18 research outputs found

    Characteristics and racial variations of polypoidal choroidal vasculopathy in tertiary centers in the United States and United Kingdom

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    PURPOSE: To evaluate the characteristics and racial variations amongst patients with polypoidal choroidal vasculopathy (PCV) in the United States and the United Kingdom. METHODS: Fundus photos and indocyanine green angiography images were evaluated in a multicenter retrospective study to establish the diagnosis of PCV. Visual acuity (VA) was recorded in ETDRS letter count. RESULTS: Eighty eyes of 71 PCV patients (average age of 69.4 ± 10.4 years) were included in the analysis. Of the total 71 subjects, 46 (65%) were women, 33 (46.5%) were Blacks, 16 (22.5%) were Whites, 19 (26.8%) were Asians and 3 (4.2%) belonged to other races. The Black subgroup had vision gain of 3.5 letters. The White and Asian subgroups had vision loss of 13.1 and 3.5 letters, respectively. There was female predominance in Blacks (67%), Whites (69%), and Asians (58%). PCV was found to be a bilateral disease in 14 patients (20%). There was significant decrease of 7 letters with every decade increase in age (p = 0.005). Final VA was worse in males when compared to females (p = 0.042), and worse in Whites when compared to Blacks (p = 0.005). For every 10 letters worse in initial VA upon diagnosis with PCV, the final VA was worse by 6 letters (p < 0.001). The location of the polypoidal lesion within the macula was associated with significant decrease of 14 letters in BCVA (p = 0.02). The length of follow up was significantly associated with worse visual outcome (p = 0.012). Final VA had no significant correlation with the lens status, or the different treatment modalities. CONCLUSIONS: Based on our cohort from tertiary centers in the United States and United Kingdom, PCV is a bilateral disease in one-fifth of patients. It features a variable female predominance based on ethnicity. Increased age, worse vision upon initial presentation, longer follow up and macular location of the polyp were associated with worse visual outcome

    GA-based multi-objective optimization of active nonlinear quarter car suspension system—PID and fuzzy logic control

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    Background The primary function of a suspension system is to isolate the vehicle body from road irregularities thus providing the ride comfort and to support the vehicle and provide stability. The suspension system has to perform conflicting requirements; hence, a passive suspension system is replaced by the active suspension system which can supply force to the system. Active suspension supplies energy to respond dynamically and achieve relative motion between body and wheel and thus improves the performance of suspension system. Methods This study presents modelling and control optimization of a nonlinear quarter car suspension system. A mathematical model of nonlinear quarter car is developed and simulated for control and optimization in Matlab/Simulink® environment. Class C road is selected as input road condition with the vehicle traveling at 80 kmph. Active control of the suspension system is achieved using FLC and PID control actions. Instead of guessing and or trial and error method, genetic algorithm (GA)-based optimization algorithm is implemented to tune PID parameters and FLC membership functions’ range and scaling factors. The optimization function is modeled as a multi-objective problem comprising of frequency weighted RMS seat acceleration, Vibration dose value (VDV), RMS suspension space, and RMS tyre deflection. ISO 2631-1 standard is adopted to assess the ride and health criterion. Results The nonlinear quarter model along with the controller is modeled and simulated and optimized in a Matlab/Simulink environment. It is observed that GA-optimized FLC gives better control as compared to PID and passive suspension system. Further simulations are validated on suspension system with seat and human model. Parameters under observation are frequency-weighted RMS head acceleration, VDV at the head, crest factor, and amplitude ratios at the head and upper torso (AR_h and AR_ut). Simulation results are presented in time and frequency domain. Conclusion Simulation results show that GA-based FLC and PID controller gives better ride comfort and health criterion by reducing RMS head acceleration, VDV at the head, CF, and AR_h and AR_ut over passive suspension system

    Retinal vasculitis and intraocular inflammation after intravitreal injection of Brolucizumab

