%). Primary KPros were performed in 23% of eyes for limbal stem cell deficiency secondary to chemical burns and aniridia, and for herpetic disease. Median preoperative BCVA was hand motions with an overall improvement to 20/330 (range 20/20 to hand motions) at nine months postoperatively; mean BCVA was 20/600 (range 20/40 to NLP) at last follow-up. Twenty eyes (67%) had a preoperative history of glaucoma with eight of those eyes (40%) having undergone prior glaucoma surgery. Twenty-one eyes (70%) underwent concomitant glaucoma surgery. Postoperative increased IOP (22 mmHg or higher) was noted in 15 eyes (50%) while definite glaucoma development or progression was noted in 7 of those 15 eyes (23% of total eyes). Mean BCVA at last follow-up in eyes with glaucoma development or progression was 3/200 compared to 20/563 in the remaining 23 eyes. Six patients (20%) required repeat KPro implantation, and retroprosthetic membranes developed in 23 eyes (77%). No patient developed vitritis or infectious endophthalmitis. Conclusions The Boston Type 1 KPro

  8. Modus of filtration.

    PubMed

    Meltzer, Theodore H

    2006-01-01

    Experience teaches that particles larger than the pores of a filter cannot negotiate its passage. Other retention mechanisms are less obvious than sieve retention or size exclusion. They are electrical in nature, and find expression in the bonding alliances that mutually attract (or repel) filters and particles. The influence of hydrogen bonds, of van der Waals forces, of hydrophobic adsorptions, and of transient polarities on particle retentions are set forth in terms of the double electrical layer concept that also governs colloidal destabilizations. The origins of differences in membrane porosities is explained, as also the importance of the filtration conditions. The singularity of the particle-fluid-filter relationship on organism and/or pore size alteration is stressed.

  9. Microscope-integrated optical coherence tomography for image-aided positioning of glaucoma surgery

    NASA Astrophysics Data System (ADS)

    Li, Xiqi; Wei, Ling; Dong, Xuechuan; Huang, Ping; Zhang, Chun; He, Yi; Shi, Guohua; Zhang, Yudong

    2015-07-01

    Most glaucoma surgeries involve creating new aqueous outflow pathways with the use of a small surgical instrument. This article reported a microscope-integrated, real-time, high-speed, swept-source optical coherence tomography system (SS-OCT) with a 1310-nm light source for glaucoma surgery. A special mechanism was designed to produce an adjustable system suitable for use in surgery. A two-graphic processing unit architecture was used to speed up the data processing and real-time volumetric rendering. The position of the surgical instrument can be monitored and measured using the microscope and a grid-inserted image of the SS-OCT. Finally, experiments were simulated to assess the effectiveness of this integrated system. Experimental results show that this system is a suitable positioning tool for glaucoma surgery.

  10. Evaluating glaucoma damage: emerging imaging technologies

    PubMed Central

    Kostanyan, Tigran; Wollstein, Gadi; Schuman, Joel S

    2015-01-01

    The use of ocular imaging tools to estimate structural and functional damage in glaucoma has become a common clinical practice and a substantial focus of vision research. The evolution of the imaging technologies through increased scanning speed, penetration depth, image registration and development of multimodal devices has the potential to detect the pathology more reliably and in earlier stages. This review is focused on new ocular imaging modalities used for glaucoma diagnosis. PMID:27087829

  11. Filtration: Principles and practices. 2. edition

    SciTech Connect

    Matteson, M.J.; Orr, C.

    1998-12-31

    This new book is the most authoritative and comprehensive guide to essential, state-of-the-art data. It provides the very latest theoretical and practical data on filtration for gas and liquids. The 2nd edition has been revised and updated to include several new chapters which detail filtration in the mineral industry, high-efficiency air filtration, cartridge filters, and ultrafiltration. The contents include: Gas filtration theory; Liquid-filtration theory; Filter media; Industrial gas filtration; Filtration pretreatment; Filtration in the chemical process industry; Ultrafiltration; Filtration in the mineral industry; Filtration in heating, ventilating, and air conditioning; Cartridge filtration; High-efficiency air filtration; Analytical applications of filtration; and Filter evaluation and testing.

  12. Genetic and Biochemical Biomarkers in Canine Glaucoma.

    PubMed

    Graham, K L; McCowan, C; White, A

    2017-03-01

    In many health-related fields, there is great interest in the identification of biomarkers that distinguish diseased from healthy individuals. In addition to identifying the diseased state, biomarkers have potential use in predicting disease risk, monitoring disease progression, evaluating treatment efficacy, and informing pathogenesis. This review details the genetic and biochemical markers associated with canine primary glaucoma. While there are numerous molecular markers (biochemical and genetic) associated with glaucoma in dogs, there is no ideal biomarker that allows early diagnosis and/or identification of disease progression. Genetic mutations associated with canine glaucoma include those affecting ADAMTS10, ADAMTS17, Myocilin, Nebulin, COL1A2, RAB22A, and SRBD1. With the exception of Myocilin, there is very limited crossover in genetic biomarkers identified between human and canine glaucomas. Mutations associated with canine glaucoma vary between and within canine breeds, and gene discoveries therefore have limited overall effects as a screening tool in the general canine population. Biochemical markers of glaucoma include indicators of inflammation, oxidative stress, serum autoantibodies, matrix metalloproteinases, tumor necrosis factor-α, and transforming growth factor-β. These markers include those that indicate an adaptive or protective response, as well as those that reflect the damage arising from oxidative stress.

  13. A PERSPECTIVE OF RIVERBANK FILTRATION

    EPA Science Inventory

    Riverbank filtration is a process in which pumping of wells located along riverbanks induce a portion of the river water to flow toward the pumping wells. The process has many similarities to the slow sand filtration process. River water contaminants are attenuated due to a combi...

  14. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that does... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water...

  15. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that does... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water...

  16. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that does... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water...

  17. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that does... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water...

  18. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that does... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water...

  19. What Do Patients With Glaucoma See? Visual Symptoms Reported by Patients With Glaucoma

    PubMed Central

    Hu, Cindy X.; Zangalli, Camila; Hsieh, Michael; Gupta, Lalita; Williams, Alice L.; Richman, Jesse

    2014-01-01

    Abstract: Background: Vision loss from glaucoma has traditionally been described as loss of “peripheral vision.” In this prospective study, we aimed to improve our clinical understanding of the visual symptoms caused by glaucoma by asking patients specific detailed questions about how they see. Methods: Patients who were clinically diagnosed with various types and stages of glaucoma were included. All had a comprehensive ocular examination, including Octopus visual field testing. Patients were excluded if they had other ocular conditions that affected their vision, including cornea, lens or retina pathologies. Patients responded to an oral questionnaire about their visual symptoms. We investigated the visual symptoms described by patients with glaucoma and correlated the severity of visual field loss with visual symptoms reported. Results: Ninety-nine patients completed the questionnaire. Most patients (76%) were diagnosed with primary open-angle glaucoma. The most common symptoms reported by all patients, including patients with early or moderate glaucoma, were needing more light and blurry vision. Patients with a greater amount of field loss (Octopus mean defect >+9.4 dB) were more likely to report difficulty seeing objects to one or both sides, as if looking through dirty glasses and trouble differentiating boundaries and colors. Conclusions: Vision loss in patients with glaucoma is not as simple as the traditional view of loss of peripheral vision. Needing more light and blurry vision were the most common symptoms reported by patients with glaucoma. PMID:24992392

  20. Glaucoma

    MedlinePlus

    ... group of diseases that can damage the eye's optic nerve. It is a leading cause of blindness ... pressure inside the eyes slowly rises, damaging the optic nerve. Often there are no symptoms at first. ...

  1. Maladaptive coping strategies and glaucoma progression.

    PubMed

    Freeman, Ellen E; Lesk, Mark R; Harasymowycz, Paul; Desjardins, Daniel; Flores, Veronica; Kamga, Hortence; Li, Gisèle

    2016-08-01

    The identification of modifiable risk factors for glaucoma progression is needed. Our objective was to determine whether maladaptive coping styles are associated with recent glaucoma progression or worse visual field mean deviation.A hospital-based case-control study was conducted in the Glaucoma Service of Maisonneuve-Rosemont Hospital in Montreal, Canada. Patients with primary open angle glaucoma or normal tension glaucoma with ≥4 years of follow-up and ≥5 Humphrey visual fields were included. Cases had recent visual field progression as defined according to the Early Manifest Glaucoma Trial pattern change probability maps. Controls had stable visual fields. The Brief Cope questionnaire, a 28-item questionnaire about 14 different ways of coping with the stress of a chronic disease, was asked. Questions were also asked about demographic and medical factors, and the medical chart was examined. Outcomes included glaucoma progression (yes, no) and visual field mean deviation. Logistic and linear regressions were used.A total of 180 patients were included (82 progressors and 98 nonprogressors). Although none of the 14 coping scales were associated with glaucoma progression (P > 0.05), higher denial was correlated with worse visual field mean deviation (r = -0.173, P = 0.024). In a linear regression model including age, sex, education, depression, intraocular pressure, and family history of glaucoma, greater levels of denial (β = -1.37, 95% confidence interval [CI] -2.32, -0.41), Haitian ethnicity (β = -7.78, 95% CI -12.52, -3.04), and the number of glaucoma medications (β = -1.20, 95% CI -2.00, -0.38) were statistically significantly associated with visual field mean deviation.The maladaptive coping mechanism of denial was a risk factor for worse visual field mean deviation. Further prospective research will be required to verify the pathways by which denial may exert an effect on glaucomatous visual field loss.

  2. A framework to explore the visual brain in glaucoma with lessons from models and man.

    PubMed

    Yucel, Yeni H; Gupta, Neeru

    2015-12-01

    Vision loss in glaucoma is associated with death of retinal ganglion cells. High intraocular pressure is a major risk factor for vision loss from glaucoma, and lowering eye pressure is the goal of all available medical and surgical treatments. Taking a bold step forward, the restoration of vision after severe glaucoma damage is a new Audacious Goal established by National Eye Institute (Sieving, 2012). This means that retinal ganglion cell repair, and replacement, must be considered in the context of visual function restoration. To restore visual function, retinal ganglion cells, after long-distance axonal growth and guidance, should connect to specific target neurons in subcortical visual structures. At the time of the establishment of these connections, the fate of target cells is critical along with the health of retinal ganglion cells. In fact, several lines of evidence demonstrate glaucomatous neural degeneration occurs throughout the central visual system where most information processing takes place. Evidence from multiple studies in experimental glaucoma models, human autopsy cases and neuroimaging studies point to the degeneration of neurons in the lateral geniculate nucleus, a subcortical hub of functional connectivity between the eye and the visual cortex. Maintaining and re-establishing connections of retinal ganglion cells to target neurons in major visual structures is a key endpoint for regenerative medicine strategies. This paper critically reviews studies of visual brain changes in man and experimental animal models, and discusses key factors in the experimental design that are relevant to restoring vision loss in human disease.

  3. The School's Role in Preventing Blindness from Glaucoma.

    ERIC Educational Resources Information Center

    Penland, Lynn R.; Penland, William R.

    1980-01-01

    While glaucoma generally strikes those over 35 years of age, awareness of glaucoma should be promoted in junior and senior high school and college by incorporating information into a unit on eye health or chronic diseases. (MJB)

  4. Philadelphia Telemedicine Glaucoma Detection and Follow-Up Study

    ClinicalTrials.gov

    2017-04-06

    Glaucoma; Glaucoma Suspect; Diabetic Retinopathy; Ocular Hypertension; Cataract; Branch Retinal Vein Occlusion; Branch Retinal Arterial Occlusion; Central Retinal Vein Occlusion; Central Retinal Artery Occlusion; Epi-retinal Membrane; Macular Degeneration; Drusen; Loss of Vision

  5. U.S. Glaucoma Cases Expected to Surge by 2030

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_162924.html U.S. Glaucoma Cases Expected to Surge by 2030 Routine eye ... 6, 2017 FRIDAY, Jan. 6, 2017 (HealthDay News) -- Glaucoma affects more than 3 million Americans, but that ...

  6. Regional Image Features Model for Automatic Classification between Normal and Glaucoma in Fundus and Scanning Laser Ophthalmoscopy (SLO) Images.

    PubMed

    Haleem, Muhammad Salman; Han, Liangxiu; Hemert, Jano van; Fleming, Alan; Pasquale, Louis R; Silva, Paolo S; Song, Brian J; Aiello, Lloyd Paul

    2016-06-01

    Glaucoma is one of the leading causes of blindness worldwide. There is no cure for glaucoma but detection at its earliest stage and subsequent treatment can aid patients to prevent blindness. Currently, optic disc and retinal imaging facilitates glaucoma detection but this method requires manual post-imaging modifications that are time-consuming and subjective to image assessment by human observers. Therefore, it is necessary to automate this process. In this work, we have first proposed a novel computer aided approach for automatic glaucoma detection based on Regional Image Features Model (RIFM) which can automatically perform classification between normal and glaucoma images on the basis of regional information. Different from all the existing methods, our approach can extract both geometric (e.g. morphometric properties) and non-geometric based properties (e.g. pixel appearance/intensity values, texture) from images and significantly increase the classification performance. Our proposed approach consists of three new major contributions including automatic localisation of optic disc, automatic segmentation of disc, and classification between normal and glaucoma based on geometric and non-geometric properties of different regions of an image. We have compared our method with existing approaches and tested it on both fundus and Scanning laser ophthalmoscopy (SLO) images. The experimental results show that our proposed approach outperforms the state-of-the-art approaches using either geometric or non-geometric properties. The overall glaucoma classification accuracy for fundus images is 94.4% and accuracy of detection of suspicion of glaucoma in SLO images is 93.9 %.

  7. Evaluation of an Injectable Thermosensitive Hydrogel As Drug Delivery Implant for Ocular Glaucoma Surgery

    PubMed Central

    Zhao, Feng; Zheng, Qiongjuan; Li, Xiaoning; Luo, Jing; Liu, Ji; Quan, Daping; Ge, Jian

    2014-01-01

    In this study, a biodegradable thermo-sensitive hydrogel from poly(trimethylene carbonate)15-F127-poly(trimethylene carbonate)15 (PTMC15-F127-PTMC15) was designed and evaluated as an injectable implant during ocular glaucoma filtration surgery in vivo and in vitro. Mitomycin C (MMC) was loaded into this hydrogel for controlled released to prolong the efficacy and to reduce the long-term toxicity. The properties of the hydrogel were confirmed using 1H NMR and gel permeation chromatography (GPC). Compared to the Pluronic F127 hydrogel, the PTMC15-F127-PTMC15 hydrogel showed a good solution-gel transition temperature at 37°C, a lower work concentration of 5% w/v and a longer mass loss time of more than 2 weeks. The in vitro study showed that the drug could be released from PTMC15-F127-PTMC15 (5% w/v) hydrogel for up to 16 days with only 57% of drug released in the first day. Moreover, the cell toxicity, which was tested via LDH and ANNEXIN V/PI, decreased within 72 h in human tenon's fibroblast cells (HTFs). The in vivo behavior in a rabbit glaucoma filtration surgery model indicated that this hydrogel loaded with 0.1 mg/ml MMC led to a better functional bleb with a prolonged mean bleb survival time (25.5±2.9 days). The scar tissue formation, new collagen deposition and myofibroblast generation appeared to be reduced upon histological and immunohistochemistry examinations, with no obvious side effects and inflammatory reactions. The in vitro and in vivo results demonstrated that this novel hydrogel is a safe and effective drug delivery candidate in ocular glaucoma surgery. PMID:24950176

  8. Efficacy and Safety of Trabectome Surgery in Chinese Open-Angle Glaucoma

    PubMed Central

    Lee, Jacky W.Y.; Yick, Doris W.F.; Tsang, Susanna; Yuen, Can Y.F.; Lai, Jimmy S.M.

    2016-01-01

    Abstract To investigate the clinical outcome of the Trabectome in Chinese open-angle glaucoma (OAG). This prospective case series recruited pseudophakic glaucoma subjects with open-angle configuration. Trabeculectomy ab interno was performed using the Trabectome to 120° of the trabecular meshwork. Intraocular pressure (IOP) and medications were recorded preoperatively and every 3 months postoperatively. Visual acuity was measured preoperatively and at 1 and 6 months postoperatively. One-way ANOVA with Tukey Multiple Comparison Test were used to measure the pre and postoperative parameters. In 19 eyes of 19 Chinese subjects, 26.3% were uveitic, 68.4% were primary open-angle glaucoma, and 5.3% had a history of chronic angle-closure glaucoma with open-angles after cataract extraction. The subjects’ mean age was 67.5 ± 14.4 years, with 4 females and 15 males. Two patients required secondary filtration procedure. At 6 months, the IOP reduced by 34.8% (24.4 ± 4.4 mm Hg to 15.9 ± 5.1 mm Hg, P < 0.0001). The number of types of antiglaucoma medications was reduced by 28.2% (3.9 ± 0.8–2.8 ± 1.6, P < 0.0001). The visual acuity was static at 1 and 6 months postoperatively (P = 0.4). There were no intraoperative complications. 26.3% of subjects had a transient IOP spike > 21 mm Hg, 1 had hyphema requiring washout, and 1 had reactivation of herpetic keratitis. The success rate at 6 months was 89.5%. Trabectome achieved a modest reduction in IOP and medications in the majority of pseudophakic Chinese OAG eyes. PMID:27082559

  9. Is Estrogen a Therapeutic Target for Glaucoma?

    PubMed Central

    Dewundara, Samantha; Wiggs, Janey; Sullivan, David A.; Pasquale, Louis R.

    2016-01-01

    Objective To provide an overview of the association between estrogen and glaucoma. Methods A literature synthesis of articles published in peer review journals screened through May 05, 2015 using the PubMed database. Key words used were “estrogen and glaucoma,” “reproductive factors and glaucoma,” “estrogen, nitric oxide and eye.” Forty three journal articles were included. Results Markers for lifetime estrogen exposure have been measured by several studies and show that the age of menarche onset, oral contraceptive (OC) use, bilateral oophorectomy, age of menopause onset and duration between menarche to menopause are associated with primary open angle (POAG) risk. The Blue Mountain Eye Study found a significantly increased POAG risk with later (>13 years) compared with earlier (≤12 years) age of menarche. Nurses’ Health Study (NHS) investigators found that OC use of greater than 5 years was associated with a 25% increased risk of POAG. The Mayo Clinic Cohort Study of Oophorectomy and Aging found that women who underwent bilateral oophorectomy before age 43 had an increased risk of glaucoma. The Rotterdam Study found that women who went through menopause before reaching the age of 45 years had a higher risk of open-angle glaucoma (2.6-fold increased risk) while the NHS showed a reduced risk of POAG among women older than 65 who entered menopause after age ≥ 54 years. Increased estrogen states may confer a reduced risk of glaucoma or glaucoma related traits such as reduced intraocular pressure (IOP). Pregnancy, a hyperestrogenemic state, is associated with decreased IOP during the third trimester. Though the role of post-menopausal hormone (PMH) use in the reduction of IOP is not fully conclusive, PMH use may reduce the risk of POAG. From a genetic epidemiologic perspective, estrogen metabolic pathway single nucleotide polymorphisms (SNPs) were associated with POAG in women and polymorphisms in endothelial nitric oxide synthase, a gene receptive to

  10. Influence of Diastolic Blood Pressure on Glaucoma Progression in Glaucoma Patients with Systemic Hypertension.

    PubMed

    Suić, Smiljka Popović; Skegro, Ivan; Jandroković, Sonja; Kordić, Rajko; Kutija, Maria Barisić

    2015-09-01

    The aim of this study is to determine relationship between glaucoma progression and diastolic blood pressure. It was conducted on 64 glaucoma patients at the Department of Ophthalmology of Clinical Hospital Centre Zagreb in three years period. The patients were on anti glaucoma therapy and had mean intraocular pressure values under 20 mmHg. At the same time they were on antihypertensive drug therapy. Patients were classified according Glaucoma Staging System based on the perimetric indices mean deviation (MD) and Pattern Standard Deviation into stage 2-4 (moderate glaucoma) at baseline. Rate of visual field progression was calculated in db/year for MD in the last three visits. Patients were divided in 3 groups according to progression--stabile, moderate and progressive. There was no statistically significant difference between 3 groups in terms of intraocular pressure values at baseline and in follow up period. After reviewing their blood pressure, the progressive group showed a significantly lower diastolic blood pressure compared to both stable group and the group with moderate progression. There was no statistical difference between the group with moderate progression and the stable group in terms of diastolic blood pressure. Results suggest that greater risk of glaucoma progression is connected with lower diastolic blood pressure. Diastolic pressure values could be important as one of the risk factors for progression in glaucoma patients with controlled intraocular pressure values.

  11. Topical glaucoma therapy cost in Mexico.

    PubMed

    Lazcano-Gomez, Gabriel; Hernandez-Oteyza, Alejandra; Iriarte-Barbosa, María José; Hernandez-Garciadiego, Carlos

    2014-04-01

    Glaucoma is an important cause of irreversible blindness that represents a significant economic burden; most direct costs of glaucoma are drug-related. We calculated the annual cost of some of the most commonly prescribed glaucoma medications in Mexico, according to their average wholesale price (AWP) and dose regimen. Annual costs ranged from USD4.97 for Imot 15 ml (timolol 0.5 %; Laboratorios Sophia) to USD675.39 for Alphagan 5 ml (brimonidine 0.2 %; Allergan, Inc.). β-Blockers were the least expensive glaucoma medications (range USD20.44-55.44). Alphagan 5 ml was 250 % more expensive than other selective α(2)-agonists. Of the carbonic anhydrase inhibitors, dorzolamide 2 % was less expensive than brinzolamide 1 % (USD326.91 vs. USD418.96). The annual cost for prostaglandin analogs ranged from USD235.58 for bimatoprost 0.03 % to USD337.78 for latanoprost 0.005 %. Some fixed combinations were less expensive than separate combinations. The average annual cost for all treatments increased by 27.87 ± 10.09 % between 2009 and 2012. Annual glaucoma therapy cost seems to be lower in Mexico than in other countries, due to a lower AWP, especially for some medications made by Mexican laboratories.

  12. Placement of a collagen glaucoma drainage device to control intraocular pressure and chronic iritis secondary to juvenile rheumatoid arthritis.

    PubMed

    Price, Francis W; Ziemba, Steven L

    2002-01-01

    A patient with juvenile rheumatoid arthritis and chronic iritis is reported with intraocular pressure near 30 mm Hg and previous episodes of intraocular pressure as high as 50 mm Hg despite maximally tolerated medical therapy. Because of the potential risk involved with a full-thickness filtration procedure, it was decided that a nonpenetrating deep sclerectomy would be appropriate, followed by placement of a collagen glaucoma drainage device to maintain aqueous outflow. Immediately postoperatively, intraocular pressure was stabilized. At 24 months postoperatively, intraocular pressure was well controlled at 15 mm Hg with patient receiving only Lotemax. No significant complications were noted at any point in the postoperative course. Because of the patient's predisposition for serious complications frequently associated with trabeculectomy, nonpenetrating deep sclerectomy with the collagen glaucoma drainage device was an effective alternative for this patient.

  13. Optical Coherence Tomography Angiography Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes

    PubMed Central

    Yarmohammadi, Adeleh; Zangwill, Linda M.; Diniz-Filho, Alberto; Suh, Min Hee; Manalastas, Patricia Isabel; Fatehee, Naeem; Yousefi, Siamak; Belghith, Akram; Saunders, Luke J.; Medeiros, Felipe A.; Huang, David; Weinreb, Robert N.

    2016-01-01

    Purpose The purpose of this study was to compare retinal nerve fiber layer (RNFL) thickness and optical coherence tomography angiography (OCT-A) retinal vasculature measurements in healthy, glaucoma suspect, and glaucoma patients. Methods Two hundred sixty-one eyes of 164 healthy, glaucoma suspect, and open-angle glaucoma (OAG) participants from the Diagnostic Innovations in Glaucoma Study with good quality OCT-A images were included. Retinal vasculature information was summarized as a vessel density map and as vessel density (%), which is the proportion of flowing vessel area over the total area evaluated. Two vessel density measurements extracted from the RNFL were analyzed: (1) circumpapillary vessel density (cpVD) measured in a 750-μm-wide elliptical annulus around the disc and (2) whole image vessel density (wiVD) measured over the entire image. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy. Results Age-adjusted mean vessel density was significantly lower in OAG eyes compared with glaucoma suspects and healthy eyes. (cpVD: 55.1 ± 7%, 60.3 ± 5%, and 64.2 ± 3%, respectively; P < 0.001; and wiVD: 46.2 ± 6%, 51.3 ± 5%, and 56.6 ± 3%, respectively; P < 0.001). For differentiating between glaucoma and healthy eyes, the age-adjusted AUROC was highest for wiVD (0.94), followed by RNFL thickness (0.92) and cpVD (0.83). The AUROCs for differentiating between healthy and glaucoma suspect eyes were highest for wiVD (0.70), followed by cpVD (0.65) and RNFL thickness (0.65). Conclusions Optical coherence tomography angiography vessel density had similar diagnostic accuracy to RNFL thickness measurements for differentiating between healthy and glaucoma eyes. These results suggest that OCT-A measurements reflect damage to tissues relevant to the pathophysiology of OAG. PMID:27409505

  14. Health benefits of particle filtration.

    PubMed

    Fisk, W J

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, for example, 7% to 25%. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  15. Health Benefits of Particle Filtration

    SciTech Connect

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  16. Health Benefits of Particle Filtration

    SciTech Connect

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  17. Linkage studies in primary open angle glaucoma

    SciTech Connect

    Avramopoulos, D.; Grigoriadu, M.; Kitsos, G.

    1994-09-01

    Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with an open, normal appearing anterior chamber angle and is termed primary open angle glaucoma (POAG, MIM 137760). It is characterized by elevated intraocular pressure and onset in middle age or later. A subset of POAG with juvenile onset has recently been linked to chromosome 1q in two families with autosomal dominant inheritance. Eleven pedigrees with autosomal dominant POG (non-juvenile-onset) have been identified in Epirus, Greece. In the present study DNA samples have been collected from 50 individuals from one large pedigree, including 12 affected individuals. Preliminary results of linkage analysis with chromosome 1 microsatellites using the computer program package LINKAGE Version 5.1 showed no linkage with the markers previously linked to juvenile-onset POAG. Further linkage analysis is being pursued, and the results will be presented.

  18. Novel therapies for open-angle glaucoma

    PubMed Central

    Wentz, Scott M.; Kim, Nathaniel J.; Wang, Jenny; Amireskandari, Annahita; Siesky, Brent

    2014-01-01

    Open-angle glaucoma is a multifactorial optic neuropathy characterized by progressive loss of retinal ganglion cells and their axons. It is an irreversible disease with no established cure. The only currently approved treatment is aimed at lowering intraocular pressure, the most significant risk factor known to date. However, it is now clear that there are other risk factors involved in glaucoma's pathophysiology. To achieve future improvements in glaucoma management, new approaches to therapies and novel targets must be developed. Such therapies may include new tissue targets for lowering intraocular pressure, molecules influencing ocular hemodynamics, and treatments providing neuroprotection of retinal ganglion cells. Furthermore, novel drug delivery systems are in development that may improve patient compliance, increase bioavailability, and decrease adverse side effects. PMID:25580256

  19. Diagnostic tools for glaucoma detection and management.

    PubMed

    Sharma, Pooja; Sample, Pamela A; Zangwill, Linda M; Schuman, Joel S

    2008-11-01

    Early diagnosis of glaucoma is critical to prevent permanent structural damage and irreversible vision loss. Detection of glaucoma typically relies on examination of structural damage to the optic nerve combined with measurements of visual function. To aid the clinician in evaluation of visual function and structure, computer-based devices such as confocal scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography provide quantitative assessments of structural damage, and visual function testing includes standard automated perimetry as well as selective techniques, including short-wavelength automated perimetry and frequency-doubling technology perimetry are available. This article will review current literature on diagnostic modalities available for glaucoma with emphasis on the best evidence available in the literature to support their use in clinical practice.

  20. [Glaucoma in the over-eighties].

    PubMed

    Detry-Morel, M

    2007-11-01

    Due to the recent rapid increase in the aging population, glaucoma in the over-eighties population will become a significant problem of ocular health in the coming decades. It is important to determine the natural effects of aging on the optic nerve head and aqueous humor dynamics in these patients for early diagnosis and monitoring of glaucoma. Its characteristics, context, management, and treatment are very perceptibly different from those of the younger glaucomatous patient. For many reasons, such as its frequent association with macular age-related degeneration, diagnosis of glaucoma in the over-eighties may be difficult. Management of the over-eighties glaucoma is frequently difficult and time-consuming. Less aggressive than in a younger patient and based on topical medications in most cases, it must be discussed case by case and will be based on the general context, the quality of compliance, and especially on the potential consequences of the glaucomatous visual-field defects on the patient's quality of life. In any case, overtreatment as well as treatments that are too complex must be avoided. Given the reduced metabolism in the very elderly, the safest medications must also be selected. It is important to always consider glaucoma medications as part of the patient's medicine regimen. Associated risk factors, especially concomitant systemic hypotension, will be simultaneously treated. Laser trabeculoplasties probably have broader indications than in younger patients. Except for phacoextraction, which is very frequently helpful in controlling IOP, incisional filtering procedures or laser diode cyclophotocoagulations remain infrequently indicated in over-eighties glaucoma patients.

  1. [Influence of Luxury Foodstuffs on Glaucoma].

    PubMed

    Huber-van der Velden, K K

    2017-02-01

    The term "luxury foodstuffs" refers to foods which are not consumed because of their nutritional value. Classic modern luxury foodstuffs are alcohol, caffeine-containing drinks, cocoa, sugar and tobacco. The following review article examines some of these modern luxury foodstuffs in detail, as well as their influence on glaucoma. Thus, small quantities of alcohol lower high intraocular pressure and have a positive influence on the blood circulation of the optic nerve. In addition, red wine polyphenols exert vasoprotective effects. In general, however, alcohol consumption appears to have no significant effect on the prevalence of glaucoma. The most important source of caffeine intake is coffee consumption. In some studies, coffee consumption caused no changes in intraocular pressure, while others reported a rise. A large study showed a connection between heavy coffee consumption and the risk of pseudoexfoliation glaucoma. Green and black teas are rich sources of flavonoids with antioxidant activity. In addition, a slight trend for lowering the intraocular pressure has been measured. As regards chocolate, flavonoid-rich dark chocolate should be favoured, due to its antioxidant activity. It lowers blood pressure and improves endothelium-dependent vascular relaxation. Excessive sugar consumption over many years can lead to increased body mass index (BMI) and type 2 diabetes. Many studies show a positive relationship between BMI and intraocular pressure. Some studies have identified significant correlations between type 2 diabetes and the risk of glaucoma. Smoking is a very widespread stimulant; it narrows the blood vessels and thus reduces the blood circulation of the optic nerve. Otherwise, studies on the role of smoking as a risk factor for glaucoma have been very inconsistent. Luxury foodstuffs may effect glaucoma and should be included in the medical history.

  2. Nanofiber filter media for air filtration

    NASA Astrophysics Data System (ADS)

    Raghavan, Bharath Kumar

    Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200--300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling. The particle loading on a microfibrous filter were studied for air filtration tests. The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers

  3. Secondary glaucoma in CAPN5-associated neovascular inflammatory vitreoretinopathy

    PubMed Central

    Cham, Abdourahman; Bansal, Mayank; Banda, Himanshu K; Kwon, Young; Tlucek, Paul S; Bassuk, Alexander G; Tsang, Stephen H; Sobol, Warren M; Folk, James C; Yeh, Steven; Mahajan, Vinit B

    2016-01-01

    Objective The objective of this study was to review the treatment outcomes of patients with secondary glaucoma in cases of autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV), a hereditary autoimmune uveitis due to mutations in CAPN5. Patients and methods A retrospective, observational case series was assembled from ADNIV patients with secondary glaucoma. The main outcome measures were intraocular pressure (IOP), visual acuity, use of antiglaucoma medications, ocular surgeries, and adverse outcomes. Perimetry and optic disk optical coherence tomography (OCT) were also analyzed. Results Nine eyes of five ADNIV patients with secondary glaucoma were reviewed. Each received a fluocinolone acetonide (FA) implant for the management of posterior uveitis. Following implantation, no eyes developed neovascular glaucoma. Five eyes (in patients 1, 2, and 5) required Ahmed glaucoma valve surgery for the management of steroid-responsive glaucoma. Patient 2 also developed angle closure with iris bombe and underwent laser peripheral iridotomy. Patient 4 had both hypotony and elevated IOP that required periodic antiglaucoma medication in the FA-implanted eye. Patient 3 did not develop steroid-response glaucoma in either eye. Optic disk examinations were obscured by fibrosis and better assessed with OCT. Conclusion ADNIV patients show combined mechanism secondary glaucoma best assessed by OCT of the optic disk. The FA implants have reduced uveitic and neovascular glaucoma. Nevertheless, IOP management remains complex due to steroid-response glaucoma, angle closure glaucoma, and hypotony. PMID:27390515

  4. Rare Diseases Leading to Childhood Glaucoma: Epidemiology, Pathophysiogenesis, and Management

    PubMed Central

    Abdolrahimzadeh, Solmaz; Fameli, Valeria; Mollo, Roberto; Contestabile, Maria Teresa; Perdicchi, Andrea; Recupero, Santi Maria

    2015-01-01

    Noteworthy heterogeneity exists in the rare diseases associated with childhood glaucoma. Primary congenital glaucoma is mostly sporadic; however, 10% to 40% of cases are familial. CYP1B1 gene mutations seem to account for 87% of familial cases and 27% of sporadic cases. Childhood glaucoma is classified in primary and secondary congenital glaucoma, further divided as glaucoma arising in dysgenesis associated with neural crest anomalies, phakomatoses, metabolic disorders, mitotic diseases, congenital disorders, and acquired conditions. Neural crest alterations lead to the wide spectrum of iridocorneal trabeculodysgenesis. Systemic diseases associated with childhood glaucoma include the heterogenous group of phakomatoses where glaucoma is frequently encountered in the Sturge-Weber syndrome and its variants, in phakomatosis pigmentovascularis associated with oculodermal melanocytosis, and more rarely in neurofibromatosis type 1. Childhood glaucoma is also described in systemic disorders of mitotic and metabolic activity. Acquired secondary glaucoma has been associated with uveitis, trauma, drugs, and neoplastic diseases. A database research revealed reports of childhood glaucoma in rare diseases, which do not include glaucoma in their manifestation. These are otopalatodigital syndrome, complete androgen insensitivity, pseudotrisomy 13, Brachmann-de Lange syndrome, acrofrontofacionasal dysostosis, caudal regression syndrome, and Wolf-Hirschhorn syndrome. PMID:26451378

  5. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  6. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  7. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  8. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  9. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  10. Definition, Classification, and Pathophysiology of Canine Glaucoma.

