Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 92
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Glob Chang Biol ; 23(10): 4222-4234, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28407457

RESUMEN

Coastal wetlands are known for high carbon storage within their sediments, but our understanding of the variation in carbon storage among intertidal habitats, particularly over geomorphological settings and along elevation gradients, is limited. Here, we collected 352 cores from 18 sites across Moreton Bay, Australia. We assessed variation in sediment organic carbon (OC) stocks among different geomorphological settings (wetlands within riverine settings along with those with reduced riverine influence located on tide-dominated sand islands), across elevation gradients, with distance from shore and among habitat and vegetation types. We used mid-infrared (MIR) spectroscopy combined with analytical data and partial least squares regression to quantify the carbon content of ~2500 sediment samples and provide fine-scale spatial coverage of sediment OC stocks to 150 cm depth. We found sites in river deltas had larger OC stocks (175-504 Mg/ha) than those in nonriverine settings (44-271 Mg/ha). Variation in OC stocks among nonriverine sites was high in comparison with riverine and mixed geomorphic settings, with sites closer to riverine outflow from the east and south of Moreton Bay having higher stocks than those located on the sand islands in the northwest of the bay. Sediment OC stocks increased with elevation within nonriverine settings, but not in riverine geomorphic settings. Sediment OC stocks did not differ between mangrove and saltmarsh habitats. OC stocks did, however, differ between dominant species across the research area and within geomorphic settings. At the landscape scale, the coastal wetlands of the South East Queensland catchments (17,792 ha) are comprised of approximately 4,100,000-5,200,000 Mg of sediment OC. Comparatively high variation in OC storage between riverine and nonriverine geomorphic settings indicates that the availability of mineral sediments and terrestrial derived OC may exert a strong influence over OC storage potential across intertidal wetland systems.


Asunto(s)
Carbono , Humedales , Australia , Bahías , Ecosistema , Sedimentos Geológicos , Queensland
2.
Ann Bot ; 114(4): 667-76, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24534674

RESUMEN

BACKGROUND: Stem diameter variations are mainly determined by the radial water transport between xylem and storage tissues. This radial transport results from the water potential difference between these tissues, which is influenced by both hydraulic and carbon related processes. Measurements have shown that when subjected to the same environmental conditions, the co-occurring mangrove species Avicennia marina and Rhizophora stylosa unexpectedly show a totally different pattern in daily stem diameter variation. METHODS: Using in situ measurements of stem diameter variation, stem water potential and sap flow, a mechanistic flow and storage model based on the cohesion-tension theory was applied to assess the differences in osmotic storage water potential between Avicennia marina and Rhizophora stylosa. KEY RESULTS: Both species, subjected to the same environmental conditions, showed a resembling daily pattern in simulated osmotic storage water potential. However, the osmotic storage water potential of R. stylosa started to decrease slightly after that of A. marina in the morning and increased again slightly later in the evening. This small shift in osmotic storage water potential likely underlaid the marked differences in daily stem diameter variation pattern between the two species. CONCLUSIONS: The results show that in addition to environmental dynamics, endogenous changes in the osmotic storage water potential must be taken into account in order to accurately predict stem diameter variations, and hence growth.


Asunto(s)
Adaptación Fisiológica , Avicennia/fisiología , Modelos Biológicos , Rhizophoraceae/fisiología , Agua/fisiología , Avicennia/anatomía & histología , Avicennia/crecimiento & desarrollo , Ambiente , Ósmosis , Tallos de la Planta/anatomía & histología , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/fisiología , Rhizophoraceae/anatomía & histología , Rhizophoraceae/crecimiento & desarrollo , Xilema/anatomía & histología , Xilema/crecimiento & desarrollo , Xilema/fisiología
3.
J Cataract Refract Surg ; 50(1): 78-83, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37718512

