Improving foveal avascular zone segmentation in fluorescein angiograms by leveraging manual vessel labels from public color fundus pictures.

In clinical routine, ophthalmologists frequently analyze the shape and size of the foveal avascular zone (FAZ) to detect and monitor retinal diseases. In order to extract those parameters, the contours of the FAZ need to be segmented, which is normally achieved by analyzing the retinal vasculature (RV) around the macula in fluorescein angiograms (FA). Computer-aided segmentation methods based on deep learning (DL) can automate this task. However, current approaches for segmenting the FAZ are often tailored to a specific dataset or require manual initialization. Furthermore, they do not take the variability and challenges of clinical FA into account, which are often of low quality and difficult to analyze. In this paper we propose a DL-based framework to automatically segment the FAZ in challenging FA scans from clinical routine. Our approach mimics the workflow of retinal experts by using additional RV labels as a guidance during training. Hence, our model is able to produce RV segmentations simultaneously. We minimize the annotation work by using a multi-modal approach that leverages already available public datasets of color fundus pictures (CFPs) and their respective manual RV labels. Our experimental evaluation on two datasets with FA from 1) clinical routine and 2) large multicenter clinical trials shows that the addition of weak RV labels as a guidance during training improves the FAZ segmentation significantly with respect to using only manual FAZ annotations.

Identification of Subclinical Microvascular Biomarkers in Coronary Heart Disease in Retinal Imaging.

Purpose: Cardiovascular disease and foremost coronary heart disease (CHD) are the worldwide leading causes of death. The aim of this study was to use non-invasive, multimodel retinal imaging to define microvascular features in patients with and without coronary angiography (CA)-confirmed CHD. Methods: In this prospective, cross-sectional pilot study we included adult patients who presented to a tertiary referral center for elective CA due to suspected CHD. All patients underwent widefield fundus photography for retinopathy grading. Optical coherence tomography angiography was used to measure vessel density (VD) of the individual capillary plexuses in 6 × 6-mm macular volume scans. Adaptive optics imaging was performed to assess the first-order arteriolar lumen diameter (LD), total diameter (TD), wall-to-lumen ratio (WLR), and wall cross-section area, as well as to qualitatively describe vessel morphology. Results: Of the included 45 patients (13 females; 65 ± 10 years old), 27 were confirmed with CHD in elective CA. The most prevalent retinal vascular pathologies were arteriovenous nickings, focal arterial narrowings, and microaneurysms. VD in the superficial capillary plexus, deep capillary plexus, and choriocapillaris was lower in CHD patients, although the odds ratios were not significantly different from 1 (P = 0.06-0.92). Median arterial LD, TD, and WLR values were 98.3 µm (interquartile range [IQR] = 13.0), 122.9 µm (IQR = 17.6), and 0.26 µm (IQR = 0.07), respectively, with a trend toward a higher WLR in CHD patients. Conclusions: In a cardiovascular risk population, high-resolution quantitative and qualitative microvascular phenotyping in the retina may provide valuable subclinical indicators for coronary artery impairment, although larger clinical trials are needed. Translational Relevance: Subclinical retinal microvascular changes may serve as non-invasive, cost-effective biomarkers for risk stratification of patients with CHD.

Impact of large choroidal vessels on choriocapillaris flow deficit analyses in optical coherence tomography angiography.

PURPOSE: To investigate the impact of large choroidal vessels (LCV) on Choriocapillaris (CC) flow deficit (FD) analyses with swept-source optical coherence tomography angiography (SS-OCTA). DESIGN: Prospective, cross-sectional study. METHODS: Macular 6x6mm SS-OCTA scans were obtained from intermediate age-related macular degeneration (iAMD) and healthy eyes. Images were captured and processed according to most common standards and analyzed for percentage of flow-deficits (FD%) within four 1x1mm squares at the corners of each image. Choroidal thickness (CT), iris color and refraction error were considered as potential influential factors for LCV visibility. A linear mixed model and logistic regression models were calculated for statistical evaluation. RESULTS: Sixty-nine iAMD and 49 age-matched healthy eyes were enrolled. LCV were visible in at least one sector in 52% of iAMD and 47% of healthy eyes. Within the iAMD group FD% were significantly lower in areas containing LCV (p = 0.0029). Increasing CT resulted in an odds ratio decrease of LCV (OR: 0.94, p<0.0001). Below a CT value of ≤118µm LCV could be expected with a sensitivity of 86% and a specificity of 85%. CONCLUSIONS: LCV can significantly affect CC FD analyses of SS-OCTA images. Their visibility is negatively associated with CT. The impact of LCV should be taken into account when performing CC FD assessments, especially in patients where reduced CT is to be expected and inclusion of affected areas should be considered carefully.

Causes and consequences of past and projected Scandinavian summer temperatures, 500-2100 AD.