    PubMed

    Pizzirani, Stefano

    2015-11-01

    Glaucoma is a common ocular condition in humans and dogs leading to optic nerve degeneration and irreversible blindness. Primary glaucoma is a group of spontaneous heterogeneous diseases. Multiple factors are involved in its pathogenesis and these factors vary across human ethnic groups and canine breeds, so the clinical phenotypes are numerous and their classification can be challenging and remain superficial. Aging and oxidative stress are major triggers for the manifestation of disease. Multiple, intertwined inflammatory and biochemical cascades eventually alter cellular and extracellular physiology in the optic nerve and trabecular meshwork and lead to vision loss.

  11. [Differential diagnosis of juvenile normal pressure glaucoma].

    PubMed

    Geidel, K; Wiedemann, P; Unterlauft, J D

    2016-12-05

    The case of a 50-year-old female patient with autosomal dominant optic atrophy is described, which was initially misinterpreted and treated as normal pressure glaucoma. Bilateral partial optic atrophy can be diagnosed by chance with mild manifestation of symptoms and can initially be misinterpreted as glaucoma. Taking a detailed medical history and performing a thorough optic nerve head examination can raise the suspicion of hereditary optic atrophy. The reliable detection of autosomal dominant optic atrophy by genetic investigations should be strived for in such cases.

  12. Current Approach in the Diagnosis and Management of Uveitic Glaucoma

    PubMed Central

    Muñoz-Negrete, Francisco J.; Moreno-Montañés, Javier; Hernández-Martínez, Paula; Rebolleda, Gema

    2015-01-01

    Uveitic glaucoma (UG) typically is associated with very high intraocular pressure (IOP) and more intense optic nerve damage than other glaucoma types. This secondary glaucoma requires an early diagnosis and adequate management of both uveitis and glaucoma. It is mandatory to identify the mechanisms of IOP elevation that in many eyes have multiple combined mechanisms. Management of these patients commonly requires an interdisciplinary approach that includes a glaucoma specialist and rheumatologist to control the inflammation and IOP. Glaucoma surgery is required early in these patients due to the high IOP usually present and is less successful than in primary open-angle glaucoma. Recurrent uveitic episodes, multiple mechanism, and the complications associated with uveitis make surgical management of UG challenging. In this review, the management and treatment of UG are updated to clarify the pathogenesis and prevent optic nerve damage. PMID:26558280

  13. Uveitis and glaucoma: new insights in the pathogenesis and treatment.

    PubMed

    Sng, Chelvin C A; Ang, Marcus; Barton, Keith

    2015-01-01

    Glaucoma is a potentially blinding complication of uveitis, where intraocular inflammation, secondary corticosteroid response, and varying types and degrees of angle abnormalities contribute to its pathogenesis. Management of uveitic glaucoma remains challenging. Treatment is targeted at reducing the inflammation and lowering the intraocular pressure. Recent studies have highlighted the role of viruses, such as cytomegalovirus, herpes simplex virus, and more recently Ebola virus, in the pathogenesis of uveitic glaucoma. Antiviral therapy may be beneficial in eyes with detectable viral DNA. The success of glaucoma surgery is decreased in eyes with uveitic glaucoma, and surgical interventions are associated with a higher incidence of postoperative complications. Novel glaucoma surgical and laser treatments may improve the predictability of surgery for uveitic glaucoma, but these require further evaluation.

  14. Particle Dynamics in Tangential Flow Filtration

    NASA Astrophysics Data System (ADS)

    Garcia, Mike; Pennathur, Sumita

    2015-11-01

    Tangential Flow Filtration (TFF) is a rapid and efficient method for filtration and separation of solutions containing particles such as viruses, bacteria or cellular material. Enhancing the efficiency of TFF not only requires a detailed understanding of the individual mechanisms behind particle transport, but the interaction between these transport mechanisms and a porous wall. In this work, we numerically and experimentally explore how inertial migration is affected by the presence of a permeate flow through the porous walls of a microchannel in order to develop a platform for further studies of particle transport in a TFF device. Numerically, we use COMSOL multiphysics to model the large parameter space of permeate versus inertial forces. Experimentally, we develop a MEMS fabricated TFF device to confirm the results of the numerical model, where the permeate flow is controlled using multiple pumps and pressure transducers regulated by a feedback loop. Experimental and numerical results reveal interesting dynamics, including the competition between permeate and inertial forces and the consequences of this competition on particle trajectories and equilibrium location.

  15. Characterization and modification of particulate properties to enhance filtration performance

    SciTech Connect

    Snyder, T.R.; Vann Bush, P.; Robinson, M.S.

    1990-06-01

    The specific objectives of this project are to characterize the particulate properties that determine the filtration performance of fabric filters, and to investigate methods for modifying these particulate properties to enhance filtration performance. Inherent in these objectives is the development of an experimental approach that will lead to full-scale implementation of beneficial conditioning processes identified during the project. The general approach has included a large number of laboratory evaluations to be followed by optional field tests of a new successful conditioning processes performed on a sidestream device. This project was divided into five tasks. The schedule followed for these tasks is shown in Figure 4. Tasks 2 and 3 each focus on one of the two complementary parts of the project. Task 2 Parametric Tests of Ashes and Fabrics, evaluates the degree to which ash properties and fabric design determine filtration performance. Task 3 Survey of Methods to Modify the Particle Filtration Properties, provides a literature review and laboratory study of techniques to modify ash properties. The results of these two tasks were used in Task 4 Proof-of-Concept Tests of Methods to Modify Particle Filtration Properties to demonstrate the effects on filtration performance of modifying ash properties. The findings of all the tasks are summarized in this Final Report. 13 refs.

  16. Anterior Chamber Angle Shape Analysis and Classification of Glaucoma in SS-OCT Images

    PubMed Central

    Ni Ni, Soe; Tian, J.; Marziliano, Pina; Wong, Hong-Tym

    2014-01-01

    Optical coherence tomography is a high resolution, rapid, and noninvasive diagnostic tool for angle closure glaucoma. In this paper, we present a new strategy for the classification of the angle closure glaucoma using morphological shape analysis of the iridocorneal angle. The angle structure configuration is quantified by the following six features: (1) mean of the continuous measurement of the angle opening distance; (2) area of the trapezoidal profile of the iridocorneal angle centered at Schwalbe's line; (3) mean of the iris curvature from the extracted iris image; (4) complex shape descriptor, fractal dimension, to quantify the complexity, or changes of iridocorneal angle; (5) ellipticity moment shape descriptor; and (6) triangularity moment shape descriptor. Then, the fuzzy k nearest neighbor (fkNN) classifier is utilized for classification of angle closure glaucoma. Two hundred and sixty-four swept source optical coherence tomography (SS-OCT) images from 148 patients were analyzed in this study. From the experimental results, the fkNN reveals the best classification accuracy (99.11 ± 0.76%) and AUC (0.98 ± 0.012) with the combination of fractal dimension and biometric parameters. It showed that the proposed approach has promising potential to become a computer aided diagnostic tool for angle closure glaucoma (ACG) disease. PMID:25197561

  17. Predegenerated Schwann cells–a novel prospect for cell therapy for glaucoma: neuroprotection, neuroregeneration and neuroplasticity

    PubMed Central

    Smedowski, Adrian; Liu, Xiaonan; Pietrucha-Dutczak, Marita; Matuszek, Iwona; Varjosalo, Markku; Lewin-Kowalik, Joanna

    2016-01-01

    Glaucoma is an optic neuropathy that leads to irreversible blindness. Because the current therapies are not sufficient to protect against glaucoma-induced visual impairment, new treatment approaches are necessary to prevent disease progression. Cell transplantation techniques are currently considered to be among the most promising opportunities for nervous system damage treatment. The beneficial effects of undifferentiated cells have been investigated in experimental models of glaucoma, however experiments were accompanied by various barriers, which would make putative treatment difficult or even impossible to apply in a clinical setting. The novel therapy proposed in our study creates conditions to eliminate some of the identified barriers described for precursor cells transplantation and allows us to observe direct neuroprotective and pro-regenerative effects in ongoing optic neuropathy without additional modifications to the transplanted cells. We demonstrated that the proposed novel Schwann cell therapy might be promising, effective and easy to apply, and is safer than the alternative cell therapies for the treatment of glaucoma. PMID:27034151

  18. 3D Air Filtration Modeling for Nanofiber Based Filters in the Ultrafine Particle Size Range

    NASA Astrophysics Data System (ADS)

    Sambaer, Wannes; Zatloukal, Martin; Kimmer, Dusan

    2011-07-01

    In this work, novel 3D filtration model for nanofiber based filters has been proposed and tested. For the model validation purposes, filtration efficiency characteristics of two different polyurethane nanofiber based structures (prepared by the electrospinning process) were determined experimentally in the ultrafine particle size range (20-400 nm). It has been found that the proposed model is able to reasonably predict the measured filtration efficiency curves for both tested samples.

  19. [Initial clinical experience with deep sclerectomy in ambulatory surgery in glaucoma].

    PubMed

    Pitrová, S; Pesková, H; Lesták, J

    1999-01-01

    Deep sclerectomy is a non-perforating filtering operation used in surgical treatment of open angle glaucomas. The advantage of the operation is the creation of gradual filtration due to the thin trabecular Descement membrane which reduces markedly the risk of development of postoperative complications typical for perforating antiglaucomatous operations. The authors operated at the out-patient department 10 eyes of 8 patients (age 46-81 years). Indications for deep sclerectomy was seven times primary open angle glaucoma (POAG), once capsular glaucoma and twice normotensive glaucoma (NTG). In all eyes deep sclerectomy was indicated because of decompensation of the intraocular pressure with maximum tolerated therapy before surgery. None of the eyes were operated previously. The mean value of intraocular pressure before surgery was 25.1 +/- 6.5 mm Hg. From the results ensues that in nine operated eyes the intraocular pressure at the end of the 6-month follow-up period was compensated without supplementary therapy, only in one eye beta-blockers were prescribed one month after surgery. The cause of failure of filtration was the development of superficial adherence at the site of microperforatiion of the trabecular Descemet membrane which developed during operation. The mean intraocular pressure values at the end of the investigation period were 14.3 +/- 2.8 mm Hg. In two eyes haemorrhage into the anterior chamber was observed on the first day after surgery, the blood was absorbed within 24 hours. Hypotonia in two eyes was only transient and was not associated with a change in the depth of the anterior chamber or other complications. In none of the patients a decline of visual acuity was observed. In three operated eyes a change of refraction was necessary due to discontinuation of miotics after surgery. Deep sclerectomy is a delicate microsurgical technique which calls for experience and skill of the surgeon. The most complicated task is to prevent perforation of the

  20. Characterization of Filtration Scale-Up Performance

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Luna, Maria L.; Cantrell, Kirk J.; Peterson, Reid A.; Bonebrake, Michael L.; Shimskey, Rick W.; Jagoda, Lynette K.

    2009-03-09

    The scale-up performance of sintered stainless steel crossflow filter elements planned for use at the Pretreatment Engineering Platform (PEP) and at the Waste Treatment and Immobilization Plant (WTP) were characterized in partial fulfillment (see Table S.1) of the requirements of Test Plan TP RPP WTP 509. This test report details the results of experimental activities related only to filter scale-up characterization. These tests were performed under the Simulant Testing Program supporting Phase 1 of the demonstration of the pretreatment leaching processes at PEP. Pacific Northwest National Laboratory (PNNL) conducted the tests discussed herein for Bechtel National, Inc. (BNI) to address the data needs of Test Specification 24590-WTP-TSP-RT-07-004. Scale-up characterization tests employ high-level waste (HLW) simulants developed under the Test Plan TP-RPP-WTP-469. The experimental activities outlined in TP-RPP-WTP-509 examined specific processes from two broad areas of simulant behavior: 1) leaching performance of the boehmite simulant as a function of suspending phase chemistry and 2) filtration performance of the blended simulant with respect to filter scale-up and fouling. With regard to leaching behavior, the effect of anions on the kinetics of boehmite leaching was examined. Two experiments were conducted: 1) one examined the effect of the aluminate anion on the rate of boehmite dissolution and 2) another determined the effect of secondary anions typical of Hanford tank wastes on the rate of boehmite dissolution. Both experiments provide insight into how compositional variations in the suspending phase impact the effectiveness of the leaching processes. In addition, the aluminate anion studies provide information on the consequences of gibbsite in waste. The latter derives from the expected fast dissolution of gibbsite relative to boehmite. This test report concerns only results of the filtration performance with respect to scale-up. Test results for boehmite

  1. [The place of SLT in managing glaucoma].

    PubMed

    Nordmann, J-P

    2008-07-01

    Selective laser trabeculoplasty (SLT) is effective in reducing intraocular pressure (IOP) in glaucomatous patients and patients with ocular hypertension. Equivalent to argon laser trabeculoplasty in terms of IOP reduction, SLT has the advantage of preserving surrounding structures. Easy and rapid to perform, SLT may be an interesting therapeutic approach in the management of glaucoma.

  2. Childhood glaucoma surgery in the 21st Century

    PubMed Central

    Papadopoulos, M; Edmunds, B; Fenerty, C; Khaw, P T

    2014-01-01

    Most children with glaucoma will require surgery in their lifetime, often in their childhood years. The surgical management of childhood glaucoma is however challenging, largely because of its greater potential for failure and complications as compared with surgery in adults. The available surgical repertoire for childhood glaucoma has remained relatively unchanged for many years with most progress owing to modifications to existing surgery. Although the surgical approach to childhood glaucoma varies around the world, angle surgery remains the preferred initial surgery for primary congenital glaucoma and a major advance has been the concept of incising the whole of the angle (circumferential trabeculotomy). Simple modifications to the trabeculectomy technique have been shown to considerably minimise complications. Glaucoma drainage devices maintain a vital role for certain types of glaucoma including those refractory to other surgery. Cyclodestruction continues to have a role mainly for patients following failed drainage/filtering surgery. Although the prognosis for childhood glaucoma has improved significantly since the introduction of angle surgery, there is still considerable progress to be made to ensure a sighted lifetime for children with glaucoma all over the world. Collaborative approaches to researching and delivering this care are required, and this paper highlights the need for more high-quality prospective surgical trials in the management of the childhood glaucoma. PMID:24924446

  3. Filtrates and Residues: Gel Filtration--An Innovative Separation Technique.

    ERIC Educational Resources Information Center

    Blumenfeld, Fred; Gardner, James

    1985-01-01

    Gel filtration is a form of liquid chromatography that separates molecules primarily on the basis of their size. Advantages of using this technique, theoretical aspects, and experiments (including procedures used) are discussed. Several questions for students to answer (with answers) are also provided. (JN)

  4. Image processing based automatic diagnosis of glaucoma using wavelet features of segmented optic disc from fundus image.

    PubMed

    Singh, Anushikha; Dutta, Malay Kishore; ParthaSarathi, M; Uher, Vaclav; Burget, Radim

    2016-02-01

    Glaucoma is a disease of the retina which is one of the most common causes of permanent blindness worldwide. This paper presents an automatic image processing based method for glaucoma diagnosis from the digital fundus image. In this paper wavelet feature extraction has been followed by optimized genetic feature selection combined with several learning algorithms and various parameter settings. Unlike the existing research works where the features are considered from the complete fundus or a sub image of the fundus, this work is based on feature extraction from the segmented and blood vessel removed optic disc to improve the accuracy of identification. The experimental results presented in this paper indicate that the wavelet features of the segmented optic disc image are clinically more significant in comparison to features of the whole or sub fundus image in the detection of glaucoma from fundus image. Accuracy of glaucoma identification achieved in this work is 94.7% and a comparison with existing methods of glaucoma detection from fundus image indicates that the proposed approach has improved accuracy of classification.

  5. Filtration combustion: Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  6. Improving IAQ Via Air Filtration.

    ERIC Educational Resources Information Center

    Monk, Brian

    1999-01-01

    Provides tips on using air filtration to control indoor air quality in educational facilities, including dedicated spaces with unique air quality conditions such as in libraries, museums and archival storage areas, kitchens and dining areas, and laboratories. The control of particulate contaminants, gaseous contaminants, and moisture buildup are…

  7. MICROBIOLOGICAL REMOVAL BY FILTRATION PROCESSES

    EPA Science Inventory

    Filtration ws originally used to remove contaminants that affect the appearance, odor, and taste of drinking water. Later it was demonstrated that bacteria in drinking water were causative agents of disease. Water treatment technology improved with the addition of disinfection, c...

  8. Health benefits of particle filtration

    EPA Science Inventory

    This product was developed under an interagency agreement between the U.S. EPA and the U.S. Department of Energy - Lawrence Berkeley National Laboratory (LBNL). The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews o...

  9. The Endocannabinoid System as a Therapeutic Target in Glaucoma

    PubMed Central

    Cairns, Elizabeth A.; Baldridge, William H.; Kelly, Melanie E. M.

    2016-01-01

    Glaucoma is an irreversible blinding eye disease which produces progressive retinal ganglion cell (RGC) loss. Intraocular pressure (IOP) is currently the only modifiable risk factor, and lowering IOP results in reduced risk of progression of the disorder. The endocannabinoid system (ECS) has attracted considerable attention as a potential target for the treatment of glaucoma, largely due to the observed IOP lowering effects seen after administration of exogenous cannabinoids. However, recent evidence has suggested that modulation of the ECS may also be neuroprotective. This paper will review the use of cannabinoids in glaucoma, presenting pertinent information regarding the pathophysiology of glaucoma and how alterations in cannabinoid signalling may contribute to glaucoma pathology. Additionally, the mechanisms and potential for the use of cannabinoids and other novel agents that target the endocannabinoid system in the treatment of glaucoma will be discussed. PMID:26881140

  10. Alternative therapy in glaucoma management: is there any role?

    PubMed

    Parikh, Rajul S; Parikh, Shefali R

    2011-01-01

    Glaucoma is one of the leading causes of blindness worldwide. Various randomized controlled clinical trials have shown that lowering intraocular pressure (IOP) does reduce progression of primary open-angle glaucoma. However, there is lots of interest in nonpharmacological options that includes lifestyle adjustment and alternative and complementary therapy (ACT). At least 5% glaucoma population uses ACT. Various lifestyle activities like exercise and alcohol can reduce IOP by 1 to 2 mm Hg but would have small effect on glaucoma. The psychological stress can increase IOP. Hypothetically and few studies do show neuroprotective effect (or effect on ocular blood flow) of alcohol, Gingko biloba, bilberry, but the current evidence is weak for its routine use. We must also remember the side effects of 'medications' (e.g., marijuana, alcohol) before promoting as remedy for glaucoma. In current armamentarium of glaucoma management, ACT cannot substitute the conventional treatment available to lower IOP.

  11. Dynamics and filtration of microgel suspensions

    NASA Astrophysics Data System (ADS)

    Naegele, Gerhard; Roa, Rafael; Riest, Jonas

    Microgel suspensions exhibit interesting transport properties determined by direct and hydrodynamic interactions. Using an annulus model to account for solvent permeability, we calculate the diffusion function and sedimentation coefficient of PNiPAM microgel suspensions, in excellent agreement with experimental results. Moreover, an extension of our precise analytic methods to long-time properties including viscosity and self-diffusion coefficient is presented, with results compared to simulation and experimental data. The predicted transport properties are an important ingredient to the modeling of convective-diffusive transport in membrane ultrafiltration of permeable particles. The efficiency of the separation process depends on hydrodynamic boundary conditions, membrane properties and particle interactions. We calculate the concentration polarization layer and permeate flux at different operating conditions for cross-flow ultrafiltration of non-ionic and ionic microgels. Small microgel permeability already affects the filtration significantly.

  12. Glaucoma: genes, phenotypes, and new directions for therapy.

    PubMed

    Fan, Bao Jian; Wiggs, Janey L

    2010-09-01

    Glaucoma, a leading cause of blindness worldwide, is characterized by progressive optic nerve damage, usually associated with intraocular pressure. Although the clinical progression of the disease is well defined, the molecular events responsible for glaucoma are currently poorly understood and current therapeutic strategies are not curative. This review summarizes the human genetics and genomic approaches that have shed light on the complex inheritance of glaucoma genes and the potential for gene-based and cellular therapies that this research makes possible.

  13. Microwave cyclodestruction for glaucoma in a rabbit model

    SciTech Connect

    Finger, P.T.; Moshfeghi, D.M.; Smith, P.D.; Perry, H.D. )

    1991-07-01

    Microwave thermotherapy was used to treat experimentally induced glaucoma. Microwave-induced cyclodestruction was successful in reducing intraocular pressure in all treated glaucomatous eyes for 4 weeks. Two additional glaucomatous eyes were left untreated to serve as controls, and were noted to have persistently elevated intraocular pressures. Six additional eyes were then subjected to an equivalent treatment (50 degrees C in five 1-minute applications), which resulted in approximately 180 degrees of heat treatment just posterior to the corneoscleral limbus. These specimens were evaluated with light microscopy at baseline, 24 hours, and 7 days after treatment. The authors clinical and histopathologic evaluations suggested that microwave thermotherapy (delivered under thermometry control) allowed for chorioretinal/ciliary body destruction that resulted in reductions of intraocular pressure in glaucomatous eyes.

  14. Trabeculectomy with mitomycin C in the treatment of post-traumatic angle recession glaucoma

    PubMed Central

    Manners, T; Salmon, J; Barron, A; Willies, C; Murray, A

    2001-01-01

    AIM—The presence of traumatic angle recession is a risk factor for failure of glaucoma filtration surgery and a previous study has suggested that antimetabolite treatment should be used in these patients. This study was undertaken to determine for the first time the mid term results of trabeculectomy with intraoperative application of mitomycin C in patients with post-traumatic angle recession glaucoma.
METHODS—A retrospective analysis was made of 43 consecutive trabeculectomy procedures in 41 young black/mixed race patients followed for a mean period of 25 months (range 2-66 months). Mitomycin C 0.02% was applied between the sclera and conjunctiva for 1-5 minutes at the time of surgery. The intraocular pressure and visual acuity were measured postoperatively. The success of this technique was analysed by using a Kaplan-Meier cumulative survival curve.
RESULTS—The intraocular pressure was successfully controlled at last follow up without topical treatment in 77% (33/43 eyes) and the visual acuity was the same or better in 81% (35/43 eyes). Cumulative probability of success was 85% at 1 year follow up, 81% at 2 years, and 66% at 3 years and thereafter. Hypotonous maculopathy occurred in one patient and no cases of late bleb infection were found.
CONCLUSIONS—In medically uncontrolled post-traumatic angle recession glaucoma trabeculectomy with mitomycin C is an effective surgical procedure with an acceptable complication rate. Good intraocular pressure control and preservation of vision can be expected in most patients.

 PMID:11159478

  15. Glaucoma Surgery in Pregnancy: A Case Series and Literature Review

    PubMed Central

    Razeghinejad, Mohammad Reza; Masoumpour, Masoumeh; Eghbal, Mohammad Hossein; Myers, Jonathan S.; Moster, Marlene R.

    2016-01-01

    Glaucoma management in pregnant patients is a real challenge, especially when the glaucoma is not controlled with medications. We report the results of 6 incisional glaucoma surgeries for the management of medically uncontrolled glaucoma patients during pregnancy. This retrospective, case series was conducted on the 6 eyes of 3pregnant patients with uncontrolled glaucoma using maximum tolerable medications. Details of the glaucoma surgical management of these patients as well as their postoperative care and pregnancy and clinical outcomes on longitudinal follow-up are discussed. All 3 patients had juvenile open-angle glaucoma and were on various anti-glaucoma medications, including oral acetazolamide. The first case described underwent trabeculectomy without antimetabolites in both eyes because of uncontrolled intraocular pressure with topical medications. The surgery was done with topical lidocaine jelly and subconjunctival lidocaine during the second and third trimesters. The second patient had an Ahmed valve implantation in both eyes during the second and third trimesters because of uncontrolled IOP with topical medications and no response to selective laser trabeculoplasty. Surgery was done with topical tetracaine and subconjunctival and sub-Tenon’s lidocaine. The third case had a Baerveldt valve implantation under general anesthesia in the second trimester. In selected pregnant glaucoma patients with medically uncontrolled intraocular pressure threatening vision, incisional surgery may lead to good outcomes for the patient with no risk for the fetus. PMID:27582594

  16. Differentiating Leber Hereditary Optic Neuropathy from Normal-Tension Glaucoma.

    PubMed

    Souto, Fernanda Maria Silveira; de Vasconcellos, José Paulo Cabral; de Melo, Mônica Barbosa; Sartorato, Edi Lúcia; Moura, Frederico Castelo

    2017-04-01

    Glaucoma is a neurodegenerative disorder characterized by thinning of neuroretinal rim, enlarged cup-to-disc ratio (CDR) and visual field damage. Although raised intraocular pressure is main risk factor for development of glaucoma, it can occur with consistently normal measurements in the intraocular pressure as normal tension glaucoma (NTG). Enlargement of CDR is a classical sign of glaucoma, but it can also result from non-glaucomatous optic neuropathies such as Leber hereditary optic neuropathy (LHON). We describe a case of LHON with increased CDR, discuss its differential diagnosis with NTG and highlight the reasons for misdiagnoses between these two entities.

  17. Filtration Understanding: FY10 Testing Results and Filtration Model Update

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P.; Shimskey, Rick W.

    2011-04-04

    This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.

  18. Altered mechanobiology of Schlemm’s canal endothelial cells in glaucoma

    PubMed Central

    Overby, Darryl R.; Zhou, Enhua H.; Vargas-Pinto, Rocio; Pedrigi, Ryan M.; Fuchshofer, Rudolf; Braakman, Sietse T.; Gupta, Ritika; Perkumas, Kristin M.; Sherwood, Joseph M.; Vahabikashi, Amir; Dang, Quynh; Kim, Jae Hun; Ethier, C. Ross; Stamer, W. Daniel; Fredberg, Jeffrey J.; Johnson, Mark

    2014-01-01

    Increased flow resistance is responsible for the elevated intraocular pressure characteristic of glaucoma, but the cause of this resistance increase is not known. We tested the hypothesis that altered biomechanical behavior of Schlemm’s canal (SC) cells contributes to this dysfunction. We used atomic force microscopy, optical magnetic twisting cytometry, and a unique cell perfusion apparatus to examine cultured endothelial cells isolated from the inner wall of SC of healthy and glaucomatous human eyes. Here we establish the existence of a reduced tendency for pore formation in the glaucomatous SC cell—likely accounting for increased outflow resistance—that positively correlates with elevated subcortical cell stiffness, along with an enhanced sensitivity to the mechanical microenvironment including altered expression of several key genes, particularly connective tissue growth factor. Rather than being seen as a simple mechanical barrier to filtration, the endothelium of SC is seen instead as a dynamic material whose response to mechanical strain leads to pore formation and thereby modulates the resistance to aqueous humor outflow. In the glaucomatous eye, this process becomes impaired. Together, these observations support the idea of SC cell stiffness—and its biomechanical effects on pore formation—as a therapeutic target in glaucoma. PMID:25201985

  19. Histological biocompatibility of a stainless steel miniature glaucoma drainage device in humans: a case report.

    PubMed

    De Feo, Fabio; Jacobson, Stewart; Nyska, Abraham; Pagani, Paola; Traverso, Carlo Enrico

    2009-06-01

    The purpose of this study was to evaluate the histological biocompatibility of a stainless steel miniature glaucoma drainage device. Twenty-four months before death due to heart failure, this seventy-three-year-old female patient underwent filtration surgery for primary open-angle glaucoma uncontrolled in the right eye. The device was implanted at the limbus under a scleral flap. For histopathological evaluation, two corneoscleral specimens were embedded in methacrylate blocks sectioned to a thickness of 50 microns, polished and stained with periodic acid schiff. Some sections included a longitudinal cross-section of the implant. At the interface between the spur and the flange of the device and the cornea, there was a small shoulder of fibrous tissue. A thin, fibrous capsule covered the remainder of the body of the device up to the distal tip. No inflammatory cells occurred within the fibrous capsule. No material or blockage was noted within the lumen. Our results support the biological inertness of the device.

  20. Ocular Drug Delivery for Glaucoma Management

    PubMed Central

    Gooch, Nathan; Molokhia, Sarah A.; Condie, Russell; Burr, Randon Michael; Archer, Bonnie; Ambati, Balamurali K.; Wirostko, Barbara

    2012-01-01

    Current glaucoma management modalities are hindered by low patient compliance and adherence. This can be due to highly complex treatment strategies or poor patient understanding. Treatments focus on the management or reduction of intraocular pressure. This is most commonly done through the use of daily topical eye drops. Unfortunately, despite effective therapies, glaucoma continues to progress, possibly due to patients not adhering to their treatments. In order to mitigate these patient compliance issues, many sustained release treatments are being researched and are entering the clinic. Conjunctival, subconjunctival, and intravitreal inserts, punctal plugs, and drug depots are currently in clinical development. Each delivery system has hurdles, yet shows promise and could potentially mitigate the current problems associated with poor patient compliance. PMID:24300188

  1. Lasers in the treatment of glaucoma

    NASA Astrophysics Data System (ADS)

    Kecik, Tadeusz

    1995-03-01

    The task of the laser methods of glaucoma treatment used up to the present day is to reduce the intraocular pressure. They are the modification of the surgical procedures. The radiation of the laser is the tool that enables us to perform the procedure in a more precise and safe manner. Most of the procedures are ambulatory, thus, making the expenses for the treatment lower. The results of the treatment are satisfactory, and in many cases, enable the patient to avoid surgical procedures. In practice, for the anti-glaucoma procedures the argon laser, YAG Nd+3, of free generation, and Q-switch, Holm laser, are being used. The perspectives to use other lasers also exist.

  2. Approximate theory for radial filtration/consolidation

    SciTech Connect

    Tiller, F.M.; Kirby, J.M.; Nguyen, H.L.

    1996-10-01

    Approximate solutions are developed for filtration and subsequent consolidation of compactible cakes on a cylindrical filter element. Darcy`s flow equation is coupled with equations for equilibrium stress under the conditions of plane strain and axial symmetry for radial flow inwards. The solutions are based on power function forms involving the relationships of the solidosity {epsilon}{sub s} (volume fraction of solids) and the permeability K to the solids effective stress p{sub s}. The solutions allow determination of the various parameters in the power functions and the ratio k{sub 0} of the lateral to radial effective stress (earth stress ratio). Measurements were made of liquid and effective pressures, flow rates, and cake thickness versus time. Experimental data are presented for a series of tests in a radial filtration cell with a central filter element. Slurries prepared from two materials (Microwate, which is mainly SrSO{sub 4}, and kaolin) were used in the experiments. Transient deposition of filter cakes was followed by static (i.e., no flow) conditions in the cake. The no-flow condition was accomplished by introducing bentonite which produced a nearly impermeable layer with negligible flow. Measurement of the pressure at the cake surface and the transmitted pressure on the central element permitted calculation of k{sub 0}.

  3. Spontaneous water filtration of bio-inspired membrane

    NASA Astrophysics Data System (ADS)

    Kim, Kiwoong; Kim, Hyejeong; Lee, Sang Joon

    2016-11-01

    Water is one of the most important elements for plants, because it is essential for various metabolic activities. Thus, water management systems of vascular plants, such as water collection and water filtration have been optimized through a long history. In this view point, bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. However, most of the underlying biophysical features of the optimized water management systems remain unsolved In this study, the biophysical characteristics of water filtration phenomena in the roots of mangrove are experimentally investigated. To understand water-filtration features of the mangrove, the morphological structures of its roots are analyzed. The electrokinetic properties of the root surface are also examined. Based on the quantitatively analyzed information, filtration of sodium ions in the roots are visualized. Motivated by this mechanism, spontaneous desalination mechanism in the root of mangrove is proposed by combining the electrokinetics and hydrodynamic transportation of ions. This study would be helpful for understanding the water-filtration mechanism of the roots of mangrove and developing a new bio-inspired desalination technology. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract Grant Number: 2008-0061991).

  4. Recurrent vitreous occlusion of glaucoma drainage device tube in a patient with glaucoma in aphakia: a case report

    PubMed Central

    2010-01-01

    Patients with spontaneous lens dislocation and glaucoma can be challenging to manage. We present a forty-six year old Caucasian lady who was referred with bilateral high intraocular pressure, and was subsequently diagnosed with glaucoma in association with lens dislocation and Marfan syndrome. Baerveldt glaucoma drainage device tubes were inserted in both eyes due to poor response to medical therapy. However, this was complicated by recurrent vitreous occlusion of both glaucoma drainage tubes requiring further multiple surgical interventions. There have not been any further recurrences of vitreous incarceration or posterior segment complications since, but the patient remains under close follow-up. PMID:20181147

  5. Drug-induced Angle-Closure Glaucoma

    PubMed Central

    Khurana, Aruj K; Khurana, Bhawna

    2012-01-01

    Drug-induced angle-closure glaucoma is an important entity for the ophthalmologist as well as the general physician as it represents a preventable cause of potential blindness. This brief review highlights the fact that a high index of suspicion, in a susceptible individual followed by confirmation on appropriate imaging modality (UBM, ultrasound or anterior segment OCT) can alleviate the threat to sight and also help to institute appropriate therapy. PMID:27990064

  6. Latanoprost in the treatment of glaucoma.

    PubMed

    Alm, Albert

    2014-01-01

    Prostaglandins are approved by the European Glaucoma Society guidelines as first-line treatment for glaucoma. This review focuses on latanoprost, an ester prodrug of prostaglandin (PG) F2α, which was the first of the currently available topical PGF2α analogs to be launched for glaucoma or ocular hypertension and which still accounts for the majority of prescriptions. It is better absorbed than the parent compound through the cornea, and peak concentration of the active drug is in the aqueous humor 1-2 hours after topical dosing (15-30 ng/mL). Metabolism occurs mainly in the liver. Latanoprost (0.005%) has been very well studied in clinical trials and meta-analyses that show it to be generally as effective as the other PG analogs (bimatoprost, travoprost, and tafluprost) and more effective than timolol, dorzolamide, and brimonidine. Latanoprost has good short- and long-term safety and tolerability profiles. In common with other prostaglandins, it lacks systemic effects, but can cause ocular adverse events such as conjunctival hyperemia, pigmentation of the iris, periocular skin or eyelashes, hypertrichosis, and ocular surface effects or irritation. Latanoprost is significantly better tolerated than either bimatoprost or travoprost. Patients treated with latanoprost have better compliance and persist with therapy longer than those that are given other drugs. An improved formulation of latanoprost without the preservative benzalkonium chloride has recently been developed. It is as effective as conventional latanoprost, has a lower incidence of hyperemia, and can be stored at room temperature. In conclusion, latanoprost has the best efficacy-tolerability ratio of the PG analogs available for glaucoma treatment, and has good compliance and persistence. These factors should be improved further by the recent development of preservative-free latanoprost.

