RESUMO
PURPOSE: To investigate and compare the morphological features and differences among Gaussian, Sagittal, and Tangential anterior corneal curvature maps obtained with an anterior segment optical coherence tomographer combined with a Placido disc MS-39 device in keratoconus (KC) and normal eyes. METHODS: Prospective, cross-sectional study including 37 KC and 51 healthy eyes. The pattern of astigmatism and maximum keratometry (Kmax), keratometry at the thinnest point (Ktp) and 2 mm diameter (K 2mm ), and inferior-superior dioptric asymmetry values were obtained and calculated from Gaussian, Tangential, and Sagittal curvature maps using the MS-39 (CSO). RESULTS: In KC eyes, an asymmetric bowtie pattern was observed in 64.86% (24/37), 64.86% (24/37), and 0% in the Sagittal, Tangential, and Gaussian maps, respectively. In normal eyes, 51.0% (26/51), 51.0% (26/51), and 0% showed a symmetric bowtie pattern in the Sagittal, Tangential, and Gaussian maps, respectively. There was a significant difference for the variables Kmax, Ktp, and K 2mm inferior among the Gaussian, Tangential, and Sagittal maps in both normal and KC groups. Sensitivity discriminating between normal and KC eyes was 100%, 97.3%, and 90.9% and specificity was 94.1%, 100%, and 100% for Kmax coming from the Tangential, Gaussian, and Sagittal maps, respectively. CONCLUSIONS: Gaussian maps displayed significantly different morphological features when compared with Sagittal and Tangential maps in normal and KC eyes. Anterior curvature maps from Gaussian maps do not show the morphological pattern of symmetric bowtie in normal eyes nor asymmetric bowtie in KC eyes. Kmax from Gaussian maps are more specific, however less sensitive than Tangential maps in discriminating KC from normal eyes.
Assuntos
Topografia da Córnea , Ceratocone , Tomografia de Coerência Óptica , Humanos , Ceratocone/diagnóstico , Ceratocone/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Estudos Prospectivos , Masculino , Estudos Transversais , Feminino , Adulto , Adulto Jovem , Topografia da Córnea/métodos , Córnea/patologia , Córnea/diagnóstico por imagem , Segmento Anterior do Olho/diagnóstico por imagem , Segmento Anterior do Olho/patologia , Pessoa de Meia-Idade , Distribuição NormalRESUMO
PURPOSE: To evaluate and compare the biometric characteristics of the anterior chamber of a group of patients with significant endothelial cell loss (ECL) who required phakic intraocular lens (pIOL) explantation and a group of patients who did not fulfill the explantation criteria related to corneal decompensation. DESIGN: Retrospective, consecutive, interventional case series. METHODS: The study included all consecutive patients receiving a pIOL implantation at Oftalmosalud Instituto de Ojos, Lima, Peru, between 2001 and 2012. The explanted group (E group) consisted of eyes in which the pIOLs were explanted due to ECL, and the nonexplanted group (NE group) consisted of eyes randomly selected in which the pIOL was not explanted with a minimum follow-up time of 8 years. Slit-lamp biomicroscopy, visual acuity, refraction, endothelial cell count, and anterior segment optical coherence tomography were assessed at the preoperative evaluation for both groups and before explantation in the E group and 8 years post-implantation in the NE group. RESULTS: pIOLs were implanted in 265 eyes. The annual percentage of ECL was 1.47% and 5.55% in the NE group and E group, respectively (P < .001). The mean minimum endothelial lens distance (ELD) was 1.44 ± 0.22 mm and 1.05 ± 0.23 mm in the NE group and E group, respectively (P < 0.001). The mean time for explantation was 12.58 ± 3.79 years for the E group. Annual ECL could accurately discriminate between the NE group and E group; a cutoff point of 3.5 (%/year) or 86.5 (cells/years) had a 100% sensitivity and specificity. A cutoff of 1.21 mm in the minimum ELD has a 91% sensitivity and 79% specificity to discriminate between the E group and NE group. CONCLUSIONS: pIOL explantation due to ECL occurs in eyes with a significantly postoperative lower minimum ELD. Annual ECL and minimum ELC can effectively discriminate between the E and NE groups.
