Increasing the size of a small peripheral iridotomy widens the anterior chamber angle:An ultrasound biomicroscopy study

Purpose: A peripheral iridotomy (PI) is the treatment of choice for pupillary block. In this study we investigated the effect of enlarging the size of a small PI on the anterior chamber angle in patients with angle closure using ultrasound biomicroscopy (UBM). Patients and Methods: Patients who had been treated with laser peripheral iridotomy for angle closure and were identified to have a small patent PI (<100 µm) with still appositionally closed anterior chamber angle were selected prospectively. The anterior chamber angle was assessed using UBM. The angle opening distance 500 µm from the scleral spur (AOD500) as well as the anterior and posterior chamber depth (ACD and PCD) 1000 µm from the scleral spur was measured. In addition, the ACD/PCD ratio was calculated. Afterwards, the PI was enlarged using an Nd: YAG laser and the UBM measurements were repeated as described above. Results: Six eyes of six patients were examined. After the enlargement of the PI the average AOD500 increased from 109 µm (±36) to 147 µm (±40) (p

Laser peripheral iridoplasty for angle-closure

BACKGROUND: Angle-closure glaucoma is a leading cause of irreversible blindness in the world. Treatment is aimed at opening the anterior chamber angle and lowering the IOP with medical and/or surgical treatment (e.g. trabeculectomy, lens extraction). Laser iridotomy works by eliminating pupillary block and widens the anterior chamber angle in the majority of patients. When laser iridotomy fails to open the anterior chamber angle, laser iridoplasty may be recommended as one of the options in current standard treatment for angle-closure. Laser peripheral iridoplasty works by shrinking and pulling the peripheral iris tissue away from the trabecular meshwork. Laser peripheral iridoplasty can be used for crisis of acute angle-closure and also in non-acute situations.

OBJECTIVES: To assess the effectiveness of laser peripheral iridoplasty in the treatment of narrow angles (i.e. primary angle-closure suspect), primary angle-closure (PAC) or primary angle-closure glaucoma (PACG) in non-acute situations when compared with any other intervention. In this review, angle-closure will refer to patients with narrow angles (PACs), PAC and PACG.

SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 12), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 5 January 2012.

SELECTION CRITERIA: We included only randomised controlled trials (RCTs) in this review. Patients with narrow angles, PAC or PACG were eligible. We excluded studies that included only patients with acute presentations, using laser peripheral iridoplasty to break acute crisis.

DATA COLLECTION AND ANALYSIS: No analysis was carried out as only one trial was included in the review.

MAIN RESULTS: We included one RCT with 158 participants. The trial reported laser peripheral iridoplasty as an adjunct to laser peripheral iridotomy compared to iridotomy alone. The authors report no superiority in using iridoplasty as an adjunct to iridotomy for IOP, number of medications or need for surgery.

AUTHORS' CONCLUSIONS: There is currently no strong evidence for laser peripheral iridoplasty's use in treating angle-closure.

Laser peripheral iridoplasty for angle-closure

BACKGROUND: Angle-closure glaucoma is a leading cause of irreversible blindness in the world. Treatment is aimed at opening the anterior chamber angle and lowering the IOP with medical and/or surgical treatment (e.g. trabeculectomy, lens extraction). Laser iridotomy works by eliminating pupillary block and widens the anterior chamber angle in the majority of patients. When laser iridotomy fails to open the anterior chamber angle, laser iridoplasty may be recommended as one of the options in current standard treatment for angle-closure. Laser peripheral iridoplasty works by shrinking and pulling the peripheral iris tissue away from the trabecular meshwork. Laser peripheral iridoplasty can be used for crisis of acute angle-closure and also in non-acute situations. OBJECTIVES: To assess the effectiveness of laser peripheral iridoplasty in the treatment of narrow angles (i.e. primary angle-closure suspect), primary angle-closure (PAC) or primary angle-closure glaucoma (PACG) in non-acute situations when compared with any other intervention. In this review, angle-closure will refer to patients with narrow angles, PAC and PACG. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library), MEDLINE, EMBASE and LILACS (Latin American and Caribbean Literature on Health Sciences). The databases were last searched on 11 February 2008. SELECTION CRITERIA: Only randomised controlled trials (RCTs) were eligible for inclusion in this review. Patients with narrow angles, PAC or PACG were eligible. Studies that included only patients with acute presentations, using laser peripheral iridoplasty to break acute crisis were excluded. DATA COLLECTION AND ANALYSIS: No analysis was carried out due to lack of trials. MAIN RESULTS: There were no RCTs assessing laser peripheral iridoplasty in the non-acute setting of angle-closure. AUTHORS' CONCLUSIONS: There is currently no strong evidence for laser peripheral iridoplasty's use in treating angle-closure.