RESUMEN

PURPOSE: To model postoperative forces involved in Descemet membrane endothelial keratoplasty (DMEK) tissue adherence and bubble management, including the impact of surface tension on graft support, with a view towards clinical applications. SETTING: Tennent Institute of Ophthalmology, Glasgow, and James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom. DESIGN: Mathematical modelling and computer simulation. METHODS: Theoretical modelling of biphasic flow and interaction of gas, liquid and tissue within the anterior chamber for static horizontal scenario A (adherent DMEK with mobile bubble) and dynamic vertical scenario B (release of bubble due to pupil block following DMEK). RESULTS: The model assumed incompressibility for both fluids within realistically achievable pressure ranges. Cahn-Hilliard Navier-Stokes equations were discretised through the application of the Finite Element Method. Mathematical modelling and computer simulation showed bubble size, corneal curvature and force intensity influences surface tension support for DMEK tissue in scenario A. Scenario B demonstrated complex, uneven distribution of surface pressure on the DMEK graft during uncontrolled bubble release. Uneven pressure concentration can cause local tissue warping, with air/fluid displacement via capillary waves generated on the fluid-air interface adversely impacting DMEK support. CONCLUSIONS: We have quantitatively and qualitatively modelled the forces involved in DMEK adherence in normal circumstances. We have shown releasing air/gas can abruptly reduce DMEK tissue support via generation of large pressure gradients at the liquid/bubble/graft interfaces, creating negative local forces. Surgeons should consider these principles to reduce DMEK graft dislocation rates via optimised bubble size to graft size, longer acting bubble support and avoiding rapid decompression where possible.


Asunto(s)
Queratoplastia Endotelial de la Lámina Limitante Posterior , Humanos , Simulación por Computador , Queratoplastia Endotelial de la Lámina Limitante Posterior/métodos , Cámara Anterior , Periodo Posoperatorio , Reino Unido , Lámina Limitante Posterior/cirugía , Endotelio Corneal , Estudios Retrospectivos
4.
Acta Ophthalmol ; 102(3): e215-e228, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37427851

RESUMEN

Topical antimicrobials and antiseptics are used perioperatively to reduce the ocular surface bacteria flora (OSBF) that are involved in the development of post-operative infectious complications. However, their effectiveness is still a controversial topic. This systematic review, performed according to the PRISMA guidelines and registered in PROSPERO, aims to provide an overview of the efficacy of the agents currently used in peri-cataract surgery and -intravitreal injections (IVI) in lowering the OSBF. Although effective in lowering OSBF, perioperative topical antimicrobials are associated with the risk of resistance development, with no obvious additional benefit compared with topical antisepsis. Conversely, the effectiveness of topical antiseptics before cataract surgery and IVI is strongly supported. Based on the available evidence, perioperative antimicrobials are not recommended, whereas the perioperative use of antiseptics is strongly recommended as prophylactic treatment for lowering the infection due to OSBF. Post-operative antimicrobials may be considered in eyes at higher risk for infection.


Asunto(s)
Antiinfecciosos Locales , Catarata , Humanos , Antibacterianos/uso terapéutico , Bacterias , Ojo
5.
Artículo en Inglés | MEDLINE | ID: mdl-38958960

RESUMEN

PURPOSE: To evaluate how temperature impacts the rheology of common Ophthalmic Viscoelastic Devices (OVDs) and clinical implications. SETTING: Tennent Institute of Ophthalmology, Glasgow, with Department of Mechanical and Aerospace Engineering, and Advanced Materials Research Laboratory, University of Strathclyde, Glasgow, UK. DESIGN: Laboratory pilot study. METHODS: The viscous and elastic responses of three OVDs (Eyefill-SC/Eyefill-C/Eyefill-HD; Bausch & Lomb) were measured using rotational and extensional rheometers at clinically relevant temperatures (5°C, 25°C, 37°C). Thermal properties were evaluated using differential scanning calorimetry and laser-flash analysis. RESULTS: The OVDs tested exhibited viscoelastic properties and shear-thinning behaviour. Apparent viscosities and relaxation time were higher at lower temperatures. The Eyefill-C and Eyefill-SC exhibited predominantly viscous character at low frequencies with a transition to predominantly elastic behaviour at high frequencies. An increase in temperature led to a decrease in relaxation time under shear and extension. At low frequencies, Eyefill-C and Eyefill-SC moduli increase with decreasing temperatures. Eyefill-HD at 25°C and 37°C displays two cross-over points, with the storage modulus dominating at low and high frequencies indicating a predominantly elastic behaviour. Thermal property analysis revealed Eyefill-C had the lowest thermal conductivity. CONCLUSIONS: This pilot study confirms our clinical experience that OVD properties are affected by low temperatures, with increased viscosities at low shear rates and higher relaxation times.Cold OVD can cause greater resistance to initiation of IOL injection system forces (compared to warmer OVD). Excessively forced injection using cold OVD could contribute to inadvertent cannula detachment if incorrectly assembled, or uncontrolled IOL release leading to avoidable injury.