  7. Latanoprost in the treatment of glaucoma

    PubMed Central

    Alm, Albert

    2014-01-01

    Prostaglandins are approved by the European Glaucoma Society guidelines as first-line treatment for glaucoma. This review focuses on latanoprost, an ester prodrug of prostaglandin (PG) F2α, which was the first of the currently available topical PGF2α analogs to be launched for glaucoma or ocular hypertension and which still accounts for the majority of prescriptions. It is better absorbed than the parent compound through the cornea, and peak concentration of the active drug is in the aqueous humor 1–2 hours after topical dosing (15–30 ng/mL). Metabolism occurs mainly in the liver. Latanoprost (0.005%) has been very well studied in clinical trials and meta-analyses that show it to be generally as effective as the other PG analogs (bimatoprost, travoprost, and tafluprost) and more effective than timolol, dorzolamide, and brimonidine. Latanoprost has good short- and long-term safety and tolerability profiles. In common with other prostaglandins, it lacks systemic effects, but can cause ocular adverse events such as conjunctival hyperemia, pigmentation of the iris, periocular skin or eyelashes, hypertrichosis, and ocular surface effects or irritation. Latanoprost is significantly better tolerated than either bimatoprost or travoprost. Patients treated with latanoprost have better compliance and persist with therapy longer than those that are given other drugs. An improved formulation of latanoprost without the preservative benzalkonium chloride has recently been developed. It is as effective as conventional latanoprost, has a lower incidence of hyperemia, and can be stored at room temperature. In conclusion, latanoprost has the best efficacy–tolerability ratio of the PG analogs available for glaucoma treatment, and has good compliance and persistence. These factors should be improved further by the recent development of preservative-free latanoprost. PMID:25328381

  8. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma

    PubMed Central

    Mierlo, Camille Van; Pinto, Luis Abegão

    2015-01-01

    ABSTRACT Introduction: Iatrogenic pigment dispersion syndrome generally originates from a repetitive, mechanical trauma to the pigmented posterior epithelium of the iris. This trauma can arise after intraocular surgery, most commonly due to an abnormal contact between the intraocular lens (IOL) and the iris. Whether surgical removal of this primary insult can lead to a successful intraocular pressure (IOP) control remains unclear. Methods: Case-series. Patients with IOP elevation and clinical signs of pigment dispersion were screened for a diagnosis of iatrogenic IOL-related pigment dispersion. Results: Three patients in which the IOL or the IOL-bag complex caused a pigment dispersion through a repetitive iris chafing were selected. In two cases, replacement of a sulcus-based single-piece IOL (patient 1) or a sub-luxated in-the-bag IOL (patient 2) by an anterior-chamber (AC) iris-fixed IOL led to a sustained decrease in IOP. In the third case, extensive iris atrophy and poor anatomical AC parameters for IOL implantation precluded further surgical intervention. Conclusion: IOL-exchange appears to be a useful tool in the management of iatrogenic pigment dispersion glaucoma due to inappropriate IOL implantation. This cause-oriented approach seems to be effective in controlling IOP, but should be offered only if safety criteria are met. How to cite this article: Van Mierlo C, Abegao Pinto L, Stalmans I. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma. J Curr Glaucoma Pract 2015;9(1):28-32. PMID:26997830

  9. Fellow Eye in Unilateral Primary Congenital Glaucoma

    PubMed Central

    2017-01-01

    ABSTRACT Aim This is a report of the incidence of bilateral cases in a cohort of primary congenital glaucoma (PCG) cases and a study of the biometric characteristics of the fellow normal eyes in unilateral cases. Materials and methods The charts of 134 PCG children were reviewed, of which 78 cases (58.2%) were found to have bilateral disease. The remaining 56 patients (41.8%) with unilateral disease had their fellow normal eyes compared with an age-matched cohort of ophthalmologically free children. Results There were no differences between the normal fellow eyes of PCG cases and the control eyes in the corneal diameter and central corneal thickness (CCT), whereas the normal fellow eyes of PCG cases had higher intraocular pressure (IOP) and cup/disc (C/D) ratios. Conclusion The fellow eyes of apparently unilateral PCG cases are not typically normal anatomically like other children unaffected by PCG. Clinical significance A very high index of suspicion has to be kept for PCG cases that present apparently unilaterally, and meticulous prolonged follow-up is mandatory. How to cite this article Bayoumi NHL. Fellow Eye in Unilateral Primary Congenital Glaucoma. J Curr Glaucoma Pract 2017;11(1):28-30. PMID:28138215

  10. Analysis of visual field progression in glaucoma.

    PubMed Central

    Fitzke, F W; Hitchings, R A; Poinoosawmy, D; McNaught, A I; Crabb, D P

    1996-01-01

    BACKGROUND: Despite the widespread use of computerised perimetry the diagnosis of visual field deterioration in following glaucoma patients over time remains particularly difficult. A new method of analysis using a novel graphical display of longitudinal field data is presented. METHODS: A linear regression model of the luminance sensitivity at each stimulus location against time of follow up transforms the quantitative data from a series of fields into a colour coded form which illustrates the spatial configuration of change to aid the interpretation of field loss. The method of analysis and the developed computer software (PROGRESSOR) is described. Comparison with STATPAC-2 glaucoma change probability analysis is given including levels of agreement between the techniques using series of fields of 10 eyes from patients with normal tension glaucoma. RESULTS: Examples of this new method compare well with STATPAC-2 analysis. The level of agreement between the techniques to separate progressing from stable retinal locations is good (kappa = 0.62; SE = 0.04). CONCLUSIONS: This new technique, which combines the change in perimetric sensitivity over time with colour coding of significant change into one image may provide an efficient method to detect true progression in glaucomatous field loss. Images PMID:8664231

  11. [Basic biochemical processes in glaucoma progression].

    PubMed

    von Thun und Hohenstein-Blaul, N; Kunst, S; Pfeiffer, N; Grus, F H

    2015-05-01

    The term glaucoma summarizes a group of eye diseases that are accompanied by impairments of the optic nerve and related visual field deficits. An early diagnosis of glaucoma is currently not possible due to a lack of diagnostic tests; therefore, in most cases the disease is diagnosed many years after onset, which prevents an early therapy. The known risk factors for the development and progression of glaucomatous optic neuropathy comprise elevated intraocular pressure and a broad range of pressure fluctuations as well as lipometabolic disorders, genetic factor and diabetes. The consequences include the induction of anti-inflammatory proteins, elevated levels of oxidative stress and the destruction of retinal ganglion cells. Changes in the autoantibody repertoire have also been observed in the course of the disease. Basic ophthalmological research therefore focuses on the investigation of basic biochemical processes in the course of the disease. A better understanding of physiological and biochemical events is sought in order to develop new and more sensitive diagnostic options and to allow more targeted therapeutic measures. The understanding of biochemical processes allows a better insight into glaucoma progression to be gained, which will lead to improvements in diagnosis and therapy.

  12. High Temperature Particle Filtration Technology

    SciTech Connect

    Besmann, T.M.

    2001-11-13

    High temperature filtration can serve to improve the economic, environmental, and energy performance of chemical processes. This project was designed to evaluate the stability of filtration materials in the environments of the production of dimethyldichlorosilane (DDS). In cooperation with Dow Corning, chemical environments for the fluidized bed reactor where silicon is converted to DDS and the incinerator where vents are cornbusted were characterized. At Oak Ridge National Laboratory (ORNL) an exposure system was developed that could simulate these two environments. Filter samples obtained from third parties were exposed to the environments for periods up to 1000 hours. Mechanical properties before and after exposure were determined by burst-testing rings of filter material. The results indicated that several types of filter materials would likely perform well in the fluid bed environment, and two materials would be good candidates for the incinerator environment.

  13. Centrifugal membrane filtration -- Task 9

    SciTech Connect

    1996-08-01

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{micro}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  14. Single clear corneal incision for glaucoma drainage device shortening in pediatric glaucoma.

    PubMed

    Radke, Phillip M; Bitrian, Elena; Grajewski, Alana L

    2016-06-01

    Glaucoma drainage devices are commonly used for management of glaucoma in adults and children. With time, the position of the tube can change and cause damage such as corneal scarring, iris or lens contact, and uveitis. Most of these problems can be improved with tube shortening and/or excision of adherent iris or fibrous tissue. We describe a surgical technique that uses a single clear corneal incision to externalize and trim the shunt in pediatric patients. The technique has a short surgical. We review the indications and outcomes for this procedure in 13 eyes of 12 children who required shunt revision.

  15. Effect of health education on patients' beliefs about glaucoma and compliance.

    PubMed

    Rendell, J

    2000-01-01

    A pretest-posttest control group experimental design (n = 100) was used to determine the effectiveness of an interactive patient education program compared with a didactic approach for persons with primary open angle glaucoma at a major specialist eye hospital in England. This study used a questionnaire with a knowledge test to explore patients' glaucoma knowledge, a series of vignettes to explore understanding of compliance and health motivation, and health locus of control scales to assess the effect of these variables. The improved posttest results (P = .000) suggest that patients benefit from education programs and that the ophthalmic nurse is an effective patient teacher. The interactive program has no statistically significant difference from the didactic presentation. Other types of interactive programs may prove to be more beneficial.

  16. Relation Between Filtration and Soil Consolidation Theories

    NASA Astrophysics Data System (ADS)

    Strzelecki, Tomasz; Strzelecki, Michał

    2015-03-01

    This paper presents a different, than commonly used, form of equations describing the filtration of a viscous compressible fluid through a porous medium in isothermal conditions. This mathematical model is compared with the liquid flow equations used in the theory of consolidation. It is shown that the current commonly used filtration model representation significantly differs from the filtration process representation in Biot's and Terzaghi's soil consolidation models, which has a bearing on the use of the methods of determining the filtration coefficient on the basis of oedometer test results. The present analysis of the filtration theory equations should help interpret effective parameters of the non-steady filtration model. Moreover, equations for the flow of a gas through a porous medium and an interpretation of the filtration model effective parameters in this case are presented.

  17. Primary congenital glaucoma associated with Patau syndrome with long survival.

    PubMed

    Jaru-Ampornpan, Pimkwan; Kuchtey, John; Dev, V G; Kuchtey, Rachel

    2010-06-23

    Ocular abnormalities are common in Patau syndrome (trisomy 13), but only a few cases with congenital glaucoma have been reported, some of which were associated with other ocular defects. This report describes a case of primary congenital glaucoma in an 11-year-old patient with full trisomy 13.

  18. Giant prolactinoma mimicking low-tension glaucoma at presentation.

    PubMed

    Karl, David; Gillan, Stewart Neil; Goudie, Colin; Sanders, Roshini

    2015-02-06

    We describe a case of a 68-year-old man, referred by his optometrist with suspected low-tension glaucoma, who presented with advanced cupped optic discs and field of vision loss that were subsequently found to be due to a giant prolactinoma. Failing vision in low-tension glaucoma suspects should have a low threshold for neuroimaging.

  19. Isolated Microspherophakia Presenting with Angle-Closure Glaucoma

    PubMed Central

    Şimşek, Tülay; Beyazyıldız, Emrullah; Şimşek, Enver; Öztürk, Faruk

    2016-01-01

    We report a case of 13-year-old girl presenting to our clinic with blurred vision in both eyes. Ophthalmic examination revealed high myopia and angle-closure glaucoma due to pupillary block caused by small, spherical crystalline lenses. Treatment approaches to glaucoma in patients with microspherophakia are discussed in this case report. PMID:28058167

  20. Brain: The Potential Diagnostic and Therapeutic Target for Glaucoma.

    PubMed

    Faiq, Muneeb A; Dada, Rima; Kumar, Ashutosh; Saluja, Daman; Dada, Tanuj

    2016-01-01

    Glaucoma is a form of multifactorial ocular neurodegeneration with immensely complex etiology, pathogenesis and pathology. Though the mainstream therapeutic management of glaucoma is lowering of intraocular pressure, there is, as of now, no cure for the disease. New evidences ardently suggest brain involvement in all aspects of this malady. This consequently advocates the opinion that brain should be the spotlight of glaucoma research and may form the impending and promising target for glaucoma diagnosis and treatment. The present analysis endeavors at understanding glaucoma vis-à-vis brain structural and/or functional derangement and central nervous system (CNS) degeneration. Commencing with the premise of developing some understanding about the brain-nature of ocular structures; we discuss the nature of the cellular and molecular moieties involved in glaucoma and Alzheimer's disease. Substantial deal of literature implies that glaucoma may well be a disease of the brain, nevertheless, manifesting as progressive loss of vision. If that is the case, then targeting brain will be far more imperative in glaucoma therapeutics than any other remedial regimen currently being endorsed.

  1. Two cases of malignant glaucoma unresolved by pars plana vitrectomy

    PubMed Central

    Hosoda, Yoshikatsu; Akagi, Tadamichi; Yoshimura, Nagahisa

    2014-01-01

    Malignant glaucoma, which is characterized by a shallow or flat anterior chamber with high intraocular pressure, can usually be resolved by pars plana vitrectomy with anterior hyaloidectomy. We describe two cases in which malignant glaucoma was refractory to conventional treatment and complete vitrectomy. Case one an 88-year-old woman with pseudoexfoliation glaucoma underwent trabeculotomy and subsequently developed malignant glaucoma. Four months after transient recovery by pars plana vitrectomy, the malignant glaucoma recurred. She underwent peripheral iridectomy and local zonulectomy with successful control of her intraocular pressure. In case two, an 85-year-old man had a history of pseudoexfoliation glaucoma. Seven months after phacoemulsification and intraocular lens implantation, he developed malignant glaucoma that was refractory to pars plana vitrectomy. He underwent peripheral iridectomy, goniosynechialysis and trabectome surgery resulting in the successful control of his intraocular pressure. In rare cases of malignant glaucoma refractive to vitrectomy, peripheral iridectomy with or without local zonulectomy is a reasonable and minimally invasive surgical procedure. PMID:24729683

  2. Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma

    PubMed Central

    Mohindroo, Chirayu; Kumar, Suresh

    2016-01-01

    Glaucoma may be caused by an interplay of elevated intraocular pressure (IOP), vascular, genetic, anatomical, brain, and immune factors. The direct assessment of ocular hemodynam-ics offers promise for glaucoma detection, differentiation, and possibly new treatment modalities. All the methods currently in use to measure ocular blood flow have inherent limitations and measure different aspects of ocular blood flow. This review article attempts to provide detailed information on ocular perfu-sion pressure as well as an overview of the newly developed imaging technologies used to investigate ocular blood flow in glaucoma patients. How to cite this article Mohindroo C, Ichhpujani P, Kumar S. Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma. J Curr Glaucoma Pract 2016;10(3):104-112. PMID:27857490

  3. Marijuana for Glaucoma: A Recipe for Disaster or Treatment?

    PubMed

    Sun, Xiaoshen; Xu, Chaoying S; Chadha, Nisha; Chen, Allshine; Liu, Ji

    2015-09-01

    Marijuana has been shown to lower intraocular pressure (IOP) but with limited duration of action and numerous adverse effects. Use of marijuana to lower IOP as a means of glaucoma treatment would require frequent use throughout the day, leading to significant adverse effects, possible progression toward Cannabis Use Disorder (CUD), and/or withdrawal symptoms. The treatment of glaucoma based on the cannabis plant or drugs based on the cannabinoid molecule should be considered carefully before being prescribed. Considerations should include the adverse physical and psychological adverse effects, including substance abuse. Currently, the deleterious effects of marijuana outweigh the benefits of its IOP-lowering capacity in most glaucoma patients. Under extremely rare circumstances, a few categories of glaucoma patients may be potential candidates for treatment with medical marijuana. Further studies on alternate routes and more focused means of cannabinoid molecule delivery to the eye for glaucoma treatment are needed.

  4. Malignant Glaucoma: A Review of the Modern Literature

    PubMed Central

    Shahid, H.; Salmon, J. F.

    2012-01-01

    Malignant glaucoma is a rare form of glaucoma that typically follows surgery in patients with primary angle closure and primary angle-closure glaucoma. In this paper, the clinical features, classification, pathogenesis, and principles of management are discussed. Despite a high prevalence of primary angle closure glaucoma in South-East Asia, the vast majority of cases of malignant glaucoma are reported in White populations. This may reflect differing mechanisms of angle closure in White and Asian patients, which somehow reduces the likelihood of an aberrant relationship developing between the lens, ciliary body, anterior hyaloid, and vitreous structures within the eye. Although the exact underlying pathogenic mechanism remains unclear, the prognosis is good with modern medical, laser, and surgical treatment modalities. PMID:22545204

  5. Marijuana for Glaucoma: A Recipe for Disaster or Treatment?

    PubMed Central

    Sun, Xiaoshen; Xu, Chaoying S.; Chadha, Nisha; Chen, Allshine; Liu, Ji

    2015-01-01

    Marijuana has been shown to lower intraocular pressure (IOP) but with limited duration of action and numerous adverse effects. Use of marijuana to lower IOP as a means of glaucoma treatment would require frequent use throughout the day, leading to significant adverse effects, possible progression toward Cannabis Use Disorder (CUD), and/or withdrawal symptoms. The treatment of glaucoma based on the cannabis plant or drugs based on the cannabinoid molecule should be considered carefully before being prescribed. Considerations should include the adverse physical and psychological adverse effects, including substance abuse. Currently, the deleterious effects of marijuana outweigh the benefits of its IOP-lowering capacity in most glaucoma patients. Under extremely rare circumstances, a few categories of glaucoma patients may be potential candidates for treatment with medical marijuana. Further studies on alternate routes and more focused means of cannabinoid molecule delivery to the eye for glaucoma treatment are needed. PMID:26339209

  6. Nanotechnology and glaucoma: a review of the potential implications of glaucoma nanomedicine.

    PubMed

    Kim, Nathaniel J; Harris, Alon; Gerber, Austin; Tobe, Leslie Abrams; Amireskandari, Annahita; Huck, Andrew; Siesky, Brent

    2014-04-01

    The purpose of this review is to discuss the evolution of nanotechnology and its potential diagnostic and therapeutic applications in the field of ophthalmology, particularly as it pertains to glaucoma. We reviewed literature using MEDLINE and PubMed databases with the following search terms: glaucoma, nanotechnology, nanomedicine, nanoparticles, ophthalmology and liposomes. We also reviewed pertinent references from articles found in this search. A brief history of nanotechnology and nanomedicine will be covered, followed by a discussion of the advantages and concerns of using this technology in the field of glaucoma. We will look at various studies concerning the development of nanomedicine, its potential applications in ocular drug delivery, diagnostic and imaging modalities and, surgical techniques. In particular, the challenges of assuring safety and efficacy of nanomedicine will be examined. We conclude that nanotechnology offers a novel approach to expanding diagnostic, imaging and surgical modalities in glaucoma and may contribute to the knowledge of disease pathogenesis at a molecular level. However, more research is needed to better elucidate the mechanism of cellular entry, the potential for nanoparticle cytotoxicity and the assurance of clinical efficacy.

  7. Structural basis for reduced glomerular filtration capacity in nephrotic humans.

    PubMed Central

    Drumond, M C; Kristal, B; Myers, B D; Deen, W M

    1994-01-01

    Previous studies have established that in a variety of human glomerulopathies the reduced glomerular filtration rate (GFR) is due to a marked lowering of the ultrafiltration coefficient (Kf). To identify the factors which lower Kf, we measured the filtering surface area per glomerulus, filtration slit frequency, basement membrane thickness, and GFR and its determinants in patients with minimal change and membraneous nephropathies and in age-matched healthy controls. Overall values of Kf for the two kidneys were calculated from GFR, renal plasma flow rate, systemic colloid osmotic pressure, and three assumed values for the transcapillary pressure difference. "Experimental" values of the glomerular hydraulic permeability (kexp) were then calculated from Kf, glomerular filtering surface area, and estimates of the total number of nephrons of the two kidneys. Independent estimates of the glomerular hydraulic permeability (kmodel) were obtained using a recent mathematical model that is based on analyses of viscous flow through the various structural components of the glomerular capillary wall. Individual values of basement membrane thickness and filtration slit frequency were used as inputs in this model. The results indicate that the reductions of Kf in both nephropathies can be attributed entirely to reduced glomerular hydraulic permeability. The mean values of kexp and kmodel were very similar in both disorders and much smaller in the nephrotic groups than in healthy controls. There was good agreement between kexp and kmodel for any given group of subjects. It was shown that, in both groups of nephrotics, filtration slit frequency was a more important determinant of the water flow resistance than was basement membrane thickness. The decrease in filtration slit frequency observed in both disorders caused the average path length for the filtrate to increase, thereby explaining the decreased hydraulic permeability. Images PMID:8083359

  8. Water Filtration Using Plant Xylem

    PubMed Central

    Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

    2014-01-01

    Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings. PMID:24587134

  9. Sioux City Riverbank Filtration Study

    NASA Astrophysics Data System (ADS)

    Mach, R.; Condon, J.; Johnson, J.

    2003-04-01

    The City of Sioux City (City) obtains a large percentage of their drinking water supply from both a horizontal collector well system and vertical wells located adjacent to the Missouri River. These wells are set in either the Missouri Alluvium or the Dakota Sandstone aquifer. Several of the collector well laterals extend out beneath the Missouri River, with the laterals being over twenty feet below the river channel bottom. Due to concerns regarding ground water under direct surface water influence, the Iowa Department of Natural Resources (IDNR) required the City to expand their water treatment process to deal with potential surface water contaminant issues. With the extensive cost of these plant upgrades, the City and Olsson Associates (OA) approached the IDNR requesting approval for assessing the degree of natural riverbank filtration for water treatment. If this natural process could be ascertained, the level of treatment from the plant could be reduced. The objective of this study was to quantify the degree of surface water (i.e. Missouri River) filtration due to the underlying Missouri River sediments. Several series of microscopic particulate analysis where conducted, along with tracking of turbidity, temperature, bacteria and a full scale particle count study. Six particle sizes from six sampling points were assessed over a nine-month period that spanned summer, fall and spring weather periods. The project was set up in two phases and utilized industry accepted statistical analyses to identify particle data trends. The first phase consisted of twice daily sample collection from the Missouri River and the collector well system for a one-month period. Statistical analysis of the data indicated reducing the sampling frequency and sampling locations would yield justifiable data while significantly reducing sampling and analysis costs. The IDNR approved this modification, and phase II included sampling and analysis under this reduced plant for an eight

  10. A Novel Implantable Glaucoma Valve Using Ferrofluid

    PubMed Central

    Paschalis, Eleftherios I.; Chodosh, James; Sperling, Ralph A.; Salvador-Culla, Borja; Dohlman, Claes

    2013-01-01

    Purpose To present a novel design of an implantable glaucoma valve based on ferrofluidic nanoparticles and to compare it with a well-established FDA approved valve. Setting Massachusetts Eye & Ear Infirmary, Boston, USA. Methods A glaucoma valve was designed using soft lithography techniques utilizing a water-immiscible magnetic fluid (ferrofluid) as a pressure-sensitive barrier to aqueous flow. Two rare earth micro magnets were used to calibrate the opening and closing pressure. In-vitro flow measurements were performed to characterize the valve and to compare it to Ahmed™ glaucoma valve. The reliability and predictability of the new valve was verified by pressure/flow measurements over a period of three months and X-ray diffraction (XRD) analysis over a period of eight weeks. In vivo assessment was performed in three rabbits. Results In the in vitro experiments, the opening and closing pressures of the valve were 10 and 7 mmHg, respectively. The measured flow/pressure response was linearly proportional and reproducible over a period of three months (1.8 µl/min at 12 mmHg; 4.3 µl/min at 16 mmHg; 7.6 µl/min at 21 mmHg). X-ray diffraction analysis did not show oxidization of the ferrofluid when exposed to water or air. Preliminary in vivo results suggest that the valve is biocompatible and can control the intraocular pressure in rabbits. Conclusions The proposed valve utilizes ferrofluid as passive, tunable constriction element to provide highly predictable opening and closing pressures while maintaining ocular tone. The ferrofluid maintained its magnetic properties in the aqueous environment and provided linear flow to pressure response. Our in-vitro tests showed reliable and reproducible results over a study period of three months. Preliminary in-vivo results were very promising and currently more thorough investigation of this device is underway. PMID:23840691

  11. Driving Simulation as a Performance-based Test of Visual Impairment in Glaucoma

    PubMed Central

    Medeiros, Felipe A.; Weinreb, Robert N.; Boer, Erwin; Rosen, Peter N.

    2013-01-01

    The fundamental goal of glaucoma management is to prevent patients from developing visual impairment sufficient to produce disability in their daily lives and impair their quality of life. Ultimately, patients are interested in how their vision will impact their ability to perform daily activities, such as driving. Although technological advancements such as automated perimetry and devices for optic nerve imaging have resulted in great improvement in our ability to quantify structural and functional damage in glaucoma, the impact on vision-related quality of life of some of the information acquired from these tests remain elusive. On the other hand, performance-based measures may be better correlated to traditional measures of vision health and, more importantly, they provide a more direct measure of disability. Driving simulators can be used as a performance-based test for evaluation of functional impairment in glaucoma. Their use can potentially help the evaluation of driving safety and performance of diseased subjects and provide insight into the different mechanisms involved in causing driving impairment in this disease. The ability to do this in an experimentally controlled and standardized setting enables testing of a much larger number of hypotheses compared to on-road evaluations. Besides evaluating driver fitness, simulators could also potentially be used as a sophisticated test to evaluate cognitive impairment in the context of an everyday task (driving) that has not been available through traditional neuropsychological assessment. PMID:21467952

  12. Caveolin-1 modulates intraocular pressure: implications for caveolae mechanoprotection in glaucoma

    PubMed Central

    Elliott, Michael H.; Ashpole, Nicole E.; Gu, Xiaowu; Herrnberger, Leonie; McClellan, Mark E.; Griffith, Gina L.; Reagan, Alaina M.; Boyce, Timothy M.; Tanito, Masaki; Tamm, Ernst R.; Stamer, W. Daniel

    2016-01-01

    Polymorphisms in the CAV1/2 genes that encode signature proteins of caveolae are associated with glaucoma, the second leading cause of blindness worldwide, and with its major risk factor, intraocular pressure (IOP). We hypothesized that caveolin-1 (Cav-1) participates in IOP maintenance via modulation of aqueous humor drainage from the eye. We localize caveolae proteins to human and murine conventional drainage tissues and show that caveolae respond to mechanical stimulation. We show that Cav-1-deficient (Cav-1−/−) mice display ocular hypertension explained by reduced pressure-dependent drainage of aqueous humor. Cav-1 deficiency results in loss of caveolae in the Schlemm’s canal (SC) and trabecular meshwork. However, their absence did not appear to impact development nor adult form of the conventional outflow tissues according to rigorous quantitative ultrastructural analyses, but did affect cell and tissue behavior. Thus, when IOP is experimentally elevated, cells of the Cav-1−/− outflow tissues are more susceptible to plasma membrane rupture indicating that caveolae play a role in mechanoprotection. Additionally, aqueous drainage from Cav-1−/− eyes was more sensitive to nitric oxide (NO) synthase inhibition than controls, suggesting that excess NO partially compensates for outflow pathway dysfunction. These results provide a functional link between a glaucoma risk gene and glaucoma-relevant pathophysiology. PMID:27841369

  13. Learning ECOC Code Matrix for Multiclass Classification with Application to Glaucoma Diagnosis.

    PubMed

    Bai, Xiaolong; Niwas, Swamidoss Issac; Lin, Weisi; Ju, Bing-Feng; Kwoh, Chee Keong; Wang, Lipo; Sng, Chelvin C; Aquino, Maria C; Chew, Paul T K

    2016-04-01

    Classification of different mechanisms of angle closure glaucoma (ACG) is important for medical diagnosis. Error-correcting output code (ECOC) is an effective approach for multiclass classification. In this study, we propose a new ensemble learning method based on ECOC with application to classification of four ACG mechanisms. The dichotomizers in ECOC are first optimized individually to increase their accuracy and diversity (or interdependence) which is beneficial to the ECOC framework. Specifically, the best feature set is determined for each possible dichotomizer and a wrapper approach is applied to evaluate the classification accuracy of each dichotomizer on the training dataset using cross-validation. The separability of the ECOC codes is maximized by selecting a set of competitive dichotomizers according to a new criterion, in which a regularization term is introduced in consideration of the binary classification performance of each selected dichotomizer. The proposed method is experimentally applied for classifying four ACG mechanisms. The eye images of 152 glaucoma patients are collected by using anterior segment optical coherence tomography (AS-OCT) and then segmented, from which 84 features are extracted. The weighted average classification accuracy of the proposed method is 87.65 % based on the results of leave-one-out cross-validation (LOOCV), which is much better than that of the other existing ECOC methods. The proposed method achieves accurate classification of four ACG mechanisms which is promising to be applied in diagnosis of glaucoma.

  14. Pig manure treatment and purification by filtration.

    PubMed

    Makara, A; Kowalski, Z

    2015-09-15

    This study aimed to develop a new, complex pig manure treatment and filtration process. The final scheme, called the AMAK process, comprised the following successive steps: mineralization with mineral acids, alkalization with lime milk, superphosphate addition, a second alkalization, thermal treatment, and pressure filtration. The proposed method produced a filtrate with 95%, 80%, and 96% reductions in chemical oxygen demand, nitrogen content, and phosphorus content, respectively. An advantage of the proposed method was that it incorporated a crystalline phase into the solid organic part of the manure, which enabled high filtration rates (>1000 kg m(-2) h(-1)) and efficient separation. The process also eliminated odor emissions from the filtrate and sediment. The treated filtrate could be used to irrigate crops or it could be further treated in conventional biological wastewater treatment plants. The sediment could be used for producing mineral-organic fertilizer. The AMAK process is inexpensive, and it requires low investment costs.

  15. Membrane filtration of food suspensions.

    PubMed Central

    Sharpe, A N; Peterkin, P I; Dudas, I

    1979-01-01

    Factors affecting the membrane filtration of food suspensions were studied for 58 foods and 13 membrane filters. Lot number within a brand, pore size (0.45 or 0.8 micrometer), and time elapsed before filtration had little effect on filterability. Brand of membrane filter, flow direction, pressure differential, age (microbiological quality) of the food, duration of the blending process, temperature, and concentration of food in the suspension had significant and often predictable effects. Preparation of suspensions by Stomacher (relative to rotary blender) addition of surfactant (particularly at elevated temperature) and prior incubation with proteases sometimes had dramatic effects of filterability. In contrast to popular opinion, foods can be membrane filtered in quantities pertinent to the maximums used in conventional plating procedures. Removal of growth inhibitors and food debris is possible by using membrane filters. Lowering of the limits of detection of microorganisms by concentration on membrane filters can be considered feasible for many foods. The data are particularly relevant to the use of hydrophobic grid-membrane filters (which are capable of enumerating up to 9 X 10(4) organisms per filter) in instrumented methods of food microbiological analysis. Images PMID:760637

  16. Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  17. Loading and filtration characteristics of filtering facepieces.

    PubMed

    Chen, C C; Lehtimäki, M; Willeke, K

    1993-02-01

    Most filtering facepieces used today are made of electret material (material with significant electrical charges on the filter fibers). Because of the addition of this electrical removal force, the filtration efficiency can be significantly increased without increasing the air pressure drop inside the respirator; pressure drop is closely related to physiological load. However, the removal by electrical forces is reduced in time, as aerosols deposit on the filter fibers. We have studied the contribution of this electrical removal and its change in time as a function of aerosol loading. To prove the change in aerosol penetration is due to the reduction of electrical force, the electrical charges were removed from new facepieces by the application of appropriate chemicals. The dust-mist filtering facepieces tested have similar fiber diameters and packing densities, as determined by scanning electron microscopy and pressure drop data. At a face velocity of 10 cm/s (corresponding to 100 L/min through a complete filtering facepiece) and an aerosol size of 0.16 microns, electrical force removal accounts for 69% of the total filtration for the respirator found to have the best filter quality but only 25% for the respirator (from a different manufacturer) found to have the worst filter quality. Our experimental data show that the removal efficiency of these facepieces is reduced in time by as much as this amount. However, under normal wear conditions, the total aerosol particle load is not as high as shown and the filtering facepieces are likely to be discarded before the fiber charges (i.e., the electrostatic attractions) are significantly diminished.

  18. Present and New Treatment Strategies in the Management of Glaucoma

    PubMed Central

    Kolko, M.

