| 1. |
- Abdalla Elsayed, Maram E.A., et al.
(författare)
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Incidence of Intraocular Lens Exchange after Cataract Surgery
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Intraocular lens (IOL) exchange after cataract surgery is unusual but may be associated with suboptimal visual outcome. The incidence of IOL exchange has not been consistently estimated. Such information is invaluable when counseling patients prior to cataract surgery. We examined the incidence of, and indications and risk factors for, IOL exchange after cataract surgery. We also assessed visual outcome of eyes that had an IOL exchange. A cohort design was used to estimate the incidence of IOL exchange and a case-control design to identify factors associated with it. All phacoemulsification surgeries with IOL (n = 17415 eyes) during 2010-2017 and those that had a subsequent IOL removal or replacement during the same time period were identified (n = 34 eyes). The incidence of IOL exchange was 2 per 1000 surgeries (95% confidence interval [CI] 1 to 3) over 8 years. Eyes that underwent subsequent IOL removal or replacement were compared with eyes that had cataract surgery only (n = 47) across demographic and clinical characteristics. In a binary logistic regression analysis, two factors were significantly associated with IOL exchange/removal: an adverse event during cataract surgery (adjusted odds ratio [aOR] 19.45; 95% CI 4.89-77.30, P < 0.001) and a pre-existing ocular comorbidity (aOR 10.70; 95% CI 1.69-67.63, P = 0.021). The effect of gender was marginally significant (P = 0.077). Eyes that underwent IOL exchange or explantation were nearly two and a half times more likely to have a final best-corrected visual acuity of <20/60 compared to those that had cataract surgery alone (adjusted RR 2.60 95% CI, 1.13-6.02; P = 0.025).
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| 2. |
- Abdalla Elsayed, Maram E.A., et al.
(författare)
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Sickle cell retinopathy. A focused review
- 2019
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Ingår i: Graefe's Archive for Clinical and Experimental Ophthalmology. - : Springer Science and Business Media LLC. - 0721-832X .- 1435-702X. ; 257:7, s. 1353-1364
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Forskningsöversikt (refereegranskat)abstract
- Purpose: To provide a focused review of sickle cell retinopathy in the light of recent advances in the pathogenesis, multimodal retinal imaging, management of the condition, and migration trends, which may lead to increased prevalence of the condition in the Western world. Methods: Non-systematic focused literature review. Results: Sickle retinopathy results from aggregation of abnormal hemoglobin in the red blood cells in the retinal microcirculation, leading to reduced deformability of the red blood cells, stagnant blood flow in the retinal precapillary arterioles, thrombosis, and ischemia. This may be precipitated by hypoxia, acidosis, and hyperosmolarity. Sickle retinopathy may result in sight threatening complications, such as paracentral middle maculopathy or sequelae of proliferative retinopathy, such as vitreous hemorrhage and retinal detachment. New imaging modalities, such as wide-field imaging and optical coherence tomography angiography, have revealed the microstructural features of sickle retinopathy, enabling earlier diagnosis. The vascular growth factor ANGPTL-4 has recently been identified as a potential mediator of progression to proliferative retinopathy and may represent a possible therapeutic target. Laser therapy should be considered for proliferative retinopathy in order to prevent visual loss; however, the evidence is not very strong. With recent development of wide-field imaging, targeted laser to ischemic retina may prove to be beneficial. Exact control of intraoperative intraocular pressure, including valved trocar vitrectomy systems, may improve the outcomes of vitreoretinal surgery for complications, such as vitreous hemorrhage and retinal detachment. Stem cell transplantation and gene therapy are potentially curative treatments, which may prevent retinopathy. Conclusions: There is lack of evidence regarding the optimal management of sickle retinopathy. Further study is needed to determine if recent progress in the understanding of the pathophysiology and diagnosis of sickle retinopathy may translate into improved management and outcome.
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| 3. |
- Schatz, Patrik, et al.
(författare)
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Serous retinal detachment after panretinal photocoagulation for proliferative diabetic retinopathy : A case report
- 2017
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Ingår i: Journal of Medical Case Reports. - : Springer Science and Business Media LLC. - 1752-1947. ; 11:1, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Proliferative diabetic retinopathy is a major cause of visual impairment in working-age adults worldwide. Panretinal photocoagulation is a cornerstone in its management; however, it may include a range of side effects and complications, one of these being serous retinal detachment. To the best of our knowledge, this is the first report of the use of intravitreal injection of bevacizumab for serous retinal detachment after panretinal photocoagulation. Case presentation: A 24-year-old Saudi man with poorly controlled type 1 diabetes presented with bilateral progressive proliferative retinopathy in spite of several sessions of panretinal photocoagulation. After one additional such session, he developed bilateral serous retinal detachment and vision loss, which was managed with a single bilateral intravitreal bevacizumab injection. The serous retinal detachment subsided with partial recovery of vision. Conclusions: Serous retinal detachment after panretinal photocoagulation for proliferative diabetic retinopathy is a rare complication nowadays. In this case, it seems that excessive photocoagulation exceeded the energy-absorbing capacity of the retinal pigment epithelium, leading to a disruption of the blood-retinal barrier. A single injection of bilateral intravitreal bevacizumab was sufficient to control the serous retinal detachment. This effect may have been due to a reduction of vascular leakage resulting from the mechanism of action of this drug. No complications were noted from the injection. Caution should be exerted when attempting bilateral panretinal photocoagulation.
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| 4. |
- Tinetti, G., et al.
(författare)
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A chemical survey of exoplanets with ARIEL
- 2018
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Ingår i: Experimental Astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 46:1, s. 135-209
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Tidskriftsartikel (refereegranskat)abstract
- Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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