Evaluation of the different thresholding strategies for quantifying choriocapillaris using optical coherence tomography angiography

Background: In this paper, we evaluate the different thresholding strategies that have been used for the quantification of the choriocapillaris (CC) and explore their repeatability and the interchangeability of the measurements resulting from its application. Methods: Observational study. Eighteen eyes from nine healthy volunteers aged >18 years were imaged four consecutive times with a SD-OCTA system (Heidelberg Engineering, Germany) using a 10°×10° high-resolution protocol centered on the fovea. Projection artifacts were removed, and the CC was bracketed between 10 and 30 µm below Bruch’s membrane. For the quantification of CC, we used four flow deficits (FD) parameters: FD number, mean FD size, total FD area and FD density. We performed a systematic review of literature to collect the thresholding methods that have been used for the quantification of CC. The CC quantification parameters were then evaluated after applying each of the thresholding strategies. Intraclass correlation coefficient (ICC) and Pearson’s correlation analysis were used to compare the repeatability and interchangeability among the different thresholding strategies for quantifying the CC. Results: A total of 72 optical coherence tomography angiography (OCTA) examinations were considered. The systematic review allowed us to conclude that three local thresholding strategies (Phansalkar, mean and Niblack) and three global thresholding strategies (mean, default, Otsu) have been used for CC quantification. These strategies were evaluated in our observational study. We found a high agreement within the same method in the quantification of FD number, mean FD size, total FD area and FD density but a poor agreement with different strategies. Local strategies achieved a significantly superior ICC than global ones in CC quantification. Conclusions: In conclusion, the interchangeability of the CC quantification using different thresholding strategies is low, and direct comparisons should not be performed. Local thresholding strategies are significantly superior to global ones for quantifying CC and should be preferred. There is an unmet need for a uniform strategy to quantify CC in future studies.publishersversionpublishe

Quantitative optical coherence tomography angiography biomarkers in a treat-and-extend dosing regimen in neovascular age-related macular degeneration

Purpose: To evaluate the association between quantitative optical coherence tomography angiography (OCT-A) parameters and clinical outcomes in treatment-naïve neovascular age-related macular degeneration (nAMD) patients treated with a treat-and-extend dosing regimen on a 12-month follow-up interval. Methods: Observational, prospective study of consecutive patients. The treatment protocol was based on a loading dose of three anti-vascular endothelial growth factor (VEGF) intravitreal injections (IVI) followed by a treat-and-extend regimen. Eyes were evaluated by swept-source OCT-A at baseline, 1 month after the loading dose and at 12 months. A quantitative analysis was issued for fractal dimension (FD), lacunarity index (LAC), blood flow surface area (SA), and vessel density (VD). An association of these parameters with the anatomic response and functional responses, and IVI number at 12 months of follow-up was assessed. A level of significance α = 0.05 was considered. Results: Sixty-four patients were included, 52 of whom (81%) completed the 12-month study protocol. The median number of injections at 12 months was 7 (P25-P75: 6-12). FD and SA were reduced 1 month after the loading dose of anti-VEGF (P < 0.001). The generalized linear models using baseline FD and baseline SA achieved the best performance in discriminating a lower treatment burden (area under the curve [AUC] = 0.78; 95% confidence interval [CI]: 0.64–0.91 and AUC = 0.76; 95% CI: 0.63–0.90, respectively). Conclusions: Baseline OCT-A may provide useful biomarkers for the treatment burden in nAMD. Translational Relevance: The application of fractal dimension and automatic blood flow area algorithms to OCT-A data can distinguish patients with distinct treatment burdens in the first year of nAMD.publishersversionpublishe

Injuries in Portuguese Amateur Youth Football Players: A Six Month Prospective Descriptive Study

Introduction: This study analyzed the incidence and characteristics of injuries sustained by amateur youth football players in Portugal during season 2015 - 2016. Material and Methods: This is an observational descriptive study. We analyzed Portuguese youth football players’ injuries over six months of a season. A total of 529 players were divided according to their age in two groups (Under-17 and Under-19). Data on injuries were collected. Results: Throughout all 62 062.0 hours of exposure recorded, 248 injuries were reported in 173 different players. The average incidence of injury was 3.87 (95% CI = 2.81; 4.94) per 1000 hours of football exposure. There was a significantly higher average incidence of injury during matches – 14.22 (95% CI = 10.35; 18.09) per 1000 hours of exposure – when compared to the average incidence of injury during training – 2.06 (95% CI = 1.22; 2.90) per 1000 hours of exposure. This significance was also observed when the comparison was made within each age group. A traumatic mechanism was involved in 76.6% of all the injuries, while overuse was reported in 12.9%. The most common type was the injury that affected muscles and tendons (52.8%). The body location most commonly affected by injuries was the thigh (24.6%). Discussion: Even though is essential a better characterization of Portuguese athletes of younger age groups such as those discussed in this study, the results of the studied population are in agreement with the existing literature. However, this study provides more information that may be important to better target the Portuguese athletes’ training for injury prevention. Conclusion: This study provides descriptive data on injuries developed in a subpopulation of Portuguese amateur youth football players that could represent a focus for future prevention

O Impacto da Pandemia COVID-19 no Internato de Formação Específica de Oftalmologia em Portugal

Introduction: The purpose of this study was to provide objective and real-life data concerning the impact of the COVID-19 pandemic on ophthalmology residency training in Portugal. Material and Methods: Descriptive survey-based study applied to current Portuguese ophthalmology residents (n = 80 eligible). Results: Seventy-five residents participated (94% response rate). All except one (99%) admitted a change in their routine clinical practice during the pandemic, and most (89%) continued to be engaged in ophthalmology department duties. Twenty-five percent were deployed to COVID-19 units, which was combined with ophthalmological activities in about half of them (47%). A significant proportion of participants stated that they were enrolled in the following ophthalmological activities: emergency/inpatient care (87%), outpatient visits (73%; general 70% vs subspecialty 29%), and surgical procedures (64%). Twenty-five percent did not assist in any outpatient visits and 36% did not participate in any surgical procedures. On a scale from 1 (no impact) to 5 (maximum impact), most participants classified their perceived negative impact of the pandemic on the training program as 3 (24%), 4 (40%), or 5 (27%). Participants highly agreed with the extension of the residency program (80%) in order to to make up for training disruption. Discussion: Most trainees provided ophthalmological care during the pandemic. However, those clinical activities were essentially related to general and emergency care. Surgical experience was significantly curtailed. As such, strategies are needed to guarantee a high-quality learning process. Further studies are required to develop an international perspective on how ophthalmology training programs have been affected so that educational organizations can make recommendations regarding standardized adjustments to training programs. Conclusion: The COVID-19 pandemic has significantly impacted the training of ophthalmology residents nationwide.Introdução: Este estudo teve como objetivo avaliar o impacto da pandemia COVID-19 no internato de Formação Específica de Oftalmologia em Portugal. Material e Métodos: Estudo descritivo dos resultados obtidos de um questionário aplicado a todos os internos de Formação Específica de Oftalmologia em Portugal (n = 80). Resultados: Setenta e cinco internos participaram no estudo (taxa de resposta de 94%). Excetuando um caso, todos (99%) admitiram alteração da sua prática clínica durante a pandemia, e a maioria (89%) manteve atividades clínicas no seu serviço de Oftalmologia. Vinte e cinco por cento foram integrados em unidades COVID-19, e metade desses inquiridos (47%) desempenharam concomitantemente atividades no âmbito da oftalmologia. Uma percentagem significativa dos inquiridos referiu estar envolvido nas seguintes atividades clínicas oftalmológicas: serviço de Urgência/consultas internas (87%), consultas externas (73%: geral 70% vs subespecialidade 29%), e cirurgias (64%). Vinte e cinco por cento não participaram em consultas externas, e 36% em procedimentos cirúrgicos. Numa escala de 1 (sem impacto) a 5 (máximo impacto), a maioria dos inquiridos classificou o impacto percecionado da pandemia no internato de Formação Específica de Oftalmologia em 3 (34%), 4 (40%) e 5 (27%). Oitenta porcento dos inquiridos enumerou a extensão do período do internato de Formação Específica como uma medida a adotar para minimizar o impacto negativo da pandemia. Discussão: A maioria dos internos mantiveram-se a desempenhar atividades clínicas no seu serviço de Oftalmologia, principalmente no âmbito da oftalmologia geral e de urgência. O desempenho de atividade cirúrgica foi largamente afetado. São necessárias estratégias adaptativas para garantir a continuação adequada da formação dos internos. Futuros estudos noutros contextos geográficos permitirão perceber de que forma os programas de formação em oftalmologia estão a ser afetados ao nível internacional, para que as organizações educacionais possam elaborar recomendações. Conclusão: A pandemia COVID-19 teve um impacto significativo no internato de Formação Específica de Oftalmologia em Portugalinfo:eu-repo/semantics/publishedVersio

Nonexudative Macular Neovascularization – A Systematic Review of Prevalence, Natural History, and Recent Insights from OCT Angiography

To review the available literature on the prevalence, incidence, natural history, and exudative conversion rates of subclinical (treatment-naïve) nonexudative macular neovascularization (MNV) in patients with age-related macular degeneration (AMD). Nonexudative MNV is now known to be more prevalent in patients with AMD than initially thought and is bringing new insights into both the natural history and management of this very prevalent disease. We conducted a literature search on PubMed, Scopus, and Web of Science, along with a manual search, from January 2014 to June 2019. We included studies that used optical coherence tomography angiography (OCTA) as a primary diagnostic tool to evaluate subclinical (treatment-naïve), nonexudative, neovascular AMD. Of the 258 screened articles, 12 were included. The prevalence of subclinical nonexudative neovascular AMD in the fellow eyes of patients with unilateral exudative AMD ranged from 6.25% to 27%. Although these lesions were not associated with a significant decrease in visual acuity, the presence of nonexudative MNV seems to be an important predictor of exudative disease. Incidence of exudation in the reviewed studies ranged from 20% to 80% (follow-up 6 months to 2 years). There is some evidence that nonexudative MNV may slow down the growth of adjacent geographic atrophy (GA). As long as exudation does not occur, it appears that subclinical nonexudative MNV is not responsible for the deterioration of visual function. Nonexudative MNV is an asymptomatic condition. Although nonexudative MNV seems to be a precursor for the formation of exudative neovascular AMD, there is evidence suggesting a protective effect in slowing the progression of GA. Early detection of nonexudative MNV before exudation develops should result in better monitoring of patients who are at high risk of conversion to exudative AMD. Though no controlled clinical trial has been performed to provide definitive recommendations, the authors of the studies included in this review agree that nonexudative lesions should not be treated until symptomatic exudation develops. Moreover, the existence of a nonexudative form of neovascular AMD would suggest that the term “neovascular AMD” should be preceded by either “exudative” or “nonexudative” when describing this neovascular stage of AMD

Impact of the COVID-19 Pandemic on Ophthalmology Residency Training in Portugal

INTRODUCTION: The purpose of this study was to provide objective and real-life data concerning the impact of the COVID-19 pandemicon ophthalmology residency training in Portugal. MATERIAL AND METHODS: Descriptive survey-based study applied to current Portuguese ophthalmology residents (n = 80 eligible). RESULTS: Seventy-five residents participated (94% response rate). All except one (99%) admitted a change in their routine clinical practice during the pandemic, and most (89%) continued to be engaged in ophthalmology department duties. Twenty-five percent were deployed to COVID-19 units, which was combined with ophthalmological activities in about half of them (47%). A significant proportion of participants stated that they were enrolled in the following ophthalmological activities: emergency/inpatient care (87%), outpatient visits (73%; general 70% vs subspecialty 29%), and surgical procedures (64%). Twenty-five percent did not assist in any outpatient visits and 36% did not participate in any surgical procedures. On a scale from 1 (no impact) to 5 (maximum impact), most participants classified their perceived negative impact of the pandemic on the training program as 3 (24%), 4 (40%), or 5 (27%). Participants highly agreed with the extension of the residency program (80%) in order to to make up for training disruption. DISCUSSION: Most trainees provided ophthalmological care during the pandemic. However, those clinical activities were essentially related to general and emergency care. Surgical experience was significantly curtailed. As such, strategies are needed to guarantee a high-quality learning process. Further studies are required to develop an international perspective on how ophthalmology training programs have been affected so that educational organizations can make recommendations regarding standardized adjustments to training programs. CONCLUSION: The COVID-19 pandemic has significantly impacted the training of ophthalmology residents nationwide.status: publishe

Glaucoma as a systemic disease: when we have to look beyond the eye

Introduction: Growing evidence suggests an association between Glaucoma and changes in the immune system. Particularly in those with Normal Tension Glaucoma (NTG), an autoimmune or vascular mechanism may be responsible for optic nerve head damage. Case Report: A 67-year-old woman presented for a routine eye exam at our office visit. About her past medical history, she only mentioned Raynauds Disease. Her best-corrected visual acuity was 20/20 on both eyes, and slit-lamp examination was normal. Intraocular pressure was 10 mmHg in both eyes and fundoscopy revealed cup to disc ratio 0.8 bilaterally. On physical examination, we found microstomy and puffy hands with pitting scars. Optical Coherence Tomography (OCT) demonstrated an inferotemporal decrease of the peripapillary Retinal Nerve Fiber Layer (RFNLpp) on the RE and in the inferotemporal and superotemporal sectors of the LE. OCT-Angiography was also performed to complement the study. Computerized Static Perimetry (CSP) revealed pericentral scotomas on both eyes. Water Drinking Test (WDT) and Diurnal IOP curve were performed with a significant fluctuation. A 24-hour ambulatory blood pressure monitoring demonstrated nocturnal hypotension. After a clinical process review, we found the diagnostic of PSS. The patient initiated hypotensive drugs and was oriented for adjustment of therapy. Conclusion: If we do not look beyond the eye to observe patient phenotype and past medical history we can miss important clues for the correct diagnosis and treatment, often with complementary multidisciplinary approaches