    2015-01-01

    Glaucoma is a neurodegenerative disease characterized by retinal ganglion cell (RGC) death and axonal loss. It remains a major cause of blindness worldwide. All current modalities of treatment are focused on lowering intraocular pressure (IOP), and it is evident that increased IOP is an important risk factor for progression of the disease. However, it is clear that a significant number of glaucoma patients show disease progression despite of pressure lowering treatments. Much attention has been given to the development of neuroprotective treatment strategies, but the identification of such has been hampered by lack of understanding of the etiology of glaucoma. Hence, in spite of many attempts no neuroprotective drug has yet been clinically approved. Even though neuroprotection is without doubt an important treatment strategy, many glaucoma subjects are diagnosed after substantial loss of RGCs. In this matter, recent approaches aim to rescue RGCs and regenerate axons in order to restore visual function in glaucoma. The present review seeks to provide an overview of the present and new treatment strategies in the management of glaucoma. The treatment strategies are divided into current available glaucoma medications, new pressure lowering targets, prospective neuroprotective interventions, and finally possible neuroregenrative strategies. PMID:26069521

  19. Glaucoma related Proteomic Alterations in Human Retina Samples

    PubMed Central

    Funke, Sebastian; Perumal, Natarajan; Beck, Sabine; Gabel-Scheurich, Silke; Schmelter, Carsten; Teister, Julia; Gerbig, Claudia; Gramlich, Oliver W.; Pfeiffer, Norbert; Grus, Franz H.

    2016-01-01

    Glaucoma related proteomic changes have been documented in cell and animal models. However, proteomic studies investigating on human retina samples are still rare. In the present work, retina samples of glaucoma and non-glaucoma control donors have been examined by a state-of-the-art mass spectrometry (MS) workflow to uncover glaucoma related proteomic changes. More than 600 proteins could be identified with high confidence (FDR < 1%) in human retina samples. Distinct proteomic changes have been observed in 10% of proteins encircling mitochondrial and nucleus species. Numerous proteins showed a significant glaucoma related level change (p < 0.05) or distinct tendency of alteration (p < 0.1). Candidates were documented to be involved in cellular development, stress and cell death. Increase of stress related proteins and decrease of new glaucoma related candidates, ADP/ATP translocase 3 (ANT3), PC4 and SRFS1-interacting protein 1 (DFS70) and methyl-CpG-binding protein 2 (MeCp2) could be documented by MS. Moreover, candidates could be validated by Accurate Inclusion Mass Screening (AIMS) and immunostaining and supported for the retinal ganglion cell layer (GCL) by laser capture microdissection (LCM) in porcine and human eye cryosections. The workflow allowed a detailed view into the human retina proteome highlighting new molecular players ANT3, DFS70 and MeCp2 associated to glaucoma. PMID:27425789

  20. Modeling Human Glaucoma: Lessons from the in vitro Models.

    PubMed

    Aires, Inês Dinis; Ambrósio, António Francisco; Santiago, Ana Raquel

    2017-01-01

    Glaucoma, a leading cause of blindness worldwide, is a degenerative disease characterized by retinal ganglion cell (RGC) loss and optic nerve atrophy. Elevated intraocular pressure (IOP) is a main risk factor for onset and progression of the disease. Since increased IOP is the only modifiable risk factor, relevant models for glaucoma would comprise RGC and optic nerve damage triggered by ocular hypertension. Animal models of glaucoma have greatly contributed to the understanding of the molecular mechanisms of this pathology, and they have also facilitated the development of new pharmacological interventions. Although animal models of glaucoma have provided valuable information about the disease, there is still no ideal model for studying glaucoma due to its complexity. There is a recognized demand for in vitro models that can replace or reduce the need for animal experiments. Several in vitro models have emerged as a great opportunity in the field of glaucoma research, helping to clarify the mechanisms involved in disease progression. Several types of equipment have been developed to expose cells and tissue cultures to elevated pressures. Herein, we discuss the methodology used to increase pressure, the main findings, and the relevance of in vitro models for the study of the pathophysiology of glaucoma.

  1. Targeting Oxidative Stress for Treatment of Glaucoma and Optic Neuritis

    PubMed Central

    Kimura, Atsuko; Namekata, Kazuhiko; Guo, Xiaoli; Noro, Takahiko; Harada, Chikako

    2017-01-01

    Glaucoma is a neurodegenerative disease of the eye and it is one of the leading causes of blindness. Glaucoma is characterized by progressive degeneration of retinal ganglion cells (RGCs) and their axons, namely, the optic nerve, usually associated with elevated intraocular pressure (IOP). Current glaucoma therapies target reduction of IOP, but since RGC death is the cause of irreversible vision loss, neuroprotection may be an effective strategy for glaucoma treatment. One of the risk factors for glaucoma is increased oxidative stress, and drugs with antioxidative properties including valproic acid and spermidine, as well as inhibition of apoptosis signal-regulating kinase 1, an enzyme that is involved in oxidative stress, have been reported to prevent glaucomatous retinal degeneration in mouse models of glaucoma. Optic neuritis is a demyelinating inflammation of the optic nerve that presents with visual impairment and it is commonly associated with multiple sclerosis, a chronic demyelinating disease of the central nervous system. Although steroids are commonly used for treatment of optic neuritis, reduction of oxidative stress by approaches such as gene therapy is effective in ameliorating optic nerve demyelination in preclinical studies. In this review, we discuss oxidative stress as a therapeutic target for glaucoma and optic neuritis. PMID:28270908

  2. Glaucoma in Iran and Contributions of Studies in Iran to the Understanding of the Etiology of Glaucoma

    PubMed Central

    Suri, Fatemeh; Yazdani, Shahin; Elahi, Elahe

    2015-01-01

    Epidemiologic and genetic/molecular research on glaucoma in Iran started within the past decade. A population-based study on the epidemiology of glaucoma in Yazd, a city in central Iran, revealed that 4.4% of studied individuals were affected with glaucoma: 1.6% with high tension primary open angle glaucoma (POAG), 1.6% with normal tension POAG, and 0.4% each with primary angle closure glaucoma (PACG) and pseudoexfoliation glaucoma (PEXG), and other types of secondary glaucoma. Two notable observations were the relatively high frequency of normal tension glaucoma cases (1.6%) and the large fraction of glaucoma affected individuals (nearly 90%) who were unaware of their condition. The first and most subsequent genetic studies on glaucoma in Iran were focused on primary congenital glaucoma (PCG) showing that cytochrome P450 1B1 (CYP1B1) is the cause of PCG in the majority of Iranian patients, many different CYP1B1 mutations are present among Iranian patients but only four mutations constitute the vast majority, and the origins of most mutations in the Iranians are identical by descent (IBD) with the same mutations in other populations. Furthermore, most of the PCG patients are from the northern and northwestern provinces of Iran. A statistically significant male predominance of PCG was observed only among patients without CYP1B1 mutations. Clinical investigations on family members of PCG patients revealed that CYP1B1 mutations exhibit variable expressivity, but almost complete penetrance. A great number of individuals harboring CYP1B1 mutations become affected with juvenile onset POAG. Screening of JOAG patients showed that an approximately equal fraction of the patients harbor CYP1B1 and (myocilin) MYOC mutations; MYOC is a well-known adult onset glaucoma causing gene. Presence of CYP1B1 mutations in JOAG patients suggests that in some cases, the two conditions may share a common etiology. Further genetic analysis of Iranian PCG patients led to identification of

  3. Persistent homology in graph power filtrations

    PubMed Central

    Marchette, David J.

    2016-01-01

    The persistence of homological features in simplicial complex representations of big datasets in Rn resulting from Vietoris–Rips or Čech filtrations is commonly used to probe the topological structure of such datasets. In this paper, the notion of homological persistence in simplicial complexes obtained from power filtrations of graphs is introduced. Specifically, the rth complex, r ≥ 1, in such a power filtration is the clique complex of the rth power Gr of a simple graph G. Because the graph distance in G is the relevant proximity parameter, unlike a Euclidean filtration of a dataset where regional scale differences can be an issue, persistence in power filtrations provides a scale-free insight into the topology of G. It is shown that for a power filtration of G, the girth of G defines an r range over which the homology of the complexes in the filtration are guaranteed to persist in all dimensions. The role of chordal graphs as trivial homology delimiters in power filtrations is also discussed and the related notions of ‘persistent triviality’, ‘transient noise’ and ‘persistent periodicity’ in power filtrations are introduced. PMID:27853540

  4. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    PubMed Central

    Jamal, Sondus; Chang, Sheng; Zhou, Hongde

    2014-01-01

    This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP) increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA. PMID:25007243

  5. Effect of leukocyte filtration on the P-selectin expression of apheresis platelets.

    PubMed

    Xie, Z T; Chen, C; Zhang, S H; Yang, H M; Tao, Z H

    2015-06-01

    The aim of this study was to investigate the effect of leukocyte filtration on the P-selectin (CD62P) surface expression of apheresis platelets during the retention period. Ten bags of apheresis platelets stored for 1 day (0-24 h) and 10 bags of apheresis platelets stored for 2 days (24-48 h) were used for leukocyte filtration (experimental group). Ten bags of apheresis platelets with the corresponding retention periods but without filtration were used as a negative control (control group). Thereafter, 100 μL of platelet suspensions from apheresis platelets with or without leukocyte filtration were sampled before and after leukocyte filtration for the detection of CD62P surface expression by flow cytometry. No statistical difference in the CD62P surface expression of apheresis platelets was observed before and after leukocyte filtration (P > 0.05), neither did the CD62P surface expression exhibit any change among the different retention periods. Leukocyte filtration does not affect the CD62P surface expression of apheresis platelets stored for up to 2 days, which indicates that leukocyte filtration does not damage the activation of apheresis platelets within the retention period.

  6. Novel filtration mode for fouling limitation in membrane bioreactors.

    PubMed

    Wu, Jinling; Le-Clech, Pierre; Stuetz, Richard M; Fane, Anthony G; Chen, Vicki

    2008-08-01

    A novel filtration mode is presented to reduce fouling propensity in membrane bioreactors (MBR). During this mode, an elevated high instantaneous flux (60Lm(-2)h(-1)) is initially applied for a short time (120s), followed by a longer filtration (290s) at lower flux (10.3Lm(-2)h(-1)) and a backwash in each filtration cycle. The mixed mode is expected to limit irreversible fouling as the reversible fouling created during the initial stage appears to protect the membrane. Hydraulic performance and the components of foulants were analyzed and compared with conventional continuous and backwash modes. It was found that the mixed mode featured lower trans-membrane pressure (TMP) after 24h of filtration when compared to other modes. The mixed mode was effective in preventing soluble microbial products (SMP) attaching directly onto the membrane surface, keeping the cake layer weakly compressed, and reducing the mixed liquor suspended solids (MLSS) accumulation on the membrane. This strategy reduced the resistances of both the cake layer and the gel layer. A factorial experimental design was carried out for eight runs with different conditions to identify the major operational parameters affecting the hydraulic performances. The results showed that the value of the flux in the initial high-flux period had the most effect on the performance of the mixed mode: high initial flux (60Lm(-2)h(-1)) led to improved performance.

  7. Prevalence of glaucoma in rural Myanmar: the Meiktila Eye Study

    PubMed Central

    Casson, R J; Newland, H S; Muecke, J; McGovern, S; Abraham, L; Shein, W K; Selva, D; Aung, T

    2007-01-01

    Aim To determine the prevalence of glaucoma in the Meiktila district of central, rural Myanmar. Methods A cross‐sectional, population‐based survey of inhabitants ⩾40 years of age from villages in Meiktila district, Myanmar, was performed; 2481 eligible participants were identified and 2076 participated in the study. The ophthalmic examination included Snellen visual acuity, slit‐lamp examination, tonometry, gonioscopy, dilated stereoscopic fundus examination and full‐threshold perimetry. Glaucoma was classified into clinical subtypes and categorised into three levels according to diagnostic evidence. Results Glaucoma was diagnosed in 1997 (80.5%) participants. The prevalence of glaucoma of any category in at least one eye was 4.9% (95% CI 4.1 to 5.7; n = 101). The overall prevalence of primary angle‐closure glaucoma (PACG) was 2.5% (95% CI 1.5 to 3.5) and of primary open‐angle glaucoma (POAG) was 2.0% (95% CI 0.9 to 3.1). PACG accounted for 84% of all blindness due to glaucoma, with the majority due to acute angle‐closure glaucoma (AACG). Conclusion The prevalence of glaucoma in the population aged ⩾40 years in rural, central Myanmar was 4.9%. The ratio of PACG to POAG was approximately 1.25:1. PACG has a high visual morbidity and AACG is visually devastating in this community. Screening programmes should be directed at PACG, and further study of the underlying mechanisms of PACG is needed in this population. PMID:17510475

  8. Adaptive optics optical coherence tomography in glaucoma.

    PubMed

    Dong, Zachary M; Wollstein, Gadi; Wang, Bo; Schuman, Joel S

    2017-03-01

    Since the introduction of commercial optical coherence tomography (OCT) systems, the ophthalmic imaging modality has rapidly expanded and it has since changed the paradigm of visualization of the retina and revolutionized the management and diagnosis of neuro-retinal diseases, including glaucoma. OCT remains a dynamic and evolving imaging modality, growing from time-domain OCT to the improved spectral-domain OCT, adapting novel image analysis and processing methods, and onto the newer swept-source OCT and the implementation of adaptive optics (AO) into OCT. The incorporation of AO into ophthalmic imaging modalities has enhanced OCT by improving image resolution and quality, particularly in the posterior segment of the eye. Although OCT previously captured in-vivo cross-sectional images with unparalleled high resolution in the axial direction, monochromatic aberrations of the eye limit transverse or lateral resolution to about 15-20 μm and reduce overall image quality. In pairing AO technology with OCT, it is now possible to obtain diffraction-limited resolution images of the optic nerve head and retina in three-dimensions, increasing resolution down to a theoretical 3 μm(3). It is now possible to visualize discrete structures within the posterior eye, such as photoreceptors, retinal nerve fiber layer bundles, the lamina cribrosa, and other structures relevant to glaucoma. Despite its limitations and barriers to widespread commercialization, the expanding role of AO in OCT is propelling this technology into clinical trials and onto becoming an invaluable modality in the clinician's arsenal.

  9. Active noncontact tonometer for glaucoma detection

    NASA Astrophysics Data System (ADS)

    Han, Yanmei; Bryanston-Cross, Peter J.; Lee, Wing K. A.; Hero, Mark

    2002-09-01

    Glaucoma is an increasingly common cause of visual impairment, and in some cases causes blindness. The approach to develop a low cost and non-contact tonometer for the detection of glaucoma, to replace the Goldmann tonometer used worldwide, is presented in this paper. The new tonometer exploits the vibration property of the cornea - the resonance frequency of the cornea rises with increasing intra-ocular pressure (IOP). An audio frequency signal is used to vibrate the cornea of the eye, the vibration of the cornea is measured using a fibre optic lever probe, and then the IOP can be calculated from the detected resonance frequency of the cornea. The initial PC-version experiment system of the new tonometer has been demonstrated and preliminary testing has been performed, showing a suitable sensitivity in detecting the resonance frequency against the IOP using both the simulated-eye model and the pig's eye. The initial system has been improved to be suitable for greater than 15mm detecting distance, and the measurement of vibrations of human cornea in-vivo has been carried out. Work is now focusing on increasing the sensitivity of the fibre probe, and reducing the measuring time to less than 1 second.

  10. Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma.

    PubMed

    Mohindroo, Chirayu; Ichhpujani, Parul; Kumar, Suresh

    2016-01-01

    Glaucoma may be caused by an interplay of elevated intraocular pressure (IOP), vascular, genetic, anatomical, brain, and immune factors. The direct assessment of ocular hemodynam-ics offers promise for glaucoma detection, differentiation, and possibly new treatment modalities. All the methods currently in use to measure ocular blood flow have inherent limitations and measure different aspects of ocular blood flow. This review article attempts to provide detailed information on ocular perfu-sion pressure as well as an overview of the newly developed imaging technologies used to investigate ocular blood flow in glaucoma patients.

  11. Central retinal artery occlusion (reversible in sickle trait with glaucoma.

    PubMed Central

    Radius, R L; Finkelstein, D

    1976-01-01

    We report a case of central retinal artery occlusion in an 18-year-old black woman with sickle-trait haemoglobinopathy and acute glaucoma after hyphaema. The central retinal artery occlusion occurred immediately after treatment of the glaucoma with osmotic agents, raising the possibility that they played a precipitating role. We suggest that osmotic agents be used with extreme caution in sickle patients with glaucoma. The occlusion was treated by anterior chamber paracentesis with eventual return of good vision. The reversibility of retinal and optic nerve function after total ischaemia is discussed. PMID:952815

  12. Clinical Utility of Optical Coherence Tomography in Glaucoma

    PubMed Central

    Dong, Zachary M.; Wollstein, Gadi; Schuman, Joel S.

    2016-01-01

    Optical coherence tomography (OCT) has established itself as the dominant imaging modality in the management of glaucoma and retinal diseases, providing high-resolution visualization of ocular microstructures and objective quantification of tissue thickness and change. This article reviews the history of OCT imaging with a specific focus on glaucoma. We examine the clinical utility of OCT with respect to diagnosis and progression monitoring, with additional emphasis on advances in OCT technology that continue to facilitate glaucoma research and inform clinical management strategies. PMID:27537415

  13. Systematic Review of Educational Interventions to Improve Glaucoma Medication Adherence

    PubMed Central

    Newman-Casey, Paula Anne; Weizer, Jennifer S.; Heisler, Michele; Lee, Paul P.; Stein, Joshua D.

    2014-01-01

    Adherence to prescribed glaucoma medications is often poor, and proper adherence can be challenging for patients. We systematically reviewed the literature and identified eight studies using educational interventions to improve glaucoma medication adherence. Overall, five of the eight studies found that educational interventions lead to a significant improvement in medication adherence, and the remaining studies found a trend towards improvement. Using information from this systematic review and Health Behavior Theory, we constructed a conceptual framework to illustrate how counseling and education can improve glaucoma medication adherence. More rigorous studies grounded in Health Behavior Theory with adequately powered samples and longer follow-up are needed. PMID:23697623

  14. Is 24-hour Intraocular Pressure Monitoring Necessary in Glaucoma?

    PubMed Central

    Mansouri, Kaweh; Weinreb, Robert N.; Medeiros, Felipe A.

    2013-01-01

    Although intraocular pressure (IOP) is the only treatable risk factor for glaucoma, its 24-hour behavior is poorly understood. Conflicting information is available in the literature with regard to the importance and predictive value of IOP peaks and fluctuations on the risk of glaucoma development and progression. This may be secondary to lack of prospective studies designed to address this issue. This article critically reviews the current evidence for the importance of 24-h IOP measurements in glaucoma and discusses shortcomings of current methods to assess 24-h IOP data, drawing attention to new developments in this field. PMID:23697618

  15. [Value of non-IOP lowering therapy for glaucoma].

    PubMed

    Cybulska-Heinrich, A; Mozaffarieh, M; Flammer, J

    2013-02-01

    It is well established that an IOP reduction improves, on average, the prognosis of all types of glaucoma. It is also known, however, that even an ideal IOP does not stop progression in all patients. The insight into the pathogenesis of glaucomatous damage leads to new therapeutic approaches. Whilst most of these new avenues of treatment are still in the experimental phase, others, such as magnesium, Ginkgo, salt and fludrocortisone are already used by some physicians. Blood pressure dips can be avoided by intake of salt or fludrocortisone. Vascular regulation can be improved either locally by carbonic anhydrase inhibitors or systemically with magnesium or with low doses of calcium channel blockers. A number of other food ingredients such as polyphenolic flavonoids occurring in tea, coffee, dark chocolate or red wine and anthocyanosides found in bilberries have potential antioxidative effects. The oxidative stress at the level of the mitochondria can be reduced by Ginkgo biloba. Experimentally, glaucomatous optic neuropathy can be prevented by inhibition of astrocyte activation, either by blockage of epidermal growth factor receptor or by counteracting endothelin. Glaucomatous optic neuropathy can also be prevented by nitric oxide-2 synthase inhibition. Inhibition of matrix metalloproteinase-9 inhibits apoptosis of retinal ganglion cells and tissue remodelling. Up-regulation of heat shock proteins protects the retinal ganglion cells and the optic nerve head.

  16. Impaired motion sensitivity as a predictor of subsequent field loss in glaucoma suspects: the Roscommon Glaucoma Study

    PubMed Central

    Wu, J; Coffey, M; Reidy, A; Wormald, R

    1998-01-01

    AIM—To determine if impaired motion sensitivity is a significant predictor of subsequent field loss in glaucoma suspects.
METHOD—A population based prospective study; a 5 year follow up of all glaucoma suspects who had been identified from a population based random sample survey in the west of Ireland. 78 glaucoma suspects whose visual field function was annually measured by Henson CFS 2000 and for whom data on family history of glaucoma, ocular status, and motion impairment had been recorded. Visual field loss was defined as Henson visual field survival score of 94 or less.
RESULTS—18 people developed visual field loss in at least one eye. Motion impairment at baseline was associated with a 2-18 times greater risk of development of the visual field loss (p<0.001). This association was independent of sex, family history of glaucoma, intraocular pressure, and C/D ratio at baseline. The Cox's proportional hazards regression analysis confirmed the above results after adjustment for age and the C/D ratio.
CONCLUSION—Motion impairment is an independent predictor of visual field loss in glaucoma suspects, although it is not clear how long motion impairment precedes visual field loss.

 Keywords: glaucoma; perimetry; screening; motion PMID:9713062

  17. Tangential flow filtration of hemoglobin.

    PubMed

    Palmer, Andre F; Sun, Guoyong; Harris, David R

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P(50)) and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (alpha) and beta (beta) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the alpha and beta globin chains agreed well with the calculated theoretical mass of the alpha- and beta- globin chains. Taken together, our results demonstrate that HPLC-grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers.

  18. Inter-eye comparison of retinal oximetry and vessel caliber between eyes with asymmetrical glaucoma severity in different glaucoma subtypes

    PubMed Central

    Cheng, Clarissa Shu Ming; Lee, Yi Fang; Ong, Charles; Yap, Zhu Li; Tsai, Andrew; Mohla, Aditi; Nongpiur, Monisha E; Aung, Tin; Perera, Shamira A

    2016-01-01

    Background To compare retinal vessel oxygenation and vessel caliber in primary angle-closure glaucoma (PACG), primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), and normal controls, as well as between eyes of asymmetrical glaucoma severity. Methods This was a prospective, cross-sectional study. The 159 subjects (PACG, n=39; POAG, n=41; NTG, n=41; normal controls, n=38) underwent retinal oxygen saturation measurements using the Oxymap T1 Retinal Oximeter, optical coherence tomography, and Humphrey visual field testing. Retinal oxygen saturation and vessel diameter were compared between the glaucoma groups and normal controls, as well as between eyes of asymmetrical glaucoma severity. Kruskal–Wallis test was performed for comparison among different subtypes of glaucoma. Wilcoxon signed-rank test was used to compare the inter-eye differences. Results Compared to normal controls, arteriolar oxygen saturation was increased in PACG eyes (P=0.048) but not in POAG or NTG eyes. There were no significant differences in oxygen saturation in venules or arteriovenous (AV) difference in all three glaucoma groups. Venular diameter was significantly reduced in all glaucoma groups compared to normal controls (P<0.001), but no such change was observed in arteriolar diameter (P=0.10). When comparing between eyes of asymmetrical glaucoma severity, arteriolar oxygen saturation (P=0.03) and AV difference (P=0.04) were significantly higher, while arteriolar diameter was significantly lower (P=0.001) in the worse eye in PACG group. There were no significant differences in oximetric parameters or vessel calibers between the worse and the better eyes in POAG and NTG groups. Conclusion Eyes with PACG showed increased arteriolar oxygen saturation and increased AV difference. This was not observed in POAG and NTG eyes. Arteriolar diameter in PACG and venular diameter in all three glaucoma groups were reduced. The difference observed in PACG eyes may be due to an increased

  19. Mechanism of reduced glomerular filtration rate in chronic malnutrition.

    PubMed

    Ichikawa, I; Purkerson, M L; Klahr, S; Troy, J L; Martinez-Maldonado, M; Brenner, B M

    1980-05-01

    rats, we studied a third group of seven rats (group 3) allowed an ad lib. intake of the same high protein diet as given to group 2 rats. Average values for single nephron glomerular filtration rate and its determinants were found to be indistinguishable between groups 2 and 3. These results suggest that low protein intake, rather than calorie deficiency per se, is primarily responsible for the reduction in filtration rate seen in this experimental model of chronic malnutrition.

  20. Influence of external cake formation on optimization of crossflow filtration

    NASA Astrophysics Data System (ADS)

    Kuberkar, Vinod Trimbakrao

    The external foulant cake is an extremely important aspect of membrane filtration processes, influencing permeation rates of all species. This thesis work provides understanding of the mechanisms of formation and removal of the external cake, and of its influence on permeation rates. The prevention of formation of non-adhesive cakes using backpulsing was studied by solving the convection-diffusion equation for concentration polarization and depolarization during cyclic operation of forward filtration and reverse filtration. The theory predicted an optimum duration of the forward filtration which maximizes the net flux. Theoretical predictions showed very good agreement with experimental results for backpulsing of washed yeast suspensions. The removal of an adhesive cake was studied using filtration of bacterial suspensions with and without backpulsing. Due to the strong adhesive nature of the bacterial cake, the removal of the external cake is incomplete. A phenomenological model based on nonuniform cleaning of the membrane was proposed. The model contains an adjustable parameter termed the cleaning efficiency which provides measure of the removal of the adhesive cake. Though the model does not have fully predictive abilities, as the cleaning efficiency depends on the operating conditions, it provides important understanding of the underlying physical phenomena. During the filtration of a multicomponent mixture, the large particles form an external cake on the membrane, which then acts as a secondary membrane for other species in the mixture, affecting their permeation rates. This phenomenon was studied for a mixture of yeast and bovine serum albumin (BSA). In the absence of yeast, BSA aggregates block the membrane pores and eventually form an external fouling layer on the membrane surface, which prevents BSA monomers from access to the membrane pores. BSA transmission then drops to 25--40%. For filtration of a yeast-BSA mixture, yeast cells form the external cake

  1. Changes to the Aqueous Humor Proteome during Glaucoma

    PubMed Central

    Kaeslin, Martha Andrea; Killer, Hanspeter Ezriel; Fuhrer, Cyril Adrian; Zeleny, Nauke; Huber, Andreas Robert; Neutzner, Albert

    2016-01-01

    Purpose To investigate the aqueous humor proteome in patients with glaucoma and a control group. Method Aqueous humor was obtained from five human donors diagnosed with primary open angle glaucoma (POAG) and five age- and sex-matched controls undergoing cataract surgery. Quantitative proteome analysis of the aqueous humor by hyper reaction monitoring mass spectrometry (HRM-MS) based on SWATH technology was performed. Results Expression levels of 87 proteins were found to be different between glaucomatous and control aqueous humor. Of the 87 proteins, 34 were significantly upregulated, whereas 53 proteins were downregulated in the aqueous humor from glaucoma patients compared to controls. Differentially expressed proteins were found to be involved in cholesterol-related, inflammatory, metabolic, antioxidant as well as proteolysis-related processes. Conclusion Glaucoma leads to profound changes to the aqueous humor proteome consistent with an altered metabolic state, an inflammatory response and impaired antioxidant defense. PMID:27788204

  2. Glaucoma expert patient programme and ocular hypotensive treatment.

    PubMed

    Amro, Raed; Cox, Carol L; Waddington, Kathryn; Siriwardena, Dilani

    Expert patient programmes (EPPs) are becoming an increasingly important aspect of chronic disease management, resulting in improved health outcomes for patients. Patients with chronic open angle glaucoma (COAG) require lifelong therapy. However, to date, no EPPs have been designed specifically for patients with chronic eye conditions like COAG. This article describes the development and implementation of the Glaucoma Expert Patient Programme (GEPP), a glaucoma-specific educational self-management programme which aims to improve glaucoma patients' knowledge, self-management skills, expectations and adherence to treatment. A review of theoretical frameworks and models which underpin the design, use and conduct of EPPs was undertaken, and the GEPP was designed based on the model by Kate Lorig (2003). The result is an educational programme which offers COAG patients a different perspective on their condition and supports them with knowledge, skills and strategies to better manage their condition on a daily basis.

  3. What Animal Models Can Tell Us About Glaucoma.

    PubMed

    Struebing, Felix L; Geisert, Eldon E

    2015-01-01

    Well defined animal models facilitate the study of ocular diseases. Each model brings a unique perspective to the understanding of the disease process, and in some cases, the models are critical to the development of therapeutic approaches for treatments. This is especially the case for glaucoma. Glaucoma is a family of diseases that can be caused by very different biological processes. The one thing in common is the end result, the loss of retinal ganglion cells and blindness. In this review, we will attempt to relate the findings from a number of animal models to specific types of glaucoma, emphasizing the contributions that each of the models makes to our overall understanding of the complex collection of diseases we call glaucoma.

  4. Immune response against ocular tissues after immunization with optic nerve antigens in a model of autoimmune glaucoma

    PubMed Central

    Reinehr, Sabrina; Kuehn, Sandra; Laspas, Panagiotis; Gramlich, Oliver W.; Kuehn, Mathias; Tischoff, Iris; von Pein, Harald D.; Dick, H. Burkhard; Grus, Franz H.

    2013-01-01

    Purpose In recent years, numerous studies have investigated the involvement of immunological mechanisms in glaucoma. Until now, it has not been determined whether the altered antibody pattern detected in patients is harmful to retinal ganglion cells (RGCs) or triggers disease formation in any way. In a model of experimental autoimmune glaucoma, RGC loss can be induced through immunization with certain ocular antigens. In the current study, the time course of the levels of autoreactivity against ocular tissues after immunization was examined. Methods Intraocular pressure was measured regularly. Ten weeks after immunization with an optic nerve homogenate antigen (ONA), the number of RGCs was determined. Immunoglobulin G levels in aqueous humor were measured via enzyme-linked immunosorbent assay at the same time point. Serum from different time points was used to analyze the possible occurrence of autoreactive antibodies against the retina or optic nerve in this autoimmune glaucoma model. Additionally, optic nerve and brain sections were evaluated for possible pathological findings. Results Intraocular pressure stayed within the normal range throughout this study. A continuous increase of autoreactive antibodies against the optic nerve and retina sections was observed. At 4, 6, and 10 weeks, antibody reactivity was significantly higher in ONA animals (p<0.01). Aqueous humor immunoglobulin G levels were also significantly higher in the ONA group (p=0.006). Ten weeks after immunization, significantly fewer RGCs were noted in the ONA group (p=0.00003). The optic nerves from ONA animals exhibited damaged axons. No pathological findings appeared in any brain sections. Conclusions Our findings suggest that these modified antibodies play a substantial role in mechanisms leading to RGC death. The slow dissolution of RGCs observed in animals with autoimmune glaucoma is comparable to the slow progressive RGC loss in glaucoma patients, thus making this a useful model to develop

  5. Smoking and incidence of glaucoma: The SUN Cohort.

    PubMed

    Pérez-de-Arcelus, Mónica; Toledo, Estefanía; Martínez-González, Miguel Á; Martín-Calvo, Nerea; Fernández-Montero, Alejandro; Moreno-Montañés, Javier

    2017-01-01

    Smoking is a serious global public health concern that has been related to many chronic diseases. However, the effect of smoking on eye disorders has been less studied. The aim of this cohort study was to assess the association between current tobacco smokers and the risk of developing glaucoma and furthermore to evaluate the relationship between passive or former smokers and glaucoma.In this prospective and dynamic cohort, 16,797 participants initially who were found not to have glaucoma were followed up for a median of 8.5 years. Validated data on lifestyle, including tobacco consumption, were assessed at baseline. Information about new diagnosis of glaucoma was collected by follow-up questionnaires every 2 years. The outcome was the incidence of self-reported glaucoma during the follow-up. A subsample was used to validate the glaucoma diagnosis.During the 8.5 years of follow-up, 184 new glaucoma cases were identified. Current smokers had a significantly higher risk of glaucoma compared to participants who had never smoked after controlling for potential confounders (Hazard ratio [HR] 1.88 [95% coefficient interval (CI): 1.26-2.81]; P = 0.002). A nonsignificant increased risk was found among former smokers (HR 1.27 [95% CI: 0.88-1.82]; P = 0.198). When we assessed the exposure as per the number of cigarette pack-years, a dose-response relationship between pack-years and the risk of glaucoma was found (HR for the 5th quintile versus the 1st quintile: 1.70 [95% IC: 1.10-2.64], P for trend, 0.009). However, no relationship was found between passive smokers and glaucoma. (HR 0.67 [95% CI: 0.37-1.21]; P = 0.189).Our results suggest a direct association between current smokers and the incidence of glaucoma. In particular, this association was related to the number of pack-years, which was not found in the case of former smokers nor in the case of passive smokers.

  6. Videographic Assessment of Glaucoma Drop Instillation

    PubMed Central

    Castillejos, Armando; Kahook, Malik; Jimenez-Roman, Jesus; Gonzalez-Salinas, Roberto

    2015-01-01

    ABSTRACT Purpose: To assess the effect of patient education on videotaped topical instillation of artificial tear drops on subsequent topical instillation. Materials and methods: Forty-five patients, who had been using glaucoma drops for at least 6 months and with a best-corrected visual acuity of 20/100 or better, were studied. The patients were asked to instill an artificial tear drop using their accustomed technique while being video recorded. The patients viewed the recordings, and the errors in their drop instillation method were pointed out. This was followed by an educational session on proper drop instillation technique. After 30 minutes, patients were videotaped instilling drops to ascertain the effect of the educational session. The variables compared were: number of drops instilled, number of drops reaching the ocular surface, and the number of times the tip of the medication bottle touched the eye or ocular adnexa. Results: Before the instruction session, patients squeezed an average of 1.5 ± 0.9 drops from the bottle, and the average number of drops reaching the conjunctival fornix was 0.9 ± 0.7. The tip of the bottle touched the ocular adnexa in 29/45 (64.4%) patients. After the education session, the patients squeezed an average of 1.2 ± 0.5 drops and an average of 1.2 ± 0.4 drops reached the conjunctival fornix. The tip of the bottle touched the ocular adnexa in 13/45 (28.9%) patients. With proper instructions, the percentage of patients that instilled just one drop on the eye increased from 66 to 82%. Conclusion: A single educational session on the proper use of topical drops improves the successful instillation of eye drops. However, it was not determined whether the patients will retain the improved instillation technique for long-term or if the intervention results in only a short-term improvement. How to cite this article: Lazcano-Gomez G, Castillejos A, Kahook M, Jimenez-Roman J, Gonzalez-Salinas R. Video-graphic Assessment of Glaucoma

  7. Confocal scanning laser ophthalmoscopy in glaucoma diagnosis and management.

    PubMed

    Alexandrescu, C; Dascalu, A M; Panca, A; Sescioreanu, A; Mitulescu, C; Ciuluvica, R; Voinea, L; Celea, C

    2010-01-01

    The early diagnosis and detection of progression are two key-elements in the actual management of glaucoma. The current opinion in clinical practice is to quantify the structural damage for a better follow-up of the patient and the standardization of the results. The present review is a concise survey of literature covering the period of 1990-2010, documenting the evidence-based role of confocal scanning laser ophthalmoscopy in glaucoma diagnosis and management.