6.
Am J Ophthalmol ; 258: 183-195, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37972748

RESUMEN

PURPOSE: To report the genetic etiology of Lisch epithelial corneal dystrophy (LECD). DESIGN: Multicenter cohort study. METHODS: A discovery cohort of 27 individuals with LECD from 17 families, including 7 affected members from the original LECD family, 6 patients from 2 new families and 14 simplex cases, was recruited. A cohort of 6 individuals carrying a pathogenic MCOLN1 (mucolipin 1) variant was reviewed for signs of LECD. Next-generation sequencing or targeted Sanger sequencing were used in all patients to identify pathogenic or likely pathogenic variants and penetrance of variants. RESULTS: Nine rare heterozygous MCOLN1 variants were identified in 23 of 27 affected individuals from 13 families. The truncating nature of 7 variants and functional testing of 1 missense variant indicated that they result in MCOLN1 haploinsufficiency. Importantly, in the homozygous and compound-heterozygous state, 4 of 9 LECD-associated variants cause the rare lysosomal storage disorder mucolipidosis IV (MLIV). Autosomal recessive MLIV is a systemic disease and comprises neurodegeneration as well as corneal opacity of infantile-onset with epithelial autofluorescent lysosomal inclusions. However, the 6 parents of 3 patients with MLIV confirmed to carry pathogenic MCOLN1 variants did not have the LECD phenotype, suggesting MCOLN1 haploinsufficiency may be associated with reduced penetrance and variable expressivity. CONCLUSIONS: MCOLN1 haploinsufficiency is the major cause of LECD. Based on the overlapping clinical features of corneal epithelial cells with autofluorescent inclusions reported in both LECD and MLIV, it is concluded that some carriers of MCOLN1 haploinsufficiency-causing variants present with LECD.


Asunto(s)
Distrofias Hereditarias de la Córnea , Mucolipidosis , Canales de Potencial de Receptor Transitorio , Humanos , Canales de Potencial de Receptor Transitorio/genética , Estudios de Cohortes , Mucolipidosis/diagnóstico , Mucolipidosis/genética , Mucolipidosis/patología , Distrofias Hereditarias de la Córnea/diagnóstico , Distrofias Hereditarias de la Córnea/genética
7.
Oecologia ; 172(2): 485-94, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23070143

RESUMEN

Water availability is a key determinant of the zonation patterns in estuarine vegetation, but water availability and the use of different water sources over space and time are not well understood. We have determined the seasonal water use patterns of riparian vegetation over an estuarine ecotone. Our aim was to investigate how the water use patterns of estuarine vegetation respond to variations in the availability of tidal creek water and rain-derived freshwater. The levels of natural stable isotopes of oxygen and hydrogen were assessed in the stem of the mangrove Avicennia marina (tall and scrub growth forms), Casuarina glauca and Melaleuca quinquenervia that were distributed along transects from river/creek-front towards inland habitats. The isotopic composition of plant tissues and the potential water sources were assessed in both the wet season, when freshwater from rainfall is present, and the dry season, when mangrove trees are expected to be more dependent on tidal water, and when Casuarina and Melaleuca are expected to be dependent on groundwater. Our results indicate that rainwater during the wet season contributes significantly to estuarine vegetation, even to creek-side mangroves which are inundated by tidal creek water daily, and that estuarine vegetation depends primarily on freshwater throughout the year. In contrast, high intertidal scrub mangroves were found to use the greatest proportion of tidal creek water, supplemented by groundwater in the dry season. Contrary to prediction, inland trees C. glauca and M. quinquenervia were found also to rely predominantly on rainwater--even in the dry season. The results of this study reveal a high level of complexity in vegetation water use in estuarine settings.


