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1.
BMC Med Educ ; 23(1): 918, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38053089

RESUMO

BACKGROUND: Failure rates on medical specialist final summative examinations in Australia are high, regardless of speciality. Examination failure can have detrimental psycho-social, financial and job security effects on the trainee, while delays in completion of training adversely impacts workforce growth and health outcomes for the community. The study aimed to explore the preparation factors that contribute to ophthalmology trainee success in their final summative examination. METHODS: Semi-structured in-depth interviews were conducted with 29 participants via telephone or Zoom with ophthalmology trainees and Fellows. To be eligible, interviewees had to have sat the Royal Australian and New Zealand College of Ophthalmologists Advanced Clinical Examination (RACE) within the past five years or were providing supervision to trainees preparing for RACE. Interviews were audio-recorded, transcribed and thematically analysed. RESULTS: Examination success was underpinned by six themes relating to preparation: (i) 'Those who fail to plan, plan to fail', which related to development and adherence to a study plan; (ii) 'It takes a village' encompassed trainees establishing and activating personal and professional supports; (iii) 'Get to know your opponent', which encompassed developing an understanding of the examination construct, format and requirements; (iv) 'There is no substitute for hard work', which related to intensive study over a period of 12-18 months; (v) 'Keep pace with the herd', which referred to benchmarking preparation efforts and progress against peers; and (vi) 'Don't jump the gun', which related to ensuring readiness to sit. CONCLUSIONS: Maximising medical specialist examination pass rates is in the best interest of trainees, training Colleges, health care systems and communities. Recognising and facilitating preparation approaches that foster success in final summative examinations are the collective responsibility of trainees, specialist training Colleges, training networks and health systems. Trainees need to plan for examination success, be self-determined to commit to intensive study over an extended time period and be realistic about their readiness to sit.


Assuntos
Currículo , Educação de Pós-Graduação em Medicina , Humanos , Austrália , Avaliação Educacional , Nova Zelândia
2.
Ophthalmic Res ; 64(2): 321-326, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32906125

RESUMO

BACKGROUND: Measurement of intraocular pressure (IOP) forms a crucial component in the diagnosis and management of glaucoma. Many devices have been developed to measure IOP with Goldmann applanation tonometry (GAT) considered the gold standard for IOP measurement. OBJECTIVES: The objective was to compare the IOP measured using Icare ic100 and GAT. METHODS: This cross-sectional study measured IOP in 1,000 eyes (500 left and 500 right) using the Icare ic100 and GAT. Central corneal thickness (CCT) was measured using a hand-held pachymeter. IOP measurements were investigated in all eyes, by IOP substrata, by CCT group, by number of topical glaucoma medications, and diagnosis. RESULTS: There was moderate agreement between ic100 and GAT IOP measurements (intraclass correlation coefficient 0.73). Mean IOP was significantly lower when measured by ic100 than by GAT (12.1 vs. 16.2 mm Hg, p < 0.0001). Mean ic100 IOPs were also significantly lower than mean GAT IOPs within each IOP strata ≤12 (7.9 vs. 9.7 mm Hg, p < 0.0001), 13-21 (12.1 vs. 16.6 mm Hg, p < 0.0001), and ≥22 (18.4 vs. 25.2 mm Hg, p < 0.0001) and within each subanalysis. CONCLUSIONS: The Icare tonometer consistently under estimated IOP compared to GAT, irrespective of CCT ranges and other subgroup analyses. The mean difference of 4.2 mm Hg can have significant clinical implications, particularly in the management of glaucoma patients.


Assuntos
Glaucoma/diagnóstico , Pressão Intraocular/fisiologia , Hipertensão Ocular/diagnóstico , Tonometria Ocular/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Desenho de Equipamento , Feminino , Glaucoma/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Hipertensão Ocular/fisiopatologia , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
3.
Clin Exp Ophthalmol ; 49(5): 418-429, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34021959

RESUMO

Researchers have been working towards the development of retinal prostheses, so called "bionic eyes" since the 1960s in an effort to restore functional vision to severely visually impaired patients. Groups from all around the world are involved in this research but in particular, groups from the United States, Germany, France, Japan and Australia have conducted clinical trials of these devices and three of these devices have achieved either FDA HDE (U.S. Food and Drug Administration Humanitarian Device Exception) or CE mark approval for commercial production. Despite this, all three of these devices are now not in commercial production. There are many challenges to overcome to develop devices suitable to implant in human patients and then reach commercial distribution. This is an exacting process and many hurdles need to be overcome to reach this point so that leaving the market after achieving this goal is a significant decision. Ongoing research is exploring the possibility of less complicated surgery with better visual processing algorithms to provide more useful visual information for our patients to provide a commercial alternative.


