[PDF] [Full Text] [Abstract] , April 1, 2003; 44 (4): 1775-1782. Invest. Ophthalmol. Vis. Sci. G. T. Higgins, J. H. Wang, P. Dockery, P. E. Cleary and H. P. Redmond Photoreceptor Outer Segments Induction of Angiogenic Cytokine Expression in Cultured RPE by Ingestion of Oxidized [PDF] [Full Text] [Abstract] , June 1, 2003; 284 (6): C1374-C1386. Am J Physiol Cell Physiol S. McGinn, P. Poronnik, M. King, E. D. M. Gallery and C. A. Pollock and hyperosmolarity High glucose and endothelial cell growth: novel effects independent of autocrine TGF-beta 1 [PDF] [Full Text] [Abstract] , October 1, 2004; 287 (4): C949-C953. Am J Physiol Cell Physiol Schaffer, Y. Fujio and J. Azuma T. Takatani, K. Takahashi, Y. Uozumi, E. Shikata, Y. Yamamoto, T. Ito, T. Matsuda, S. W. Taurine inhibits apoptosis by preventing formation of the Apaf-1/caspase-9 apoptosome [PDF] [Full Text] [Abstract] , October 1, 2007; 293 (4): F1072-F1082. Am J Physiol Renal Physiol J.-S. Huang, L.-Y. Chuang, J.-Y. Guh, Y.-J. Huang and M.-S. Hsu cells Antioxidants attenuate high glucose-induced hypertrophic growth in renal tubular epithelial [PDF] [Full Text] [Abstract] , February 1, 2009; 296 (2): H453-H461. Am J Physiol Heart Circ Physiol A. P. Kellogg, K. Converso, T. Wiggin, M. Stevens and R. Pop-Busui function in experimental diabetes Effects of cyclooxygenase-2 gene inactivation on cardiac autonomic and left ventricular

Objective: To identify an optical coherence tomography (OCT) pattern predictive of visual outcome in patients with diabetic macular edema (DME) who underwent a single dose of intravitreal triamcinolone.Design: Retrospective case analysis with prospective data collection for controls.Participants: Ninety-three cases and 25 controls.Methods: Two independent masked observers retrospectively examined preoperative macular OCTs of 93 eyes of 93 patients who were given a single dose (4 mg in 0.1 ml) of intravitreal triamcinolone for DME and categorized them as belonging to 2 groups: 1, comprised of eyes with high reflectivity (bright colors) from inner retinal layers, and 2, comprised of eyes that had low reflectivity (darker colors) from inner retinal layers. Logarithm of the minimum angle of resolution visual acuity (VA) and macular thickness measured by OCT were assessed preoperatively and postoperatively at 1 and 3 months.Main Outcome Measures: Optical coherence tomographic appearance of inner retinal layers.Results: All patients completed 3 months of follow-up. In group 1, 45 of 51 eyes (88%) experienced visual improvement of >= 2 lines on an Early Treatment Diabetic Retinopathy Study (ETDRS) chart at 1 month of follow-up. Forty-four of 51 patients (86%) experienced visual improvement of >= 2 lines on an ETDRS chart at 3 months of follow-up. In group 2, 18 of 42 patients (43%) experienced visual improvement of >= 1 lines on an ETDRS chart at 1 and 3 months of follow-up. For the remaining patients, VA remained unchanged during the postoperative course of 3 months.Conclusions: Patients in whom OCT demonstrated the high reflectivity of inner retinal layers achieved greater VA though macular thickness decreased significantly after intravitreal triamcinolone in both groups. It may be hypothesized that a lower optical reflectivity of inner retinal layers is related to the atrophy of the inner retinal layers, thus resulting in a failure of VA recovery in these patients. The level of reflectivity from inner retinal layers on OCT may provide objective criteria in predicting the response of DME to intravitreal triamcinolone and help in preoperative counseling of patients with DME.