Asunto(s)
Avicennia/fisiología , Estuarios , Magnoliopsida/fisiología , Fenómenos Fisiológicos de las Plantas , Deuterio/análisis , Ecosistema , Agua Dulce , Agua Subterránea , Modelos Lineales , Isótopos de Oxígeno/análisis , Tallos de la Planta/metabolismo , Queensland , Lluvia , Salinidad , Estaciones del Año , Agua
8.
BMJ Case Rep ; 16(8)2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37562863

RESUMEN

We report a man in his 80s who described sudden unilateral loss of vision, resulting in extensive urgent investigations by the accident and emergency department team. Subsequent evaluation of visual acuity with pinhole demonstrated significant improvement, triggering further questioning. It transpired that he was mistakenly wearing his wife's glasses, which accounted for his visual symptoms. This case illustrates the importance of a stepwise approach to visual assessment, and avoiding assumptions, as using the simple pinhole test could have avoided extensive investigations and their subsequent costs.


Asunto(s)
Anteojos , Conducta Sexual , Masculino , Humanos , Agudeza Visual
9.
Cornea ; 42(3): 365-368, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36730013

RESUMEN

PURPOSE: The purpose of this study was to report a novel approach of prepenetrating keratoplasty (PKP) corneal map biopsies to define the extent of Acanthamoeba cyst infiltration in recalcitrant Acanthamoeba keratitis. METHODS: Corneal map biopsies were performed 1 week before PKP. Four biopsies, 1 from each peripheral corneal quadrant, were obtained to delineate the extent of microscopic infection. Histological results of these map biopsies were used to determine the size and location of the subsequent PKP. RESULTS: In our first case, map biopsies revealed Acanthamoeba cysts in 2 of the 4 biopsies. This led to an inferotemporally eccentric 8.5-mm PKP. The final histology report indicated that the closest resection margin was 0.08 mm. In our second case, the peripheral map biopsies were clear and an inferiorly eccentric 8.25-mm PKP was performed. The final histology report indicated that the closest resection margin was 2.3 mm. Both grafts have remained clear at 6 months postoperatively. CONCLUSIONS: Map biopsies of the cornea can achieve total removal of the corneal tissues infested with Acanthamoeba cysts and prevent reinfection of the donor graft.


Asunto(s)
Queratitis por Acanthamoeba , Acanthamoeba , Humanos , Queratoplastia Penetrante/métodos , Queratitis por Acanthamoeba/diagnóstico , Queratitis por Acanthamoeba/cirugía , Márgenes de Escisión , Córnea/patología , Biopsia , Estudios Retrospectivos
10.
Eye (Lond) ; 37(14): 2864-2876, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-36788364

RESUMEN

A clear corneal incision (CCI) is the most commonly used entrance site in modern phacoemulsification cataract surgery. Despite some initial concerns about increased endophthalmitis rates through a self-sealing CCI, recent literature suggests that the risk of infection with proper wound construction and all other necessary precautions is minimal. The technique of creating a clear corneal incision has, with recent developments in corneal imaging, undergone critical appraisal leading to a better understanding of incision architecture. Many surgeons operate through smaller incisions, and they have a wide choice of surgical instruments to create their corneal incisions. The aim of this review is to discuss the history and the current status of clear corneal incision creation, the design and materials of surgical blades, and the current trends in manufacturing and sustainability. Although disposable instruments have some advantages and are very popular, recycling, if possible, and avoiding unnecessary plastic waste are important considerations. In any case, the step of CCI is a small one for the surgeon, but a big one for the eye. That is why it has to be done with the utmost precision and in-depth knowledge is important.


Asunto(s)
Extracción de Catarata , Catarata , Facoemulsificación , Herida Quirúrgica , Humanos , Cicatrización de Heridas , Extracción de Catarata/métodos , Facoemulsificación/métodos , Córnea/cirugía
11.
Clin Exp Ophthalmol ; 40(2): 182-6, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21745266

RESUMEN

BACKGROUND: Descemet's Stripping Endothelial Keratoplasty has been associated with a steep learning curve. Angle closure post Descemet's Stripping Endothelial Keratoplasty has been reported, either because of air posterior to the iris causing iridocorneal adhesions, or by air anterior to the iris causing pupillary block. The mechanics of floppy iris syndrome and pupil block have not been discussed. METHODS: We evaluated the various forces competing within the anterior chamber via mathematical modelling and computational simulation, and considered the influence of floppy iris on pupil block glaucoma. RESULTS: Energy formulae suggest a critical pressure value will maintain normal anterior chamber relationships, above which abnormal iris buckling may occur. This mechanical instability can be influenced intraoperatively by abnormal iris properties and intracameral forces (such as air). This critical value is lowered if the patient has a floppy iris (because of a lower elastic modulus, a mechanical measure of iris rigidity). To demonstrate this mathematical concept, a 3-D computational model was built. Simulations show that, as intracameral pressure increases, the iris ring can buckle into predictable modes of shapes. CONCLUSION: This model shows how iris buckling could occur with an intracameral air bubble leading to posterior iris displacement and mechanical pupil block. It also shows that abnormal iris behaviour in IFIS is consistent with the expected predicted buckling of an elastic disc.


