596 research outputs found
A hypothetical therapeutic effect of light peripheral panretinal photocoagulation in neovascular age-related macular degeneration
Background: Vascular endothelial growth factor (VEGF) is a significant modulator of ocular angiogenesis, including that of neovascular age-related macular degeneration (nAMD). Intravitreal injection of anti-VEGF is the benchmark treatment for most retinal vascular diseases, including nAMD, diabetic maculopathy, and macular edema secondary to retinal venous occlusion. Anti-VEGF treatment is a high-frequency, time-consuming, non-cost-effective therapy, especially in countries and regions with limited resources. This treatment is easily restricted, and in practice, maintaining long-term periodic care is challenging for patients.
Hypothesis: Light peripheral panretinal photocoagulation (PPRP) is applied in a mild form (barely visible mild light gray mark) anterior to the equator so as not to jeopardize the visual field. PPRP lessens the ischemia that causes neovascularization and decreases the metabolic demand in the peripheral retina. PPRP reduces serum angiopoietin-2 and VEGF levels in patients with type 2 diabetes mellitus with proliferative diabetic retinopathy. We propose using light PPRP to suppress VEGF secretion, aiming to attenuate the VEGF drive and halt choroidal neovascular growth in eyes with nAMD. Our regimen is based on two concepts: first, nAMD is a diffuse or generalized disease that affects the posterior segment; and second, PPRP is very effective in regressing diabetic retinopathy. PPRP has reportedly been successful in cases of macular edema (diabetic or following venous occlusion) resistant to VEGF antagonists. Light PPRP may be used as prophylaxis, adjunctive treatment, or monotherapy in nAMD when intravitreal injections of VEGF antagonists are not feasible.
Conclusions: The established light PPRP therapy could be promising as a one-time, cost-effective therapy or prophylaxis in patients with nAMD or at high risk. This proposed modality could be suitable for patients who have injection phobia or prefer a one-time affordable therapy to the long-term monthly visits to retinologists. Future trials are necessary to verify the safety and efficacy of this proposed treatment modality in selected patients with nAMD
An Affordances Apparatus for Enterprise Social Media
The current paper addresses one of the core yet complex issues in the study of technology in organizations: the relationship between the social and the material. Many scholars in the field of Information Systems have used the notion of affordance as a lens to investigate and theorize this relationship. However, knowledge contributions in this area are often abstract and impractical, or at least compel further conceptual development. This paper uses a relational view of affordances to study organizational social media affordances based on empirical data collected about the use of the Wiki technology at two large multinational organizationsâCCC and IBM. It theorizes four key mechanismsâreferring to other affordances (referential), collectively enacting significant affordances (communal), situation-dependent exploitation of affordances (situatedness), and exploiting other opportunities for action (multiplicity), that embody the interaction between the social and the material. These mechanisms make up what is labelled in this paper as âthe affordances apparatusâ. The apparatus provides a conceptual structure for the interaction between social and material features that shows operational dynamics and processes underpinning the perception, enactment and exploitation of affordances. This apparatus is the main contribution of the paper in that it gives researchers a conceptual tool for investigating affordances as relational constructs between the social and the material. It also helps in understanding how people navigate the use of technology features relative to their intentions and goals
Diabetic Macular Edema: From Old Concepts to New Therapeutic Avenues
Diabetic macular edema (DME) is an important cause of blindness in the working population and is currently challenging to treat. Current interventions include focal laser or intravitreal injections. This article outlines a new treatment protocol based on the concept that peripheral ischemia is the introduction to angiogenesis, that will ultimately gather its momentum at the fovea. Performing extreme peripheral light laser panretinal photocoagulation (PRP) back to the equator reduces excessive expression of the vascular endothelial growth factor (VEGF) in the eye. Subsequently, this decreases VEGF-induced DME and provides long-term protection for the development of neovascularization. Initial exacerbation of DME often accompanies PRP, Therefore; first injections of anti-VEGF agents (with or without dexamethasone implant) can forestall worsening of DME preventing loss of vision. However, on the other hand, applying peripheral PRP and intraocular injections can induce posterior vitreous detachment (PVD). This could help release vitreomacular adhesions (VMA) and vitreomacular traction (VMT), decreasing DME severity and improving response to intravitreal injections. The current approach works by laser ablation of the peripheral retina that should stop the drive for VEGF release; moreover, laser ablation should produce secondary, accidental and beneficial PVD. This approach precludes focal laser therapy and paves the path for prolonged anti-VEGF therapy
Assessment of freezing desalination technologies.