Aims This pilot study uses Optical Coherence Tomography (OCT) imaging to compare the difference in foveal architecture after successful retinal detachment (RD) surgery by scleral buckling or pars plana vitrectomy (PPV).Methods Prospective recruitment of patients with macular off RDs. Detachment surgery was undertaken by scleral buckling, external drainage, and air injection (group 1) or by PPV (group 2). Postoperatively patients had clinical examinations and OCT at 1, 3, 6, and 12 months. If abnormalities persisted, a further OCT was obtained at 18 months.Results Retinal reattachment, including clinical macular reattachment, was achieved in all cases within 24 h postoperatively. In group 1 (n = 22), postoperative OCT showed persistent foveal detachment in 63% of cases (n 14) at 1 and 3 months. At 6 and 12 months, 36% (n = 8) and 9% (n = 2) had a persistent foveal detachment, respectively, and at 18 months, foveal detachment eventually. In group 2 (n 21), postoperative OCT showed an attached fovea in all cases; however, foveal thickening suggesting intraretinal oedema was present in all cases. The oedematous appearance of retina on OCT settled in 1-3 months. No foveal abnormality was seen at 6 and 12 months postoperatively.Conclusions A high proportion of patients with successful retinal reattachment surgery by scleral buckling had foveal detachments postoperatively. No cases who had PPV had foveal detachments; however, transient retinal oedema was evident in all cases. The aetiology of these changes is unknown and warrants further investigation, as there is the potential of a long-term effect on vision.

To evaluate the efficacy of intravitreal triamcinolone (IVTA) for the treatment of diffuse diabetic macular oedema (DME) refractory to conventional argon macular laser therapy. A prospective, consecutive, and noncomparative case series was undertaken involving 38 eyes of 38 patients with refractory DME. Triamcinolone acetonide (4 mg) in 0.1 ml was injected intravitreally. LogMar visual acuity (VA) and macular thickness measured by ocular coherence tomography (OCT) were assessed preoperatively and postoperatively at 1, 3, and 6 months. All patients completed 6 months of follow up. VA (mean±SD) improved from 0.905±0.23 to 0.605±0.28, 0.555±0.29, and 0.730±0.30 at 1, 3, and 6 months, respectively. Macular thickness baseline (mean±SD) on OCT was 418.7±104.2 μm and this decreased to 276.9±72.6 μm, 250.6±53.1 μm, and 308.8±87.3 μm at 1, 3, and 6 months, respectively. IVTA may be a potential temporary treatment for refractory DME. It is effective in decreasing macular thickness and improving VA but the effect lasts approximately for 6 months in the majority of patients. Further investigations are required to establish the safety of IVTA for the treatment of DME.

PURPOSE:Foveal detachment after apparently successful retinal reattachment surgery for macula-on retinal detachments (RDs) has been previously documented. This pilot study aimed to utilize ocular coherence tomography (OCT) imaging to investigate foveal architecture after routine retinal detachment surgery and correlate this to visual acuity.METHODS:Prospective recruitment of patients attending one unit with macula-on RDs. Patients underwent full clinical examination including OCT preoperatively and RD surgery undertaken by scleral buckling, external drainage and air injection. Postoperatively patients had clinical examinations and OCT at 1 week, 1, 3, 6, and 12 months.RESULTS:A total of 12 consecutive patients were recruited into the study. All had macula-on RDs and normal OCTs at onset. There were no operative or postoperative complications. Retinal reattachment was achieved in all cases within 24 h postoperatively. At 1 month six of 12 patients (50%) showed foveal detachment on OCT, which was invisible on clinical examination. At 3 months, the foveal detachment persisted in four (33%) of these patients. In these cases the foveal detachment persisted at 6 months follow-up, however, a reduction in subfoveal fluid was noted. All cases had foveal reattachment by 12 months postoperatively. Visual acuity was closely correlated to the presence of foveal attachment.DISCUSSION:A high proportion of patients with successful retinal reattachment surgery had foveal detachments postoperatively. This phenomenon was associated with reduced visual acuity. The aetiology of this occurrence is unknown and warrants further investigation as there is the potential of a long-term effect on vision.