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    Purpose: To evaluate features and outcomes of eyes with retinal vasculitis and intraocular inflammation (IOI) after intravitreal injection (IVI) of brolucizumab 6 mg/0.05 ml for treatment of neovascular age-related macular degeneration. Design: Retrospective case series. Participants: Fifteen eyes from 12 patients identified from 10 United States centers. Methods: Review of patient demographics, ophthalmologic examination results, and retinal imaging findings. Main Outcome Measures: Baseline and follow-up visual acuity (VA), prior anti–vascular endothelial growth factor (VEGF) injections, clinical presentation, retinal findings, fluorescein angiography results, and treatment strategies. Results: The number of previous anti-VEGF IVIs ranged between 2 and 80 in the affected eye before switching to brolucizumab. Retinal vasculitis and IOI were diagnosed at a mean of 30 days after brolucizumab IVI. Mean VA before brolucizumab IVI was 0.426 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, 20/53) and VA at diagnosis of retinal vasculitis was 0.981 logMAR (Snellen equivalent, 20/191; range, 20/25–20/1600; P = 0.008). All affected eyes showed IOI with variable combinations of focal or elongated segmental sheathing and discontinuity of small and large retinal arteries, sclerotic arteries, regions of vascular nonperfusion, cotton-wool spots, Kyrieleis plaques, irregular venous caliber with dilated and sclerotic segments, perivenular hemorrhages, and foci of phlebitis. Fluorescein angiography revealed delayed retinal arterial filling, retinal vascular nonperfusion, and variable dye leakage from affected vessels and the optic nerve. Systemic evaluation for embolic causes was unrevealing in 2 patients, and 3 patients showed negative laboratory assessment for uveitis. Treatment consisted of various combinations of corticosteroids (systemic, intravitreal, and topical), and 2 eyes underwent vitrectomy without improvement in vision. After a mean follow-up of 25 days, mean VA was 0.833 logMAR (Snellen equivalent, 20/136), which was reduced compared with baseline (P = 0.033). Conclusions: Retinal vasculitis and IOI after brolucizumab IVI are characterized by variable occlusion of large or small retinal arteries, or both, and perivenular abnormalities. It may span from peripheral vasculitis to occlusion of large retinal arteries around the optic nerve or macula with severe vision loss. A high index of suspicion is required because vitreous cells may obscure visualization of retinal details. © 2020 American Academy of Ophthalmolog

    Consensus Nomenclature for Reporting Neovascular Age-Related Macular Degeneration Data Consensus on Neovascular Age-Related Macular Degeneration Nomenclature Study Group

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    PURPOSE: To establish a process to evaluate and standardize a state-of-the-art nomenclature for reporting neovascular age-related macular degeneration (AMD) data. DESIGN: Consensus meeting. PARTICIPANTS: An international panel of retina specialists, imaging and image reading center experts, and ocular pathologists. METHODS: During several meetings organized under the auspices of the Macula Society, an international study group discussed and codified a set nomenclature framework for classifying the subtypes of neovascular AMD and associated lesion components. MAIN OUTCOME MEASURES: A consensus classification of neovascular AMD. RESULTS: The study group created a standardized working definition of AMD. The components of neovascular AMD were defined and subclassified. Disease consequences of macular neovascularization were delineated. CONCLUSIONS: The framework of a consensus nomenclature system, a definition of AMD, and a delineation of the subtypes of neovascular AMD were developed. Establishing a uniform set of definitions will facilitate comparison of diverse patient groups and different studies. The framework presented is modified and updated readily, processes that are anticipated to occur on a periodic basis. The study group suggests that the consensus standards outlined in this article be used in future reported studies of neovascular AMD and clinical practice

    Central Serous Chorioretinopathy, Corticosteroids, and Uveitis

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    Any patient with a diagnosis of central serous chorioretinopathy (CSCR) should be questioned to determine any recent corticosteroid use, as the poor visual outcome may be due to unrecognized corticosteroid use. Atypical forms of CSCR may be misdiagnosed as an inflammatory serous retinal detachment, mainly Vogt-Koyanagi-Harada disease. CSCR that develops in association with preexisting uveitis could be a challenging diagnosis as it might be misinterpreted as a worsening of the primary inflammatory condition. Failure to differentiate CSCR from retinal or choroidal inflammatory diseases may result in inappropriate use of corticosteroids, leading to exacerbation of the condition and permanent visual loss. Discontinuation of corticosteroids should be the first step in the treatment of CSCR associated with corticosteroid therapy, and the use of immunosuppressive or immunomodulatory drugs may be required to control systemic or ocular inflammatory disease. The prognosis is usually favorable, but persistent visual loss may occur
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