Combination of CFD and DOE to analyze and improve the mass flow rate in urinary catheters

The urinary catheter is a thin plastic tube that has been designed to empty the bladder artificially, effortlessly, and with minimum discomfort. The current CH14 male catheter design was examined with a view to optimizing the mass flow rate. The literature imposed constraints to the analysis of the urinary catheter to ensure that a compromise between optimal flow, patient comfort, and everyday practicality from manufacture to use was achieved in the new design. As a result a total of six design characteristics were examined. The input variables in question were the length and width of eyelets 1 and 2 (four variables), the distance between the eyelets, and the angle of rotation between the eyelets. Due to the high number of possible input combinations a structured approach to the analysis of data was necessary. A combination of computational fluid dynamics (CFD) and design of experiments (DOE) has been used to evaluate the "optimal configuration." The use of CFD couple with DOE is a novel concept, which harnesses the computational power of CFD in the most efficient manner for prediction of the mass flow rate in the catheter. Copyright © 2009 by ASME.

Diabetic retinopathy: morphometric analysis of basement membrane thickening of capillaries in different retinal layers within arterial and venous environments

AIMS: To assess quantitatively variations in the extent of capillary basement membrane (BM) thickening between different retinal layers and within arterial and venous environments during diabetes. METHODS: One year after induction of experimental (streptozotocin) diabetes in rats, six diabetic animals together with six age-matched control animals were sacrificed and the retinas fixed for transmission electron microscopy (TEM). Blocks of retina straddling the major arteries and veins in the central retinal were dissected out, embedded in resin, and sectioned. Capillaries in close proximity to arteries or veins were designated as residing in either an arterial (AE) or a venous (VE) environment respectively, and the retinal layer in which each capillary was located was also noted. The thickness of the BM was then measured on an image analyser based two dimensional morphometric analysis system. RESULTS: In both diabetics and controls the AE capillaries had consistently thicker BMs than the VE capillaries. The BMs of both AE and VE capillaries from diabetics were thicker than those of capillaries in the corresponding retinal layer from the normal rats (p <or = 0.005). Also, in normal AE and VE capillaries and diabetic AE capillaries the BM in the nerve fibre layer (NFL) was thicker than that in either the inner (IPL) or outer (OPL) plexiform layers (p <or = 0.001). However, in diabetic VE capillaries the BMs of capillaries in the NFL were thicker than those of capillaries in the IPL (p <or = 0.05) which, in turn, had thicker BMs than capillaries in the OPL (p <or = 0.005). CONCLUSIONS: The variation in the extent of capillary BM thickening between different retinal layers within AE and VE environments may be related to differences in levels of oxygen tension and oxidative stress in the retina around arteries compared with that around veins.

Growth of human B cell colonies from peripheral blood of patients with systemic lupus erythematosus

Human B cell colonies were grown from peripheral blood of 12 patients with systemic lupus erythematosus (SLE) and from 12 healthy control subjects. The SLE group showed a large increase (p less than 0.001) in the number of colony forming cells (CFC) present in peripheral blood as compared with controls. The CFC were of the pre-B cell type. There was also a loss of OKT8+ cell inhibition of B cell colony growth in the SLE group compared with control subjects.

Central venous catheterization - An anatomical review of a clinical skill - Part 1: Subclavian vein via the infraclavicular approach.

The safe and successful performance of a central venous catheterization (CVC) requires a specific knowledge of anatomy in addition to a working knowledge. Misunderstanding the anatomy may result in failure or complications. This review aims to aid understanding of the anatomical framework, pitfalls, and complications of CVC of the subclavian (SCV). CVC is common practice amongst surgeons, anesthesiologists, and emergency room physicians during the preparations for major surgical procedures such as open-heart surgery, as well as, for intensive care monitoring and rapid restoration of blood volume. Associated with this technique are certain anatomical pitfalls and complications that can be successfully avoided if one possesses a thorough knowledge of the contraindications, regional anatomy, and rationale of the technique.

Cyanoacrylate glue versus suture in peripheral nerve reanastomosis

OBJECTIVE: To assess the effectiveness of n-butyl-2-cyanoacrylate glue compared with microsuturing technique in peripheral nerve reanastomosis in rats.

STUDY DESIGN: Fourteen young adult white rats were used. Bilateral sciatic neurotomies were performed in 12 of them and then reanastomosed with 3 epineural microsutures in the right side (study group G1) and with n-butyl-2-cyanoacrylate glue in the left side (study group G2). On the remaining 2 rats (control group G3), sham surgery was done on both sides. Biopsies were harvested 12 weeks after surgery and examined under light microscope using Osmic acid stains. The number of nerve fibers was counted in the distal and proximal nerve segments, and the results were analyzed and compared in all groups.