PURPOSE:Normal aging is associated with accumulation of lipofuscin pigment in the retinal pigment epithelium (RPE). This may occur as a result of phagocytosis and incomplete degradation of oxidized photoreceptor outer segments (POS). This study was undertaken to determine whether phagocytosis of UV-irradiated POS (artificial lipofuscin) would increase expression in the RPE of various chemotactic and angiogenic cytokines.METHODS:ARPE-19 cells were exposed to latex beads (0.76 micro m), naïve bovine POS, and UV-irradiated POS (Ox-POS; 2 x 10(7)/mL), and supernatants were collected at 18 and 36 hours. The supernatants were assayed for IL-8, monocyte chemotactic protein-(MCP)-1, and TNF-alpha by ELISA. Protein synthesis and NFkappaB activity were inhibited by actinomycin D and SN50, respectively. Phagocytosis and generation of intracellular reactive oxygen species were assessed by flow cytometry. Confocal and electron microscopy studies were also performed to verify phagocytosis and cellular integrity.RESULTS:IL-8 and MCP-1 levels were decreased in the naïve POS group (IL-8: 473.76 +/- 66.9 pg/mL, P = 0.0005; MCP-1: 550.1 +/- 21.8 pg/mL, P = 0.0001), but were increased in the Ox-POS group (IL-8: 1348.8 +/- 164.9 pg/mL; MCP-1: 1772.28 +/- 65.19 pg/mL) compared with the control (IL-8: 741.09 +/- 39.8 pg/mL; MCP-1: 1413.47 +/- 38.4 pg/mL) and latex bead groups (data not shown). TNF-alpha levels were not affected. At 12 hours (but not at 6 hours), ROS were increased in the Ox-POS group. The cytokine increases observed were dependent on de novo protein synthesis and were NF-kappaB dependent.CONCLUSIONS:Ingestion by RPE of oxidized bovine POS stimulates expression of the chemotactic and angiogenic factors IL-8 and MCP-1 that have the capability to promote angiogenesis directly, or indirectly through the accumulation of immune cells such as macrophages, which themselves may release angiogenic promoters and degrade Bruch's membrane. This may be of significance in the development of exudative AMD.

BACKGROUND:The beneficial effects of adjuvant treatment with agents such as autologous platelet concentrate (APC) or autologous serum (AS) in the surgical management of macular holes remain uncertain. The purpose of this study was to determine the histological changes induced by these agents compared with control on retinal wound healing in an animal model.METHODS:The right eyes of 51 pigmented rabbits were used. Under anaesthesia, full-thickness sensory retinal incisions 2 mm in length were made into avascular retina down to the level of the retinal pigment epithelium using a 23-gauge needle via a superotemporal sclerotomy. APC, AS or sterilised balanced salt solution was placed directly over the wound site. Animals were killed at 3, 7 or 14 days and the wounds examined immunohistologically. Proliferating cell nuclear antigen (PCNA) was used to detect proliferating cells.RESULTS:No difference was observed between serum-treated eyes and control eyes. A greater displacement or migration of cells toward the retinal surface was consistently found in the APC-treated wounds than in control wounds. These cells were of mixed origin but appeared to arise predominantly from the outer nuclear layer. A significantly greater number of PCNA-staining cells was found in the platelet-treated group than in controls at 3 days (P=0.038), 7 days (P=0.039) and 14 days (P=0.038).CONCLUSION:We have demonstrated a significantly greater proliferative cellular response in the healing of retinal wounds with the use of platelet concentrate than in control wounds. We consider that this model may be used in further studies on the effects of other agents on retinal wound healing.

Purpose To determine the efficacy of dacryocystoplasty with balloon dilation in the treatment of acquired obstruction of the nasolacrimal system in adults. Methods Balloon dacryocystoplasty was performed in 52 eyes of 42 patients under general anaesthetic. A Teflon-coated guidewire was introduced through the canaliculus and manipulated through the nasolacrimal system and out of the nasal aperture. A 4 mm wide 3 cm coronary angioplasty balloon catheter was threaded over the guidewire in a retrograde fashion and dilated at the site of obstruction. Results There was complete obstruction in 30% of cases and partial obstruction in 70%. The most common site of obstruction was the nasolacrimal duct. The procedure was technically successful in 94% of cases. The overall re-obstruction rate was 29% within 1 year of the procedure. There was an anatomical failure rate of 17% for partial obstruction and 69% for complete obstruction within 1 year. Conclusions Balloon dacryocystoplasty has a high recurrence rate. There may be a limited role for this procedure in partial obstructions. Further refinements of the procedure are necessary before it can be offered as a comparable alternative to a standard surgical dacryocystorhinostomy.

Editor,—Ocular toxoplasmosis is the most frequent infectious cause of chorioretinal inflammation in immunocompetent individuals.1 Diagnosis is usually made by observing the typical fundus lesion, by detecting the presence of anti- Toxoplasma antibodies in the serum, and by excluding other causes of necrotising fundus lesions.2In unusual cases, invasive procedures may be required to aid diagnosis.3 ### CASE REPORT A 17 year old white male presented complaining of floaters and reduced visual acuity in the left eye. Visual acuity was 6/9 in the left eye, 6/6 in the right. Examination revealed moderate anterior chamber activity, marked vitritis, and an active retinochoroiditis adjacent to an area of old chorioretinal scarring inferonasal to the optic disc. A diagnosis of ocular toxoplasmosis was suspected, and topical and oral steroids, …

BACKGROUND Vitrectomy and gas tamponade has become a recognised technique for the treatment of macular holes. In an attempt to improve the anatomic and visual success of the procedure, various adjunctive therapies—cytokines, serum, and platelets—have been employed. A consecutive series of 85 eyes which underwent macular hole surgery using gas tamponade alone, or gas tamponade with either the cytokine transforming growth factor β2 (TGF-β2) or autologous platelet concentrate is reported. METHODS Twenty eyes had vitrectomy and 20% SF6 gas tamponade; 15 had vitrectomy, 20% SF6gas, and TGF-β2; 50 had vitrectomy, 16% C3F8gas tamponade, and 0.1 ml of autologous platelet concentrate prepared during the procedure. RESULTS Anatomic success occurred in 86% of eyes, with 96% of the platelet treated group achieving closure of the macular hole. Visual acuity improved by two lines or more in 65% of the SF6 only group, 33% of those treated with TGF-β2, and in 74% of the platelet treated group. In the platelet treated group 40% achieved 6/12 or better and 62% achieved 6/18 or better. The best visual results were obtained in stage 2 holes. CONCLUSION Vitrectomy for macular holes is often of benefit and patients may recover good visual acuity, especially early in the disease process. The procedure has a number of serious complications, and the postoperative posturing requirement is difficult. Patients need to be informed of such concerns before surgery.

ABSTRACT Here we present a general compartment model with a time-varying transmission rate to describe the dynamics of the COVID-19 epidemic, parameterized with the demographics of Bahia, a state in northeast Brazil. The dynamics of the model are influenced by the number of asymptomatic cases, hospitalization requirements and mortality due to the disease. A locally-informed model was determined using actual hospitalization records. Together with cases and casualty data, optimized estimates for model parameters were obtained within a metaheuristic framework based on Particle Swarm Optimization. Our strategy is supported by a statistical sensitivity analysis on the model parameters, adequate to properly account for the simulated scenarios. First, we evaluated the effect of previously enforced interventions on the transmission rate. Then, we studied its effects on the number of deaths as well as hospitalization requirements, considering the state as a whole. Special attention is given to the impact of asymptomatic individuals on the dynamic of COVID-19 transmission, as these were estimated to contribute to a 68% increase in the basic reproductive number. Finally, we delineated scenarios that can set guides to protect the health care system, particularly by keeping demand below total bed occupancy. Our results underscore the challenges related to maintaining a fully capable health infrastructure during the ongoing COVID-19 pandemic, specially in a low-resource setting such as the one focused in this work. The evidences produced by our modelling-based analysis show that decreasing the transmission rate is paramount to success in maintaining health resources availability, but that current local efforts, leading to a 38% decrease in the transmission rate, are still insufficient to prevent its collapse at peak demand. Carefully planned and timely applied interventions, that result in stark decreases in transmission rate, were found to be the most effective in preventing hospital bed shortages for the longest periods.