Asunto(s)
Aire , Cámara Anterior/fisiopatología , Simulación por Computador , Queratoplastia Endotelial de la Lámina Limitante Posterior , Enfermedades del Iris/fisiopatología , Modelos Teóricos , Trastornos de la Pupila/etiología , Humanos , Hipotonía Muscular/etiología , Hipotonía Muscular/fisiopatología , Presión , Trastornos de la Pupila/fisiopatología
12.
Front Physiol ; 13: 834214, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35464073

RESUMEN

In a routine cataract operation cornea tissue may be damaged when an intra-ocular lens (IOL) injector of diameter between 1.467 and 2.011 mm is inserted through an empirically designed 2.2 mm corneal incision. We aimed to model and estimate the minimal length of the incision required to avoid wound tear. It was assumed that the damage was caused by tissue fracture at the tips of the incision, and this fracture could be studied using damage and fracture mechanics. The criterion of the damage was caused by a tear governed by the critical energy release rate (ERR) G c , which is tissue dependent. Analytical and numerical studies were both conducted indicating the possibility of a safe and effective incision in cataract surgery. Six commonly used IOL injection systems were examined. Our results suggested that the recommended 2.2 mm incision cannot be treated as a universal threshold. Quicker IOL insertion may reduce wound damage. It was also recommended to advance IOL injector via its minor axis, and to cut the tear preferably along the circumferential direction due to tissue orthotropy. This study provides useful information and a deeper insight into the potential for mechanical damage to the corneal wound in cataract surgery.

13.
Eye (Lond) ; 36(10): 1973-1976, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34616004

RESUMEN

INTRODUCTION: Ophthalmic simulation is cost-effective in complication prevention. However, there is no consistent resource allocation to provide the necessary time and finance to sustain such activities. We wished to identify the current support for the regional Simulation Leads in the UK. METHODS: An online SurveyMonkey questionnaire was sent to all 26 UK ophthalmic regional Simulation Leads in February 2021 regarding current simulation activity and the degree of time and resource support available. RESULTS: There were 22 responses within 1 month (84.6% response rate). 72.7% run regular simulation induction events for new trainees. 60% run mandatory laser simulation events. 38.1% run immersive simulation (vitreous loss fire drill). 47.6% run yearly sub-specialty events. 45.5% were required to make additional work arrangements to run simulation events. 77.3% had no job plan time allocation for simulation. 59.1% dedicated >1 hr/week to simulation. 68.2% EYESI simulators were purchased via charity/endowments. 72.7% had access to dedicated dry lab simulation (40.9% wet lab). 40.9% used deanery funds to purchase initial model eyes (supplemented by charity (36.4%) and endowments (31.8%)). 65% used unspent study leave budgets for ongoing model eyes, yet 15% reported trainees purchasing their own. CONCLUSION: Nearly all ophthalmic simulation in the UK is undertaken via goodwill and personal commitment to excellence by the regional Simulation Leads. There is minimal allowance of time or finance for these vital activities, which is sporadic at best, and unsustainable. We call for the necessary investment and dedicated time allocation to permit ophthalmic simulation to be supported and maintained.