  8. Glaucoma Medication Adherence among African Americans: Program Development

    PubMed Central

    Dreer, Laura E.; Girkin, Christopher A.; Campbell, Lisa; Wood, Andy; Gao, Liyan; Owsley, Cynthia

    2014-01-01

    Purpose To elucidate barriers and facilitators related to glaucoma medication adherence among African Americans (AA) with glaucoma and to elicit input from a community-based participatory research team in order to guide the development of a culturally informed, health promotion program for improving glaucoma medication adherence among AA’s. Methods The nominal group technique (NGT), a highly structured focus group methodology, was implemented with 12 separate groups of AA’s patients with glaucoma (N = 89) to identify barriers and facilitators related to glaucoma medication usage. Participant rank-ordering votes were summed across groups and categorized into themes. Next, an individually and culturally targeted health promotion program promoting appropriate medication adherence was developed based on focus group results and input from a community-based participatory research team. Results The top five barriers included problems with 1) forgetfulness, 2) side effects, 3) cost/affordability, 4) eye drop administration, and 5) the eye drop schedule. The most salient top five facilitators were 1) fear or thoughts about the consequences of not taking eye drops, 2) use of memory aids, cues, or strategies, 3) maintaining a regular routine or schedule for eye drop administration, 4) ability to afford eye drops, and 5) keeping eye drops in the same area. The resulting health promotion program was based on a multi-component empowerment framework that included glaucoma education, motivational interviewing, and problem-solving training to improve glaucoma medication adherence. Conclusions Barriers and facilitators related to glaucoma medication adherence among AA’s are multifactorial. Based on the NGT themes and input from the community-based participatory research team, a culturally informed, health promotion program was designed and holds great promise for improving medication adherence among this vulnerable population. PMID:23873033

  9. The current research status of normal tension glaucoma

    PubMed Central

    Mi, Xue-Song; Yuan, Ti-Fei; So, Kwok-Fai

    2014-01-01

    Normal tension glaucoma (NTG) is a progressive optic neuropathy that mimics primary open-angle glaucoma, but lacks the findings of elevated intraocular pressure or other mitigating factors that can lead to optic neuropathy. The present review summarized the causes, genetics, and mechanisms underlying NTG in both animal models and human patients. We also proposed that the neurovascular unit is a therapeutic target for NTG management. PMID:25258525

  10. Clinical Use of OCT in Assessing Glaucoma Progression

    PubMed Central

    Kotowski, Jacek; Wollstein, Gadi; Folio, Lindsey S.; Ishikawa, Hiroshi; Schuman, Joel S.

    2012-01-01

    Detection of disease progression is an important and challenging component of glaucoma management. Optical coherence tomography (OCT) has proved to be valuable in the detection of glaucomatous damage. With its high resolution and proven measurement reproducibility, OCT has the potential to become an important tool for glaucoma progression detection. This manuscript presents the capabilities of the OCT technology pertinent for detection of progressive glaucomatous damage and provides a review of the current knowledge on the device’s clinical performance. PMID:21790113

  11. Neovascular glaucoma treatment with extraction of anterior chamber fibrovascular tissue.

    PubMed

    Nadal, Jeroni; Carreras, Elisa; Kudsieh, Bachar; Canut, Maribel

    2013-08-01

    The use of antibody to vascular endothelial growth factor to treat neovascular glaucoma yields good anatomic results in most cases. However, this type of glaucoma can cause angle closure with decompensation of intraocular pressure secondary to fibrovascular tissue contraction in the anterior chamber. Our surgical technique treats the cause by removing the anterior chamber fibrous complex after administration of antibody to vascular endothelial growth factor, thus restoring the chamber angle.

  12. Outcomes of Ahmed glaucoma valve implantation in advanced primary congenital glaucoma with previous surgical failure

    PubMed Central

    Huang, Jingjing; Lin, Jialiu; Wu, Ziqiang; Xu, Hongzhi; Zuo, Chengguo; Ge, Jian

    2015-01-01

    Purpose The purpose of this study was to evaluate the intermediate surgical results of Ahmed glaucoma valve (AGV) implantation in patients less than 7 years of age, with advanced primary congenital glaucoma who have failed previous surgeries. Patients and methods Consecutive patients with advanced primary congenital glaucoma that failed previous operations and had undergone subsequent AGV implantation were evaluated retrospectively. Surgical success was defined as 1) intraocular pressure (IOP) ≥6 and ≤21 mmHg; 2) IOP reduction of at least 30% relative to preoperative values; and 3) without the need for additional surgical intervention for IOP control, loss of light perception, or serious complications. Results Fourteen eyes of eleven patients were studied. Preoperatively, the average axial length was 27.71±1.52 (25.56–30.80) mm, corneal diameter was 14.71±1.07 (13.0–16.0) mm, cup-to-disc ratio was 0.95±0.04 (0.9–1.0), and IOP was 39.5±5.7 (30–55) mmHg. The mean follow-up time was 18.29±10.96 (5–44, median 18) months. There were significant reductions in IOPs and the number of glaucoma medications (P<0.001) postoperatively. The IOPs after operation were 11.3±3.4, 13.6±5.1, 16.3±2.7, and 16.1±2.6 mmHg at 1 month, 6 months, 12 months, and 18 months, respectively. Kaplan–Meier estimates of the cumulative probability of valve success were 85.7%, 71.4%, and 71.4% at 6, 12, and 18 months, respectively. Severe surgical complications, including erosion of tube, endophthalmitis, retinal detachment, choroidal detachment, and delayed suprachoroidal hemorrhage, occurred in 28.6% cases. Conclusion AGV implantation remains a viable option for patients with advanced primary congenital glaucoma unresponsive to previous surgical intervention, despite a relatively high incidence of severe surgical complications. PMID:26082610

  13. Custom RT-qPCR-array for glaucoma filtering surgery prognosis

    PubMed Central

    Soria, Javier; Suarez, Tatiana Maria; Acera, Arantxa

    2017-01-01

    Excessive subconjunctival scarring is the main reason of failure of glaucoma filtration surgery. We analyzed conjunctival and systemic gene expression patterns after non penetrating deep sclerectomy (NPDS). To find expression patterns related to surgical failure and their correlation with the clinical outcomes. This study consisted of two consecutive stages. The first was a prospective analysis of wound-healing gene expression profile of six patients after NPDS. Conjunctival samples and peripheral blood samples were collected before and 15, 90,180, and 360 days after surgery. In the second stage, we conducted a retrospective analysis correlating the late conjunctival gene expression and the outcome of the NPDS for 11 patients. We developed a RT-qPCR Array for 88 key genes associated to wound healing. RT-qPCR Array analysis of conjunctiva samples showed statistically significant differences in 29/88 genes in the early stages after surgery, 20/88 genes between 90 and 180 days after surgery, and only 2/88 genes one year after surgery. In the blood samples, the most important changes occurred in 12/88 genes in the first 15 days after surgery. Correspondence analyses (COA) revealed significant differences between the expression of 20/88 genes in patients with surgical success and failure one year after surgery. Different expression patterns of mediators of the bleb wound healing were identified. Examination of such patterns might be used in surgery prognosis. RT-qPCR Array provides a powerful tool for investigation of differential gene expression wound healing after glaucoma surgery. PMID:28358901

  14. Complementary and Alternate Management of Glaucoma: The Verdict so Far

    PubMed Central

    Ichhpujani, Parul

    2014-01-01

    ABSTRACT Complementary and alternative medicine deserves scientific scrutiny as patients with glaucoma often lose vision despite adequate medical or surgical treatment. Most glaucomatologists abstain from recommending alternative medicine as there is little evidence to support most of the recommendations for complementary and alternate management (CAM) use in glaucoma. Megavitamin supplementation has not been shown to have a long-term beneficial effect on glaucoma. In a glaucomatous eye, a very modest benefit of IOP-lowering may be offset by the temporary elevation in IOP that accompanies exercise. There is little evidence to support the use of special diets, acupuncture, relaxation techniques, or therapeutic touch for the treatment of glaucoma. Marijuana can have a profound lowering of IOP, but the low response rate, short half-life, and significant toxicity are strong indicators that it is not an appropriate therapeutic agent. Future research must be carried out to document the effect of CAM not only on IOP, but also on perimetric tests or other objective parameters, such as ocular blood fow and nerve fiber layer thickness. How to cite this article: Bhartiya S, Ichhpujani P. Complementary and Alternate Management of Glaucoma: The Verdict so Far. J Curr Glaucoma Pract 2014;8(2):54-57. PMID:26997809

  15. Glaucoma detection based on local binary patterns in fundus photographs

    NASA Astrophysics Data System (ADS)

    Alsheh Ali, Maya; Hurtut, Thomas; Faucon, Timothée.; Cheriet, Farida

    2014-03-01

    Glaucoma, a group of diseases that lead to optic neuropathy, is one of the most common reasons for blindness worldwide. Glaucoma rarely causes symptoms until the later stages of the disease. Early detection of glaucoma is very important to prevent visual loss since optic nerve damages cannot be reversed. To detect glaucoma, purely data-driven techniques have advantages, especially when the disease characteristics are complex and when precise image-based measurements are difficult to obtain. In this paper, we present our preliminary study for glaucoma detection using an automatic method based on local texture features extracted from fundus photographs. It implements the completed modeling of Local Binary Patterns to capture representative texture features from the whole image. A local region is represented by three operators: its central pixel (LBPC) and its local differences as two complementary components, the sign (which is the classical LBP) and the magnitude (LBPM). An image texture is finally described by both the distribution of LBP and the joint-distribution of LBPM and LBPC. Our images are then classified using a nearest-neighbor method with a leave-one-out validation strategy. On a sample set of 41 fundus images (13 glaucomatous, 28 non-glaucomatous), our method achieves 95:1% success rate with a specificity of 92:3% and a sensitivity of 96:4%. This study proposes a reproducible glaucoma detection process that could be used in a low-priced medical screening, thus avoiding the inter-experts variability issue.

  16. Presence and Risk Factors for Glaucoma in Patients with Diabetes

    PubMed Central

    Song, Brian J.; Aiello, Lloyd Paul; Pasquale, Louis R.

    2017-01-01

    Diabetes mellitus represents a growing international public health issue with a near quadrupling in its worldwide prevalence since 1980. Though it has many known microvascular complications, vision loss from diabetic retinopathy is one of the most devastating for affected individuals. In addition, there is increasing evidence to suggest that diabetic patients have a greater risk for glaucoma as well. Though the pathophysiology of glaucoma is not completely understood, both diabetes and glaucoma appear to share some common risk factors and pathophysiologic similarities with studies also reporting that the presence of diabetes and elevated fasting glucose levels are associated with elevated intraocular pressure – the primary risk factor for glaucomatous optic neuropathy. While no study has completely addressed the possibility of detection bias, most recent epidemiologic evidence suggests that diabetic populations are likely enriched with glaucoma patients. As the association between diabetes and glaucoma becomes better-defined, routine evaluation for glaucoma in diabetic patients, particularly in the telemedicine setting, may become a reasonable consideration to reduce the risk of vision loss in these patients. PMID:27766584

  17. Glaucoma progression detection using nonlocal Markov random field prior.

    PubMed

    Belghith, Akram; Bowd, Christopher; Medeiros, Felipe A; Balasubramanian, Madhusudhanan; Weinreb, Robert N; Zangwill, Linda M

    2014-10-01

    Glaucoma is neurodegenerative disease characterized by distinctive changes in the optic nerve head and visual field. Without treatment, glaucoma can lead to permanent blindness. Therefore, monitoring glaucoma progression is important to detect uncontrolled disease and the possible need for therapy advancement. In this context, three-dimensional (3-D) spectral domain optical coherence tomography (SD-OCT) has been commonly used in the diagnosis and management of glaucoma patients. We present a new framework for detection of glaucoma progression using 3-D SD-OCT images. In contrast to previous works that use the retinal nerve fiber layer thickness measurement provided by commercially available instruments, we consider the whole 3-D volume for change detection. To account for the spatial voxel dependency, we propose the use of the Markov random field (MRF) model as a prior for the change detection map. In order to improve the robustness of the proposed approach, a nonlocal strategy was adopted to define the MRF energy function. To accommodate the presence of false-positive detection, we used a fuzzy logic approach to classify a 3-D SD-OCT image into a "non-progressing" or "progressing" glaucoma class. We compared the diagnostic performance of the proposed framework to the existing methods of progression detection.

  18. Updates on the Surgical Management of Pediatric Glaucoma.

    PubMed

    Tan, Yar-Li; Chua, Jocelyn; Ho, Ching-Lin

    2016-01-01

    Childhood glaucoma is known to be one of the most challenging conditions to manage. Surgical management is more complicated than in adults because of differences in anatomy from adults along with variations in anatomy caused by congenital and developmental anomalies, wide-ranging pathogenetic mechanisms, a more aggressive healing response, and a less predictable postoperative course. Challenges in postoperative examination and management in less cooperative children and the longer life expectancies preempting the need for future surgeries and reinterventions are also contributing factors. Angle surgery is usually the first-line treatment in the surgical management of primary congenital glaucoma because it has a relatively good success rate with a low complication rate. After failed angle surgery or in cases of secondary pediatric glaucoma, options such as trabeculectomy, glaucoma drainage devices, or cyclodestructive procedures can be considered, depending on several factors such as the type of glaucoma, age of the patient, and the severity and prognosis of the disease. Various combinations of these techniques have also been studied, in particular combined trabeculotomy-trabeculectomy, which has been shown to be successful in patients with moderate-to-advanced disease. Newer nonpenetrating techniques, such as viscocanalostomy and deep sclerectomy, have been reported in some studies with variable results. Further studies are needed to evaluate these newer surgical techniques, including the use of modern minimally invasive glaucoma surgeries, in this special and diverse group of young patients.

  19. Incorporating corneal pachymetry into the management of glaucoma.

    PubMed

    Iester, Michele; Mete, Maurizio; Figus, Michele; Frezzotti, Paolo

    2009-09-01

    Intraocular pressure (IOP) results from a dynamic balance between aqueous humor formation and outflow. The simplest technique to measure IOP is indentation tonometry. Another technique is applanation. These methods are related to the elasticity of the eye, which mainly depends on its thickness and hysteresis. For several decades, Goldmann applanation tonometry has been the most accepted method of measuring IOP; the Goldmann tonometer is still used in all important trials. The relationship between IOP values and central corneal thickness (CCT) is well known; Goldmann stated that this relationship only holds for an average corneal thickness of 520 microm measured by optical pachymetry. The Ocular Hypertension Treatment Study (OHTS) showed that CCT is an important risk factor for a change from ocular hypertension to primary open-angle glaucoma. In a multivariate model that included IOP, CCT was the most powerful component of the predictive model. In the Early Manifest Glaucoma Trial (EMGT) with an 11-year follow-up, CCT was a significant predictive factor for glaucoma progression in patients with higher baseline IOP but not in those with lower baseline IOP. Clinical trials such as the OHTS and EMGT cannot prove that CCT is linked to a risk for glaucoma on a biological level. Thus, in eyes with glaucoma, IOP must be treated because it has a significant influence on progression of glaucoma, regardless of the baseline IOP and CCT.

  20. Glaucoma progression detection using nonlocal Markov random field prior

    PubMed Central

    Belghith, Akram; Bowd, Christopher; Medeiros, Felipe A.; Balasubramanian, Madhusudhanan; Weinreb, Robert N.; Zangwill, Linda M.

    2014-01-01

    Abstract. Glaucoma is neurodegenerative disease characterized by distinctive changes in the optic nerve head and visual field. Without treatment, glaucoma can lead to permanent blindness. Therefore, monitoring glaucoma progression is important to detect uncontrolled disease and the possible need for therapy advancement. In this context, three-dimensional (3-D) spectral domain optical coherence tomography (SD-OCT) has been commonly used in the diagnosis and management of glaucoma patients. We present a new framework for detection of glaucoma progression using 3-D SD-OCT images. In contrast to previous works that use the retinal nerve fiber layer thickness measurement provided by commercially available instruments, we consider the whole 3-D volume for change detection. To account for the spatial voxel dependency, we propose the use of the Markov random field (MRF) model as a prior for the change detection map. In order to improve the robustness of the proposed approach, a nonlocal strategy was adopted to define the MRF energy function. To accommodate the presence of false-positive detection, we used a fuzzy logic approach to classify a 3-D SD-OCT image into a “non-progressing” or “progressing” glaucoma class. We compared the diagnostic performance of the proposed framework to the existing methods of progression detection. PMID:26158069

  1. Citicoline: A Food Beneficial for Patients Suffering from or Threated with Glaucoma

    PubMed Central

    Grieb, Pawel; Jünemann, Anselm; Rekas, Marek; Rejdak, Robert

    2016-01-01

    Oral form of citicoline, a nootropic and neuroprotective drug in use for almost five decades, recently was pronounced a food supplement in both USA and EU. The idea of adding citicoline to topical treatment of primary open angle glaucoma (POAG) aimed at decreasing intraocular pressure (IOP) appeared as a logical consequence of accepting neurodegenerative character of this disease. Experimental data, and also few clinical studies indicate that this substance has potential to counteract some important pathological mechanisms which seem to contribute to POAG initiation and progression, such as excitotoxicity and oxidative stress. PMID:27092075

  2. Epigenetics and Signaling Pathways in Glaucoma

    PubMed Central

    2017-01-01

    Glaucoma is the most common cause of irreversible blindness worldwide. This neurodegenerative disease becomes more prevalent with aging, but predisposing genetic and environmental factors also contribute to increased risk. Emerging evidence now suggests that epigenetics may also be involved, which provides potential new therapeutic targets. These three factors work through several pathways, including TGF-β, MAP kinase, Rho kinase, BDNF, JNK, PI-3/Akt, PTEN, Bcl-2, Caspase, and Calcium-Calpain signaling. Together, these pathways result in the upregulation of proapoptotic gene expression, the downregulation of neuroprotective and prosurvival factors, and the generation of fibrosis at the trabecular meshwork, which may block aqueous humor drainage. Novel therapeutic agents targeting these pathway members have shown preliminary success in animal models and even human trials, demonstrating that they may eventually be used to preserve retinal neurons and vision. PMID:28210622

  3. 8. Detail view of southwest corner of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Detail view of southwest corner of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  4. 12. View west of access bridge to top of filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View west of access bridge to top of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  5. 11. View of east entry to central corridor of filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. View of east entry to central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  6. 32. Piping under central corridor of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. Piping under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  7. 1. Perspective view southwest of filtration bed with earth mounded ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Perspective view southwest of filtration bed with earth mounded over facility. Armory Street appears in the foreground. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  8. 4. View south of rear of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View south of rear of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  9. 14. View of damage to southeast corner of filtration building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. View of damage to southeast corner of filtration building. Note construction of concrete over brick. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  10. 31. Piping under central corridor of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. Piping under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  11. 13. View of west entrance to central corridor of filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. View of west entrance to central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  12. 7. View east of southeast corner of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View east of southeast corner of filtration bed building. Laboratory building is at center left of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  13. Submicrometre particle filtration with a dc activated plasma textile

    NASA Astrophysics Data System (ADS)

    Rasipuram, S. C.; Wu, M.; Kuznetsov, I. A.; Kuznetsov, A. V.; Levine, J. F.; Jasper, W. J.; Saveliev, A. V.

    2014-01-01

    Plasma textiles are novel fabrics incorporating the advantages of cold plasma and low-cost non-woven or woven textile fabrics. In plasma textiles, electrodes are integrated into the fabric, and a corona discharge is activated within and on the surface of the fabric by applying high voltages above 10 kV between the electrodes. When the plasma textile is activated, submicrometre particles approaching the textile are charged by the deposition of ions and electrons produced by the corona, and then collected by the textile material. A stable plasma discharge was experimentally verified on the surface of the textile that was locally smooth but not rigid. A filtration efficiency close to 100% was observed in experiments conducted on salt particles with diameters ranging from 50 to 300 nm. Unlike conventional fibrous filters, the plasma textile provided uniform filtration in this range, without exhibiting a maximum particle penetration size.

  14. Filtrating forms of soil bacteria

    NASA Astrophysics Data System (ADS)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  15. Membrane fouling in a membrane bioreactor: High filtration resistance of gel layer and its underlying mechanism.

    PubMed

    Chen, Jianrong; Zhang, Meijia; Li, Fengquan; Qian, Lei; Lin, Hongjun; Yang, Lining; Wu, Xilin; Zhou, Xiaoling; He, Yiming; Liao, Bao-Qiang

    2016-10-01

    A membrane bioreactor (MBR) was continuously operated to investigate mechanisms of fouling caused by the gel layer in this study. Agar was used as a model foulant for gel layer formation, and filtration resistance of gel layers was systematically assessed. The results showed that gel layer possessed unusually high specific filtration resistance (SFR) and high measured porosity as compared with cake layer. Current knowledge cannot explain the contradiction between high filtration resistance and high porosity of gel layer. A new fouling mechanism based on Flory-Huggins theory was then proposed. Filtration resistance of agar gel layer was found to be independent of pH and ionic strength, but linearly increase with gel thickness. The results are accordant with the mechanism deductions. Simulation of the mechanism model showed that the filtration resistance induced by mixing chemical potential variation was comparable to the experimental data of filtration resistance of agar gel layer, indicating that the proposed mechanism is the predominant mechanism responsible for the high filtration resistance of gel layer. The proposed mechanism was further verified from the bound water viewpoint.

  16. Gravity filtration of suspensions: permeability effects

    NASA Astrophysics Data System (ADS)

    Soori, Tejaswi; Wang, Mengyu; Ward, Thomas

    2015-11-01

    This paper examines the filtration rates of mono-modal suspensions as a function of time and a cake layer builds up through theory and experimentation. Darcy's Law, which describes fluid flow through porous media, was applied along with the Kynch theory of sedimentation, which provides the basis for analyzing low concentration (ϕ <=20%) cake formation. Experiments were performed to study the effects of varying particle sizes (45 μm <= d <= 1400 μm) and total solid concentration ϕ on both the formation rate of the cake layer and its flow permeability (k) in conjunction with the filter media. A CCD camera was used to capture images of the cake formation and fluid drainage processes, and subsequent image and theoretical analysis found the fluid flow experienced a constant pressure loss due to the permeability of the filter media, whereas the experienced pressure loss due to the cake formation varies as a function of time, ϕ and d. The rate of cake formation was also found to be independent of ϕ but dependent on d which can be attributed to a change in porosity affecting permeability. Studies on similar systems with multi-modal suspensions are in-progress.

  17. Filtration application from recycled expanded polystyrene.

    PubMed

    Shin, C

    2006-10-01

    Water-in-oil emulsion with drop size less than 100 mum is difficult to separate. Coalescence filtration is economical and effective for separation of secondary dispersions. Coalescence performance depends on flow rate, bed depth, fiber surface properties, and drop size. The amount of surface area of the fibers directly affects the efficiency. A new recycling method was investigated in the previous work in which polystyrene (PS) sub-mum fibers were electro-spun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. The experimental results in this work show that adding nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media but also increases the pressure drop. An optimum in the performance occurs (significant increase in efficiency with minimal increase in pressure drop) with the addition of about 4% by mass of 500 nm diameter PS nanofibers to glass fibers for the filters.

  18. Plankton filtration with compressible crumb rubber packs.

    PubMed

    Karanikola, Vasiliki; Ngo, Anh T; Valdes, Julio R

    2011-01-01

    The experiments described provide insight into the feasibility of using compressible particulate packs to filter live plankton. The pore constriction sizes are controlled by subjecting the filter pack to isotropic confinement, thereby allowing for: (1) enhanced filtration upon confinement and (2) enhanced unclogging upon relaxation. Results show that filtration efficiency increases with increasing confinement; however, complete plankton retention is difficult to attain due to the plankton's ability to pass through pore constrictions that are smaller than the plankton size. The results are anticipated to offer potential benefits to ballast treatment and aquatic filtration operations.

  19. Susceptibility to glaucoma damage related to age and connective tissue mutations in mice.

    PubMed

    Steinhart, Matthew R; Cone-Kimball, Elizabeth; Nguyen, Cathy; Nguyen, Thao D; Pease, Mary E; Chakravarti, Shukti; Oglesby, Ericka N; Quigley, Harry A

    2014-02-01

    The purpose of this research was to study the effects of age and genetic alterations in key connective tissue proteins on susceptibility to experimental glaucoma in mice. We used mice haploinsufficient in the elastin gene (EH) and mice without both alleles of the fibromodulin gene (FM KO) and their wild type (WT) littermates of B6 and CD1 strains, respectively. FM KO mice were tested at two ages: 2 months and 12 months. Intraocular pressure (IOP) was measured by Tonolab tonometer, axial lengths and widths measured by digital caliper post-enucleation, and chronic glaucoma damage was measured using a bead injection model and optic nerve axon counts. IOP in EH mice was not significantly different from WT, but FM KO were slightly lower than their controls (p = 0.04). Loss of retinal ganglion cell (RGC) axons was somewhat, but not significantly greater in young EH and younger or older FM KO strains than in age-matched controls (p = 0.48, 0.34, 0.20, respectively, multivariable regression adjusting for IOP exposure). Older CD1 mice lost significantly more RGC axons than younger CD1 (p = 0.01, multivariable regression). The CD1 mouse strain showed age-dependence of experimental glaucoma damage to RGC in the opposite, and more expected, direction than in B6 mice in which older mice are more resistant to damage. Genetic alteration in two genes that are constituents of sclera, fibromodulin and elastin do not significantly affect RGC loss.

  20. Neuroprotective effect of systemic and/or intravitreal rosuvastatin administration in rat glaucoma model

    PubMed Central

    Unlu, Metin; Aktas, Zeynep; Gocun, Pinar Uyar; Ilhan, Sevil Ozger; Hasanreisoglu, Murat; Hasanreisoglu, Berati

    2016-01-01

    AIM To evaluate the neuroprotective effect of rosuvastatin, in a rat experimental glaucoma model. METHODS Ocular hypertension was induced in right eyes of Long-Evans rats (n=30) by cauterization of three episcleral veins. Left eyes were defined as controls. Rats were divided into five groups: oral rosuvastatin, intravitreal rosuvastatin, oral+intravitreal rosuvastatin, intravitreal sham and glaucoma without intervention. Rats were sacrificed at day 14. Retinal ganglion cell (RGC) number was assessed by histopathological analysis. Terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling (TUNEL) staining and the expression of glial fibrillary acidic protein (GFAP) in RGC layer was also examined. RESULTS A significant intraocular pressure (IOP) elevation was seen (P=0.002). Elevated IOP resulted in a significant decrease in number of RGCs in group 5 (70.33±8.2 cells/mm2) when compared with controls (92.50±13.72 cells/mm2; P=0.03). The RGC number in group 1 (92.4±7.3 cells/mm2) was significantly higher than group 5 (P=0.03). The numbers of RGC in groups 2, 3 (57.3±8.2 cells/mm2, 60.5±12.9 cells/mm2) were comparable with that of group 5 (P=0.18 and P=0.31). The apoptosis rates with TUNEL staining were also parallel to RGC number. Animals with experimentally induced glaucoma showed an increase in retinal GFAP immunoreactivity. CONCLUSION Decrease in RGC loss and apoptosis suggest the neuroprotective potential of oral rosuvastatin treatment in a rat model of ocular hypertension. However intravitreal rosuvastatin showed a contrary effect and further studies are required. PMID:27158600

  1. Glaucoma and Driving: On-Road Driving Characteristics

    PubMed Central

    Wood, Joanne M.; Black, Alex A.; Mallon, Kerry; Thomas, Ravi; Owsley, Cynthia

    2016-01-01

    Purpose To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Methods Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Results Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Conclusions Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness. PMID:27472221

  2. Results of Trabectome Surgery Following Failed Glaucoma Tube Shunt Implantation

    PubMed Central

    Mosaed, Sameh; Chak, Garrick; Haider, Asghar; Lin, Ken Y.; Minckler, Don S.

    2015-01-01

    Abstract To evaluate the safety and efficacy of Trabectome after failed tube shunt surgery. Twenty patients with prior failed tube shunt surgery who underwent Trabectome alone were included. All patients had at least 3 months of follow-up. Outcomes measured included intraocular pressure (IOP), glaucoma medications, and secondary glaucoma surgeries. The success for Kaplan–Meier survival analysis is defined as IOP ≤21 mm Hg, IOP reduced by at least 20% from preoperative IOP, and no secondary glaucoma surgery. Mean preoperative IOP was 23.7 ± 6.4 mm Hg and mean number of glaucoma medications was 3.2 ± 1.5. At 12 months, IOP was reduced to 15.5 ± 3.2 mm Hg (P = 0.05) and number of medications was reduced to 2.4 ± 1.5 (P = 0.44). Survival rate at 12 months was 84% and 3 patients required additional glaucoma surgery with 15 patients reaching 12 months follow-up. Other than failure of IOP control and transient hypotony (IOP < 3 mm Hg) day 1 in 2 cases, there were no adverse events. Trabecular bypass procedures have traditionally been considered an approach appropriate for early-to-moderate glaucoma; however, our study indicates benefit in refractory glaucoma as well. Eyes that are prone to conjunctival scarring and hypertrophic wound healing, such as those who have failed tube shunt surgery, may benefit from procedures that avoid conjunctival incision such as Trabectome. This study indicates potential benefits in this patient population. Trabectome was safe and effective in reducing IOP at 1-year follow-up in patients with prior failed tube shunt surgery, but not effective in reducing medication reliance in these patients. PMID:26222842

  3. Defects of the Lamina Cribrosa in High Myopia and Glaucoma

    PubMed Central

    Miki, Atsuya; Ikuno, Yasushi; Asai, Tomoko; Usui, Shinich; Nishida, Kohji

    2015-01-01

    Purpose We evaluated the prevalence and characteristics of the defects of the lamina cribrosa (LC) in high myopia and glaucoma, and compared them with control eyes using swept-source optical coherence tomography (SS-OCT). Methods One hundred fifty-nine eyes of 108 participants were divided into four subgroups; high myopia with glaucoma (MG, 67 eyes of 46 subjects), glaucoma without high myopia (G, 22 eyes of 13 subjects), high myopia without glaucoma (M, 35 eyes of 29 subjects), and a control group with neither glaucoma nor high myopia (C, 35 eyes of 20 subjects). The LC defects were identified and located using a standardized protocol in serial horizontal OCT scans. The prevalence rates of the defects were compared among the groups. Demographic and ocular factors were compared between eyes with and without defects. Results LC defects were observed in one eye (0.03%) in the C group, 8 eyes (22.9%) in the M group, 11 eyes (50%) in the G group, and 28 eyes (41.8%) in the MG group. The prevalence rates of the defects differed significantly among the groups (P = 0.0009). Most eyes with defects in the G and MG groups (79.5%) had damage in the corresponding visual hemifields. Other factors such as visual acuity, intraocular pressure, axial length, refractive error, disc ovality, or parapapillary atrophy area did not differ significantly between eyes with and without LC defects. Conclusions High myopia and glaucoma significantly increased the risk of LC damage. The LC damage in non-glaucomatous highly myopic eyes may at least partly explain the increased risk of developing glaucoma in myopic eyes. PMID:26366870

  4. Mathematical analysis for internal filtration of convection-enhanced high-flux hemodialyzer.

    PubMed

    Lee, Jung Chan; Lee, Kyungsoo; Kim, Hee Chan

    2012-10-01

    Structural modifications using a conventional hemodialyzer improved the internal filtration and clearance of middle molecular weight wastes by enhanced convection effect. In this study, we employed a mathematical model describing the internal filtration rate as well as the hemodynamic and hematologic parameters in highflux dialyzer to interpret the previous reported experimental results. Conventional high-flux hemodialysis and convection-enhanced high-flux hemodialysis were configured in the mathematical forms and integrated into the iterative numerical method to predict the internal filtration phenomena inside the dialyzers during dialysis. The distributions of blood pressure, dialysate pressure, oncotic pressure, blood flow rates, dialysate flow rates, local ultrafiltration, hematocrit, protein concentration and blood viscosity along the axial length of dialyzer were calculated in order to estimate the internal filtration volume. The results show that the filtration volumes by internal filtration is two times higher in a convection-enhanced high-flux hemodialyzer than in a conventional high-flux hemodialzer and explains the experimental result of improved clearance of middle molecular size waste in convection-enhanced high-flux hemodialyzer.

  5. Coagulation-membrane filtration of Chlorella vulgaris.

    PubMed

    Lee, Duu-Jong; Liao, Guan-Yu; Chang, Yin-Ru; Chang, Jo-Shu

    2012-03-01

    Filtration-based separation of Chlorella vulgaris, a species with excellent potential for CO(2) capture and lipid production, was investigated using a surface-modified hydrophilic polytetrafluoroethylene (PTFE) membrane. Coagulation using polyaluminum chloride (PACl) attained maximum turbidity removal at 200 mg L(-1) as Al(2)O(3). The membrane filtration flux at 1 bar increased as the PACl dose increased, regardless of overdosing in the coagulation stage. The filtered cake at the end of filtration tests peaked in solid content at 10 mg L(-1) as Al(2)O(3), reaching 34% w/w, roughly two times that of the original suspension. Differential scanning calorimetry (DSC) tests demonstrate that the cake with minimum water-solid binding strength produced the driest filter cake. Coagulation using 10 mg L(-1) PACl as Al(2)O(3), followed by PTFE membrane filtration at 1 bar, is an effective process for harvesting C. vulgaris from algal froth.

