11 resultados para Experimental surgery
Resumo:
To investigate the effect(s) of cataract surgery on the expression of pro-inflammatory genes and proteins in the retina using an experimental rodent model. An extracapsular lens extraction was performed in one eye of C57BL/6 mice (n=24); the contralateral unoperated eyes (n =24) as well as eyes from unoperated animals (n = 9) served as controls. The neurosensory retina and retinal pigment epithelium (RPE)/choroid were collected postoperatively. Expression of genes involved in the acute inflammatory/ injury response, including IL-1ß, fibroblast growth factor, transforming growth factor ß, chemokine CCL2, SDF-1, and complements C3, C4, and factor B (CFB), were examined by real-time PCR and, selectively, by immunohistochemistry. The expression of IL-1 ß and CCL2 genes was markedly upregulated (>0-fold, P >0.01) in the neurosensory retina 30 minutes postoperatively and maintained for the 2-week postoperative period of observation; IL-1 ß expression was also upregulated in RPE/choroid. The expression of complement C3 (>-fold) and CFB (>0-fold) genes in the neurosensory retina was also significantly upregulated (P
Resumo:
The main mode of failure of the acetabular component in total hip arthroplasty is aseptic loosening. Successive generations of cementation techniques have evolved to alleviate this problem.
Resumo:
We induced choroidal neovascularization in the rhesus monkey by impoverishing the blood supply to the inner retina and producing defects in Bruch's membrane by photocoagulation. Fourteen of 46 eyes undergoing photocoagulation developed neovascular fronds which were identified and categorized by histopathologic examination and fluorescein angiography. All new vessels gained access to the retina through defects in Bruch's membrane at the site of photocoagulation marks. In eight eyes the new vessels remained localized to the immediate vicinity of photocoagulation marks. In four eyes neovascular fronds infiltrated the subretinal space for distances up to 6 disk diameters from the point of entry into the retina. In the two eyes choroidovitreal neovascular complexes developed but rapidly regressed shortly after gaining the vitreous cavity. Fluorescein angiography demonstrated that all neovascular fronds were grossly incompetent to dye but that formed feeding channels had some degree of integrity. Light microscopic studies showed the proliferating networks to be composed of capillaries with well-formed basement membranes and more mature vessels with the basic structure of choroidal arteries and veins.
Resumo:
Background: The perceived difficulty of steps of manual small incision cataract surgery among trainees in rural China was assessed. Design: Cohort study. Participants: Fifty-two trainees at the end of a manual small incision cataract surgery training programme. Methods: Participants rated the difficulty of 14 surgical steps using a 5-point scale, 1 (very easy) to 5 (very difficult). Demographic and professional information was recorded for trainees. Main Outcome Measure: Mean ratings for surgical steps. Results: Questionnaires were completed by 49 trainees (94.2%, median age 38 years, 8 [16.3%] women). Twenty six (53.1%) had performed ≤50 independent cataract surgeries prior to training. Trainees rated cortical aspiration (mean score±standard deviation=3.10±1.14) the most difficult step, followed by wound construction (2.76±1.08), nuclear prolapse into the anterior chamber (2.74±1.23) and lens delivery (2.51±1.08). Draping the surgical field (1.06±0.242), anaesthetic block administration (1.14±0.354) and thermal coagulation (1.18±0.441) were rated easiest. In regression models, the score for cortical aspiration was significantly inversely associated with performing >50 independent manual small incision cataract surgery surgeries during training (P=0.01), but not with age, gender, years of experience in an eye department or total number of cataract surgeries performed prior to training. Conclusions: Cortical aspiration, wound construction and nuclear prolapse pose the greatest challenge for trainees learning manual small incision cataract surgery, and should receive emphasis during training. Number of cases performed is the strongest predictor of perceived difficulty of key steps. © 2013 Royal Australian and New Zealand College of Ophthalmologists.
Resumo:
To assess the outcomes of cataract surgery performed by novice surgeons during training in a rural programme. Design: Retrospective study. Participants: Three hundred thirty-four patients operated by two trainees under supervision at rural Chinese county hospitals. Methods: Two trainees performed surgeries under supervision. Visual acuity, refraction and examinations were carried out 3 months postoperatively. Main Outcome Measures: Postoperative uncorrected visual acuity, pinhole visual acuity, causes of visual impairment (postoperative uncorrected visual acuity<6/18) Results: Among 518 operated patients, 426 (82.2%) could be contacted and 334 (64.4% of operated patients) completed the examinations. The mean age was 74.1±8.8 years and 62.9% were women. Postoperative uncorrected visual acuity was available in 372 eyes. Among them, uncorrected visual acuity was ≥6/18 in 278 eyes (74.7%) and <6/60 in 60 eyes (16.1%), and 323 eyes (86.8%) had pinhole visual acuity≥6/18 and 38 eyes (10.2%) had pinhole visual acuity<6/60. Main causes of visual impairment were uncorrected refractive error (63.9%) and comorbid eye disease (24.5%). Comorbid eye diseases associated with pinhole visual acuity<6/60 (n=23, 6.2%) included glaucoma, other optic nerve atrophy, vitreous haemorrhage and retinal detachment. Conclusions: The findings suggest that hands-on training remains safe and effective even when not implemented in centralized training centres. Further refinement of the training protocol, providing postoperative refractive services and more accurate preoperative intraocular lens calculations, can help optimize outcomes. © 2012 The Authors Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.
Resumo:
BACKGROUND: The accuracy and impact on service uptake of early examination after cataract surgery is not known. DESIGN: Prospective cohort study. PARTICIPANTS: Cataract patients in rural Indonesia. METHODS: Visual acuity was measured preoperatively, 1day, 1-3, 4-6 and >12weeks after surgery, and 6-8months postoperatively at an outreach examination. Acceptance of second-eye surgery and spectacles was evaluated. MAIN OUTCOME MEASURE: Presenting visual acuity in the operated eye. RESULTS: Among 241 subjects (extracapsular surgery 84%), examinations at 1day, 1-3, 4-6 and >12weeks and 6-8months were completed for 100% (241), 90.9% (219), 67.6% (163), 22.0% (53) and 80.0% (193), respectively. Among subjects at the final examination (mean age 65.8±10.6years, 51.8% male), 73.6% had bilateral preoperative presenting visual acuity≤6/60. By 4-6weeks, the proportion with good (≥6/18) or poor (≤6/60) visual acuity did not differ significantly from the final examination. Among 49 persons accepting free second-eye surgery, 69.4% (34) and 16.3% (8) returned to clinic at 4-6 and >12weeks, respectively. Among 131 patients (67.9%) paying US$7 for glasses, 94 (71.8%) and 30 (22.9%) attended 4- to 6- and >12-week examinations, respectively. CONCLUSION: Even with large-incision surgery, early assessment of postoperative vision is representative of final vision, and may help deliver postoperative services to more of those needing them. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.