Asunto(s)
Oftalmólogos , Oftalmología , Ojo , Humanos , Encuestas y Cuestionarios , Reino Unido
14.
Eye (Lond) ; 36(7): 1442-1447, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34211138

RESUMEN

INTRODUCTION: As gonococcal infections continue to increase, we wanted to review the number and clinical course of recent ocular gonococcal cases presenting to ophthalmology departments in NHS Greater Glasgow and Clyde. METHODS: A 5-year retrospective review of adult ocular gonococcal cases, where the diagnosis of Neisseria gonorrhoeae was made on microbiological culture, was undertaken. RESULTS: Fifteen cases were identified (80% male). Average age was 26 years (range 17-42; median 24). Most common presenting features included purulent discharge (14/15; 93%), haemorrhagic conjunctivitis (10/15; 67%) and pre-septal cellulitis (9/15; 60%). Corneal involvement was documented in 5 (33%), with marginal ulceration in 1 (7%) but none had corneal perforation. Most common systemic treatment was IV ceftriaxone, alone or in combination with another antibiotic (6/15; 40%), followed by IM ceftriaxone, alone or in combination with another antibiotic (5/15; 33%). Median time from presentation to treatment was 1 day (0-23). All patients were referred or recommended to attend sexual health services. Seven patients (47%) attended and received complete sexually transmitted infection (STI) testing and contact tracing: 3 patients had systemic treatment initiated or changed at this visit and 1 patient had concurrent syphilis identified. CONCLUSIONS: This series confirms purulent conjunctivitis and cellulitis as the main presenting features of ocular gonococcal infection requiring hospital review. Early identification with appropriate systemic antibiotic treatment avoided corneal melting in this cohort. As concurrent STIs were identified and/or treatments changed in 4/7 (57%) following sexual health review, we recommend a shared care approach between ophthalmology, microbiology and sexual health services to effectively address all management issues.


Asunto(s)
Gonorrea , Oftalmología , Adolescente , Adulto , Antibacterianos/uso terapéutico , Ceftriaxona/uso terapéutico , Celulitis (Flemón)/tratamiento farmacológico , Femenino , Gonorrea/diagnóstico , Gonorrea/tratamiento farmacológico , Gonorrea/epidemiología , Humanos , Masculino , Neisseria gonorrhoeae , Adulto Joven
17.
Eye (Lond) ; 35(7): 1915-1921, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32929181

RESUMEN

INTRODUCTION: Posterior capsule rupture (PCR) rates are used to measure cataract surgeons' quality. We wished to evaluate the internal non-visible surfaces of metal irrigation/aspiration (I/A) tips to identify potential mechanisms for PCR via novel metallographic imaging. METHODS: Ten metal I/A instruments underwent metallographic preparation by fine sectioning to expose inner surfaces near the aspiration opening. Analysis of inner bore, lumen, and opening aperture of metal aspiration tips was performed by optical microscopy, scanning electron microscopy (SEM), and 3D volume X-ray computational tomography (XCT). Distances from external aperture to first sharp metal surface were obtained and compared with a silicone-tipped instrument. RESULTS: We identified metal burrs near the aspiration apertures and manufacturing defects within all tips. XCT confirmed optical and SEM findings of significant defects and metal irregularities within aspiration tips. Samples also showed variation in lumen size/thickness, rough surfaces and material inhomogeneity, most pronounced at the internal tip. Median distance from outer aperture opening to first metal burr was 30 microns (range 10-120) and to internal tip irregularity (manufacturing flaw) was 250 microns (range 100-350). By comparison, distance to metal from the silicone outer aperture opening was 850 microns. CONCLUSIONS: We have demonstrated the hidden sharp metallic irregularities within commonly used metal I/A tips. If an aspirated capsule encounters these sharp metal flaws, PCR could result. Minimising this risk would require lengthening potential distance between capsule and bare metal (as with polymer/silicone tips). Our study provides unique imaging evidence endorsing this principle and illustrates a hidden mechanism contributing to PCR.


Asunto(s)
Catarata , Humanos , Metales , Microscopía Electrónica de Rastreo , Siliconas
18.
Semin Ophthalmol ; 36(5-6): 379-383, 2021 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-33641615

RESUMEN

INTRODUCTION: Head stabilization may reduce intra-operative risk during cataract surgery, but could be misinterpreted as "restraint." We wanted to establish patients' attitudes towards the potential use of stability-tape. MATERIALS AND METHODS: One-hundred consecutive patients attending for local-anaesthetic cataract surgery were asked to complete a pre-operative questionnaire. This explored patient concerns and views regarding intra-operative head movement and the potential use of stability-tape. RESULTS: All 100-patients completed the questionnaire. The median head movement concern score was 2 out of 10 (range 1-9, IQR 1-5). Eighty-four percent felt stability tape should be offered to all patients and 97% would consent for its' use. Only 6% voiced concern about the use of stability-tape (95% CI 2.2%, 12.6%). CONCLUSION: Patients had low concern for moving their head during surgery. The concept of stability-tape to minimize head movements during cataract surgery was viewed positively by most patients. This strategy may promote safer surgery in selected cases.


