WAS IT LEUCONOSTOC SPECIES? A CASE OF DELAYED-ONSET ENDOPHTHALMITIS PRESENTING 14 YEARS AFTER CATARACT SURGERY.

PURPOSE: To report a case of delayed-onset endophthalmitis presenting 14 years after an uncomplicated cataract surgery. METHODS: Case report. RESULTS: An 89-year-old pseudophakic man complained of redness and reduced visual acuity in his right eye. He had no history of trauma or systemic infection, and his only surgery on the right eye was an uncomplicated cataract surgery 14 years before. On physical examination, he was found to have keratic precipitates and a white posterior capsular plaque in the right eye. He was treated with a right pars plana vitrectomy and intraocular lens removal. Microbiological classification of the samples revealed the presence of a Leuconostoc species within the vitreous humor and coagulase-negative staphylococci on the lens. Two months after placement of the intraocular lens, he achieved a best-corrected visual acuity of 20/200 in his right eye. CONCLUSION: To the best of our knowledge, this is the first reported case of delayed-onset endophthalmitis occurring more than 10 years after an uncomplicated cataract surgery. This case highlights a highly unusual presentation of delayed-onset endophthalmitis and reports a potential novel microbiological cause of plaque formation.

On the use of frequency-swept pulses and pulses designed with optimal control theory for the acquisition of ultra-wideline NMR spectra.

Frequency-swept (FS) pulses, such as wideband uniform-rate smooth-truncation (WURST) pulses, have found much success for the acquisition of ultra-wideline (UW) solid-state NMR spectra. In this preliminary study, new pulses and pulse sequences are explored in simulation and experimentally for several nuclei exhibiting UWNMR powder patterns under static conditions, including 119Sn (I = 1/2), 195Pt (I = 1/2), 2H (I = 1), and 71Ga (I = 3/2). First, hyperbolic secant (HS) and tanh/tan (THT) pulses are tested and implemented as excitation and refocusing pulses in spin-echo and Carr-Purcell/Meiboom Gill (CPMG)-type sequences, and shown to have comparable performances to analogous WURST pulses. Second, optimal control theory (OCT) is utilized for the design of new Optimal Control Theory Optimized Broadband Excitation and Refocusing (OCTOBER) pulses, using carefully parameterized WURST, THT, and HS pulses as starting points. Some of the new OCTOBER pulses used in spin-echo sequences are capable of efficient broadband excitation and refocusing, in some cases resulting in spectra with increased signal enhancements over those obtained in experiments using conventional FS pulses. Finally, careful consideration of the spin dynamics of several systems, by monitoring of the time evolution of the density matrix via the Liouville-von Neumann equation and analysis of the time-resolved Fourier transforms of the pulses, lends insight into the underlying mechanisms of the FS and OCTOBER pulses. This is crucial for understanding their performance in terms of generating uniformly excited patterns of high signal intensity, and for identifying trends that may offer pathways to generalized parameterization and/or new pulse shapes.