RESULTS: Adequate regeneration with no anastomotic ruptures was seen 12 weeks after surgery in G1 and G2. The histomorphometric assessment showed no statistically significant difference (P = .960) in the neurotization index of G1 (89.01%) compared with G2 (88.97%). There was a significant (P = .001) reduction in the mean number of axon counts distal to the repair in G1 (271.3) and G2 (272.8) compared with that of the proximal segments of each study group (304.6 and 303, respectively, as well as to that of G3 (348.5).

CONCLUSION: Both n-butyl-2-cyanoacrylate adhesive and 3-microsuture techniques showed comparable neurotization indices and were equally adequate to stabilize the nerve during regeneration period.

The effects of Chronic Lycopene Supplementation on Exercise-Induced Oxidative Stress and Glucose Homeostasis.

Lycopene can exert antioxidant effects against peripheral and cellular oxidative stress and may be associated with reduced diabetic risk. Conversely, exercise-induced free radicals are thought to underpin many of the desirable whole-body adaptations following training and the use of antioxidants within the exercise model remains debatable. PURPOSE: To investigate the effect of lycopene supplementation on oxidative stress and glucose homeostasis following acute aerobic exercise. METHOD: Twenty-eight (n=28) apparently healthy male volunteers were recruited (age 24 ± 4 years; weight 78 ± 10 kg; height 178 ± 8 cm; 2max 40 ± 7 ml·kg-1 ·min-1 ) in a randomised, single blind, placebo-controlled study. Participants were required to attend the Laboratory on two occasions: prior to and following 6 weeks of supplementation of either 10mg lycopene (LG; n=15) or placebo (PG; n=13) followed by a bout of acute exercise for one hour at 65% 2max. Exogenous glucose oxidation was then measured on an isotope ratio mass spectrometer in a sub-group of participants (n=14) following exercise, by administration of a standard oral glucose tolerance test (OGTT; 75g glucose). Venous blood samples were drawn for measurement of oxidative stress parameters, plasma glucose and insulin. RESULTS: Plasma lycopene increased in LG only (0.01 ± 0.004 vs.0.02 ± 0.007 µmol/L; P <0.05) following supplementation and remained elevated post exercise compared to PG (0.01 ± 0.004 vs. 0.02 ± 0.009 µmol/L; P <0.05). There were no changes in other markers of oxidative stress (SOD, LOOHs, F2 ISP and Alkoxyl radical) either between or within the trials, (P >0.05, respectively). A main effect for an increase in insulin was observed two hours post OGTT in the sub-groups (Pooled data, P <0.05) but trends in the HOMA scores were evident with a 57% increase for LG (2.20 ± 1.84 vs. 5.14 ± 2.5; P >0.05) and an 11% decrease for PG (2.17 ± 1.06 vs. 1.94 ± 1.53; P >0.05). No change in plasma glucose was detected at any point, or after the OGTT (P >0.05). CONCLUSION: In healthy males, lycopene supplementation had no effect on post exercise levels of ROS or markers of lipid peroxidation, despite an increase in plasma lycopene. However, lycopene supplementation may affect post exercise insulin sensitivity in response to glucose consumption, but further parallel research is required.

Diabetic retinopathy:morphometric analysis of basement membrane thickening of capillaries in different retinal layers within arterial and venous environments

AIMS: To assess quantitatively variations in the extent of capillary basement membrane (BM) thickening between different retinal layers and within arterial and venous environments during diabetes.

METHODS: One year after induction of experimental (streptozotocin) diabetes in rats, six diabetic animals together with six age-matched control animals were sacrificed and the retinas fixed for transmission electron microscopy (TEM). Blocks of retina straddling the major arteries and veins in the central retinal were dissected out, embedded in resin, and sectioned. Capillaries in close proximity to arteries or veins were designated as residing in either an arterial (AE) or a venous (VE) environment respectively, and the retinal layer in which each capillary was located was also noted. The thickness of the BM was then measured on an image analyser based two dimensional morphometric analysis system.

RESULTS: In both diabetics and controls the AE capillaries had consistently thicker BMs than the VE capillaries. The BMs of both AE and VE capillaries from diabetics were thicker than those of capillaries in the corresponding retinal layer from the normal rats (p < or = 0.005). Also, in normal AE and VE capillaries and diabetic AE capillaries the BM in the nerve fibre layer (NFL) was thicker than that in either the inner (IPL) or outer (OPL) plexiform layers (p < or = 0.001). However, in diabetic VE capillaries the BMs of capillaries in the NFL were thicker than those of capillaries in the IPL (p < or = 0.05) which, in turn, had thicker BMs than capillaries in the OPL (p < or = 0.005).

CONCLUSIONS: The variation in the extent of capillary BM thickening between different retinal layers within AE and VE environments may be related to differences in levels of oxygen tension and oxidative stress in the retina around arteries compared with that around veins.