  6. Filtration effects on ball bearing life and condition in a contaminated lubricant

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.; Moyer, D. W.

    1978-01-01

    Ball bearings were fatigue tested with a noncontaminated MIL-L-23699 lubricant and with a contaminated MIL-L-23699 lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3- and 30-micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49-micron bearings were statistically lower. The 105-micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

  7. Filtration effects on ball bearing life and condition in a contaminated lubricant

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.; Moyer, D. W.

    1978-01-01

    Ball bearings were fatigue tested with a noncontaminated lubricant and with a contaminated lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3 and 30 micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49 micron bearings were statistically lower. The 105 micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

  8. Filtration in coal liquefaction - Influence of filtration conditions in non-hydrogenated systems

    NASA Astrophysics Data System (ADS)

    Clarke, J. W.; Rantell, T. D.

    1980-01-01

    A series of experiments has been carried out to study the effects of filtration conditions upon the rate of filtration of non-hydrogenated coal digests. The results show the dependence of cake resistivity on both the filtration temperature and pressure. Filter cakes were found to be compressible, resulting in smaller increases in rate with increasing pressure than with incompressible cakes. The filtration temperature determines the packing of residual solids in the cake which in turn affects the cake resistivity. An empirical relation has been derived between filtration temperature and resistivity. With increasing temperature there is an increase in filtration rate due to the reduced viscosity, but a reduction owing to a higher packing density of solids in the filter cake.

  9. 36. JL photographer, summer 1978, general view of experimental ammonia ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. JL photographer, summer 1978, general view of experimental ammonia chlorine process equipment from ca 1930's at Baldwin Filtration Plant. - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  10. Filtration treatment of dairy processing wastewater.

    PubMed

    Samkutty, Pushpa J; Gough, Ronald H

    2002-01-01

    The effectiveness of various filtration agents in the primary treatment of dairy processing wastewater was investigated in laboratory-scale studies. The filtration agents used were: zeolite, crushed coral, charcoal, sand and crushed coral and sand and glass beads. The effectiveness of the filtration media was determined by testing parameters such as chemical oxygen demand (COD), total solids (TS) and total suspended solids (TSS) before and after filtration of wastewater. Percent reduction of the different parameters as a result of filtration was calculated. Sand combined with crushed coral or glass beads was found to be the most effective filtering medium with an average reduction of 99% in TSS, 93% in COD and 51% in TS. Charcoal filtration resulted in an average 85% reduction in TSS, 83% reduction in COD and 46% reduction in TS. Filtration using crushed coral resulted in an average 83% reduction in TSS, 78% reduction in COD and 39% reduction in TS. Zeolite was the least effective of the four media; it resulted in an average reduction of 78% in TSS, 76% in COD and 30% in TS. The differences among mean values of COD, TSS and TS after the different treatments were analyzed statistically using analysis of variance (ANOVA). When differences among means were found to be statistically significant (p < 0.0001), each mean value was compared with every other mean value using Duncan's multiple range test and least significant difference (LSD) test. Comparison of the mean values indicated the following: No significant difference between means of zeolite and crushed coral treatment. Mean values of COD, TSS, and TS of charcoal treatment were significantly different from the other treatments. Sand combined with crushed coral or glass beads was the most effective filtration agent and the means were significantly different from the means of the other treatments.

  11. Aortitis requiring aortic repair associated with glaucoma, thyroiditis, glaucoma, and neuropathy: case report

    PubMed Central

    2011-01-01

    Aortitis may be due to infectious and non-infectious causes. We observed aortitis, associated with glaucoma, thyroiditis, pericarditis, pleural effusion and neuropathy in a 63-years old woman. Despite antibiotic therapy, inflammatory signs persisted and resolved only after initiation of glucocorticoid therapy. Increasing aortic ectasia necessitated resection of the ascending aorta and implantation of a Vascutek 30 mm prosthesis. Histologically a granulomatous aortitis was diagnosed. Since all other possible causes were excluded, an immunological mechanism of the aortitis is suspected and possible triggering factors are discussed. PMID:21575249

  12. Evaluation of hyperbaric filtration for fine coal dewatering. Final report

    SciTech Connect

    Parekh, B.K.; Hogg, R.; Fonseca, A.

    1996-08-15

    The main objectives of the project were to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20% moisture. The program consisted of three phases, namely Phase 1 -- Model Development, Phase 2 -- Laboratory Studies, Phase 3 -- Pilot Plant Testing. The Pennsylvania State University led efforts in Phase 1, the University of Kentucky in Phase 2, and CONSOL Inc. in Phase 3 of the program. All three organizations were involved in all the three phases of the program. The Pennsylvania State University developed a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky conducted experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase 1 and 2 were tested in two of the CONSOL Inc. coal preparation plants using an Andritz Ruthner portable hyperbaric filtration unit.

  13. The filtration of colloidal gold nanoparticles with carbon nanotubes

    NASA Astrophysics Data System (ADS)

    de Jong, Frans Jan; Buffet, Adeline

    2016-11-01

    Understanding the local filtering of nanoparticles (NPs) is essential for the development and optimization of medical and industrial applications. Microfocus small-angle X-ray scattering (μSAXS) was used to determine the local filtration kinetics of 100 nm sized colloidal gold nanoparticles (Au NPs) within a multi-walled carbon nanotube (MWCNT) forest. To get a physical insight into the Au NP filtration process within the MWCNT forest a novel model based on the well-known DLVO theory was developed. The DLVO theory is commonly used to describe the interaction between colloidal particles. In addition to the attractive Van de Waals force and the electrostatic double-layer force, a non-DLVO force is added to account for hydration and hydrophobic effects. The model presented here shows that the Au NPs are mainly unfavorably deposited into the so-called secondary energy minimum. This latter finding is in good agreement with the experimental observations and the literature, in which unfavorable particle deposition is related to deposition into the secondary energy minimum. The use of μSAXS to get a physical insight into the local deposition kinetics of submicrometer particles opens up new pathways to optimize the preparation of MWCNT forests for filtration purposes.

  14. Glaucoma public service announcements: factors associated with follow-up of participants with risk factors for glaucoma

    PubMed Central

    Hoffelt, Zakary; Fallon, Shawn; Wong, Brad A.; Lucas, Betty; Coleman, Anne L.; Mills, Richard P.; Wilson, Richard; Mansberger, Steven L.

    2010-01-01

    Purpose To determine the prevalence of follow-up and factors associated with completing an eye exam after a glaucoma public service announcement. Design Cross-sectional observational study Participants Individuals who participated in the Glaucoma EyeCare Program by calling a toll-free telephone number and receiving referral by meeting inclusion criteria. Methods The Glaucoma EyeCare Program uses public service announcements to encourage those at increased risk for glaucoma to obtain an eye exam. The program requires interested persons to dial a toll-free telephone number to collect demographic, medical, and socioeconomic information, and refers those at higher risk of glaucoma to an ophthalmologist for a free eye exam. The ophthalmologist completes an outcome form, which indicates whether the participant obtained an eye exam, and the results of this eye exam. We determined the factors associated with obtaining an eye exam. Main Outcome Measures Sociodemographic characteristics associated with obtaining an eye exam after referral through the Glaucoma EyeCare Program Results Ophthalmologists returned outcome forms for 24% (1514/6343) of participants. Of those with outcome forms, 671 (44.3%) had an eye exam, 756 (49.9%) did not make an appointment, and 87 (5.7%) made an appointment but did not complete the exam. A multivariate logistic regression model showed younger age, female gender, lack of health insurance, medical history of diabetes, and shorter distance to be associated with obtaining an eye exam. Conclusion Public service announcements encourage participants to have an eye exam. Multiple factors alter the success of obtaining an eye exam. Future studies are needed regarding the best method of decreasing the risk of undiagnosed glaucoma. PMID:21439644

  15. [New concepts for pressure-controlled glaucoma implants].

    PubMed

    Allemann, R; Stachs, O; Falke, K; Schmidt, W; Siewert, S; Sternberg, K; Chichkov, B; Wree, A; Schmitz, K-P; Guthoff, R F

    2013-08-01

    In industrialized countries glaucoma is one of the most common causes that leads to blindness. It is also the most common cause of irreversible blindness worldwide. In addition to local treatment of intraocular pressure and filtering glaucoma surgery, alloplastic implants are increasingly being used in glaucoma therapy. As long-term results published in the literature of commonly used implants are unsatisfactory, it seems useful to search for new concepts. In order to avoid the well-known short-term and long-term postoperative complications a pressure-controlled microstent with antiproliferative surface modifications was developed. Additionally, the functionality of such a microstent should be investigated using an animal glaucoma model. This paper describes the concept of a microstent which drains aquous humour from the anterior chamber into the suprachoroidal space. In addition, the glaucoma models described in the literature are discussed. Unfortunately, none of the methods could be reproduced permanently. First results show a correct implantation of a coated microstent with valve where the anti-proliferative effect could be demonstrated histologically. The promising results should lead to further investigations and the final goal will be the testing of the stent in the human eye.

  16. Current Surgical Options for the Management of Pediatric Glaucoma

    PubMed Central

    Morales, Jose; Al Shahwan, Sami; Al Odhayb, Sami; Al Jadaan, Ibrahim; Edward, Deepak P.

    2013-01-01

    Currently, there are numerous choices for the treatment of pediatric glaucoma depending on the type of glaucoma, the age of the patient, and other particularities of the condition discussed in this review. Traditionally, goniotomy and trabeculotomy ab externo have been the preferred choices of treatment for congenital glaucoma, and a variety of adult procedures adapted to children have been utilized for other types of pediatric glaucoma with variable results and complications. More recently, seton implantations of different types have become more popular to use in children, and newer techniques have become available including visualized cannulation and opening of Schlemm's canal, deep sclerectomy, trabectome, and milder more directed cyclodestructive procedures such as endolaser and transcleral diode laser cyclophotocoagulation. This paper reviews the different surgical techniques currently available, their indications, results, and most common complications to allow the surgeon treating these conditions to make a more informed choice in each particular case. Although the outcome of surgical treatment in pediatric glaucoma has improved significantly, its treatment remains challenging. PMID:23738051

  17. Glaucoma: Focus on mitochondria in relation to pathogenesis and neuroprotection.

    PubMed

    Osborne, Neville N; Núñez-Álvarez, Claudia; Joglar, Belen; Del Olmo-Aguado, Susana

    2016-09-15

    Primary open-angle glaucoma (POAG) is a common form of glaucoma in which retinal ganglion cells (RGCs) die at varying intervals. Primary open-angle glaucoma is often associated with an increased intraocular pressure (IOP), which when reduced, can slow down the progression of the disease. However, it is essential to develop better modes of treatments for glaucoma patients. In this overview, we discuss the hypothesis that RGC mitochondria are affected during the initiation of POAG, by becoming gradually weakened, but at different rates because of their specific receptor profiles. With this in mind, we argue that neuroprotection in the context of glaucoma should focus on preserving RGC mitochondrial function and suggest a number of ways by which this can theoretically be achieved. Since POAG is a chronic disease, any neuroprotective treatment strategy must be tolerated over many years. Theoretically, topically applied substances should have the fewest side effects, but it is questionable whether sufficient compounds can reach RGC mitochondria to be effective. Therefore, other delivery procedures that might result in greater concentrations of neuroprotectants reaching RGC mitochondria are being developed. Red-light therapy represents another therapeutic alternative for enhancing RGC mitochondrial functions and has the advantage of being both non-toxic and non-invasive.

  18. Perimetry, tonometry and epidemiology: the fate of glaucoma management.

    PubMed

    Heijl, Anders

    2011-06-01

    This is the lecture that I gave when I was awarded Acta Ophthalmologica's gold medal and honorary award at the Nordic Ophthalmological Congress in Reykjavik in August 2010. I was inspired by Jared Diamond's famous book: Guns, Germs, and Steel, The Fates of Human Societies. Diamond is professor of geography and physiology at the University of California, Los Angeles. In this book, which won the Pulitzer Prize, the author explains why the European civilization took over the world. This was all because of predetermined factors of biological nature, environmental differences that were strengthened by feedback loops, and resulted in technological innovation and superiority. In this presentation, I write about the development of glaucoma knowledge and management. I suggest that the development might have been predetermined, just waiting for more facts to be unveiled by research. The technologies tonometry and perimetry have been fundamental as has epidemiological techniques and controlled trials. The new and increased knowledge about glaucoma must now be translated to improvements of clinical glaucoma care. The glaucoma scientists of today and tomorrow will continue to reveal as yet unknown facts, maybe in a predetermined way, but nevertheless of benefit to all patients with glaucoma.

  19. Psychophysical Analysis of Foveal Visual Losses in Glaucoma.

    NASA Astrophysics Data System (ADS)

    Pierce, Gilbert Eugene

    It has been suggested that glaucoma selectively damages large retinal ganglion cells. Quigley and others have shown anatomically that the larger retinal ganglion cells (M-cells) are destroyed, while the smaller retinal ganglion cells (P-cells) are relatively spared. However, others have shown, especially by measurements of color vision and color visual fields, that P-cells may also be damaged, often to a greater extent than M-cells. This study was done in an effort to determine which retinal ganglion cells are affected in glaucoma. Twenty-four glaucoma patients were tested using the color-mixture threshold technique of King-Smith. Spatial and temporal contrast sensitivity functions were also performed on each patient. It was found that red-green color vision losses were more common than achromatic visual losses (17 eyes vs. 8 eyes), suggesting that small cell losses may lead large cell losses. Correlation analyses showed that in general, eyes which had a large amount of damage to M-cells also had a large amount of damage to P-cells. We conclude that, at the fovea, P-cell damage in early glaucoma is at least as common as M-cell damage. It is hypothesized that while M-cells may be more readily destroyed than P-cells, the functional properties of P -cells at the fovea are diminished in glaucoma, possibly without their destruction.

  20. Tank-Binding Kinase 1 (TBK1) Gene and Open-Angle Glaucomas (An American Ophthalmological Society Thesis)

    PubMed Central

    Fingert, John H.; Robin, Alan L.; Scheetz, Todd E.; Kwon, Young H.; Liebmann, Jeffrey M.; Ritch, Robert; Alward, Wallace L.M.

    2016-01-01

    Purpose To investigate the role of TANK-binding kinase 1 (TBK1) gene copy-number variations (ie, gene duplications and triplications) in the pathophysiology of various open-angle glaucomas. Methods In previous studies, we discovered that copy-number variations in the TBK1 gene are associated with normal-tension glaucoma. Here, we investigated the prevalence of copy-number variations in cohorts of patients with other open-angle glaucomas—juvenile-onset open-angle glaucoma (n=30), pigmentary glaucoma (n=209), exfoliation glaucoma (n=225), and steroid-induced glaucoma (n=79)—using a quantitative polymerase chain reaction assay. Results No TBK1 gene copy-number variations were detected in patients with juvenile-onset open-angle glaucoma, pigmentary glaucoma, or steroid-induced glaucoma. A TBK1 gene duplication was detected in one (0.44%) of the 225 exfoliation glaucoma patients. Conclusions TBK1 gene copy-number variations (gene duplications and triplications) have been previously associated with normal-tension glaucoma. An exploration of other open-angle glaucomas detected a TBK1 copy-number variation in a patient with exfoliation glaucoma, which is the first example of a TBK1 mutation in a glaucoma patient with a diagnosis other than normal-tension glaucoma. A broader phenotypic range may be associated with TBK1 copy-number variations, although mutations in this gene are most often detected in patients with normal-tension glaucoma. PMID:27881886

  1. 5. View northeast of rear of filtration bed building. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View northeast of rear of filtration bed building. Note monitor roof with clerestory windows over central corridor between filtration beds at center right of photograph. Laboratory building is at extreme center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  2. 10. View west of east entry to filtration beds. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View west of east entry to filtration beds. Note monitor roof and clerestory windows over central corridor. Laboratory building is sited over the center of the filtration bed building at extreme left center of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  3. 6. Detail view northeast of rear of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail view northeast of rear of filtration bed building. Note monitor roof with clerestory windows over central corridor between filtration beds at center right of photograph. Laboratory building is at center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  4. Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries

    PubMed Central

    Masoumpour, Masoumeh B.; Nowroozzadeh, M. Hossein; Razeghinejad, M. Reza

    2016-01-01

    Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries. PMID:27014389

  5. African Descent and Glaucoma Evaluation Study (ADAGES)

    PubMed Central

    Girkin, Christopher A.; Sample, Pamela A.; Liebmann, Jeffrey M.; Jain, Sonia; Bowd, Christopher; Becerra, Lida M.; Medeiros, Felipe A.; Racette, Lyne; Dirkes, Keri A.; Weinreb, Robert N.; Zangwill, Linda M.

    2010-01-01

    Objective To define differences in optic disc, retinal nerve fiber layer, and macular structure between healthy participants of African (AD) and European descent (ED) using quantitative imaging techniques in the African Descent and Glaucoma Evaluation Study (ADAGES). Methods Reliable images were obtained using stereoscopic photography, confocal scanning laser ophthalmoscopy (Heidelberg retina tomography [HRT]), and optical coherence tomography (OCT) for 648 healthy subjects in ADAGES. Findings were compared and adjusted for age, optic disc area, and reference plane height where appropriate. Results The AD participants had significantly greater optic disc area on HRT (2.06 mm2; P<.001) and OCT (2.47 mm2; P<.001) and a deeper HRT cup depth than the ED group (P<.001). Retinal nerve fiber layer thickness was greater in the AD group except within the temporal region, where it was significantly thinner. Central macular thickness and volume were less in the AD group. Conclusions Most of the variations in optic nerve morphologic characteristics between the AD and ED groups are due to differences in disc area. However, differences remain in HRT cup depth, OCT macular thickness and volume, and OCT retinal nerve fiber layer thickness independent of these variables. These differences should be considered in the determination of disease status. PMID:20457974

  6. Flocculation, hydrophobic agglomeration and filtration of ultrafine coal

    NASA Astrophysics Data System (ADS)

    Yu, Zhimin

    In coal preparation plant circuits, fine coal particles are aggregated either by oil agglomeration or by flocculation. In a new hydrophobic agglomeration process, recently developed hydrophobic latices are utilized. While the selectivity of such aggregation processes determines the beneficiation results, the degree of aggregation has a strong effect on fine coal filtration. The aim of this research was to study the fundamentals and analyze the common grounds for these processes, including the potential effect of the coal surface properties. The selective flocculation tests, in which three types of coal, which differed widely in surface wettability, and three additives (hydrophobic latices, a semi-hydrophobic flocculant and a typical hydrophilic polyelectrolyte) were utilized, showed that coal wettability plays a very important role in selective flocculation. The abstraction of a hydrophobic latex on coal and silica revealed that the latex had a much higher affinity towards hydrophobic coal than to hydrophilic mineral matter. As a result, the UBC-1 hydrophobic latex flocculated only hydrophobic coal particles while the polyelectrolyte (PAM) flocculated all the tested coal samples and minerals, showing no selectivity in the fine coal beneficiation. The oil agglomeration was tested using kerosene emulsified with various surfactants (e.g. cationic, anionic and non-ionic). Surfactants enhance not only oil emulsification, hence reducing oil consumption (down to 0.25--0.5%), but also entirely change the electrokinetic properties of the droplets and affect the interaction energy between oil droplets and coal particles. Consequently, the results found in the course of the experimental work strongly indicate that even oxidized coals can be agglomerated if cationic surfactants are used to emulsify the oil. Oil agglomeration of the Ford-4 ultrafine coal showed that even at extremely low oil consumption (0.25 to 0.5%), a clean coal product with an ash content around 5% at over

  7. Spontaneous malignant glaucoma in a patient with patent peripheral iridotomy

    PubMed Central

    2012-01-01

    Background To report a case of spontaneous malignant glaucoma in an Asian female. To propose the term “positive vitreous pressure glaucoma” to reflect the pathophysiology, treatment and prognosis of the condition. Case presentation A 56-year old Chinese female was diagnosed of primary angle closure glaucoma and had bilateral laser peripheral iridotomy one year ago. She presented with spontaneous onset of malignant glaucoma involving the left eye. The condition was treated successfully; the final best corrected visual acuity was 0.67 (decimal notation). Conclusion This case highlights that acute angle closure attack can occur in an eye with patent peripheral iridotomy. Early recognition and treatment is essential for good visual prognosis. PMID:23241197

  8. Surgical Management in a Patient With Complex Uveitic Glaucoma

    PubMed Central

    Huang, Zhu; Wang, Xiao-Yu; Han, Wei

    2015-01-01

    Abstract Uveitic glaucoma (UG) is secondary glaucoma, present as a clinical challenge in both diagnosis and management. We report a case of complex UG, which initially presented as pupillary block and rupture of the anterior lens capsule. We performed cataract extraction with preservation of posterior capsule. Then, the case turned to aphakic malignant glaucoma. We performed anterior vitrectomy with posterior capsule resection in this case. After the second operation, the patient had a satisfactory recovery. Specifically, ultrasonographic biomicroscopy was useful during the diagnosis process and follow-up period in this case. UG presenting as pupillary block, rupture of the anterior lens capsule, and aqueous misdirection seldom presents in clinical practice. Earlier and more active surgical intervention may be necessary for effective preservation of visual function in complex cases of UG. PMID:26252285

  9. Neovascular glaucoma after helium ion irradiation for uveal melanoma

    SciTech Connect

    Kim, M.K.; Char, D.H.; Castro, J.L.; Saunders, W.M.; Chen, G.T.; Stone, R.D.

    1986-02-01

    Neovascular glaucoma developed in 22 of 169 uveal melanoma patients treated with helium ion irradiation. Most patients had large melanomas; no eyes containing small melanomas developed anterior segment neovascularization. The mean onset of glaucoma was 14.1 months (range, 7-31 months). The incidence of anterior segment neovascularization increased with radiation dosage; there was an approximately three-fold increase at 80 GyE versus 60 GyE of helium ion radiation (23% vs. 8.5%) (P less than 0.05). Neovascular glaucoma occurred more commonly in larger tumors; the incidence was not affected by tumor location, presence of subretinal fluid, nor rate of tumor regression. Fifty-three percent of patients had some response with intraocular pressures of 21 mmHg or less to a combination of antiglaucoma treatments.

  10. [Focus on the ethics problem in glaucoma management].

    PubMed

    Zhang, Chun; Shi, Yan; Zhang, Yu; Huang, Ping

    2015-02-01

    Due to the different goals of current glaucoma treatments, various treatment methods have their pros and cons. Therefore, their applications are affected by factors inside and outside medical category, thus prone to a series of problems.In clinical practice, in addition to following the related clinical guidelines and standards, medical ethics problems must be considered. And besides, based on the principles of nonmaleficence, beneficence, respect and justice in medical ethics, the treatments should be carefully selected to weigh the advantages and disadvantages to the patients.Only in this way, the efficacy and safety of glaucoma treatment can be improved, and the medical and social missions of glaucoma specialists can be more reasonably completed.

  11. [The Origin of the Disorder Named "Ryoku-naisho (Glaucoma)"].

    PubMed

    Tanihara, Hidenoba; Abe, Ikuko

    2016-05-01

    It is said that the description of an ocular disorder related to the color of the sea in the Hippocratic Corpus is the oldest medical reference to glaucoma. In the early Edo period in Japan, the Books of Secrets of the Majima school, describe a disorder called aosokohi. This nomenclature is believed to be based upon the Five Elements' Theory (Wu-Xing Thought)in ancient China, which assigned five colors for intraocular disorders ("naisho/sokohi" in Japanese), blue ("ao" in Japanese), red, yellow, white and black. In Japanese literature, in late Edo period, "ryokunaisho (glaucoma)" appeared after the publication of Dutch-Japanese translation by Dutch scholars. The Japanese name is thought to derive trom "Glaukos" which means green in ancient Greek. Since the Meiji period, "ryoku-naisho (glaucoma)" has been used inmost textbooks including those by foreign teachers and the works of Jujiro Komoto, the first Professor at the Department of Ophthalmology of (Tokyo)Imperial University.

  12. One Year of Glaucoma Research in Review: 2013 to 2014

    PubMed Central

    Van Tassel, Sarah H.; Radcliffe, Nathan M.; Demetriades, Anna M.

    2015-01-01

    Purpose The purpose of this study was to provide the practicing clinical ophthalmologist with an update of relevant glaucoma literature published from 2013 to 2014. Design Literature review. Methods The authors conducted a 1-year (October 1, 2013, to September 30, 2014) English-language glaucoma literature search on PubMed of articles containing “glaucoma” or “glaucomatous” with title/abstract as a filter. Medical Subject Headings (MeSH) filtered searching was not performed because of the newness of the reviewed material. Results Literature review yielded 2,314 articles, after which we excluded reviews and letters to the editor. We highlighted articles featuring new or updated approaches to the pathophysiology, diagnosis, or treatment of glaucoma and gave preference to human research. Conclusions This review features literature that is of interest to ophthalmologists in practice and also highlights studies that may provide insight to future developments applicable to clinical ophthalmology. PMID:26197218

  13. Environmental Technology Verification--Baghouse Filtration Products: GE Energy QG061 Filtration Media (Tested September 2008)

    EPA Science Inventory

    This report reviews the filtration and pressure drop performance of GE Energy's QG061 filtration media. Environmental Technology Verification (ETV) testing of this technology/product was conducted during a series of tests in September 2008. The objective of the ETV Program is to ...

  14. COMPARATIVE EVALUATION OF R3f GARNET BEAD FILTRATION AND MULTIMEDIA FILTRATION SYSTEMS; FINAL REPORT

    EPA Science Inventory

    This report summarizes the results of tests conducted to date at the EPA T&E Facility on the R3f filtration system utilizing fine beads (such as garnet beads or glass beads) and a conventional multimedia filtration system. Both systems have been designed and built by Enprotec, a...

  15. The role of the immune system in conjunctival wound healing after glaucoma surgery.

    PubMed

    Chang, L; Crowston, J G; Cordeiro, M F; Akbar, A N; Khaw, P T

    2000-01-01

    The immune system has a fundamental role in the development and regulation of ocular healing, which plays an important role in the pathogenesis of most blinding diseases. This review discusses the mechanisms of normal wound healing, describing the animal and fetal wound healing models used to provide further insight into normal wound repair. In particular, conjunctival wound repair after glaucoma filtration surgery will be used to illustrate the contributions that the different components of the immune system make to the healing process. The potential role of macrophages, the possible regulatory effect of lymphocytes, and the important role of growth factors and cytokines in the wound healing reaction are discussed. The significance of the immune system in the pathogenesis of aggressive conjunctival scarring is addressed, particularly assessing the predisposing factors, including drugs, age, and ethnicity. The rationale behind the pharmacological agents currently used to modulate the wound healing response and the effects these drugs have on the function of the immune system are described. Finally, potential new therapeutic approaches to regulating the wound healing response are reported.

  16. Evaluation of Central and Peripheral Visual Field Concordance in Glaucoma

    PubMed Central

    Odden, Jamie L.; Mihailovic, Aleksandra; Boland, Michael V.; Friedman, David S.; West, Sheila K.; Ramulu, Pradeep Y.

    2016-01-01

    Purpose The purpose of this study was to characterize the extent to which central visual field (VF) loss reflects peripheral VF loss in patients with varying degrees of glaucoma severity. Methods A total of 232 patients with glaucoma or suspect glaucoma completed static central VF testing using the 24-2 pattern and peripheral VF testing using the suprathreshold 30-60 pattern. Points from 24-2 tests were reclassified as normal/abnormal based on pattern deviation values. Results Strong positive correlations (r ≥ 0.7) were observed between the proportion of abnormal central and peripheral points for the full VF, superior hemifield, and inferior hemifield, although the percentage of total central and peripheral abnormal points differed by ≥10% in 45% of eyes. In eyes with an average of 10%–40% abnormal points in the central and peripheral VFs, 12.0% more abnormal peripheral points were noted compared with the percentage of abnormal central points (P < 0.001; SD, 16.7%; range, 61% more to 37% less). In eyes with an average of 60%–90% abnormal points in the central and peripheral VFs, 16.4% fewer abnormal peripheral points were noted compared with the percentage of abnormal central points (P = 0.04; SD, 20.9%; range, 19% more to 49% less). Conclusions Central 24-2 testing generally reflects the extent of damage to the more peripheral VF in glaucoma, although significant disagreement exists for individual eyes. Further work is needed to determine whether integration of peripheral test points can improve detection of true VF loss in early glaucoma or be useful in monitoring progressive glaucomatous damage to areas of preserved VF in advanced glaucoma. PMID:27214688

  17. Glaucoma associated with iridocorneal endothelial syndrome in 203 Indian subjects

    PubMed Central

    Chandran, Premanand; Rao, Harsha L.; Mandal, Anil K.; Choudhari, Nikhil S.; Garudadri, Chandra S.; Senthil, Sirisha

    2017-01-01

    Purpose To report the demographic profile, clinical features, and prevalence of glaucoma and its management in patients with Iridocorneal endothelial (ICE) syndrome. Methods Retrospective review of 203 consecutive subjects with ICE syndrome at a tertiary eye care centre between January 1988 and June 2013. Results ICE syndrome was present in 223 eyes of 203 subjects, 124 (61%) were female and 79 (39%) were male. The median age at presentation was 43 years (1st (Q1) and 3rd (Q3) quartile; 34, 51 years). ICE syndrome was unilateral in 183 (90%) subjects, and bilateral in 20 (10%) subjects. The most common clinical variant was progressive iris atrophy (PIA, 115; 52% eyes), followed by Chandler syndrome (CS, 87; 39% eyes) and Cogan-Reese syndrome (CRS, 21; 9% eyes). Glaucoma was found in 156 eyes (70%) at presentation and the median (Q1, Q3) intraocular pressure in eyes with glaucoma was 24 (16, 38) mm Hg. Seven eyes developed glaucoma during the follow-up period, increasing the percentage of eyes with glaucoma to 73%. Intraocular pressure was managed medically in 81 eyes (50%) and the other 82 eyes (50%) required surgical intervention. Corneal edema was present in 124 eyes (56%) of which, 32 eyes (14%) required keratoplasty. Conclusions In our study on ICE syndrome in Indian population, the presentation was predominantly uniocular and more common in middle aged women. Progressive iris atrophy was the most common clinical variant. ICE syndrome was associated with glaucoma in over 70% of the eyes and half of the eyes had corneal edema. PMID:28282413

  18. Spectral Domain Optical Coherence Tomography for Glaucoma (An AOS Thesis)

    PubMed Central

    Schuman, Joel S.

    2008-01-01

    Purpose Optical coherence tomography (OCT) is a rapidly evolving, robust technology that has profoundly changed the practice of ophthalmology. Spectral domain OCT (SD-OCT) increases axial resolution 2- to 3-fold and scan speed 60- to 110-fold vs time domain OCT (TD-OCT). SD-OCT enables novel scanning, denser sampling, and 3-dimensional imaging. This thesis tests my hypothesis that SD-OCT improves reproducibility, sensitivity, and specificity for glaucoma detection. Methods OCT progress is reviewed from invention onward, and future development is discussed. To test the hypothesis, TD-OCT and SD-OCT reproducibility and glaucoma discrimination are evaluated. Forty-one eyes of 21 subjects (SD-OCT) and 21 eyes of 21 subjects (TD-OCT) are studied to test retinal nerve fiber layer (RNFL) thickness measurement reproducibility. Forty eyes of 20 subjects (SD-OCT) and 21 eyes of 21 subjects (TD-OCT) are investigated to test macular parameter reproducibility. For both TD-OCT and SD-OCT, 83 eyes of 83 subjects are assessed to evaluate RNFL thickness and 74 eyes of 74 subjects to evaluate macular glaucoma discrimination. Results Compared to conventional TD-OCT, SD-OCT had statistically significantly better reproducibility in most sectoral macular thickness and peripapillary RNFL sectoral measurements. There was no statistically significant difference in overall mean macular or RNFL reproducibility, or between TD-OCT and SD-OCT glaucoma discrimination. Surprisingly, TD-OCT macular RNFL thickness showed glaucoma discrimination superior to SD-OCT. Conclusions At its current development state, SD-OCT shows better reproducibility than TD-OCT, but glaucoma discrimination is similar for TD-OCT and SD-OCT. Technological improvements are likely to enhance SD-OCT reproducibility, sensitivity, specificity, and utility, but these will require additional development. PMID:19277249

  19. Dynamic filtration of invert-emulsion muds

    SciTech Connect

    Jiao, D.; Sharma, M.M. )

    1993-09-01

    Dynamic-filtration experiments conducted on oil-based muds show that the dynamic-filtration rate is much higher than API filtration rates. The use of water-wet solids results in very poor-quality external mudcakes and high fluid-loss rates. Better external mudcakes are formed by mixing equal parts organophilic clay and mud. Filtration-loss-control additives (asphalt mineral pitches) do not reduce the equilibrium filtration rate, but do reduce spurt loss and limit solids invasion. In brine-saturated rocks, the invasion rate for oil-based muds is significantly smaller than for water-based muds because capillary pressure prevents the oil phase from entering the core in oil-based muds. Oil-based mudcakes are softer and more shear-sensitive than water-based mudcakes. Scanning electron microscope (SEM) photomicrographs indicate that oil-based mudcakes consist of individual water droplets coated with clay particles. This cake structure gives rise to the low permeability and shear sensitivity of oil-based muds.

  20. Glaucoma--diabetes of the brain: a radical hypothesis about its nature and pathogenesis.

    PubMed

    Faiq, Muneeb A; Dada, Rima; Saluja, Daman; Dada, Tanuj

    2014-05-01

    Glaucoma is the leading cause of irreversible blindness characterized by irremediable loss of retinal ganglion cells. Its risk increases with progressing age and elevated intraocular pressure. Studies have established that glaucoma is a neurodegenerative disorder in which the damage involves many brain tissues from retina to the lateral geniculate nucleus. Despite lot of research, complete pathomechanism of glaucoma is not known and there is no treatment available except modification of intraocular pressure pharmacologically and/or surgically. We here present a hypothesis inspired by studies across many areas of molecular and clinical sciences in an integrative manner that leads to a uniquely unconventional understanding of this disorder. Our hypothesis postulates that glaucoma may possibly be the diabetes of the brain. Based on the remarkable similarities between glaucoma and diabetes we propose glaucoma also to be a type of diabetes. Glaucoma and diabetes share many aspects from various molecular mechanisms to involvement of insulin and possible use of antidiabetics in glaucoma therapy. Additionally, Alzheimer's disease has already been proposed to be diabetes type-3. We show that Alzheimer's disease is cerebral glaucoma and diabetes at the same time which, by transitive property of similarities, again leads to our hypothesis that glaucoma is diabetes of the brain. Our proposition may lead to appreciation of certain important facets of glaucoma which have previously not been given due consideration. It also may lead to an alternative classification of diabetes as pancreatic and brain diabetes thereby widening the vision arena of the understanding of both these disorders.