Asunto(s)
Extracción de Catarata , Catarata , Oftalmología , Actitud , Movimientos de la Cabeza , Humanos
19.
Eye (Lond) ; 35(5): 1496-1503, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32681093

RESUMEN

INTRODUCTION: Since 2010, General Ophthalmic Services (GOS) legislation and Independent Prescribing (IP) enable community optometrists to manage primary eye conditions. No studies have assessed the effect of IP. We wished to determine the distribution of IP optometrists and associated hospital referral rates across Scotland. METHODS: In 2019, FOI requests (General Optical Council and NHS Education Scotland) identified all registered IP optometrists in Scotland and their registered postcodes. Data regarding community eye examinations and referrals to HES since 2010 were gathered via Information Services Division of NHS Scotland. RESULTS: As of March 2019, there were 278 IP optometrists in Scotland (278/1189; 23.4%). Two hundred eighteen IP optometrists work in 293 practices across 11 of Scotland's 14 health boards. There was a strong correlation (r = +0.96) between population density and number of IP optometrists. Fifty-six percent of IP optometrists work in the two most deprived quintiles. Since IP's introduction, there has been a marked increase in anterior segment supplementary visits (+290%). Optometry referrals to GPs have reduced by 10.5%, but referrals to HES have increased by 118% (to 96,315). There was no correlation between quantity of IP optometrists and referral rates to HES (r = -0.06, 95% CI -0.64 to 0.56, p = 0.86). CONCLUSIONS: This is the first analysis of IP optometrists and associated referral rates in Scotland. Despite good geographical distribution and increased supplementary attendances, optometric referrals to HES have doubled and continue to rise. We propose a ratio of primary, supplementary, non-referral and referral rates to discern the true impact of IP versus non-IP community optometric behaviour.


Asunto(s)
Optometristas , Optometría , Hospitales , Humanos , Derivación y Consulta , Escocia
20.
Eye (Lond) ; 35(2): 584-591, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32376978

RESUMEN

PURPOSE: Post-operative cystoid macular oedema (CMO) can cause deterioration of vision following routine cataract surgery. The incidence of persistent CMO (pCMO; defined as CMO present after 3 months) following uncomplicated surgery is uncertain. We wished to identify the incidence, management and visual outcomes of such patients. METHODS: A Scottish Ophthalmological Surveillance Unit (SOSU) questionnaire was sent monthly to every ophthalmic specialist in Scotland over an 18-month period from 1st January 2018 asking them to report all new patients with pCMO confirmed on OCT scanning following uncomplicated cataract surgery. A follow-up questionnaire was sent 9 months after initial presentation. RESULTS: Fourteen cases of pCMO were reported, giving an incidence of 2.2 cases of pCMO per 10,000 uncomplicated cataract surgeries. Mean age was 74.9 years (SD 10.2; range 44-86) with a male preponderance (72.7%). Two patients developed pCMO in each eye. Six cases (46.2%) had hypertension and one had diabetes. Three eyes required intracameral adjuncts (two iris hooks, one intracameral phenylephrine). Postoperative visual acuity (VA) at 3 months was logMAR 0.48 (0.2-0.8). Average mean central retinal thickness (CRT) at 3 months was 497microns (270-788). The most common initial treatment comprised topical steroids and topical NSAIDs (61.5%). Other management strategies included systemic steroids, intravitreal steroids and oral acetazolamide. At 1-year post-op, mean VA was logMAR 0.18 (0.1-0.3) with average mean CRT of 327microns (245-488). CONCLUSIONS: We identified a low incidence of pCMO following uncomplicated cataract surgery in Scotland (0.02%), with inconsistent and variable management regimes. A nationally agreed treatment protocol is required.


Asunto(s)
Extracción de Catarata , Catarata , Edema Macular , Anciano , Humanos , Incidencia , Edema Macular/epidemiología , Edema Macular/etiología , Edema Macular/terapia , Masculino , Escocia/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA