Flap and suture manipulation after trabeculectomy with adjustable sutures: titration of flow and intraocular pressure in guarded filtration surgery

PURPOSE: To describe the intraocular pressure (IOP) changes resulting from scleral flap suture and scleral flap manipulation in an experimental model of conventional guarded filtration surgery. DESIGN: Experimental study. METHODS: Trabeculectomy operations were performed with adjustable sutures on 5 donor human eyes connected to a constant flow infusion and a real-time IOP monitoring system. Three different manipulations: posterior lip massage, suture adjustment using special forceps, and suture release, were tested on the completed operation site. MAIN OUTCOME MEASURES: The success in lowering IOP to the target range of 7 to 15 mm Hg within 5 interventions, the time to reach equilibrium IOP, and the frequency of undesired outcomes. RESULTS: Posterior lip massage, suture release, and suture adjustment lowered the IOP after stabilization to the target range in less than 5 interventions in 9%, 14%, and 100% respectively (P < 0.001). The median time for IOP to stabilize at the new level after each intervention after correction for the flow rates used was 36.3 minutes for massage, 8.5 minutes for releasable sutures, and 3.7 minutes for adjustment of sutures (P < 0.001). CONCLUSIONS: These results suggest that suture adjustment may be superior to both posterior lip massage and releasable sutures for managing IOP in the early phase following glaucoma surgery. Following clinical interventions that result in loss of anterior chamber volume, IOP checks should be made at least 40 minutes post-intervention or at a later time afterwards if there is a clinical risk of low aqueous production. Manipulation of the scleral flap and associated sutures may only lower the IOP for minutes to hours if the suture tension is not decreased.     

ATP-containing immunoliposomes specific for cardiac myosin

The application of ATP-loaded liposomes has been shown effective against ischemic damage in several tissues. In this study, we have prepared ATP-containing liposomes capable of specific recognition of component (myosin) specific for ischemic myocardium. ATP-containing immunoliposomes specific towards cardiac myosin were obtained by the attachment of the monoclonal anti-cardiac myosin 2G4 antibody to the surface of ATP-containing PEGylated liposomes prepared by the freezing-thawing method. Since intracellular myosin is exposed only in the areas containing ischemically compromised cells with damaged plasmic membranes, such liposomes are expected to target these areas both in vitro and in vivo. The attachment of the antibody did not provoke their ATP release from the liposomes and only minimally influenced liposome size and size distribution. Liposome-attached anti-myosin 2G4 antibody preserved its specific activity; and anti-myosin antibody-bearing, ATP-loaded liposomes bound efficiently to the monolayer of myosin in ELISA. The preparation of myosin-specific ATP-loaded immunoliposomes represented an important step in the development of targeted delivery systems capable of providing energy support to ischemic myocardium in vivo.     

T lymphocyte mediated lysis of mitomycin C treated Tenon's capsule fibroblasts

AIMS: To evaluate the effect of T cell co-culture on mitomycin C treated and untreated Tenon's capsule fibroblasts. METHODS: IL-2 dependent allogeneic T cells were incubated over a monolayer of mitomycin C treated or control fibroblasts. Fibroblast numbers were evaluated by direct counts using phase contrast microscopy. To determine whether T cell mediated lysis was a consequence of MHC mismatch, co-culture experiments were repeated with autologous T cells. The effect of Fas receptor blockade was established by co-incubation with a Fas blocking (M3) antibody. RESULTS: T cell co-culture resulted in a dramatic reduction in fibroblast survival compared to mitomycin C treatment alone (p = 0.032). T cell killing required fibroblast/lymphocyte cell to cell contact and was observed in both allogeneic and autologous co-culture experiments. Fas blocking antibodies did not significantly inhibit T cell killing (p = 0.39). CONCLUSION: T cells augment mitomycin C treated fibroblast death in vitro. Similar mechanisms may contribute to the cytotoxic effect of mitomycin C in vivo and account for the largely hypocellular drainage blebs that are observed clinically.     

Microalbuminuria independently predicts all-cause and cardiovascular mortality in a British population: The European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) population study

BACKGROUND: In patients with diabetes or hypertension, raised albuminuria is independently associated with an increased risk of all mortality, cardiovascular morbidity and mortality, and renal insufficiency. The role of albuminuria in the general population is still controversial. We therefore undertook this study to examine the relationship between albuminuria and all-cause, cardiovascular disease (CVD) and non-CVD mortality in the general population. METHODS: Prospective population-based cohort study of 20 911 individuals aged 40-79 years recruited in 1993-1997 for the EPIC-Norfolk Study (UK) and followed-up for an average of 6.3 years. Random spot urine specimens were collected at baseline and the albumin-to-creatinine ratio measured. Participants were categorized into normoalbuminuria, microalbuminuria, and macroalbuminuria ordered groups. At follow-up, vital status and cause of death were obtained from the UK Office for National Statistics. RESULTS: During follow-up, 934 deaths were registered. Age-adjusted all-cause mortality rate increased significantly across categories of baseline albuminuria (5.3, 5.2, and 6.3/1000 person years (pyrs) across tertiles of normoalbuminuria, 8.7/1000 pyrs for microalbuminuria, and 18.4/1000 pyrs for macroalbuminuria, P < 0.001 for trend); CVD, 1.6, 1.7, 2.1, 4.3, 12.6/1000 pyrs (P < 0.001); and non-CVD, 3.7, 3.5, 4.2, 4.4, 5.8/1000 pyrs (P = 0.052) respectively. The multivariate hazard ratio for all-cause mortality associated with microalbuminuria was 1.48 (95% CI: 1.20, 1.79), and CVD 2.03 (95% CI: 1.55, 2.67). The association with non-CVD mortality was only significant in men. CONCLUSIONS: The significant increased risk of all-cause mortality especially from CVD associated with microalbuminuria, suggest that this may be a useful indicator in identifying those in the population at greatest absolute risk of fatal CVD events alongside conventional CVD risk factors.     