Assuntos
Biometria , Remoção de Dispositivo , Endotélio Corneano , Iris , Implante de Lente Intraocular , Lentes Intraoculares Fácicas , Refração Ocular , Tomografia de Coerência Óptica , Acuidade Visual , Humanos , Estudos Retrospectivos , Masculino , Feminino , Adulto , Acuidade Visual/fisiologia , Tomografia de Coerência Óptica/métodos , Iris/cirurgia , Contagem de Células , Endotélio Corneano/patologia , Seguimentos , Refração Ocular/fisiologia , Câmara Anterior/patologia , Câmara Anterior/diagnóstico por imagem , Adulto Jovem , Perda de Células Endoteliais da Córnea/diagnóstico , Miopia/cirurgia , Miopia/fisiopatologia , Pessoa de Meia-Idade , Microscopia com Lâmpada de FendaRESUMO
A 24-year-old man was referred for postrefractive surgery evaluation. The patient had a history of uneventful laser in situ keratomileusis (LASIK) in both eyes 3 months previously. According to the surgeon who originally performed the surgery, on slitlamp examination, only microstriae in the left eye was detected on postoperative day 1 and a more conservative follow-up approach was adopted without further immediate intervention. The patient returned only 3 months after surgery, complaining of low vision in the left eye that, according to the patient, had been present since postoperative week 2. The patient was then referred for examination and surgical procedure with a diagnosis of significant postoperative striae. The slitlamp examination revealed a LASIK flap with striae, epithelial filling, and a wrinkled appearance (Figure 1JOURNAL/jcrs/04.03/02158034-202312000-00017/figure1/v/2023-11-20T151558Z/r/image-tiff). There were no signs of infection or inflammation. Originally, the LASIK flap was programmed to be 110 µm. Preoperative manifest refraction in the right eye was -5.25 (20/20) and in the left eye was -5.25 (20/20). Assuming it is a case of late-approach LASIK flap striae, how would you proceed? Would you try to hydrate and lift the flap and just reposition it? Would you avoid lifting and associate phototherapeutic keratectomy (PTK) with excimer laser on top of the flap? Would you consider topo-guided surgery with regularization of the visual axis or even amputation of the flap?
Assuntos
Ceratomileuse Assistida por Excimer Laser In Situ , Ceratectomia Fotorrefrativa , Masculino , Humanos , Adulto Jovem , Adulto , Substância Própria/cirurgia , Acuidade Visual , Ceratectomia Fotorrefrativa/métodos , Lasers de Excimer/uso terapêutico , Refração OcularRESUMO
Plant disease resistance genes are widely used in agriculture to reduce disease outbreaks and epidemics and ensure global food security. In soybean, Rps (Resistance to Phytophthora sojae) genes are used to manage Phytophthora sojae, a major oomycete pathogen that causes Phytophthora stem and root rot (PRR) worldwide. This study aims to identify temporal changes in P. sojae pathotype complexity, diversity, and Rps gene efficacy. Pathotype data was collected from 5121 isolates of P. sojae, derived from 29 surveys conducted between 1990 and 2019 across the United States, Argentina, Canada, and China. This systematic review shows a loss of efficacy of specific Rps genes utilized for disease management and a significant increase in the pathotype diversity of isolates over time. This study finds that the most widely deployed Rps genes used to manage PRR globally, Rps1a, Rps1c and Rps1k, are no longer effective for PRR management in the United States, Argentina, and Canada. This systematic review emphasizes the need to widely introduce new sources of resistance to P. sojae, such as Rps3a, Rps6, or Rps11, into commercial cultivars to effectively manage PRR going forward.
Assuntos
Phytophthora , Phytophthora/genética , Genes de Plantas , Agricultura , Argentina , Canadá/epidemiologiaRESUMO
Purpose: We evaluate the long-term visual, refractive, and keratometric outcomes after corneal crosslinking (CXL) in patients with progressive keratoconus (KC) and the incidence of an extreme corneal flattening effect. Settings: Oftalmosalud Institute of Eyes, Lima, Perú. Design: Retrospective cohort study. Methods: Forty-five eyes that underwent CXL with epithelial removal between June 2006 and September 2011. Data analysis was performed at preoperative evaluation, 1 year postoperatively, and at least 10 years or more postoperatively. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and Scheimpflug (Pentacam) analysis. Progression was defined by an increase in steep keratometry (Ks) of 1.5D or greater between 2 examinations. Extreme flattening effect was defined as a decrease in K values equal to or greater than 5 diopters (D). Results: Mean follow-up time was 11 ± 1.07 years (range 10-13 years). There was a significant improvement in Ks, UCVA, CDVA, and spherical equivalent at the last visit. The overall rate of progression was 2.22% (1/45). Extreme flattening was observed in 15.5% (7/45) of the eyes, and this was associated with a loss of CDVA in 4.44% (2/45) of the eyes. One eye with corneal flattening of 11.5 D lost 7 lines of CDVA and required corneal transplantation. Conclusion: CXL is a safe and effective procedure to stop the progression of KC with a good overall long-term success rate. Extreme corneal flattening may be more common than commonly recognized, and severe corneal flattening associated with a decrease in CDVA may occur.
RESUMO
PURPOSE: The aim of this study was to evaluate the visual, pachymetric, tomographic, and biomicroscopic findings in a series of cases with laser in situ keratomileusis (LASIK) flap interface fluid syndrome (IFS) after Descemet membrane endothelial keratoplasty (DMEK). METHODS: Six cases were included in this study; all patients had a history of LASIK and underwent DMEK for the treatment of bullous keratopathy. After uneventful surgery, all patients presented with corneal edema and IFS under the LASIK flap, which was demonstrated with anterior segment optical coherence tomography (AS-OCT). Visual acuity, clinical findings, pachymetry, endothelial cell count, and AS-OCT were documented during the management of these cases. RESULTS: IFS appears 2.33 days (±1.03) after DMEK. One case improved with conservative treatment. In 5 cases, the LASIK flap was lifted, the fluid was drained, and the flap was replaced. The mean best-corrected visual acuity after fluid drainage was 0.44 logMAR (range 0.18-1.0) and mean central corneal thickness was 538 µm ± 160. Total resolution of the IFS was achieved at 14.5 days (range 4-30) after DMEK. AS-OCT showed resolution of the flap interface in 5 of 6 cases, while 1 patient required second DMEK due to reaccumulation of the interface fluid. CONCLUSIONS: IFS can occur after DMEK in patients with previous LASIK. AS-OCT is a valuable tool for monitoring these cases preoperatively and postoperatively. Early surgical management is often needed to achieve resolution.
Assuntos
Edema da Córnea , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Ceratomileuse Assistida por Excimer Laser In Situ , Humanos , Lâmina Limitante Posterior/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/efeitos adversos , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/métodos , Acuidade Visual , Edema da Córnea/diagnóstico , Edema da Córnea/etiologia , Edema da Córnea/cirurgia , Estudos Retrospectivos , Endotélio Corneano/cirurgiaRESUMO
Fusarium head blight (FHB) is a devastating fungal disease responsible for significant yield losses in wheat and other cereal crops across the globe. FHB infection of wheat spikes results in grain contamination with mycotoxins, reducing both grain quality and yield. Breeding strategies have resulted in the production of FHB-resistant cultivars, however, the underlying molecular mechanisms of resistance in the majority of these cultivars are still poorly understood. To improve our understanding of FHB-resistance, we performed a transcriptomic analysis of FHB-resistant AC Emerson, FHB-moderately resistant AC Morley, and FHB-susceptible CDC Falcon in response to Fusarium graminearum. Wheat spikelets located directly below the point of inoculation were collected at 7-days post inoculation (dpi), where dual RNA-sequencing was performed to explore differential expression patterns between wheat cultivars in addition to the challenging pathogen. Differential expression analysis revealed distinct defense responses within FHB-resistant cultivars including the enrichment of physical defense through the lignin biosynthesis pathway, and DON detoxification through the activity of UDP-glycosyltransferases. Nucleotide sequence variants were also identified broadly between these cultivars with several variants being identified within differentially expressed putative defense genes. Further, F. graminearum demonstrated differential expression of mycotoxin biosynthesis pathways during infection, leading to the identification of putative pathogenicity factors.
RESUMO
ABSTRACT: Strong evidence suggests that corneal crosslinking is a safe procedure capable of stopping or slowing down the progression of keratoconus, avoiding visual loss associated with progression, and delaying or preventing the need for corneal transplantation. The progressive and chronic nature of the disease makes the option for prompt crosslinking upon keratoconus diagnosis in a pediatric patient valid.
Assuntos
Ceratocone , Fotoquimioterapia , Criança , Humanos , Ceratocone/diagnóstico , Ceratocone/tratamento farmacológico , Reagentes de Ligações Cruzadas/uso terapêutico , Fotoquimioterapia/métodos , Colágeno/uso terapêutico , Acuidade Visual , Progressão da Doença , Fármacos Fotossensibilizantes/uso terapêutico , Riboflavina/uso terapêutico , Raios UltravioletaRESUMO
ABSTRACT Purpose: To evaluate the vision quality by measuring the objective light scatter index and objective optical quality parameters (Strehl Ratio and Modulation Transfer Function) in patients with emmetropia and ametropia. Methods: This prospective, cross-sectional study included 408 eyes. The ametropic group comprised of eyes with best-corrected visual acuity of 0.0 logMAR or better and present at least a refractive error of ≥0.25 D. Patients underwent slit lamp examination, visual acuity, refraction, and vision quality using the HD Analyzer. Results: The mean objective light scatter indices were 0.62 ± 0.63, 0.77 ± 0.70, 0.74 ± 0.30, 0.93 ± 0.55, and 0.85 ± 0.61, and mean Strehl Ratio and Modulation Transfer Function scores were 38.17 ± 10.4, 37.37 ± 10.06, 29.84 ± 9.71, 33.2 ± 12.11, and 33.13 ± 10.09 in emmetropes, myopia, hyperopia, spherical equivalent of ≥0, and spherical equivalent of <0, respectively. Differences in all variables were significant between emmetropic and corrected hyperopic and between spherical equivalent of ≥0, and spherical equivalent of <0 eyes (p<0.05). Conclusion: In spectacle-corrected conditions (with trial frames), emmetropic and simple myopic eyes had significantly better vision quality compared to hyperopic and astigmatic eyes. The clinical significance of these results should be investigated in further studies.
RESUMO Objetivo: Avaliar a qualidade óptica medindo o índice de dispersão objetiva de luz e os parâmetros de qualidade óptica objetiva (Razão de Strehl e Função de Transferência de Modulação) em indivíduos com emetropia e ametropia. Métodos: Estudo prospectivo, transversal, incluindo 408 olhos. O grupo ametrópico era de olhos com melhor acuidade visual corrigida de 0,0 logMAR ou melhor e apresentando, pelo menos, um erro refrativo de 0,25 D ou mais. Os pacientes foram submetidos a exame com lâmpada de fenda, acuidade visual, refração e qualidade óptica com o HD Analyzer. Resultados: O índice de dispersão objetiva de luz médio foi de 0,62 ± 0,63, 0,77 ± 0,70, 0,74 ± 0,30, 0,93 ± 0,55, 0,85 ± 0,61 e a média da Razão de Strehl e de Função de Transferência de Modulação foram 38,17 ± 10,4, 37,37 ± 10,06, 29,84 ± 9,71, 33,2 ± 12,11 e 33,13 ± 10,09 em olhos emetrópicos, míopes, hipermétropes, equivalente esférico ≥0 e equivalente esférico <0 respectivamente. Foram encontradas diferenças significativas em todas as variáveis entre olhos emetrópicos e com hipermetropia corrigida, equivalente esférico ≥ 0 e equivalente esférico <0 (p<0,05). Conclusão: Em condições com lentes corrigidas (com armações de prova), os olhos emetrópicos e com miopia simples apresentaram qualidade óptica significativamente melhor em comparação com os olhos hipermétropes e astigmáticos. O significado clínico destes resultados deve ser estudado posteriormente.
RESUMO
AIM: To compare the simulated safe distance (SSD) preoperatively versus real safe distance (RSD) postoperatively in patients with iris-claw phakic intraocular lens (pIOL) implantation according to iris configuration. METHODS: Totally 60 eyes of 60 patients underwent pIOL implantation for surgical correction of myopia. Anterior chamber depth (ACD) was measured with the IOLMaster 700, and nasal and temporal safety distances (SD) were measured pre- and postoperatively using Anterior Segment Visante-OCT. SD was defined as a line measured between the edge of the optic or its simulated image to the endothelium. Eyes were divided into 3 groups: convex, concave, and plane according to preoperatory iris configuration. Statistical analysis was performed using the R program, for the comparison of independent groups and multiple comparisons, the Kruskal-Wallis test and the Dunn test were used respectively. RESULTS: Mean difference between nasal preoperative SSD and postoperative RSD was -0.36±0.38, -0.29±0.48, and -0.18±0.30 mm in the concave, convex, and plane group, respectively. Mean difference between temporal SSD and RSD was -0.36±0.37, -0.14±0.38, and -0.24±0.33 mm in the concave, convex, and plane group, respectively. There were statistically significant differences between SSD and RSS for both nasal and temporal sides in the concave and plane group (P<0.002). CONCLUSION: Preoperative SSD and postoperative RSD for iris-claw pIOL shows significant differences in patients with concave and plane iris.
RESUMO
PURPOSE: To quantify the false positive rates for keratoconus (KC) and potential ectatic corneal conditions in highly astigmatism eyes when using published parameters/indices obtained from the Pentacam and Galilei units. SETTING: Oftalmosalud Instituto de Ojos, Lima, Peru. DESIGN: Prospective cohort study. METHODS: 67 consecutive eyes with corneal astigmatism > 1.5 D, with a minimum follow ups of 36 months after an uneventful LASIK procedure were included. Indices for KC and other potential ectatic corneal conditions (subclinical KC, forme fruste KC, suspect KC) were obtained using the Pentacam and Galilei Scheimpflug cameras. MAIN OUTCOME MEASURES: The false positive rates for KC and potential ectatic corneal conditions were measured. Cut off values provided by previous studies and company-based parameters were used to assess the rate of false positivity. RESULTS: The range of false positive rates for a KC diagnosis depending on the lowest and highest cutoff values were: index of height decentration (61% - 1%), index of surface variance (76% - 0%), Posterior elevation (55% - 0%), maximum Ambrosio Relational thickness (100% - 13%), Belin Ambrosio enhanced ectasia display total deviation value (100% - 4%), Average pachymetric progression index (69% - 3%), Pachymetry at the thinnest point (58% - 1%), CSI Center Surround Index (100%), Differential sector index (51%). CONCLUSION: The false positive rates for KC and ectatic corneal conditions vary dramatically depending on the cut-off values used. Some indexes used for diagnosis of potential ectatic corneal conditions are inaccurate in normal, highly astigmatic eyes.
Assuntos
Astigmatismo , Ceratocone , Córnea , Paquimetria Corneana , Topografia da Córnea/métodos , Dilatação Patológica/diagnóstico , Humanos , Ceratocone/diagnóstico , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , TecnologiaRESUMO
PURPOSE: To evaluate and compare visual and refractive outcomes after implantation of the intracorneal continuous ring 360° arc (ICCR) versus the intracorneal ring segment 340° arc (ICRS) using femtosecond laser for central keratoconus. SETTING: Research Department, Oftalmosalud, Instituto de Ojos, Lima, Peru. METHODS: Randomized study that included 40 eyes of 32 patients diagnosed with central keratoconus between November 2014 and March 2015. Twenty eyes had an implantation of ICCR (MyoRing, Dioptex GmbH, Austria) through an intrastromal pocket and 20 eyes had an implantation of ICRS (Keraring, Mediphacos, Brazil) through an intrastromal tunnel. Both procedures were performed with a femtosecond laser (LDV Z6 model, Ziemer Ophthalmic Systems AG). Visual acuity (VA), refraction, and Scheimpflug imaging analysis were performed pre- and postoperatively at 1 month and 1 year. Comparisons of means were performed using the Student's t-test. RESULTS: At 1 year, uncorrected VA improved 0.77 LogMAR (p < 0.001) in the ICCR group and 0.79 LogMAR (p = 0.01) in the ICRS group; mean sphere improvement was 5.13 Diopters (D) in the ICCR group and 6.27 D in the ICRS group (p < 0.001 both); mean Steeper Keratometry improvement was 4.24 D in the ICCR group and 5.53 D in the ICRS group (p < 0.001 both). In the ICCR group, mean decrease in the pachymetry at the thinnest point of the cornea was 32.16 µm (p = 0.01), and in the ICRS group, mean increase was 4.2 µm at 1 year (p = 0.61). CONCLUSION: Intracorneal continuous ring 360° arc (ICCR) and intracorneal ring segment 340° (ICRS) are effective treatments for central keratoconus. No significant differences between rings were found on visual acuity, refraction, and keratometry improvement.
Assuntos
Substância Própria , Ceratocone , Substância Própria/cirurgia , Topografia da Córnea , Humanos , Ceratocone/cirurgia , Lasers , Próteses e Implantes , Implantação de Prótese , Refração Ocular , Estudos RetrospectivosRESUMO
PURPOSE: To evaluate the vision quality by measuring the objective light scatter index and objective optical quality parameters (Strehl Ratio and Modulation Transfer Function) in patients with emmetropia and ametropia. METHODS: This prospective, cross-sectional study included 408 eyes. The ametropic group comprised of eyes with best-corrected visual acuity of 0.0 logMAR or better and present at least a refractive error of ≥0.25 D. Patients underwent slit lamp examination, visual acuity, refraction, and vision quality using the HD Analyzer. RESULTS: The mean objective light scatter indices were 0.62 ± 0.63, 0.77 ± 0.70, 0.74 ± 0.30, 0.93 ± 0.55, and 0.85 ± 0.61, and mean Strehl Ratio and Modulation Transfer Function scores were 38.17 ± 10.4, 37.37 ± 10.06, 29.84 ± 9.71, 33.2 ± 12.11, and 33.13 ± 10.09 in emmetropes, myopia, hyperopia, spherical equivalent of ≥0, and spherical equivalent of <0, respectively. Differences in all variables were significant between emmetropic and corrected hyperopic and between spherical equivalent of ≥0, and spherical equivalent of <0 eyes (p<0.05). CONCLUSION: In spectacle-corrected conditions (with trial frames), emmetropic and simple myopic eyes had significantly better vision quality compared to hyperopic and astigmatic eyes. The clinical significance of these results should be investigated in further studies.
Assuntos
Hiperopia , Miopia , Erros de Refração , Estudos Transversais , Emetropia , Humanos , Estudos Prospectivos , Refração OcularRESUMO
PURPOSE: To assess the repeatability of corneal dynamic response (CDR) parameters in normal and keratoconus (KC) eyes using ultra high-speed Scheimpflug imaging. METHODS: Prospective, comparative, observational study, including eyes of 112 patients that underwent high-speed Scheimpflug imaging analysis (Corvis ST, OCULUS). Twenty-one CDR parameters were evaluated to asses repeatability using: coefficient of repeatability (CR), coefficient of variation, intraclass correlation coefficient (ICC) and within-subject SD. Three consecutive measurements by the same operator were performed for each eye. RESULTS: There were no significant differences between the three consecutive measurements for all parameters in both normal and KC eyes. 71.42% (15 of the 21 parameters evaluated) and 85.71% (18 of the 21 parameters) were highly repeatable in the normal and KC group, respectively. The tomographic biomechanical index (TBI), corneal biomechanical index (CBI), and stiffness parameter (SPA1) showed an ICC of 0.978, 0.954, and 0.958 in normal and 0.982, 0.892, and 0.978 in KC eyes, respectively. The CR in normal eyes for TBI, CBI, and SPA1 were 0.169, 0.242, and 14.12, respectively, and for KC eyes 0.06, 0.23, and 13.64, respectively. CONCLUSIONS: Most of the corneal dynamic response parameters were highly repeatable in normal and KC eyes.
Assuntos
Ceratocone , Córnea/diagnóstico por imagem , Humanos , Ceratocone/diagnóstico por imagem , Estudos Prospectivos , Tomografia Computadorizada por Raios XRESUMO
Fusarium head blight (FHB) is a major disease in wheat causing severe economic losses globally by reducing yield and contaminating grain with mycotoxins. In Canada, Fusarium graminearum is the principal etiological agent of FHB in wheat, producing mainly the trichothecene mycotoxin, deoxynivalenol (DON) and its acetyl derivatives (15-acetyl deoxynivalenol (15ADON) and 3-acetyl deoxynivalenol (3ADON)). Understanding the population biology of F. graminearum such as the genetic variability, as well as mycotoxin chemotype diversity among isolates is important in developing sustainable disease management tools. In this study, 570 F. graminearum isolates collected from commercial wheat crops in five geographic regions in three provinces in Canada in 2018 and 2019 were analyzed for population diversity and structure using 10 variable number of tandem repeats (VNTR) markers. A subset of isolates collected from the north-eastern United States was also included for comparative analysis. About 75% of the isolates collected in the Canadian provinces of Saskatchewan and Manitoba were 3ADON indicating a 6-fold increase in Saskatchewan and a 2.5-fold increase in Manitoba within the past 15 years. All isolates from Ontario and those collected from the United States were 15ADON and isolates had a similar population structure. There was high gene diversity (H = 0.803-0.893) in the F. graminearum populations in all regions. Gene flow was high between Saskatchewan and Manitoba (Nm = 4.971-21.750), indicating no genetic differentiation between these regions. In contrast, less gene flow was observed among the western provinces and Ontario (Nm = 3.829-9.756) and USA isolates ((Nm = 2.803-6.150). However, Bayesian clustering model analyses of trichothecene chemotype subpopulations divided the populations into two clusters, which was correlated with trichothecene types. Additionally, population cluster analysis revealed there was more admixture of isolates among isolates of the 3ADON chemotypes than among the 15ADON chemotype, an observation that could play a role in the increased virulence of F. graminearum. Understanding the population genetic structure and mycotoxin chemotype variations of the pathogen will assist in developing FHB resistant wheat cultivars and in mycotoxin risk assessment in Canada.
Assuntos
Grão Comestível/microbiologia , Microbiologia de Alimentos , Fusarium/genética , Fusarium/metabolismo , Variação Genética , Tricotecenos/metabolismo , Triticum/microbiologia , Canadá , Grão Comestível/crescimento & desenvolvimento , Fusarium/patogenicidade , Genótipo , Repetições Minissatélites , Fenótipo , Triticum/crescimento & desenvolvimento , Estados UnidosRESUMO
Two male patients, aged 64 and 55 years old, presented at the cornea department for a Boston type 1 keratoprosthesis (Kpro I) implantation after multiple corneal graft failures. After surgery, they achieved a best corrected visual acuity of 20/200 and 20/150, respectively. However, they manifested photophobia and aesthetic complaints. Both patients underwent keratopigmentation to improve the aesthetic outcome using vegetable pigments, after mechanical corneal deepithelization, with no intraoperative or postoperative incidents or adverse events. After 1-year follow-up, the patients presented the same best corrected visual acuity with improvement of the aesthetic outcome.
Assuntos
Órgãos Artificiais , Córnea , Doenças da Córnea/cirurgia , Estética , Fotofobia/terapia , Próteses e Implantes , Tatuagem/métodos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: The purpose of this study was to evaluate and compare the 5-year efficacy and safety of accelerated transepithelial (A-epi-on) corneal collagen cross-linking (CXL) with standard CXL (epi-off) in children with progressive keratoconus (KC). METHODS: This prospective cohort study included 78 eyes of patients aged 18 years old or younger with progressive KC who underwent CXL at the Oftalmosalud Institute of Eyes, Lima, Peru. A-epi-on CXL was performed in 32 eyes (30' of impregnation/5' of irradiation at 18 mW/cm2) and epi-off CXL was performed in 46 eyes (30'of impregnation/30' minutes of irradiation at 3 mW/cm2). Visual acuity, refraction, and the Scheimpflug imaging parameters were evaluated preoperatively and postoperatively at 1 and 5 years. RESULTS: The best corrected visual acuity improved to 0.06 logarithm of the minimum angle of resolution (SD: 0.19, P = 0.03) and 0.09 logarithm of the minimum angle of resolution (SD: 0.13, P < 0.001) in the A-epi-on and epi-off groups, respectively. The mean flattening in the mean keratometry was 0.09 diopters (D) (SD: 0.68, P = 0.33) and 3.18 D (SD: 5.17, P < 0.001) in the A-epi-on CXL and Epi-off groups at the 5-year follow-up. Significant differences were found in the change at 1 and 5 years between the groups for cylinder reduction, flat and mean K, and pachymetry (all P < 0.05). The KC progression rate was 9.37% (3/32) in the A-epi-on CXL; no progression was found in the epi-off CXL group at the 5-year follow-up. CONCLUSIONS: Both procedures halted the progression of KC at the 5-year follow-up; however, epi-off CXL was safer and more effective when compared with A-epi-on CXL.
Assuntos
Colágeno/metabolismo , Substância Própria/efeitos dos fármacos , Reagentes de Ligações Cruzadas , Ceratocone/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Adolescente , Criança , Paquimetria Corneana , Substância Própria/metabolismo , Desbridamento , Epitélio Corneano/cirurgia , Feminino , Seguimentos , Humanos , Ceratocone/metabolismo , Ceratocone/fisiopatologia , Masculino , Estudos Prospectivos , Refração Ocular/fisiologia , Riboflavina/uso terapêutico , Resultado do Tratamento , Raios Ultravioleta , Acuidade Visual/fisiologiaRESUMO
PURPOSE: We sought to evaluate the visual, refractive, and biomicroscopic findings pre- and posttreatment of observed anterior stromal necrosis (ASN) after long-term Intacs intracorneal ring segment (ICRS) implantation. DESIGN: Consecutive interventional case series. METHODS: All consecutive patients implanted with Intacs ICRS at a single center by 1 of the authors between October 2006 and October 2011 with a minimum follow-up time of 5 years were included. All Intacs were implanted using the Prolate system console and instrumentation from Addition Technology Inc (Chicago, Illinois, USA). The slit lamp, refractive, and visual findings and the management of those patients are described in detail. The primary outcome measures included the size of the epithelial defect overlying the Intacs body, the intended implantation depth measured by high-magnification slit lamp photography, and the management of the cases described in detail. The percentage of eyes with ASN out of those that reached the 5-year follow-up is reported. RESULTS: One hundred twenty-seven eyes (84 patients) were implanted with 215 ICRSs during the study period, and 77.16% (98/127) eyes had a follow-up of ≥5 years, out of which 9 eyes (7 patients) had ASN corresponding to at least 9.18% (95% confidence interval 4.29%-16.72%). The mean ± standard deviation time between implantation and ASN diagnosis was 10.5 ± 1.3 years. CONCLUSION: After 5 years of implantation, INTACS-treated eyes could present with an ASN over the ICRS body. Longer-term follow-up of patients implanted with INTACS is important to monitor if this complication keeps occurring over time.
Assuntos
Doenças da Córnea/diagnóstico , Substância Própria/patologia , Gerenciamento Clínico , Lentes Intraoculares/efeitos adversos , Complicações Pós-Operatórias , Microscopia com Lâmpada de Fenda/métodos , Adulto , Doenças da Córnea/etiologia , Doenças da Córnea/terapia , Substância Própria/cirurgia , Topografia da Córnea , Feminino , Seguimentos , Humanos , Masculino , Necrose/etiologia , Necrose/patologia , Necrose/terapia , Prognóstico , Estudos Prospectivos , Fatores de TempoRESUMO
Fusarium head blight (FHB) is one of the most devastating wheat disease due to its direct detrimental effects on grain-yield, quality and marketability. Resistant cultivars offer the most effective approach to manage FHB; however, the lack of different resistance resources is still a major bottleneck for wheat breeding programs. To identify and dissect FHB resistance, a doubled haploid wheat population produced from the Canadian spring wheat cvs AAC Innova and AAC Tenacious was phenotyped for FHB response variables incidence and severity, visual rating index (VRI), deoxynivalenol (DON) content, and agronomic traits days to anthesis (DTA) and plant height (PHT), followed by single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) marker genotyping. A high-density map was constructed consisting of 10,328 markers, mapped on all 21 chromosomes with a map density of 0.35 cM/marker. Together, two major quantitative trait loci for FHB resistance were identified on chromosome 2D from AAC Tenacious; one of these loci on 2DS also colocated with loci for DTA and PHT. Another major locus for PHT, which cosegregates with locus for low DON, was also identified along with many minor and epistatic loci. QTL identified from AAC Tenacious may be useful to pyramid FHB resistance.
Assuntos
Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Resistência à Doença/genética , Fusarium/fisiologia , Doenças das Plantas/genética , Locos de Características Quantitativas , Triticum/genética , Interações Hospedeiro-Parasita , Melhoramento Vegetal , Triticum/metabolismo , Triticum/microbiologiaRESUMO
A lenticule of intrastromal corneal tissue was cut together with 2 small incisions of 3.0 mm using a low-energy femtosecond laser system, FEMTO LDV Z8; 1 incision led to the posterior plane and 1 to the anterior, allowing dissection of the lenticule. When needed, recentering of the treatment area was possible without repeating the docking stage. Five eyes were operated, and a complete dissection and removal of the lenticule was achieved in all cases without any intraoperative complications. In addition, at postoperative day 1, all patients had a clear cornea. In conclusion, guided lenticule extraction using a low-energy femtosecond laser was a promising and easy procedure.