Assuntos
Próteses Visuais , Austrália , Humanos , Japão , Estados Unidos , Visão Ocular , Percepção Visual
4.
J Headache Pain ; 22(1): 121, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34625019

RESUMO

BACKGROUND: Calcitonin gene-related peptide (CGRP) is expressed throughout the body and is a known mediator of migraine, exerting this biological effect through activation of trigeminovascular, meningeal and associated neuronal pathways located in close proximity to the central nervous system. Monoclonal antibodies (mAb) targeting the CGRP pathway are an effective new preventive treatment for migraine, with a generally favourable adverse event profile. Pre-clinical evidence supports an anti-inflammatory/immunoregulatory role for CGRP in other organ systems, and therefore inhibition of the normal action of this peptide may promote a pro-inflammatory response. CASES: We present a case series of eight patients with new or significantly worsened inflammatory pathology in close temporal association with the commencement of CGRP mAb therapy. CONCLUSION: This case series provides novel insights on the potential molecular mechanisms and side-effects of CGRP antagonism in migraine and supports clinical vigilance in patient care going forward.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Transtornos de Enxaqueca , Anticorpos Monoclonais/efeitos adversos , Calcitonina , Sistema Nervoso Central , Humanos , Transtornos de Enxaqueca/tratamento farmacológico
5.
Retina ; 40(10): 1909-1917, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31851051

RESUMO

PURPOSE: To present the distribution of time to retinal redetachment in eyes undergoing retinal detachment surgery, using a method for adjusting time to outcome in eyes with silicone oil or heavy liquid tamponade ("oil-filled eyes"). METHODS: Data from two Australian centers were used. Adjusted time to outcome was measured from the date of tamponade removal in oil-filled eyes, unless failure was diagnosed with tamponade in situ. RESULTS: 188/1257 failures were identified (15.0%). Using unadjusted time to outcome, failures in oil-filled eyes occurred later than non-oil-filled eyes (median time to failure 57 vs. 28 days, P < 0.001). After adjustment, the distribution of time to failure was similar for oil-filled and non-oil-filled eyes (median 25 vs. 28 days, P = 0.68). Larger detachments, eyes with ≥Grade B proliferative vitreoretinopathy and eyes receiving surgery for recurrent detachments were more likely to fail, but the time to failure was similar regardless of risk. CONCLUSION: Adjustment of time to outcome resulted in a similar distribution of time to failure in oil-filled and non-oil filled eyes and was similar in low- and high-risk eyes. The use of adjusted time to outcome will support consistent collection and interpretation of outcomes across different jurisdictions where time to oil removal may vary.


Assuntos
Tamponamento Interno , Descolamento Retiniano/cirurgia , Recurvamento da Esclera , Vitrectomia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Descolamento Retiniano/fisiopatologia , Óleos de Silicone/administração & dosagem , Fatores de Tempo , Falha de Tratamento , Acuidade Visual/fisiologia
6.
Clin Exp Ophthalmol ; 48(7): 964-972, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32639080

RESUMO

IMPORTANCE: Fungal endophthalmitis is an uncommon and serious intraocular infection, often with poor outcomes. This study examines the trend in this disease over 20 years, to inform clinician decision-making and optimize patient outcomes. BACKGROUND: Due to infrequent presentation of fungal endophthalmitis, there is limited understanding to formulate a standardized approach to management. DESIGN: A prospective case series over the period January 1, 1999 to December 31, 2018. PARTICIPANTS: Patients with clinically diagnosed fungal endophthalmitis managed at the Royal Victorian Eye and Ear Hospital, Melbourne, Australia. METHODS: Review of the Victorian Endophthalmitis Registry for endophthalmitis episode of each patient. MAIN OUTCOME MEASURES: Patient demographics, co-morbidities, visual acuity (VA) at presentation, aetiology, treatment, microbiology results and final VA outcome. RESULTS: Eighty-four cases of fungal endophthalmitis were identified over the study period with a median age of 43.5 years [IQR 30.8-63.0]. Then, 65.5% (n = 55) of patients were male; 81.0% (n = 68) of these cases were secondary to endogenous causes, of which 55.9% were associated with intravenous drug use (IVDU). Among the exogenous causes, penetrating eye injury (56.3%) was the most common aetiological factor. Thirty-nine patients (46.4%) grew Candida species from ocular fluid specimens, all of which were sensitive to fluconazole. CONCLUSION AND RELEVANCE: Our case series provides important insights into fungal endophthalmitis-a high degree of suspicion for fungal endophthalmitis in patients with history of IVDU, and relatively good outlook for vision when Candida is the causative organism. This should allow institutions to implement a standardized management strategy based on evidence.