  1. A review of primary congenital glaucoma in the developing world.

    PubMed

    Moore, Daniel B; Tomkins, Oren; Ben-Zion, Itay

    2013-01-01

    Primary congenital glaucoma is the most common type of infantile glaucoma, yet it remains a relatively rare disease. Treatment is principally surgical, and management lasts a lifetime. In the developing world, delayed diagnosis, limited treatment, and inadequate follow-up lead to a heavier burden on the patient and community. We highlight the epidemiology and genetics of the disease, its current management and prognosis, and the limitations facing both providers and patients in the developing world. Further efforts are necessary to provide effective, timely screening of children and allocate adequate resources to allow health care workers to reduce the rate of avoidable blindness in developing countries.

  2. Ocular surface changes in glaucoma patients related to topical medications.

    PubMed

    Kovačević, Suzana; Čanović, Samir; Pavičić, Ana Didović; Kolega, Marija Škara; Bašić, Jadranka Katušić

    2015-03-01

    Topical glaucoma therapy is a long termed, usually lifelong. Antiglaucomatous drugs have toxic effects on ocular surface, due to preservative toxicitiy or the drug itself. Adding a lubricant eyedrops to antiglaucomatous therapy, especially if considering the preservative used, can have protective effect. The purpose of this study was to evaluate the stabilty of precorneal tear film in glaucoma patient prior and after administration of lubricant eye drops with different tipe of preservatives. The study showed the protective role of ocular surface lubrication especially when using drugs with less harmful preservatives.

  3. Glaucoma in Fuchs' heterochromic cyclitis associated with congenital Horner's syndrome.

    PubMed

    Regenbogen, L S; Naveh-Floman, N

    1987-11-01

    We report a retrospective study of five patients with monocular Fuchs' heterochromic cyclitis associated with an ipsilateral Horner's syndrome. The minimum follow-up was 10 years. The presenting findings were cyclitis in three of the patients and heterochromia iridis associated with blepharoptosis in the other two. The major factors affecting all five patients were cataract and glaucoma. The intraocular pressure was uncontrolled even with maximal therapy, and antiglaucomatous surgery was performed in all cases. A short period of good postoperative control was followed by an intractable ocular hypertension, causing loss of useful vision in all patients. The remarkable combination of Horner's syndrome with glaucoma and their interaction is discussed.

  4. Systematic Review of Educational Interventions to Improve Glaucoma Medication Adherence: an update in 2015

    PubMed Central

    Newman-Casey, Paula Anne; Dayno, Megan; Robin, Alan L.

    2016-01-01

    Purpose To evaluate the current state of the research on educational interventions whose aim is to improve glaucoma medication adherence. Methods A systematic review of Pubmed, Embase and CINAHL was conducted to identify research studies evaluating educational interventions to improve glaucoma medication adherence. Studies were included if the intervention was described, the outcomes assessed glaucoma medication adherence, and the focus of the research was on adults with glaucoma. The search was conducted on June 2, 2015. Results Seventeen studies were identified that met the inclusion criteria. These included nine randomized controlled trials and eight observational studies. Eight of the studies demonstrated an impact on glaucoma medication adherence, though their outcome measures were too heterogeneous to estimate a pooled effect size.. Conclusion The interventions that successfully improved glaucoma medication adherence used an adequate dose of face-to-face counseling to overcome barriers to health behavior change alongside education about glaucoma. PMID:27134639

  5. Factors influencing the precoat filtration of boiling water reactor water streams

    SciTech Connect

    Hermansson, H.P. ); Persson, G. ); Reinvall, A. )

    1994-10-01

    A series of studies on precoat filtration were carried out on condensate and preheater drains in the Swedish and Finnish boiling water reactors (BWRs). The goal was to increase knowledge about the precoat filtration process and to find physical and chemical means to improve the performance of the precoat filters in the condensate polishing plants. To achieve this goal a number of parameters, such as type of resin, bed depth, pH, oxygen and organic contaminant concentrations (measured total organic carbon), and corrosion product particle characteristics, were selected for the study. The work was mainly carried out in the power plants using an experimental facility fed with on-line sampled condensates and drains taken from the plant sampling lines. The main results are that there is a varying influence on precoat filtration from all the aforementioned parameters. The oxygen concentration, the concentration of organic contaminants, and the type of corrosion products are, however, the factors that have the strongest influence within the parameter ranges that are representative for BWR operation. The results are rather similar when the different units are compared. There are, however, some differences that could be mainly attributed to deviations in operation parameters and the subsequent differences in the corrosion product spectra. The mechanism for precoat filtration of corrosion products in BWR condensate is complex. The filtration behavior is to a large extent governed by competition between depth filtration and electrostatic interactions. During the early stages of the filtration cycle, electrostatic interaction is of great importance, whereas depth filtration becomes more important with increasing operating time. Rapid pressure drop buildup rates have been demonstrated to be caused by the presence of amorphous corrosion products. An effect from the presence of organic contaminants has been found, although this should be of little significance.

  6. Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model.

    PubMed

    Danias, John; Shen, Fran; Kavalarakis, Manolis; Chen, Bin; Goldblum, David; Lee, Kevin; Zamora, Maria-Florencia; Su, YanLing; Brodie, Scott E; Podos, Steven M; Mittag, Thom

    2006-02-01

    Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains. IOP was raised in one eye of Wistar (N = 5) and Brown-Norway(B-N)(N = 7) rats by EVC and monitored monthly until IOP in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats (N = 7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined. Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. The group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but 1 of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs than contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared to contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (> 30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones. The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP

  7. Using Eye Tracking to Assess Reading Performance in Patients with Glaucoma: A Within-Person Study

    PubMed Central

    Smith, Nicholas D.; Glen, Fiona C.; Mönter, Vera M.; Crabb, David P.

    2014-01-01

    Reading is often cited as a demanding task for patients with glaucomatous visual field (VF) loss, yet reading speed varies widely between patients and does not appear to be predicted by standard visual function measures. This within-person study aimed to investigate reading duration and eye movements when reading short passages of text in a patient's worse eye (most VF damage) when compared to their better eye (least VF damage). Reading duration and saccade rate were significantly different on average in the worse eye when compared to the better eye (P < 0.001) in 14 patients with glaucoma that had median (interquartile range) between-eye difference in mean deviation (MD; a standard clinical measure for VF loss) of 9.8 (8.3 to 14.8) dB; differences were not related to the size of the difference in MD between eyes. Patients with a more pronounced effect of longer reading duration on their worse eye made a larger proportion of “regressions” (backward saccades) and “unknown” EMs (not adhering to expected reading patterns) when reading with the worse eye when compared to the better eye. A between-eye study in patients with asymmetric disease, coupled with eye tracking, provides a useful experimental design for exploring reading performance in glaucoma. PMID:24883203

  8. Maize genome sequencing by methylation filtration.

    PubMed

    Palmer, Lance E; Rabinowicz, Pablo D; O'Shaughnessy, Andrew L; Balija, Vivekanand S; Nascimento, Lidia U; Dike, Sujit; de la Bastide, Melissa; Martienssen, Robert A; McCombie, W Richard

    2003-12-19

    Gene enrichment strategies offer an alternative to sequencing large and repetitive genomes such as that of maize. We report the generation and analysis of nearly 100,000 undermethylated (or methylation filtration) maize sequences. Comparison with the rice genome reveals that methylation filtration results in a more comprehensive representation of maize genes than those that result from expressed sequence tags or transposon insertion sites sequences. About 7% of the repetitive DNA is unmethylated and thus selected in our libraries, but potentially active transposons and unmethylated organelle genomes can be identified. Reverse transcription polymerase chain reaction can be used to finish the maize transcriptome.

  9. Quantifying oil filtration effects on bearing life

    NASA Technical Reports Server (NTRS)

    Needelman, William M.; Zaretsky, Erwin V.

    1991-01-01

    Rolling-element bearing life is influenced by the number, size, and material properties of particles entering the Hertzian contact of the rolling element and raceway. In general, rolling-element bearing life increases with increasing level of oil filtration. Based upon test results, two equations are presented which allow for the adjustment of bearing L(sub 10) or catalog life based upon oil filter rating. It is recommended that where no oil filtration is used catalog life be reduced by 50 percent.

  10. Vacuum distillation/vapor filtration water recovery

    NASA Technical Reports Server (NTRS)

    Honegger, R. J.; Neveril, R. B.; Remus, G. A.

    1974-01-01

    The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

  11. Filtration of A Hanford AN-104 Sample

    SciTech Connect

    Poirier, MichaelR

    2004-03-01

    The Savannah River Technology Center (SRTC) conducted ultrafiltration tests with samples from the Hanford Site's AN-104 tank. The test objectives were to measure filter flux during dewatering and the removal of soluble species during washing. The filtration tests were conducted with the Cells Unit Filter (CUF) currently installed in Cell 16 of the SRTC High Activity Caves. Following filtration, personnel performed inhibited water washing to remove soluble species. Because of the limited volume of concentrated slurry, the washing was performed with a volumetric flask rather than a crossflow filter.Following the washing, personnel chemically cleaned the filter with 1 M nitric acid and periodically measured the clean water flux.

  12. Filtration of a Hanford AN-104 Sample

    SciTech Connect

    POIRIER, MICHAEL

    2004-04-19

    The Savannah River Technology Center (SRTC) conducted ultrafiltration tests with samples from the Hanford Site's 241-AN-104 tank. The test objectives were to measure filter flux during dewatering and the removal of soluble species during washing. The filtration tests were conducted with the Cells Unit Filter (CUF) currently installed in Cell 16 of the SRTC High Activity Caves. Following filtration, personnel performed inhibited water washing to remove soluble species. Because of the limited volume of concentrated slurry, the washing was performed with a volumetric flask rather than a crossflow filter. Following the washing, personnel chemically cleaned the filter with 1 M nitric acid and periodically measured the clean water flux.

  13. The Perspective of Riverbank Filtration in China

    NASA Astrophysics Data System (ADS)

    Li, J.; Teng, Y.; Zhai, Y.; Zuo, R.

    2014-12-01

    Sustainable drinking water supply can affect the health of people, and the surrounding ecosystems. According to statistics of the monitoring program of drinking water sources in 309 at or above prefecture level of China in 2013, the major pollutants index were total phosphorus, ammonia and manganese in surface drinking water sources, respectively, iron, ammonia and manganese in groundwater drinking water sources, respectively. More than 150 drinking water emergency environmental accidents happened since 2006, 52 of these accidents led to the disruption of water supply in waterworks, and a population of over ten million were affected. It indicated that there is a potential risk for people's health by the use of river water directly and it is necessary to require alternative techniques such as riverbank filtration for improving the drinking water quality. Riverbank filtration is an inexpensive natural process, not only smoothing out normal pollutant concentration found in surface water but also significantly reducing the risk from such emergency events as chemical spill into the river. Riverbank filtration technique has been used in many countries more than 100 years, including China. In China, in 1950s, the bank infiltration technique was first applied in northeast of China. Extensive bank infiltration application was conducted in 1980s, and more than 300 drinking water sources utilities bank infiltration established mainly near the Songhua River Basin, the Yellow River Basin, Haihe River Basin. However, the comparative lack of application and researches on riverbank filtration have formed critical scientific data gap in China. As the performance of riverbank filtration technique depend on not only the design and setting such as well type, pumping rate, but also the local hydrogeology and environmental properties. We recommend more riverbank filtration project and studies to be conducted to collect related significant environmental geology data in China

  14. Filtration of nano-particles by a gas-solid fluidized bed.

    PubMed

    Liu, Kuang-Yu; Wey, Ming-Yen

    2007-08-17

    The filtration of 80 nm SiO2 and Al(2)O(3) particles in a gas stream using fluidized beds was studied. Silica sand and activated carbon (A.C.) were adopted as bed materials to filtrate 80 nm SiO2 and Al(2)O(3) particles. The collected particles were elutriated from the fluidized bed, so the filtration was a dynamic process and the variations of the removal efficiency with time were studied. Experimental results showed that the filtrations of 80 nm SiO2 and Al(2)O(3) particles with a bed material of silica sand were not dynamic processes but the filtration by A.C. was. The removal efficiencies for SiO2 and Al(2)O(3) particles using silica sand as bed material were held steady and found to be equal, between 86 and 93%. A.C. is considered to be more efficient than silica sand because it has a high specific surface area. However, the experimental data yield conflicting results. The removal efficiency of Al(2)O(3) particles fell from 92% initially to 80% at the end of test-a little lower than that obtained by filtration using silica sand. A higher voidage of A.C. than silica sand weakens the removal of nanoparticles since the diffusion mechanism dominates. The removal efficiency of SiO2 by A.C. decayed from 83 to 40% with time passed. The huge differences between the filtration efficiency of SiO2 and that of Al(2)O(3) particles by A.C. was associated with the extensive segregation of SiO2 and A.C. particles, which caused more SiO2 particles to move to the top of the bed, where they were elutriated. The weak inter-particle force for SiO2 decreased the removal efficiency also.

  15. Mechanisms of pressure filtration of liquid aluminum alloys

    NASA Astrophysics Data System (ADS)

    Cao, X.

    2006-12-01

    The Prefil Footprinter, a portable pressure filtration instrument, is usually used to detect the quality of liquid aluminum alloys. However, no investigations have ever been done to calculate the cake resistance to date. Based on the identification and classification of flow behavior using the first derivative method for filtrate mass vs filtration time curves, conventional filtration equations are successfully employed to understand the filtration behaviors. From the analyses of the variations of cake resistance with filtration time, the filtration mechanisms are discussed in detail over the different filtration stages. During the steady stage, either incompressible or compressible cake mode is the main mechanism. At the initial and terminal transient stages, however, deep-bed filtration, complete straining, and solidification clogging may appear. Solid inclusions in liquid metal have significant influence on the cake structures and properties. Some important issues related to the heterogeneity of filter media and test methodology are highlighted in this work.

  16. Membrane filtration and sonication for industrial wastewater reuse.

    PubMed

    Caretti, C; Coppini, E; Fatarella, E; Lubello, C

    2011-01-01

    This paper presents an experimental study aimed at estimating the efficiency of the innovative process of ultrafiltration (UF) combined with sonication (Son.) for the refinement of treated effluent to be reused in wet textile processes. Such a novel approach, which has not yet been employed on a full industrial scale, has been experienced at pilot scale on the secondary effluent of the Baciacavallo wastewater treatment plant (WWTP), which treats part of the effluent from one of the largest textile industry districts in Italy. The combined treatment efficiency was assessed both on ozonated and non-ozonated Baciacavallo secondary effluent. The membrane filtration process was optimized in terms of running time, backwash, chemical addition and cleaning procedures. The sonication treatment was optimized on laboratory-scale with synthetic solutions (demineralized water added with dyestuffs) in terms of hydroxyl radicals formation rate, frequency, acoustic power, hydrogen peroxide addition, contact time and pH. The optimal conditions have been applied on the pilot-scale sonicator which was used in combination with the UF treatment. According to the experimental results, the best configuration within the Baciacavallo WWTP was the sonication of non-ozonated wastewater followed by the UF. The combined treatment guaranteed the compliance with the target values for wastewater reuse in wet textile industries. This study is part of the Research Project PURIFAST (Purification of industrial and mixed wastewater by combined membrane filtration and sonochemical technologies) LIFE + ENV/IT/000439.

  17. Measurement of filtration efficiency of Nuclepore filters challenged with polystyrene latex nanoparticles: experiments and modeling

    NASA Astrophysics Data System (ADS)

    Ling, Tsz Yan; Wang, Jing; Pui, David Y. H.

    2011-10-01

    Membrane filtration has been demonstrated to be effective for the removal of liquid-borne nanoparticles (NPs). Such technique can be applied to purify and disinfect drinking water as well as remove NPs in highly pure chemicals used in the industries. This study aims to study the filtration process of a model membrane filter, the Nuclepore filter. Experiments were carried out using standard filtration tools and the nanoparticle tracking analysis (NTA) technique was used to measure particle (50-500 nm) concentration upstream and downstream of the filter to determine the filtration efficiency. The NTA technique has been calibrated using 150-nm polystyrene latex particles to determine its accuracy of particle concentration measurement. Measurements were found reliable within a certain concentration limit (about 108-1010 particles/cm3), which is dependent on the camera settings during the measurement. Experimental results are comparable with previously published data obtained using the aerosolization method, validating the capability of the NTA technique. The capillary tube model modified from that developed for aerosol filtration was found to be useful to represent the experimental results, when a sticking coefficient of 0.15 is incorporated. This suggests that only 15% of the particle collisions with the filter results in successful attachment. The small sticking coefficient found can be explained by the unfavorable surface interactions between the particles and the filter medium.

  18. Experimental study of colloid filtration by compacted bentonite

    SciTech Connect

    Kurosawa, Susumu; Yui, Mikazu; Yoshikawa, Hideki

    1997-12-31

    In this study, the transport behavior of colloids through compacted bentonite and sand-bentonite mixtures was investigated. Colloidal gold was used to simulate mobile colloids because it was well characterized and its dispersivity was controlled. The bentonite used was a sodium bentonite. The sand-bentonite mixtures were prepared by mixing up to 50 wt.% silica sand with the bentonite. The bentonite and the sand-bentonite mixtures were compacted to dry densities of 1,000 and 1,800 kg/m{sup 3} and then saturated with distilled water. The sand-bentonite mixture was also saturated with synthetic sea-water. Column experiments were performed to investigate colloidal transport. Further, colloidal particles stabilities in high ionic strength water such as bentonite porewater or saline groundwater were interpreted based on the repulsion potential from the double layer force and the attraction potential from the van der Waals force. The results indicated that the colloidal particles were effectively filtered by both the compacted bentonite and the sand-bentonite mixtures. This study indicated that the effect of colloids on radionuclide transport in compacted bentonite is negligible for the safety assessment of high level radioactive waste (HLW) disposal.

  19. Comparison of Prelaminar Thickness between Primary Open Angle Glaucoma and Normal Tension Glaucoma Patients

    PubMed Central

    Jung, Youn Hea; Park, Hae-Young L.; Jung, Kyoung In; Park, Chan Kee

    2015-01-01

    Main Objective The thinning of prelaminar tissue and prelamina cupping is known to occur by ischemia, as we see in anterior ischemic optic neuropathy. Since normal tension glaucoma (NTG) is thought to be more related to vascular factor than in primary open-angle glaucoma (POAG), we hypothesized that prelamina thinning may occur prominently in NTG patients. This study investigated the difference in prelaminar tissue thickness between patients with POAG and NTG and verified the factors related to prelaminar thinning. Methods Complete ophthalmic examination including standard automatic perimetry was performed in all patients. The prelaminar tissue thickness was measured in all patients by performing enhanced depth imaging with a Heidelberg Spectralis Optical Coherence Tomography. The retinal nerve fiber layer and optic nerve head parameters were obtained using the Heidelberg Retina Tomography II and Cirrus Optical Coherence Tomography. Various ocular factors and their relationships with prelaminar thickness were analyzed. Results The mean prelaminar tissue thickness was significantly thinner in patients with POAG than in those with NTG. The difference in the prelaminar thickness between patients with POAG and those with NTG was greater in the early field defect group than in the moderate and severe field groups. In multivariate analysis, the mean prelaminar thickness was related to the intraocular pressure, mean deviation, cup-disc ratio, and cup volume. Conclusions The prelaminar tissue was thinner in patients with POAG than in patients with NTG, and intraocular pressure had a strong influence on the prelaminar thickness in both POAG and NTG. This may indicate that mechanical compression is the main pathogenic factor in both POAG and NTG. PMID:25793734

  20. [Historical notes on the terms "glaucoma" and "cataract" (author's transl)].

    PubMed

    Rintelen, F

    1977-02-01

    The Greek term "glaucoma" has nothing to do with the disease we call glaucoma today and that we use to translate incorrectly with "grüner Star" throughout the German-speaking countries. The Greek adjective "glaucos" does not mean green but gleaming, sparkling. It signified the discolouring of the pupil in glaucoma. It was later replaced by the pathogenetic term hypochysis, Latin suffusio, denoting the supposed "trübe Feuchte" (opaque humour) that was taught to gather and congeal in front of the crystalline lens. Later on "glaukosis" was reserved for incurable cases, disease of the crystalline lens itself, which was looked at as the "organon visus" up to Felix Plater. The word "cataract"--waterfall--does not exist in Greek medicine. It appears in Salernitan medical science around the year 1000 as a synonym for hypochysis, the disease we call cataract today and which has been identified as opacity of the lens since Brisseau (1705). The nature of "incurable" glaucoma, later considered as a disease of the vitreous body, was clearly recognized as a consequence of intraocular increase of pressure only by v. Graefe.

  1. Canaloplasty: A Minimally Invasive and Maximally Effective Glaucoma Treatment

    PubMed Central

    Khaimi, Mahmoud A.

    2015-01-01

    Canaloplasty is a highly effective, minimally invasive, surgical technique indicated for the treatment of open-angle glaucoma that works by restoring the function of the eye's natural outflow system. The procedure's excellent safety profile and long-term efficacy make it a viable option for the majority of glaucoma patient types. It can be used in conjunction with existing drug based glaucoma treatments, after laser or other types of incisional surgery, and does not preclude or affect the outcome of future surgery. Numerous scientific studies have shown Canaloplasty to be safe and effective in lowering IOP whilst reducing medication dependence. A recent refinement of Canaloplasty, known as ab-interno Canaloplasty (ABiC), maintains the IOP-lowering and safety benefits of traditional (ab-externo) Canaloplasty using a more efficient, simplified surgical approach. This paper presents a review of Canaloplasty indications, clinical data, and complications, as well as comparisons with traditional incisional glaucoma techniques. It also addresses the early clinical evidence for ABiC. PMID:26495135

  2. Surgical management in primary congenital glaucoma: four debates.

    PubMed

    Chang, Ta C; Cavuoto, Kara M

    2013-01-01

    Primary congenital glaucoma is a worldwide diagnostic and therapeutic challenge. Although medical management is often a temporizing measure, early surgical intervention is the definitive treatment. As the abundance of surgical treatment options continues to expand, the authors will compare and contrast the available options and attempt to provide a consensus on surgical management.

  3. Management of glaucoma in pregnancy: risks or choices, a dilemma?

    PubMed

    Sethi, Harinder Singh; Naik, Mayuresh; Gupta, Vishnu Swarup

    2016-01-01

    The treatment of glaucoma in and around pregnancy offers the unique challenge of balancing the risk of vision loss to the mother as against the potential harm to the fetus or newborn. Most anti-glaucoma drugs (i.e. beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors topical and systemic, cholinergics, anticholinesterases, and apraclonidine) are considered category C agents and ophthalmologists are usually limited to treating patients with the category B drugs of brimonidine and dipivefrin. Brimonidine is generally the preferred first-line drug in the first, second and early third trimester. Late in the third trimester, brimonidine should be discontinued because it can induce central nervous system depression in newborns wherein topical carbonic anhydrase inhibitors may be the optimal choice. Glaucoma surgery can be performed with caution in second and third trimester if the patients have a strong indication for the procedure. However, anesthetics, sedative agents, and antimetabolites still have potential risk for the fetus. Argon laser trabeculoplasty (ALT) or selective laser trabeculoplasty (SLT) is an alternative treatment that can be performed in all trimesters. Carbonic anhydrase inhibitors and β-blockers are certified by the American Academy of Pediatrics for use during nursing. However, low doses of these medications should be considered when used in the breast feeding period. Optimum treatment for glaucoma in pregnancy must not be withheld so as to prevent any further deterioration in progressive vision loss and quality of life.

  4. Biomarkers and surrogate endpoints in glaucoma clinical trials.

    PubMed

    Medeiros, Felipe A

    2015-05-01

    Surrogate endpoints are often used as replacements for true clinically relevant endpoints in several areas of medicine, as they enable faster and less expensive clinical trials. However, without proper validation, the use of surrogates may lead to incorrect conclusions about the efficacy and safety of treatments. This article reviews the general requirements for validating surrogate endpoints and provides a critical assessment of the use of intraocular pressure (IOP), visual fields, and structural measurements of the optic nerve as surrogate endpoints in glaucoma clinical trials. A valid surrogate endpoint must be able to predict the clinically relevant endpoint and fully capture the effect of an intervention on that endpoint. Despite its widespread use in clinical trials, no proper validation of IOP as a surrogate endpoint has ever been conducted for any class of IOP-lowering treatments. Evidence has accumulated with regard to the role of imaging measurements of optic nerve damage as surrogate endpoints in glaucoma. These measurements are predictive of functional losses in the disease and may explain, at least in part, treatment effects on clinically relevant endpoints. The use of composite endpoints in glaucoma trials may overcome weaknesses of the use of structural or functional endpoints in isolation. Unless research is dedicated to fully develop and validate suitable endpoints that can be used in glaucoma clinical trials, we run the risk of inappropriate judgments about the value of new therapies.

  5. Review on the Management of Primary Congenital Glaucoma

    PubMed Central

    Yu Chan, Julia Yan; Choy, Bonnie NK; Ng, Alex LK

    2015-01-01

    ABSTRACT Despite being documented in medical history from over 2400 years ago, primary congenital glaucoma (PCG), being a disease with low incidence rate, remains a challenge to ophthalmologists. The article provides a broad overview on the pathophysiology and diagnostic approach to PCG with major emphasis on the treatment options of PCG. While reviewing on the well-established treatment options, namely goniotomy, trabeculo-tomy and combined trabeculotomy-trabeculectomy, emphasis has also been made to recent updates on secondary treatments: trabeculectomy, antimetabolites, glaucoma-drainage devices and cyclodestructive procedures. It is, however, important to note that the rarity of PCG places limitations on study design, most studies are, thus, retrospective, nonrandomized and have different definitions of surgical success. Ophthalmologists need to interpret the results with critical thinking and formulate individual treatment plans for each patient. How to cite this article: Yu Chan JY, Choy BNK, Alex LK Ng, Shum JWH. Review on the Management of Primary Congenital Glaucoma. J Curr Glaucoma Pract 2015;9(3):92-99. PMID:26997844

  6. Ocular perfusion pressure and ocular blood flow in glaucoma

    PubMed Central

    Cherecheanu, A Popa; Garhofer, G; Schmidl, D; Werkmeister, R; Schmetterer, L

    2013-01-01

    Glaucoma is a progressive optic neuropathy of unknown origin. It has been hypothesized that a vascular component is involved in glaucoma pathophysiology. This hypothesis has gained support from studies showing that reduced ocular perfusion pressure is a risk factor for the disease. The exact nature of the involvement is, however, still a matter of debate. Based on recent evidence we propose a model including primary and secondary insults in glaucoma. The primary insult appears to happen at the optic nerve head. Increased intraocular pressure and ischemia at the post-laminar optic nerve head affects retinal ganglion cell axons. Modulating factors are the biomechanical properties of the tissues and cerebrospinal fluid pressure. After this primary insult retinal ganglion cells function at a reduced energy level and are sensitive to secondary insults. These secondary insults may happen if ocular perfusion pressure falls below the lower limit of autoregulation or if neurovascular coupling fails. Evidence for both faulty autoregulation and reduced hyperemic response to neuronal stimulation has been provided in glaucoma patients. The mechanisms appear to involve vascular endothelial dysfunction and impaired astrocyte-vessel signaling. A more detailed understanding of these pathways is required to direct neuroprotective strategies via the neurovascular pathway. PMID:23009741

  7. Management of glaucoma in pregnancy: risks or choices, a dilemma?

    PubMed Central

    Sethi, Harinder Singh; Naik, Mayuresh; Gupta, Vishnu Swarup

    2016-01-01

    The treatment of glaucoma in and around pregnancy offers the unique challenge of balancing the risk of vision loss to the mother as against the potential harm to the fetus or newborn. Most anti-glaucoma drugs (i.e. beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors topical and systemic, cholinergics, anticholinesterases, and apraclonidine) are considered category C agents and ophthalmologists are usually limited to treating patients with the category B drugs of brimonidine and dipivefrin. Brimonidine is generally the preferred first-line drug in the first, second and early third trimester. Late in the third trimester, brimonidine should be discontinued because it can induce central nervous system depression in newborns wherein topical carbonic anhydrase inhibitors may be the optimal choice. Glaucoma surgery can be performed with caution in second and third trimester if the patients have a strong indication for the procedure. However, anesthetics, sedative agents, and antimetabolites still have potential risk for the fetus. Argon laser trabeculoplasty (ALT) or selective laser trabeculoplasty (SLT) is an alternative treatment that can be performed in all trimesters. Carbonic anhydrase inhibitors and β-blockers are certified by the American Academy of Pediatrics for use during nursing. However, low doses of these medications should be considered when used in the breast feeding period. Optimum treatment for glaucoma in pregnancy must not be withheld so as to prevent any further deterioration in progressive vision loss and quality of life. PMID:27990376

  8. Scientometric analysis and mapping of 20 years of glaucoma research

    PubMed Central

    Ramin, Shahrokh; Pakravan, Mohammad; Habibi, Gholamreza; Ghazavi, Roghayeh

    2016-01-01

    AIM To provide a scientometric analysis in the field of glaucoma. METHODS A bibliometric method was used to obtain a view of the scientific production in field of glaucoma by data extracted from the Institute for Scientific Information (ISI) from 1993 to 2013. Specific parameters were retrieved from the ISI. Articles about glaucoma were analyzed regarding the topics' structure, history, and document relationships using HistCite software. Also, the trends in the most influential publications and authors were analyzed. RESULTS The number of articles was constantly increasing, and most highly cited articles addressed clinical and epidemiologic topics in this field. During the past three years, there has been a trend towards genomic research studies and also more molecular translational research. CONCLUSION This was the first scientometric report on glaucoma, analyzing the characteristics of papers and the trends in scientific production. A constant increase was observed in the number of papers, while the subject of papers had a shift in the past three years towards genomic research studies. PMID:27672601

  9. CYP1B1-mediated Pathobiology of Primary Congenital Glaucoma.

    PubMed

    Faiq, Muneeb A; Dada, Rima; Qadri, Rizwana; Dada, Tanuj

    2015-01-01

    CYP1B1 is a dioxin-inducible enzyme belonging to the cytochrome P450 superfamily. It has been observed to be important in a variety of developmental processes including in utero development of ocular structures. Owing to its role in the developmental biology of eye, its dysfunction can lead to ocular developmental defects. This has been found to be true and CYP1B1 mutations have been observed in a majority of primary congenital glaucoma (PCG) patients from all over the globe. Primary congenital glaucoma is an irreversibly blinding childhood disorder (onset at birth or early infancy) typified by anomalous development of trabecular meshwork (TM). How CYP1B1 causes PCG is not known; however, some basic investigations have been reported. Understanding the CYP1B1 mediated etiopathomechanism of PCG is very important to identify targets for therapy and preventive management. In this perspective, we will make an effort to reconstruct the pathomechanism of PCG in the light of already reported information about the disease and the CYP1B1 gene. How to cite this article: Faiq MA, Dada R, Qadri R, Dada T. CYP1 B1-mediated Pathobiology of Primary Congenital Glaucoma. J Curr Glaucoma Pract 2015;9(3):77-80.

  10. CYP1B1-mediated Pathobiology of Primary Congenital Glaucoma

    PubMed Central

    Faiq, Muneeb A; Dada, Rima; Qadri, Rizwana

    2015-01-01

    ABSTRACT CYP1B1 is a dioxin-inducible enzyme belonging to the cytochrome P450 superfamily. It has been observed to be important in a variety of developmental processes including in utero development of ocular structures. Owing to its role in the developmental biology of eye, its dysfunction can lead to ocular developmental defects. This has been found to be true and CYP1B1 mutations have been observed in a majority of primary congenital glaucoma (PCG) patients from all over the globe. Primary congenital glaucoma is an irreversibly blinding childhood disorder (onset at birth or early infancy) typified by anomalous development of trabecular meshwork (TM). How CYP1B1 causes PCG is not known; however, some basic investigations have been reported. Understanding the CYP1B1 mediated etiopathomechanism of PCG is very important to identify targets for therapy and preventive management. In this perspective, we will make an effort to reconstruct the pathomechanism of PCG in the light of already reported information about the disease and the CYP1B1 gene. How to cite this article: Faiq MA, Dada R, Qadri R, Dada T. CYP1 B1-mediated Pathobiology of Primary Congenital Glaucoma. J Curr Glaucoma Pract 2015;9(3):77-80. PMID:26997841

  11. Drug Attitude and Adherence to Anti-Glaucoma Medication

    PubMed Central

    Hong, Samin; Kang, Sung Yong; Yoon, Jong Uk; Kang, Uicheon; Seong, Gong Je

    2010-01-01

    Purpose The purpose of this study is to assess patient attitudes towards anti-glaucoma medication and their association with adherence, visual quality of life, and personality traits. Materials and Methods One hundred and forty-seven glaucoma patients were enrolled this study. The participants were divided into 'pharmacophobic' and 'pharmacophilic' groups according to their scores on the Modified Glaucoma Drug Attitude Inventory (MG-DAI). To establish a correlation with patient drug attitude, each group had their subjective drug adherence, visual quality of life, and personality traits examined. For personality traits, the Myers-Briggs Type Indicator (MBTI) was used to sub-classify each group. Results Among the patients analyzed, 91 (72.80%) patients showed a 'pharmacophobic' attitude and 34 (27.20%) patients showed a 'pharmacophilic' attitude. The pharmacophobic group tended to have worse adherence than the pharmacophilic group. Personality dichotomies from the MBTI also showed different patterns for each group. Conclusion In glaucoma patients, pharmacological adherence was influenced by their attitude towards drugs; an association might exist between drug attitude and underlying personality traits. PMID:20191020

  12. Pharmacodynamics of citicoline relevant to the treatment of glaucoma.

    PubMed

    Grieb, Pawel; Rejdak, Robert

    2002-01-15

    Citicoline (exogenous CDP-choline) is a nontoxic and well-tolerated drug used in pharmacotherapy of brain insufficiency and some other neurological disorders, such as stroke, brain trauma, and Parkinson's disease. A few reports indicate that citicoline treatment may also be beneficial in glaucoma. Currently glaucoma is considered a neurodegenerative disease in which retinal ganglion cells (RGC) slowly die, likely in the apoptotic mechanism. Endogenous CDP-choline is a natural precursor of cellular synthesis of phospholipids, mainly phosphatydylcholine (PtdCho). Enhancement of PtdCho synthesis may counteract neuronal apoptosis and provide neuroprotection. Citicoline, when administered, undergoes a quick transformation to cytidine and choline, which are believed to enter brain cells separately and provide neuroprotection by enhancing PtdCho synthesis; similar effect may be expected to occur in glaucomatous RGC. Furthermore, citicoline stimulates some brain neurotransmitter systems, including the dopaminergic system, and dopamine is known as a major neurotransmitter in retina and postretinal visual pathways. In a double-blind, placebo-controlled study, treatment of glaucoma resulted in functional improvement in the visual system noted with electrophysiological methods. Development of citicoline as a treatment for glaucoma is indicated.

