Radiation forces on a Mie particle in the evanescent field of a resonance waveguide structure.

Evanescent waves of a guided mode carry both momentum and energy, which enables them to move small objects located on a waveguide surface. This optical force can be used for optical near-field manipulation, arrangement, and acceleration of particles. In this paper, using arbitrary beam theory, the optical force on a dielectric particle in the evanescent wave of a resonance waveguiding structure is investigated. Using Maxwell's equations and applying the boundary conditions, all the field components and a generalized dispersion relation are obtained. An expression for the evanescent field is derived in terms of the spherical wave functions. Cartesian components of the radiation force are analytically formulated and numerically evaluated by ignoring the multiple scattering that occurs between the sphere and plane surface of the structure. Our numerical data show that both the horizontal and vertical force components and the forward particle velocity are enhanced significantly in the proposed resonance structure compared to those reported for three-layer conventional waveguides. Exerting stronger force on macro- and nanoparticles can be very useful to perform advanced experiments in solutions with high viscosity and experiments on biological cells. In addition, this resonance planar structure can be mounted on an inverted optical microscope stage for imaging the motion of nanoparticles especially when the particle collides and interacts with objects.

Retraction notice to "Endophthalmitis Occurring after Cataract Surgery: Outcomes of More Than 480 000 Cataract Surgeries, Epidemiologic Features, and Risk Factors" (Ophthalmology. 2016;123:295-301).

This article has been retracted: please see Elsevier policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The editors wish to note that concerns were raised regarding coding errors in the data set that formed the basis of this study. Patient record numbers were found to be duplicated, so that the number of endophthalmitis cases was unclear as was the associated treatment, and the number of unique patients estimated to be far less than the 480,000 reported. Upon review of the information provided, Ophthalmology has determined the dataset to be flawed with unverifiable elements from which reliable conclusions cannot be drawn, and therefore has made the decision to issue a retraction of the manuscript.

Endophthalmitis Occurring after Cataract Surgery: Outcomes of More Than 480 000 Cataract Surgeries, Epidemiologic Features, and Risk Factors.

PURPOSE: To report the incidence of endophthalmitis after senile cataract surgery and to describe the epidemiology and main risk factors. DESIGN: Retrospective, single-center, cross-sectional descriptive study. PARTICIPANTS: Patients who underwent cataract surgery in Farabi Eye Hospital from 2006 through 2014. METHODS: All patients were evaluated retrospectively to compare risk factors, epidemiologic factors, and prophylaxis methods related to endophthalmitis. Patient records were used to gather the data. MAIN OUTCOME MEASURES: Epidemiologic factors, systemic diseases, other ocular pathologic characteristics, complications during the surgery, technique of cataract surgery, intraocular lens type, method of antibiotic prophylaxis, surgeon experience, vitreous culture, and vision outcome were evaluated in these patients. RESULTS: One hundred twelve endophthalmitis cases among 480 104 operations reported, equaling an incidence of 0.023%. Patients with diabetes mellitus (14.3%) and of older age (mean age, 81 years), perioperative communication with the vitreous (17.9%), extracapsular cataract surgery procedure (11%), and surgery on the left eye (58.9% vs. 41.1% for right eye; P = 0.03) showed a statistically significant association with endophthalmitis. Short-term treatment with topical or systemic preoperative antibiotics or postoperative subconjunctival injection was associated with a 40% to 50% reduced odds of endophthalmitis compared with no prophylaxis (P = 0.2). No cases of endophthalmitis were observed among the 25 920 patients who received intracameral cefuroxime, suggesting that this approach to antibiotic prophylaxis may be far more effective than traditional topical or subconjunctival approaches. CONCLUSIONS: The incidence of endophthalmitis after cataract surgery in our center was 0.023%, comparable with that of other previously published international studies. Older rural patients with immune suppressive diseases, such as diabetes mellitus, are particularly more prone to endophthalmitis. Vitreous loss at the time of surgery was associated with a significantly increased risk. Whereas antibiotic prophylaxis overall showed a 40% to 50% reduction in risk, intracameral cefuroxime was 100% effective in preventing endophthalmitis in this series.