Assuntos
Endoftalmite , Infecções Oculares Fúngicas , Adulto , Endoftalmite/diagnóstico , Endoftalmite/tratamento farmacológico , Endoftalmite/epidemiologia , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Centros de Atenção Terciária , Acuidade Visual , Vitrectomia
7.
Clin Exp Ophthalmol ; 48(6): 813-820, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32348002

RESUMO

IMPORTANCE: This is the largest Gram-negative endophthalmitis specific series and provides important evidence to guide management. BACKGROUND: Endophthalmitis is a sight-threatening emergency. Gram-negative infections are associated with poorer visual outcomes; however, there is limited literature pertaining to this uncommon condition. DESIGN: Prospective case series. PARTICIPANTS: All patients presenting with endophthalmitis to a tertiary institution over a 20-year period. METHODS: Data were collected prospectively and entered into a registry. Patients with microbiological evidence of Gram-negative infection were included in the analysis. MAIN OUTCOMES MEASURES: Final visual acuity (VA), precipitating events, causative organisms, antibiotic sensitivity profiles and risk factors for poor visual outcomes were reported. RESULTS: One hundred Gram-negative organisms were isolated in 97 eyes. Final VA was worse than 6/60 in 65 (67.0%) eyes at follow-up and 29 (29.9%) eyes were eviscerated or enucleated. Microbial keratitis (26.8%, n = 26) and Pseudomonas aeruginosa (34.0%, n = 34) were the most common precipitating event and causative organism, respectively. Eight (8.0%) isolates were third-generation cephalosporin resistant; of which, 7 (88.0%) were sensitive to ciprofloxacin. Preceding microbial keratitis (OR = 13.16, P = .015) or P. aeruginosa infections (OR = 3.40, P = .045) were strongly associated with poorer visual outcomes (worse than 6/60). CONCLUSIONS AND RELEVANCE: Visual outcomes following Gram-negative endophthalmitis are extremely poor, with almost 30% of patients being eviscerated or enucleated. A majority of ceftazidime resistant organisms are sensitive to ciprofloxacin, providing evidence to support the empirical use of quinolones. Clinicians should be mindful that infections secondary to P. aeruginosa or microbial keratitis carry a particularly poor prognosis.


Assuntos
Endoftalmite , Infecções Oculares Bacterianas , Antibacterianos/uso terapêutico , Ceftazidima/uso terapêutico , Endoftalmite/diagnóstico , Endoftalmite/tratamento farmacológico , Endoftalmite/epidemiologia , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Estudos Prospectivos , Estudos Retrospectivos
9.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1863(7): 750-761, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29660533

RESUMO

The human retina is a complex structure of organised layers of specialised cells that support the transmission of light signals to the visual cortex. The outermost layer of the retina, the retinal pigment epithelium (RPE), forms part of the blood retina barrier and is implicated in many retinal diseases. Lysophosphatidic acid (LPA) is a bioactive lipid exerting pleiotropic effects in various cell types, during development, normal physiology and disease. Its producing enzyme, AUTOTAXIN (ATX), is highly expressed by the pigmented epithelia of the human eye, including the RPE. Using human pluripotent stem cell (hPSC)-derived retinal cells, we interrogated the role of LPA in the human RPE and photoreceptors. hPSC-derived RPE cells express and synthesize functional ATX, which is predominantly secreted apically of the RPE, suggesting it acts in a paracrine manner to regulate photoreceptor function. In RPE cells, LPA regulates tight junctions, in a receptor-dependent mechanism, with an increase in OCCLUDIN and ZONULA OCCLUDENS (ZO)-1 expression at the cell membrane, accompanied by an increase in the transepithelial resistance of the epithelium. High concentration of LPA decreases phagocytosis of photoreceptor outer segments by the RPE. In hPSC-derived photoreceptors, LPA induces morphological rearrangements by modulating the actin myosin cytoskeleton, as evidenced by Myosin Light Chain l membrane relocation. Collectively, our data suggests an important role of LPA in the integrity and functionality of the healthy retina and blood retina barrier.


Assuntos
Barreira Hematorretiniana/fisiologia , Lisofosfolipídeos/fisiologia , Células Fotorreceptoras de Vertebrados/fisiologia , Doenças Retinianas/patologia , Epitélio Pigmentado da Retina/metabolismo , Linhagem Celular , Citoesqueleto/metabolismo , Humanos , Fagocitose/fisiologia , Diester Fosfórico Hidrolases/metabolismo , Células-Tronco Pluripotentes , Doenças Retinianas/cirurgia , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/patologia , Junções Íntimas/metabolismo , Vitrectomia
10.
Clin Exp Ophthalmol ; 46(4): 424-431, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28949429

RESUMO

IMPORTANCE: Streptococcal endophthalmitis has devastating sequelae. This study aims to identify factors which may be targeted to optimize patient outcomes. BACKGROUND: This study investigated characteristics influencing visual outcomes and the role of early vitrectomy. DESIGN: Retrospective observational case series of consecutive patients was conducted. PARTICIPANTS: All patients with a culture-positive diagnosis of streptococcal endophthalmitis treated at a tertiary ophthalmology referral centre between July 1997 and February 2012 were included. METHODS: Patient records were reviewed and data collected on their presentation, examination, microbiology results, procedures and final outcome. MAIN OUTCOME MEASURES: Visual acuity (VA) and enucleation/evisceration were measured. RESULTS: Of the 101 patients, 35.6% presented with a VA of hand movements and 42.6% with light perception (LP). Final VA was poor (6/60 or worse) in 77.6% and 24.7% were enucleated/eviscerated. Presenting VA of LP or worse (P = 0.008), no view of fundus (P = 0.001), large number of organisms (P < 0.001), recognition of Streptococcus on Gram stain (P = 0.010), heavy growth on culture (P < 0.001) and more intravitreal injections (P = 0.038) were significantly associated with poor visual outcome (6/60 or worse). Presenting VA of LP or worse (P = 0.042) and non-viridans Streptococcus species (P = 0.002) were significantly associated with enucleation/evisceration. Fifteen patients (14.9%) had early vitrectomy within 48 h which was not associated with poor final VA or removal of the eye (P = 1.000). CONCLUSIONS AND RELEVANCE: Early vitrectomy did not influence visual outcome in this cohort. Microbiology results were useful in predicting poor outcomes, and may allow clinicians to make early treatment decisions and provide prognostic information for patients.


Assuntos
Endoftalmite/cirurgia , Infecções Oculares Bacterianas/cirurgia , Infecções Estreptocócicas/cirurgia , Streptococcus/isolamento & purificação , Acuidade Visual , Vitrectomia/métodos , Corpo Vítreo/microbiologia , Endoftalmite/microbiologia , Endoftalmite/fisiopatologia , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/fisiopatologia , Feminino , Seguimentos , Previsões , Humanos , Masculino , Estudos Retrospectivos , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/fisiopatologia , Tempo para o Tratamento , Corpo Vítreo/cirurgia
11.
Kidney Int ; 92(2): 461-469, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28601198

RESUMO

Recurrent glomerulonephritis after kidney transplantation is a feared complication because it is unpredictable and may have a negative impact on graft outcomes. To better understand this we collected data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry accumulated over 30 years. The incidence, risk factors, and outcomes of recurrent glomerulonephritis in transplant recipients were determined using adjusted Cox proportional hazard and competing risk modeling. A total of 6,597 recipients with biopsy-proven glomerulonephritis as the primary cause of end-stage kidney disease were followed for 51,871 person-years (median duration 7.7 years). The four most common types of glomerulonephritis were IgA nephropathy in 2501 patients, focal segmental glomerulosclerosis (FSGS) in 1403, membranous in 376, and membranoproliferative (MPGN) nephropathy in 357 patients. Among these four types, recurrence was reported in 479 of 4637 patients, and of these, 212 lost their allograft due to recurrence. Older age at transplantation (adjusted hazard ratio [per year increase] 0.96 [95% confidence interval 0.95 - 0.97]) was associated with a lower risk of recurrence. Significantly, the five-year graft survival was 30% for recipients with recurrent MPGN and 57-59% for recipients with FSGS, IgA, and membranous nephropathy. Transplant recipients with recurrent disease were twice as likely to lose their allografts compared to those without recurrence (adjusted hazard ratio 2.04 [1.81-2.31]). Thus, recurrent glomerulonephritis remains a significant cause of graft loss in transplant recipients.


Assuntos
Glomerulonefrite/epidemiologia , Transplante de Rim , Complicações Pós-Operatórias/epidemiologia , Adolescente , Adulto , Idoso , Austrália/epidemiologia , Criança , Estudos de Coortes , Feminino , Sobrevivência de Enxerto , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Recidiva , Adulto Jovem
13.
Clin Exp Ophthalmol ; 45(2): 135-142, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27564396

RESUMO

BACKGROUND: Endogenous Klebsiella pneumoniae endophthalmitis (EKPE) is a well-known entity in South-East Asia. We demonstrate a range of differing clinical features and outcomes of EKPE, and highlight the increasing incidence of EKPE in major centres in Sydney and Melbourne, Australia. DESIGN: Retrospective observational case study and case series in the hospital setting. PARTICIPANTS: Four cases of EKPE. METHODS: EKPE cases from 2005 to 2015 were identified through established endophthalmitis databases as well as hospital-based microbiological searches. MAIN OUTCOME MEASURES: EKPE cases were confirmed with positive K. pneumoniae intraocular samples. RESULTS: Rising trends of EKPE were noted in major centres in Australia. Six eyes of four patients with EKPE from January 2011 to December 2015 are reported. The mean age was 49 years (range 43-58 years). Two patients had bilateral involvement. There were systemic symptoms up to 10 days prior to ocular symptoms. The source of sepsis in all cases was a hepatic abscess. Two patients had diabetes mellitus. Five eyes had hypopyon panuveitis on presentation. All eyes underwent vitrectomy. The patient with the most delayed presentation underwent enucleation following globe perforation. Final best corrected visual acuity (BCVA) in one patient with bilateral EKPE was light perception (LP) only. The other three eyes had BCVA in at least one eye of 6/24 or better. CONCLUSIONS: EKPE is an emerging condition in Australia. Although rare, EKPE is a sight-threatening and potentially life-threatening emergency that can initially present to ophthalmologists. One should suspect EKPE in septic patients with a B-scan showing a vitreous or retinal abscess.


Assuntos
Endoftalmite/epidemiologia , Infecções Oculares Bacterianas/epidemiologia , Previsões , Klebsiella pneumoniae/isolamento & purificação , Adulto , Endoftalmite/microbiologia , Infecções Oculares Bacterianas/microbiologia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade/tendências , New South Wales/epidemiologia , Estudos Retrospectivos , Vitória/epidemiologia
14.
Ophthalmology ; 123(1): 178-82, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26526634

RESUMO

PURPOSE: To evaluate visual outcomes after femtosecond laser-assisted cataract surgery (LCS) with phacoemulsification cataract surgery (PCS). DESIGN: Prospective, multicenter, comparative case series. PARTICIPANTS: Consecutive patients undergoing femtosecond LCS or PCS with intraocular lens insertion. METHODS: A total of 1876 eyes of 1238 patients (422 male and 772 female) who underwent cataract surgery between January 2012 and June 2014 were included in the study: 1017 eyes from center A and 859 eyes from center B. Cases underwent clinico-socioeconomic selection. Patients with absolute LCS contraindications were assigned to PCS; otherwise, all patients were offered LCS and elected on the basis of their decision to pay (the out-of-pocket cost for LCS). Demographic and postoperative data were collected to determine differences between groups. MAIN OUTCOME MEASURES: Six-month postoperative visual and refractive outcomes. Masked subjective refractions were performed 2 to 6 months postoperatively. RESULTS: There were 988 eyes in the LCS group and 888 eyes in the PCS group. Baseline best-corrected visual acuity (BCVA) was better in LCS compared with PCS (20/44.0 vs. 20/51.5; P < 0.0003). Preoperative surgical refractive aim differed significantly between groups (LCS -0.28 vs. PCS -0.23; P < 0.0001). More patients who received LCS had Toric lenses implanted compared with PCS (47.4% vs. 34.8%; P < 0.0001). Postoperative BCVA was better after LCS (20/24.5 vs. 20/26.4; P = 0.0003) with a greater proportion of LCS cases achieving BCVA >20/30 (LCS 89.7% vs. PCS 84.2%; P = 0.0006) and 20/40 (LCS 96.6% vs. PCS 93.9%; P = 0.0077). However, PCS cases had more letters gained compared with LCS cases (13.5 vs. 12.5 letters; P = 0.0088), reflecting baseline BCVA differences. Mean absolute error was higher in LCS compared with PCS (0.41 diopters [D] vs. 0.35 D; P < 0.0011). The percentage of eyes within 0.5 D of error from preoperative aim refraction was higher in the PCS group (LCS 72.2% vs. PCS 82.6%; P < 0.0001). CONCLUSIONS: Femtosecond LCS did not demonstrate clinically meaningful improvements in visual outcomes over conventional PCS.