The production of both fresh water and waste streams are progressively increasing over the years due to ongoing population growth coupled with high levels of increase in water consumption. The ongoing growth of human activities, such as industry, recreation, and agriculture, are significantly contributing to the increase in both water demand and severity of degradation of natural water resources. The majority of the industrial wastewaters have a significant impact on the environment; some of which may pose a number of threats to human health and the surrounding environment. Thus, discharge of such waste streams into a surface water and/or groundwater presents a major source of water pollution in many countries. Therefore, these waste streams must be disposed of in an environmentally acceptable manner. The primary concern of the PhD thesis is to seek the most feasible and applicable freezing desalination technologies that are potentially capable to concentrate the dissolved ionic content of the liquid streams, especially for those causing severe pollution problems. Therefore, various forms of melt crystallisation processes, namely; agitated and static crystallisation processes, ice maker machines, a Sulzer falling film crystallisation process, the Sulzer suspension crystallisation process, and the Sulzer static crystallisation process, were experimentally used and investigated. The experimental investigations were carried out on the laboratory bench scale and/or straightforward pilot plant by using aqueous solutions of sodium chloride and/or process brines as feed samples. The study was focused on a number of important parameters influencing the separation performance of the investigated treatment systems. In general, the resulting experimental data for each innovative process were highly encouraging in minimising the volume of the waste stream, and substantially increasing the amount of product water. The obtained product water was ready for immediate use either as drinking water or as a saline water of near brackish water or seawater qualities. Also, relationships between the influences and the separation performance, in terms of salt rejection and water recovery ratios, were explored and determined for the investigated technologies. Based on the experimental results, the Sulzer melt crystallisation processes were scaled up and were combined into a commercial reverse osmosis membrane desalination plant. As a result, three novel treatment option configurations were proposed for minimising the waste stream, whilst increasing the production rate of drinking water and/or preserving a substantial amount of natural water resource from the RO plant's exploitation
Diabetic Macular Edema: From Old Concepts to New Therapeutic Avenues
Diabetic macular edema (DME) is an important cause of blindness in the working population and is currently challenging to treat. Current interventions include focal laser or intravitreal injections. This article outlines a new treatment protocol based on the concept that peripheral ischemia is the introduction to angiogenesis, that will ultimately gather its momentum at the fovea. Performing extreme peripheral light laser panretinal photocoagulation (PRP) back to the equator reduces excessive expression of the vascular endothelial growth factor (VEGF) in the eye. Subsequently, this decreases VEGF-induced DME and provides long-term protection for the development of neovascularization. Initial exacerbation of DME often accompanies PRP, Therefore; first injections of anti-VEGF agents (with or without dexamethasone implant) can forestall worsening of DME preventing loss of vision. However, on the other hand, applying peripheral PRP and intraocular injections can induce posterior vitreous detachment (PVD). This could help release vitreomacular adhesions (VMA) and vitreomacular traction (VMT), decreasing DME severity and improving response to intravitreal injections. The current approach works by laser ablation of the peripheral retina that should stop the drive for VEGF release; moreover, laser ablation should produce secondary, accidental and beneficial PVD. This approach precludes focal laser therapy and paves the path for prolonged anti-VEGF therapy
Posterior Scleritis in Familial Mediterranean Fever
Purpose: Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disease presenting as sporadic paroxysmal attacks of fever and abdominal pain. The inflammation of serosal spaces, joints, and skin is caused by the production of an abnormal protein called pyrin. Ocular pathology is scarce in FMF. Case Report: Herein we describe a case of FMF presenting with painful loss of vision in the left eye. Serous macular detachment assessed by OCT, leaky pinpoint subretinal foci temporal to the fovea examined by fluorescein angiography, scleral and choroidal thickening seen on ultrasonography, and a negative systemic workup for vasculitis established the diagnosis of FMF-related posterior scleritis. The posterior scleritis responded promptly to moderate-dose oral corticosteroids with return of vision to baseline and resolution of the subretinal fluid. Conclusions: FMF rarely involves the posterior pole. Visual loss in FMF results from either posterior scleritis or posterior uveitis. A high degree of suspicion of posterior scleritis is warranted in female patients with known FMF presenting with cloudy serous macular detachment
Microvascular Capillary Plexus Findings of Commotio Retinae on Optical Coherence Tomography Angiography
Optical coherence tomography (OCT) and histopathology features of commotio retinae (CR) have been established, but alterations of the microvascular macular capillary plexus on OCT angiography (OCTA) has not been previously studied. We present a 46-year-old man who sustained a tennis ball injury to the right eye with visual acuity reduction to 20/30 and grey-white deep macular discoloration, suggestive of CR. Spectral-domain OCT (SD-OCT) showed increased reflectivity and thickness of the ellipsoid zone (junction of photoreceptor inner and outer segments). OCTA revealed no apparent microvascular alterations (right versus left eye) in the foveal avascular zone superficial (0.42 vs. 0.43 mm2) and deep (0.45 vs. 0.44 mm2), superficial foveal capillary density (34.1 vs. 32.6%), and superficial parafoveal capillary density (55.2 vs. 52.2%). Deep macular capillary plexus and choriocapillaris were qualitatively comparable between the two eyes. At 2 monthsâ follow-up, SD-OCT had normalized. CR is characterized by disruption of the ellipsoid zone without detectable alteration of the capillary plexuses
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