Tree rings dominate millennium-long temperature reconstructions and many records originate from Scandinavia, an area for which the relative roles of external forcing and internal variation on climatic changes are, however, not yet fully understood. Here we compile 1,179 series of maximum latewood density measurements from 25 conifer sites in northern Scandinavia, establish a suite of 36 subset chronologies, and analyse their climate signal. A new reconstruction for the 1483-2006 period correlates at 0.80 with June-August temperatures back to 1860. Summer cooling during the early 17th century and peak warming in the 1930s translate into a decadal amplitude of 2.9°C, which agrees with existing Scandinavian tree-ring proxies. Climate model simulations reveal similar amounts of mid to low frequency variability, suggesting that internal ocean-atmosphere feedbacks likely influenced Scandinavian temperatures more than external forcing. Projected 21st century warming under the SRES A2 scenario would, however, exceed the reconstructed temperature envelope of the past 1,500 years.

The effect of periodontal therapy on the survival rate and incidence of complications of multirooted teeth with furcation involvement after an observation period of at least 5 years: a systematic review.

OBJECTIVE: To systematically review the survival rate and incidence of complications of furcation-involved multirooted teeth following periodontal therapy after at least 5 years. MATERIAL AND METHODS: Electronic and manual searches were performed up to and including January 2008. Publication selection, data extraction and validity assessment were performed independently by three reviewers. RESULTS: Twenty-two publications met the inclusion criteria. Because of the heterogeneity of the data, a meta-analysis could not be performed. The survival rate of molars treated non-surgically was >90% after 5-9 years. The corresponding values for the different surgical procedures were: Surgical therapy: 43.1% to 96%, observation period: 5-53 years. Tunnelling procedures: 42.9% to 92.9%, observation period: 5-8 years. Surgical resective procedures including amputation(s) and hemisections: 62% to 100%, observation period: 5-13 years. Guided tissue regeneration (GTR): 83.3% to 100%, observation period: 5-12 years. The most frequent complications included caries in the furcation area after tunnelling procedures and root fractures after root-resective procedures. CONCLUSIONS: Good long-term survival rates (up to 100%) of multirooted teeth with furcation involvement were obtained following various therapeutic approaches. Initial furcation involvement (Degree I) could be successfully managed by non-surgical mechanical debridement. Vertical root fractures and endodontic failures were the most frequent complications observed following resective procedures.

Long-term results of supportive periodontal therapy (SPT) in HIV-seropositive and HIV-seronegative patients.

AIM: The aim of the present study was to investigate the long-term results of periodontal supportive therapy in HIV-seropositive and HIV-seronegative patients. MATERIAL AND METHODS: Baseline examination of 18 HIV-seropositive patients (14 males and four females, median age of 29.7 years) revealed the following periodontal diagnoses: eight patients with linear gingival erythema, four patients with necrotizing periodontitis, five patients with conventional gingivitis and one patient with chronic periodontitis. In the HIV-seronegative group, out of 16 patients (12 males and four females, median age 35.5 years), one patient presented with conventional gingivitis and 15 patients with chronic periodontitis. Periodontal therapy and maintenance care consisted of supra- and subgingival removal of plaque and calculus and instruction in oral hygiene. Based on the individual patient's needs, the mechanical therapy was repeated. RESULTS: In the test group, the mean maintenance period was 22.7 +/- 9.4 months (range 11.0-37.4) and in the control group, 48.9 +/- 32.0 months (range 9.3-110.8). In the test group, the mean PlI (1.1 +/- 0.8) remained at the same level (1.1 +/- 0.5; p = 0.73, Wilcoxon sign rank test, p < 0.05) throughout the observation period, the mean GI was reduced from 1.6 +/- 0.5 to 1.4 +/- 0.4 (p = 0.18), the mean PPD was reduced from 2.9 +/- 0.3 to 2.8 +/- 0.2 (p = 0.15) and the mean PAL (3.1 +/- 0.5) remained unaltered as well (3.1 +/- 0.4; p = 0.83). None of these differences was statistically significant. In the control group, PPD (3.0 +/- 0.4) and PAL (3.0 +/- 0.5) were significantly reduced: PPD = 2.7 +/- 0.2 (p = 0.0003) and PAL = 2.9 +/- 0.5 (p = 0.0034). CONCLUSION: In HIV-seropositive patients, attachment level can be maintained. However, oral hygiene and compliance are the key factors for this.

Comprehensive treatment concept in a young adult patient with severe periodontal disease: a case report.

This case report describes the comprehensive treatment of generalized, advanced periodontal disease in a young patient. In view of the necessary reconstruction, the extensive destruction of the periodontal tissues required a systematic approach to determine the possibilities and the expectations of the patient. The subsequent oral rehabilitation was accomplished with fixed prosthodontics. In the mandible, strategically important anchor teeth were replaced with implants, allowing smaller units to be inserted. The long-term treatment result, however, can only be ensured with the full cooperation of the patient and consistent periodontal maintenance care.