Determinants of intraocular pressure and its association with glaucomatous optic neuropathy in Chinese Singaporeans: the Tanjong Pagar Study

PURPOSE: To examine the relationship between intraocular pressure (IOP), anthropomorphic, demographic, socioeconomic, systemic, and ocular factors and glaucomatous optic neuropathy (GON) in Chinese people. METHODS: Chinese people (n = 2000), aged 40 to 79 years, were selected from the Singapore electoral register. Of the 1717 considered eligible for examination, 1232 participated, representing a response rate of 71.8%. IOP was estimated with Goldmann applanation tonometry. The drainage angle was assessed with static and dynamic gonioscopy. The optic nerve was examined at high magnification through a dilated pupil with a fundus contact lens or a +78-D lens. Static automated visual field testing was performed on subjects with suspected glaucoma. GON was diagnosed on the basis of structural and functional abnormalities of the optic nerve. RESULTS: The main independent determinants of higher IOP were higher systolic blood pressure (P < 0.001), quadrants of any peripheral anterior synechiae (PAS, P = 0.02) and width of the drainage angle (P = 0.049). A 100- micro m increase in corneal thickness was associated with an increase in mean IOP of 1.5 to 1.8 mm Hg (P < 0.001). Odds of GON increased 1.2 times per 1-mm Hg increase in screening IOP. A clear association between corneal thickness and GON was not identified. CONCLUSIONS: Clinical IOP estimates are related to systolic blood pressure and corneal thickness. Variation in IOP with angle width may suggest that trabecular compaction significantly contributes to causes of the increase in IOP, independent of angle-closure. GON is an IOP-related phenomenon among Chinese Singaporeans.     

Beta irradiation: new uses for an old treatment: a review

Beta radiation has a long history as a treatment modality in ophthalmology. It is a convenient and practical method of applying radiation and has the advantage of minimal tissue penetration. There has been a recent resurgence in the use of beta radiation in other areas in medicine, such as the prevention of restenosis after coronary artery stenting. Beta radiation has been shown in vitro and in vivo to inhibit proliferation of human Tenon's fibroblasts, which enter a period of growth arrest but do not die. Effects on the cell cycle controller p53 have been shown to be important in this process. In ophthalmology, beta radiation has been used widely for the treatment of pterygium and is under evaluation for treatment of age-related macular degeneration and for controlling wound healing after glaucoma drainage surgery. In this latter role, beta radiation may be particularly appropriate for use in developing countries to improve the results of trabeculectomy while potentially avoiding some of the side effects of other antimetabolites.     

UK Food Standards Agency Optimal Nutrition Status Workshop: environmental factors that affect bone health throughout life

The UK Food Standards Agency (FSA) convened a group of expert scientists to discuss and review UK FSA- and Department of Health-funded research on diet and bone health. This research focused on the lifestyle factors that are amenable to change and may significantly affect bone health and the risk of osteoporotic fracture. The potential benefits of fruits and vegetables, meat, Ca, vitamins D and K and phyto-oestrogens were presented and discussed. Other lifestyle factors were also discussed, particularly the effect of physical activity and possible gene-nutrient interactions affecting bone health.     

Randomized controlled study of colloid preload before spinal anaesthesia for caesarean section

We randomized women having elective Caesarean section to receiveeither no preload (control group, n=33) or 4% gelatin solution(Gelofusine) 15 ml kg^–1 (colloid group, n=35)i.v. before spinal anaesthesia. Intravenous metaraminol wastitrated at 0.25–0.75 mg min^–1 to maintainsystolic arterial pressure (SAP) in the target range 90–100%of baseline after the spinal injection. The control group requiredmore vasopressor in the first 10 min [median 1.7 (range 0–2.9)mg vs 1.4 (0–2.8), P=0.02] at a greater maximum infusionrate [0.5 (0–0.75) vs 0.25 (0–0.5) mg min^–1,P=0.0005] and had a lower minimum SAP [90 (51–109) vs101 (75–127) mm Hg, P=0.006] than the colloid group. Nauseawas less frequent in the colloid group (6 vs 24%) but neonataloutcome was similar in the two groups. Colloid preload improvedhaemodynamic stability but did not affect neonatal outcome whenarterial pressure was maintained with an infusion of metaraminolduring spinal anaesthesia for Caesarean section. Br J Anaesth 2001; 87: 772–4