  13. What was Glaucoma Called Before the 20th Century?

    PubMed Central

    Leffler, Christopher T.; Schwartz, Stephen G.; Giliberti, Francesca M.; Young, Matthew T.; Bermudez, Dennis

    2015-01-01

    Glaucoma involves a characteristic optic neuropathy, often with elevated intraocular pressure. Before 1850, poor vision with a normal eye appearance, as occurs in primary open-angle glaucoma, was termed amaurosis, gutta serena, or black cataract. Few observers noted palpable hardness of the eye in amaurosis. On the other hand, angle-closure glaucoma can produce a green or gray pupil, and therefore was called, variously, glaucoma (derived from the Greek for glaucous, a nonspecific term connoting blue, green, or light gray) and viriditate oculi. Angle closure, with palpable hardness of the eye, mydriasis, and anterior prominence of the lens, was described in greater detail in the 18th and 19th centuries. The introduction of the ophthalmoscope in 1850 permitted the visualization of the excavated optic neuropathy in eyes with a normal or with a dilated greenish-gray pupil. Physicians developed a better appreciation of the role of intraocular pressure in both conditions, which became subsumed under the rubric “glaucoma”. PMID:26483611

  14. Plasma discharge self-cleaning filtration system

    SciTech Connect

    Cho, Young I.; Fridman, Alexander; Gutsol, Alexander F.; Yang, Yong

    2014-07-22

    The present invention is directed to a novel method for cleaning a filter surface using a plasma discharge self-cleaning filtration system. The method involves utilizing plasma discharges to induce short electric pulses of nanoseconds duration at high voltages. These electrical pulses generate strong Shockwaves that disintegrate and dislodge particulate matter located on the surface of the filter.

  15. Gel Filtration Chromatography: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Hurlbut, Jeffrey A.; Schonbeck, Niels D.

    1984-01-01

    Describes a rapid, visual demonstration of protein separation by gel filtration chromatography. The procedure separates two highly colored proteins of different molecular weights on a Sephadex G-75 in 45 minutes. This time includes packing the column as well. Background information, reagents needed, procedures used, and results obtained are…

  16. [Clinical experience of automated double filtration plasmapheresis].

    PubMed

    Lee, C T; Chuang, F R; Hsu, K T; Lam, K K; Liao, S C; Liu, C C; Chen, J B; Jang, S W; Chien, Y S; Pan, H H

    1996-12-01

    Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

  17. Filtration engineering study to upgrade the ETF

    SciTech Connect

    McDonald, F.N.N.

    1995-10-18

    Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal

  18. Contamination control through filtration of microorganisms

    NASA Technical Reports Server (NTRS)

    Stabekis, P. D.; Lyle, R. G.

    1972-01-01

    A description is given of the various kinds of gas and liquid filters used in decontamination and sterilization procedures. Also discussed are filtration mechanisms, characteristics of filter materials, and the factors affecting filter performance. Summaries are included for filter testing and evaluation techniques and the possible application of the filters to spacecraft sterilization.

  19. DEMONSTRATION BULLETIN: MEMBRANE FILTRATION - SBP TECHNOLOGIES, INC.

    EPA Science Inventory

    SBP Technologies Inc. (SBP) has developed a membrane-based separation technology that can reduce the volume of contaminated groundwater requiring treatment. The SBP Filtration Unit consists of porous, sintered, stainless steel tubes arranged in a shell-and-tube module configurati...

  20. Gene therapy in glaucoma-part 2: Genetic etiology and gene mapping.

    PubMed

    Mahdy, Mohamed Abdel-Monem Soliman

    2010-05-01

    Glaucoma diagnosis, identification of people at risk, initiation of treatment and timing of surgical intervention remains a problem. Despite new and improving diagnostic and therapeutic options for glaucoma, blindness from glaucoma is increasing and glaucoma remains a major public health problem. The role of heredity in ocular disease is attracting greater attention as the knowledge and recent advances of Human Genome Project and the HapMap Project have made genetic analysis of many human disorders possible.Glaucoma offers a variety of potential targets for gene therapy. All risk factors for glaucoma and their underlying causes are potentially susceptible to modulation by gene transfer.The discovery of genes responsible for glaucoma has led to the development of new methods of Deoxyribonucleic acid (DNA)-based diagnosis and treatment. As genetic defects responsible for glaucoma are identified and the biochemical mechanisms underlying the disease are recognized, new methods of therapy can be developed. It is of utmost importance for the ophthalmologists and glaucoma specialists to be familiar with and understand the basic molecular mechanisms, genes responsible for glaucoma and the ways of genetic treatment. METHOD OF LITERATURE SEARCH: The literature was searched on the Medline database, using the PubMed interface.

  1. Epidemiology of Glaucoma in Sub-Saharan Africa: Prevalence, Incidence and Risk Factors

    PubMed Central

    Kyari, Fatima; Abdull, Mohammed M.; Bastawrous, Andrew; Gilbert, Clare E.; Faal, Hannah

    2013-01-01

    Purpose: The purpose of this study is to review the epidemiology of different types of glaucoma relevant to Sub-Saharan Africa (SSA) and to discuss the evidence regarding the risk factors for onset and progression of glaucoma, including risk factors for glaucoma blindness. Methods: Electronic databases (PubMed, MedLine, African Journals Online- AJOL) were searched using the full text, Medical Subject Headings (MeSH) terms, author(s) and title to identify publications since 1982 in the following areas: population-based glaucoma prevalence and incidence studies in SSA and in African-derived black populations outside Africa; population-based prevalence and incidence of blindness and visual impairment studies in SSA including rapid assessment methods, which elucidate the glaucoma-specific blindness prevalence; studies of risk factors for glaucoma; and publications that discussed public health approaches for the control of glaucoma in Africa. Results: Studies highlighted that glaucoma in SSA is a public health problem and predominantly open-angle glaucoma. It is the second-leading cause of blindness, has a high prevalence, an early onset and progresses more rapidly than in Caucasians. These factors are further compounded by poor awareness and low knowledge about glaucoma even by persons affected by the condition. Conclusion: Glaucoma care needs to be given high priority in Vision 2020 programs in Africa. Many questions remain unanswered and there is a need for further research in glaucoma in SSA in all aspects especially epidemiology and clinical care and outcomes involving randomized controlled trials. Genetic and genome-wide association studies may aid identification of high-risk groups. Social sciences and qualitative studies, health economics and health systems research will also enhance public health approaches for the prevention of blindness due to glaucoma. PMID:23741130

  2. Structural Change Can Be Detected in Advanced-Glaucoma Eyes

    PubMed Central

    Belghith, Akram; Medeiros, Felipe A.; Bowd, Christopher; Liebmann, Jeffrey M.; Girkin, Christopher A.; Weinreb, Robert N.; Zangwill, Linda M.

    2016-01-01

    Purpose To compare spectral-domain optical coherence tomography (SD-OCT) standard structural measures and a new three-dimensional (3D) volume optic nerve head (ONH) change detection method for detecting change over time in severely advanced-glaucoma (open-angle glaucoma [OAG]) patients. Methods Thirty-five eyes of 35 patients with very advanced glaucoma (defined as a visual field mean deviation < −21 dB) and 46 eyes of 30 healthy subjects to estimate aging changes were included. Circumpapillary retinal fiber layer thickness (cpRNFL), minimum rim width (MRW), and macular retinal ganglion cell–inner plexiform layer (GCIPL) thicknesses were measured using the San Diego Automated Layer Segmentation Algorithm (SALSA). Progression was defined as structural loss faster than 95th percentile of healthy eyes. Three-dimensional volume ONH change was estimated using the Bayesian-kernel detection scheme (BKDS), which does not require extensive retinal layer segmentation. Results The number of progressing glaucoma eyes identified was highest for 3D volume BKDS (13, 37%), followed by GCPIL (11, 31%), cpRNFL (4, 11%), and MRW (2, 6%). In advanced-OAG eyes, only the mean rate of GCIPL change reached statistical significance, −0.18 μm/y (P = 0.02); the mean rates of cpRNFL and MRW change were not statistically different from zero. In healthy eyes, the mean rates of cpRNFL, MRW, and GCIPL change were significantly different from zero. (all P < 0.001). Conclusions Ganglion cell–inner plexiform layer and 3D volume BKDS show promise for identifying change in severely advanced glaucoma. These results suggest that structural change can be detected in very advanced disease. Longer follow-up is needed to determine whether changes identified are false positives or true progression. PMID:27454660

  3. Glaucoma and Driving Risk under Simulated Fog Conditions

    PubMed Central

    Diniz-Filho, Alberto; Boer, Erwin R.; Elhosseiny, Ahmed; Wu, Zhichao; Nakanishi, Masaki; Medeiros, Felipe A.

    2016-01-01

    Purpose We evaluate driving risk under simulated fog conditions in glaucoma and healthy subjects. Methods This cross-sectional study included 41 glaucoma patients and 25 age-matched healthy subjects who underwent driving simulation. Tests consisted of curve negotiation without and with fog preview at 30 m of distance and two controlled speeds (slow and fast). Inverse time-to-line crossing (invTLC) was used as metric to quantify risk; higher invTLC values indicating higher risk, as less time is available to avoid drifting out of the road. Piecewise regression models were used to investigate the relationship between differences in invTLC in fog and nonfog conditions and visual field loss. Results Glaucoma patients had greater increase in driving risk under fog compared to controls, as indicated by invTLC differences (0.490 ± 0.578 s−1 and 0.208 ± 0.106 s−1, respectively; P = 0.002). Mean deviation (MD) of the better eye was significantly associated with driving risk under fog, with a breakpoint of −9 dB identified by piecewise regression. For values below the breakpoint, each 1 dB lower MD of better eye was associated with 0.117 s−1 higher invTLC under fast speed (adjusted R2 = 57.9%; P < 0.001). Conclusions Glaucoma patients have a steeper increase in driving risk under fog conditions when compared to healthy subjects, especially when the severity of visual field damage falls below −9 dB of MD in the better eye. Translational Relevance By investigating the relationship between driving risk and disease severity breakpoint, this study may provide guidance to clinicians in recognizing glaucoma patients who may be unfit to drive in complex situations such as fog. PMID:27980878

  4. Treatment outcomes of micropulse transscleral cyclophotocoagulation in advanced glaucoma.

    PubMed

    Kuchar, Sarah; Moster, Marlene R; Reamer, Courtney B; Waisbourd, Michael

    2016-02-01

    Glaucoma is the leading cause of irreversible blindness worldwide. The goal of this study was to describe our experience with the novel micropulse transscleral cyclophotocoagulation (MP-TSCPC; IRIDEX IQ810 Laser Systems, CA) in patients with advanced glaucoma. Patients with advanced glaucoma who underwent MP-TSCPC were included in our study. Laser settings were 2000 mW of 810 nm infrared diode laser set on micropulse delivery mode. The laser was delivered over 360° for 100-240 s. The duty cycle was 31.3 %, which translated to 0.5 ms of "on time" and 1.1 ms of "off time." Surgical success was defined as an intraocular pressure (IOP) of 6-21 mmHg or a reduction of IOP by 20 % at the last follow-up visit. Failure was defined as an inability to meet the criteria for success or a need for incisional glaucoma surgery. Nineteen patients underwent MP-TSCPC with mean follow-up of 60.3 days. Mean IOP dropped from 37.9 mmHg preoperatively to 22.7 mmHg at last follow-up, representing a 40.1 % decrease. The success rate for initial treatment was 73.7 % (n = 14). Three patients underwent a second treatment, increasing the overall success rate to 89.5 % (n = 17). Four patients gained one line of vision, and four patients lost one line of vision. The novel MP-TSCPC laser had a high rate of surgical success after a short follow-up period in patients with advanced glaucoma. Further long-term evaluation and comparison to the traditional transscleral cyclophotocoagulation are warranted.

  5. A Rare Manifestation of Uveitis-glaucoma-hyphema Syndrome

    PubMed Central

    Leal, Inês; Faria, Mun Yueh; Pinto, Luís Abegão

    2016-01-01

    ABSTRACT Aims: To report a case of a patient who developed uveitis-glaucoma-hyphema (UGH) syndrome after an uneventful cataract surgery and to discuss risk factors, diagnostic challenges, management options, and clinical implications. Background: Uveitis-glaucoma-hyphema syndrome is a rare but potentially serious cataract surgery complication. Clinical manifestations include increased intraocular pressure (IOP), anterior chamber inflammation, and recurrent hyphema or microhyphema. Uveitis-glaucoma-hyphema Plus syndrome also includes accompanying vitreous hemorrhage. Although classically associated with rigid anterior chamber intraocular lenses (lOLs), cases of malpositioning and subluxated posterior chamber lOLs have also been described as possible triggers. Case description: We report a case of a 70-year-old Caucasian man who developed UGH Plus syndrome after an uneventful cataract surgery with an lOL implanted in the capsular bag. During postoperative follow-up, persistent intraocular inflammation, increased IOP, hyphema, and vitreous hemorrhage were consistent with this diagnosis. Slit-lamp examination demonstrated progressive localized iris atrophy, compatible with chafing of the posterior iris by the IOL haptic as the trigger for UGH syndrome. A pars plana vitrectomy was performed and a retropupillary intraocular lens was implanted. No further complications occurred during follow-up. Conclusion and clinical significance: Given the increasing prevalence of single-piece lOLs implanted in the capsular bag, it is important to recognize UGH syndrome as a rare but potentially serious complication. How to cite this article: Sousa DC, Leal I, Faria MY, Pinto LA. A Rare Manifestation of Uveitis-glaucoma-hyphema Syndrome. J Curr Glaucoma Pract 2016;10(2):76-78. PMID:27536051

  6. Familial glaucoma iridogoniodysplasia maps to a 6p25 region implicated in primary congenital glaucoma and iridogoniodysgenesis anomaly.

    PubMed Central

    Jordan, T; Ebenezer, N; Manners, R; McGill, J; Bhattacharya, S

    1997-01-01

    Familial glaucoma iridogoniodysplasia (FGI) is a form of open-angle glaucoma in which developmental anomalies of the iris and irido-corneal angle are associated with a juvenile-onset glaucoma transmitted as an autosomal dominant trait. A single large family with this disorder was examined for genetic linkage to microsatellite markers. A peak LOD score of 11.63 at a recombination fraction of 0 was obtained with marker D6S967 mapping to chromosome 6p25. Haplotype analysis places the disease gene in a 6.4-cM interval between the markers D6S1713 and D6S1600. Two novel clinical appearances extend the phenotypic range and provide evidence of variable expressivity. The chromosome 6p25 region is now implicated in FGI, primary congenital glaucoma, and iridogoniodysgenesis anomaly. This may indicate the presence of a common causative gene or, alternatively, a cluster of genes involved in eye development/function. Images Figure 2 PMID:9382099

  7. Autophagy and Mitochondrial Dysfunction in Tenon Fibroblasts from Exfoliation Glaucoma Patients

    PubMed Central

    Want, Andrew; Gillespie, Stephanie R.; Wang, Zheng; Gordon, Ronald; Iomini, Carlo; Ritch, Robert; Wolosin, J. Mario; Bernstein, Audrey M.

    2016-01-01

    Purpose To test the hypothesis that autophagy dysfunction is involved in exfoliation syndrome (XFS), a systemic disorder of extracellular elastic matrices that causes a distinct form of human glaucoma. Methods Fibroblasts derived from tenon tissue discards (TFs) from filtration surgery to relieve intraocular pressure in XFS patients were compared against age-matched TFs derived from surgery in primary open-angle glaucoma (POAG) patients or from strabismus surgery. Differential interference contrast light, and electron microscopy were used to examine structural cell features. Immunocytochemistry was used to visualize LOXL1 and Fibulin-5, lysosomes, endosomes, Golgi, and microtubules. Light scatter, Cyto-IDTM and JC1 flow cytometry were used to measure relative cell size, autophagic flux rate and mitochondrial membrane potential (MMPT), respectively. Enhanced autophagy was induced by serum withdrawal. Results In culture, XFS-TFs were 1.38-fold larger (by light scatter ratio, p = 0.05), proliferated 42% slower (p = 0.026), and were morphologically distinct in 2D and 3D culture compared to their POAG counterparts. In extended 3D cultures, XFS-TFs accumulated 8–10 times more Fibulin-5 than the POAG-TFs, and upon serum withdrawal, there were marked deficiencies in relocation of endosomes and lysosomes to the perinuclear area. Correspondingly, the XFS-TFs displayed significant accumulation of the autophagasome marker LC3 II (3.9 fold increase compared to POAG levels, p = 0.0001) and autophagic flux rate as measured by Cyto-ID dye was 53% lower in XFS-TFs than in POAG-TFs (p = 0.01), indicating reduced clearance of autophagasomes. Finally the percent of cells with diminished MMPT was 3–8 times larger in the XFS-TFs than in POAG-TFs (p = 0.02). Conclusions Our results provide for the first time a link between XFS pathology to autophagy dysfunction, a major contributor to multiple age related diseases systemically throughout the body, in the brain and in the retina. A

  8. A general approach for predicting the filtration of soft and permeable colloids: the milk example.

    PubMed

    Bouchoux, Antoine; Qu, Peng; Bacchin, Patrice; Gésan-Guiziou, Geneviève

    2014-01-14

    Membrane filtration operations (ultra-, microfiltration) are now extensively used for concentrating or separating an ever-growing variety of colloidal dispersions. However, the phenomena that determine the efficiency of these operations are not yet fully understood. This is especially the case when dealing with colloids that are soft, deformable, and permeable. In this paper, we propose a methodology for building a model that is able to predict the performance (flux, concentration profiles) of the filtration of such objects in relation with the operating conditions. This is done by focusing on the case of milk filtration, all experiments being performed with dispersions of milk casein micelles, which are sort of ″natural″ colloidal microgels. Using this example, we develop the general idea that a filtration model can always be built for a given colloidal dispersion as long as this dispersion has been characterized in terms of osmotic pressure Π and hydraulic permeability k. For soft and permeable colloids, the major issue is that the permeability k cannot be assessed in a trivial way like in the case for hard-sphere colloids. To get around this difficulty, we follow two distinct approaches to actually measure k: a direct approach, involving osmotic stress experiments, and a reverse-calculation approach, that consists of estimating k through well-controlled filtration experiments. The resulting filtration model is then validated against experimental measurements obtained from combined milk filtration/SAXS experiments. We also give precise examples of how the model can be used, as well as a brief discussion on the possible universality of the approach presented here.

  9. 11. DETAIL VIEW OF FILTER TANK IN FILTRATION PLANT (#1773), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. DETAIL VIEW OF FILTER TANK IN FILTRATION PLANT (#1773), LOOKING NORTHWEST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  10. 3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF THE FILTRATION APPARATUS. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  11. Linkage analysis of primary open-angle glaucoma excludes the juvenile glaucoma region on chromosome 1q

    SciTech Connect

    Wirtz, M.K.; Acott, T.S.; Samples, J.R. |

    1994-09-01

    The gene for one form of juvenile glaucoma has been mapped to chromosome 1q21-q31. This raises the possibility of primary open-angle glaucoma (POAG) also mapping to this region if the same defective gene causes both diseases. To ask this question linkage analysis was performed on a large POAG kindred. Blood samples or skin biopsies were obtained from 40 members of this family. Individuals were diagnosed as having POAG if they met two or more of the following criteria: (1) Visual field defects compatible with glaucoma on automated perimetry; (2) Optic nerve head and/or nerve fiber layer analysis compatible with glaucomatous damage; (3) high intraocular pressures (> 20 mm Hg). Patients were considered glaucoma suspects if they only met one criterion. These individuals were excluded from the analysis. Of the 40 members, seven were diagnosed with POAG; four were termed suspects. The earliest age of onset was 38 years old, while the average age of onset was 65 years old. We performed two-point and multipoint linkage analysis, using five markers which encompass the region 1q21-q31; specifically, D1S194, D1S210, D1S212, D1S191 and LAMB2. Two-point lod scores excluded tight linkage with all markers except D1S212 (maximum lod score of 1.07 at theta = 0.0). In the multipoint analysis, including D1S210-D1S212-LAMB2 and POAG, the entire 11 cM region spanned by these markers was excluded for linkage with POAG; that is, lod scores were < -2.0. In conclusion, POAG in this family does not map to chromosome 1q21-q31 and, thus, they carry a gene that is distinct from the juvenile glaucoma gene.

  12. Filtration Combustion in Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard

    1999-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS, a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized, as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS. Nevertheless, the two applications have much in common, so that what is learned in one application can be used to advantage in the other. We have

  13. Alkaline hydrothermal conversion of fly ash filtrates into zeolites 2: utilization in wastewater treatment.

    PubMed

    Somerset, Vernon; Petrik, Leslie; Iwuoha, Emmanuel

    2005-01-01

    Filtrates were collected using a codisposal reaction wherein fly ash was reacted with acid mine drainage. These codisposal filtrates were then analyzed by X-ray Fluorescence spectrometry for quantitative determination of the SiO2 and Al2O3 content. Alkaline hydrothermal zeolite synthesis was then applied to the filtrates to convert the fly ash material into zeolites. The zeolites formed under the experimental conditions were faujasite, sodalite, and zeolite A. The use of the fly ash-derived zeolites and a commercial zeolite was explored in wastewater decontamination experiments as it was applied to acid mine drainage in different dosages. The concentrations of Ni, Zn, Cd, As, and Pb metal ions in the treated wastewater were investigated. The results of the treatment of the acid mine drainage with the prepared fly ash zeolites showed that the concentrations of Ni, Zn, Cd, and Hg were decreased as the zeolite dosages of the fly ash zeolite (FAZ1) increased.

  14. Effect of particle size on the performance of batchwise centrifugal filtration.

    PubMed

    Hwang, K J

    2001-01-01

    The effect of particle size distribution on the performance of batchwise centrifugal filtration is studied. By analyzing the velocity of particles in a filter, a numerical program is designed for simulating the migration and deposition of particles. The particle size distributions and the average specific filtration resistances of cake are then estimated under various rotating speeds of the centrifuge. A large deviation of particle concentration profiles in the filter chamber will occur if the particle size distribution is not taken into consideration. A more heterogeneous cake will form under a lower rotating speed due to the sedimentation effect of particles. The predicted results of particle size distribution and average specific filtration resistance of cake agree well with the available experimental data.

  15. 20. View of sand filtration bed. Wheelbarrow was used to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. View of sand filtration bed. Wheelbarrow was used to remove schmutzdeck (top, dirty sand layer containing particulate contamination, dead microorganisms and debris) for cleaning and or disposal. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  16. 2. View east of filtration bed building. Access bridge to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View east of filtration bed building. Access bridge to earth covering over reinforced concrete roof is at center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  17. 3. View southeast of northwest corner of filtration bed. Laboratory ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View southeast of northwest corner of filtration bed. Laboratory building is at center right of photograph. East rock appears directly behind the laboratory building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  18. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Filtration sampling requirements....

  19. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Filtration sampling requirements....

  20. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source...

  1. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  2. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration sampling requirements....

  3. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source...

  4. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Filtration sampling requirements....

  5. 15. View west of central corridor between filtration beds which ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View west of central corridor between filtration beds which are located to the left and right of the photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  6. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Filtration sampling requirements....

  7. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source...

  8. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source...

  9. 16. View west from center of central corridor between filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. View west from center of central corridor between filtration beds which are located to the left and right of the photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  10. 30. Valves under central corridor of filtration bed building. Main ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Valves under central corridor of filtration bed building. Main flood valves is at left and crossover valve is a right. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  11. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source...

  12. Membrane filtration technology for the metals fabrication industry

    SciTech Connect

    Peden, J.; Lindsey, T.

    1995-12-31

    Membrane filtration for separating contaminants from aqueous cleaning solutions based on molecular size, shape, and charge is described in this paper. Ultrafiltration is a pressure driven membrane filtration technique capable of producing high quality filtrate from wastewater. Three case studies are briefly described where ultrafiltration has been incorporated into the manufacturing process.

  13. 21. Overflow pipe in filtration bed. Located at each corner ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Overflow pipe in filtration bed. Located at each corner of the bed, the pipes drain off any excess water and maintain a limit on water depth. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  14. Internal filtration in dialyzers with different membrane permeabilities.

    PubMed

    Sato, Yuichi; Kimura, Kenjiro; Chikaraishi, Tatsuya

    2010-07-01

    Over the last decade, hemodialysis with enhanced internal filtration (IF) has been investigated as an alternative to conventional dialysis. Several factors affect IF, including the geometry and permeability of hollow-fiber dialyzers. Although various studies have been performed, the association between IF and membrane permeability has not been fully examined because of the difficulty in measuring IF. Therefore, in this study, we set up an experimental circuit and attempted to directly measure IF as well as membrane permeability in five dialyzers. In the circuit, we placed two dialyzers of the same type in series, and a special sampling port between them, thereby making it possible to determine IF by measuring the extent to which blood was concentrated between the two dialyzers. We showed that a significant amount of IF occurred in this tandem-dialyzer circuit, ranging from 23.5 to 100 ml/min, which increased linearly with increasing membrane permeability. We also showed that membrane permeability was reduced in the first dialyzer to a greater extent than in the second one after four hours of circulation, suggesting that filtration caused substantial membrane fouling. In this study we practically demonstrated that membrane permeability is highly relevant to the phenomenon of IF.

  15. Filtration of bioaerosols using a granular metallic filter with micrometer-sized collectors

    SciTech Connect

    Damit, Brian E; Bischoff, Brian L; Phelps, Tommy Joe; Wu, Dr. Chang-Yu; Cheng, Mengdawn

    2014-01-01

    Several experimental studies with granular bed filters composed of micrometer-sized spherical or sintered metallic granules have demonstrated their use in aerosol filtration. However, the effectiveness of these metallic membrane filters against bioaerosols has not been established. In this work, the filtration efficiency and filter quality of these filters against airborne B. subtilis endospore and MS2 virus were determined as a function of face velocity and loading time. In experiments, a physical removal efficiency greater than 99.9% and a viable removal efficiency of greater than 5-log were observed for both bacterial spore and viral aerosols. A lower face velocity produced both higher collection efficiency and filter quality for virus but was not statistically significant for spore filtration. Although the filter had high filtration efficiency of the test bioaerosols, the filter's high pressure drop resulted in a low filter quality (0.25-0.75 kPa- 1). Overall, filters with micrometer-sized collectors capture bioaerosols effectively but their applications in aerosol filtration may be limited by their high pressure drop.

  16. Effect of filtration rate on coal-sand dual-media filter performances for microalgae removal.

    PubMed

    Sabiri, Nour-Eddine; Monnier, Elodie; Raimbault, Virginie; Massé, Anthony; Séchet, Véronique; Jaouen, Pascal

    2017-02-01

    This study tested the efficiency of granular filtration using a bilayer sand filter for microalgae removal from culture dilutions ranging from 10,000 to 17,000 cells/mL. The objective is to evaluate the removal capacity of the filter without chemical coagulation. Two filter media, sand and anthracite, with mean grain sizes of 0.395 and 1.2 mm, respectively, were used in constant-flow-rate experiments (down-flow mode) with suspensions containing Heterocapsa triquetra microalga. The conventional rapid filtration which usually operates at a constant rate of approximately 5 m(3)/m(2) h is compared to high-rate filtration. Two filtration velocities (5 and 10 m/h) were investigated with bed depth of 1100 mm. Average microalgal cell removal rates were 90% at 5 m/h and 68% at 10 m/h. Turbidity removal was more than 71% at 5 m/h but just 57% at 10 m/h. Head losses did not increase significantly, and values measured at process end were 32 mbar at 5 m/h and 78 mbar at 10 m/h. Retention probabilities were calculated from experimental data. A theoretical model was used to evaluate the contributions of the different drivers of microalgae removal. Hypotheses are developed on the understanding of change in the mechanisms of retention as a function of filtration velocity.

  17. Effect of filtration on rolling-element-bearing life in contaminated lubricant environment

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.; Moyer, D. W.; Sherlock, J. J.

    1978-01-01

    Fatigue tests were conducted on groups of 65 millimeter-bore ball bearings under four levels of filtration with and without a contaminated MIL-L-23699 lubricant. The baseline series used noncontaminated oil with 49 micron absolute filtration. In the remaining tests contaminants of the composition found in aircraft engine filters were injected into the filter's supply line at a constant rate of 125 milligrams per bearing-hour. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns (0.45, 10, 30, and 70 microns nominal), respectively. Bearings were tested at 15,000 rpm under 4580 newtons radial load. Bearing life and running tract condition generally improved with finer filtration. The 3 and 30 micron filter bearings in a contaminated lubricant had statistically equivalent lives, approaching those from the baseline tests. The experimental lives of 49 micron bearings were approximately half the baseline bearing's lives. Bearings tested with the 105 micron filter experienced wear failures. The degree of surface distress, weight loss, and probable failure mode were found to be dependent on filtration level, with finer filtration being clearly beneficial.

  18. Current and Future of Laser Therapy in the Management of Glaucoma

    PubMed Central

    Ekici, Feyzahan; Waisbourd, Michael; Katz, L. Jay

    2016-01-01

    There has been tremendous progress in the past decades in the utilization of lasers for treating patients with glaucoma. This article reviews the use of lasers in different areas of glaucoma, including the shift from argon laser trabeculoplasty (ALT) to selective laser trabeculoplasty (SLT), laser trabeculoplasty as an initial treatment for glaucoma, new laser trabeculoplasty procedures under investigation, and other recent laser treatment modalities such as endoscopic cyclophotocoagulation and laser-assisted deep sclerectomy. PMID:27014388

  19. The direction of research into visual disability and quality of life in glaucoma

    PubMed Central

    2011-01-01

    Background Glaucoma will undoubtedly impact on a person's ability to function as they go about their day-to-day life. The purpose of this study is to investigate the amount of published knowledge in quality of life (QoL) and visual disability studies for glaucoma, and make comparisons with similar research in other chronic conditions. Methods A systematic literature search of the Global Health, EMBASE Psychiatry and MEDLINE databases. Title searches for glaucoma and six other example chronic diseases were entered alongside a selection of keywords chosen to capture studies focusing on QoL and everyday task ability. These results were further filtered during a manual search of resulting abstracts. Outcomes were the number of publications per year for each disease, number relating to QoL and type of glaucoma QoL research. Results Fifteen years ago there were no published studies relating to the impact of glaucoma on QoL but by 2009 this had risen to 1.2% of all glaucoma articles. The number of papers relating to QoL as a proportion of all papers in glaucoma in the past 10 years (0.6%) is smaller than for AMD and some other disabling chronic diseases. Most QoL studies in glaucoma (82%) involve questionnaires. Conclusion QoL studies in glaucoma are increasing in number but represent a tiny minority of the total publications in glaucoma research. There are fewer QoL articles in glaucoma compared to some other disabling chronic conditions. The majority of QoL articles in glaucoma research use questionnaires; performance-based measures of visual disability may offer an additional method of determining how the disease impacts on QoL. PMID:21816060

  20. Cost and detection rate of glaucoma screening with imaging devices in a primary care center

    PubMed Central

    Anton, Alfonso; Fallon, Monica; Cots, Francesc; Sebastian, María A; Morilla-Grasa, Antonio; Mojal, Sergi; Castells, Xavier

    2017-01-01

    Purpose To analyze the cost and detection rate of a screening program for detecting glaucoma with imaging devices. Materials and methods In this cross-sectional study, a glaucoma screening program was applied in a population-based sample randomly selected from a population of 23,527. Screening targeted the population at risk of glaucoma. Examinations included optic disk tomography (Heidelberg retina tomograph [HRT]), nerve fiber analysis, and tonometry. Subjects who met at least 2 of 3 endpoints (HRT outside normal limits, nerve fiber index ≥30, or tonometry ≥21 mmHg) were referred for glaucoma consultation. The currently established (“conventional”) detection method was evaluated by recording data from primary care and ophthalmic consultations in the same population. The direct costs of screening and conventional detection were calculated by adding the unit costs generated during the diagnostic process. The detection rate of new glaucoma cases was assessed. Results The screening program evaluated 414 subjects; 32 cases were referred for glaucoma consultation, 7 had glaucoma, and 10 had probable glaucoma. The current detection method assessed 677 glaucoma suspects in the population, of whom 29 were diagnosed with glaucoma or probable glaucoma. Glaucoma screening and the conventional detection method had detection rates of 4.1% and 3.1%, respectively, and the cost per case detected was 1,410 and 1,435€, respectively. The cost of screening 1 million inhabitants would be 5.1 million euros and would allow the detection of 4,715 new cases. Conclusion The proposed screening method directed at population at risk allows a detection rate of 4.1% and a cost of 1,410 per case detected. PMID:28243057