Assuntos
Terapia a Laser/métodos , Refração Ocular/fisiologia , Acuidade Visual/fisiologia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Facoemulsificação/métodos , Período Pós-Operatório , Estudos Retrospectivos , Resultado do Tratamento
15.
Artif Organs ; 40(3): E12-24, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26416723

RESUMO

Successful visual prostheses require stable, long-term attachment. Epiretinal prostheses, in particular, require attachment methods to fix the prosthesis onto the retina. The most common method is fixation with a retinal tack; however, tacks cause retinal trauma, and surgical proficiency is important to ensure optimal placement of the prosthesis near the macula. Accordingly, alternate attachment methods are required. In this study, we detail a novel method of magnetic attachment for an epiretinal prosthesis using two prostheses components positioned on opposing sides of the retina. The magnetic attachment technique was piloted in a feline animal model (chronic, nonrecovery implantation). We also detail a new method to reliably control the magnet coupling force using heat. It was found that the force exerted upon the tissue that separates the two components could be minimized as the measured force is proportionately smaller at the working distance. We thus detail, for the first time, a surgical method using customized magnets to position and affix an epiretinal prosthesis on the retina. The position of the epiretinal prosthesis is reliable, and its location on the retina is accurately controlled by the placement of a secondary magnet in the suprachoroidal location. The electrode position above the retina is less than 50 microns at the center of the device, although there were pressure points seen at the two edges due to curvature misalignment. The degree of retinal compression found in this study was unacceptably high; nevertheless, the normal structure of the retina remained intact under the electrodes.


Assuntos
Imãs/química , Implantação de Prótese/métodos , Retina/cirurgia , Próteses Visuais/química , Animais , Gatos , Eletrodos Implantados , Temperatura Alta , Magnetismo/métodos , Desenho de Prótese , Retina/ultraestrutura
17.
Clin Exp Ophthalmol ; 44(7): 570-573, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26946462

RESUMO

BACKGROUND: To evaluate the visual outcomes of femtosecond laser-assisted cataract surgery (LCS) compared with phacoemulsification cataract surgery (PCS) in patients undergoing Toric IOL insertion. DESIGN: A non-randomized, single surgeon, prospective, comparative cohort case series PARTICIPANTS: Patients undergoing LCS and PCS between January 2012 and July 2014 at a single center. METHODS: The LCS group underwent femtosecond laser pretreatment for the anterior capsulotomy and lens fragmentation. Otherwise standard phacoemulsification surgery and foldable toric intraocular lens insertion proceeded. MAIN OUTCOME MEASURES: Best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), pre and post operative cylinder and mean absolute refractive error. RESULTS: A total of 418 eyes from 323 patients were included in the study; with 95 eyes in the PCS group and 323 in the LCS group. There were 243 (75.5%) LCS eyes with a pre-operative BCVA of 20/40 or better and 54 (56.8%) in the PCS group (p < 0.001). For post-operative BCVA, 315 (97.5 %) LCS and 81 (85.3%) PCS eyes had a BCVA of 20/40 or better (p = <0.001). However, there was no significant difference for change in BCVA between the groups (mean gain in EDTRS letter 11.0 for LCS and 10.3 for PCS p = 0.64) or in MAE (mean 0.56D PCS vs 0.65D LCS p = 0.18). CONCLUSION: In patients receiving toric intraocular lenses, there is similar improvement in terms of letters gained with LCS and PCS. Overall, there is no additional benefit for patients undergoing LCS in this cohort.


Assuntos
Extração de Catarata/métodos , Terapia a Laser/métodos , Implante de Lente Intraocular , Pseudofacia/fisiopatologia , Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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