Color fundus autofluorescence to determine activity of macular neovascularization in age-related macular degeneration

Purpose: To evaluate with color fundus autofluorescence (FAF) different lesion components of macular neovascularization (MNV) secondary to age-related macular degeneration (AMD) and to assess its activity. Methods: In total, 137 eyes (102 patients) with MNV underwent a complete eye exami-nation, including color fundus photography, optical coherence tomography (OCT), OCT angiography, and confocal color FAF, with an excitation wavelength at 450 nm. Each image was imported into a custom-image analysis software for quantitative estimation of emission wavelength and green and red emission fluorescence (GEFC/REFC) inten-sity, considering both single components of neovascular AMD and different MNV types (type 1 and type 2 MNV, active and inactive MNV). Results: Subretinal fluid (SRF) had significantly higher values of GEFC (P = 0.008 and P = 0.0004) and REFC intensity (P = 0.005 and P = 0.0003) versus fibrosis and atrophy. The emission wavelength from SRF was lower compared to atrophy (P = 0.024) but not to fibrosis (P = 0.46). No significant differences were detected between type 1 and 2 MNV. Considering active versus inactive MNVs, a difference was detected for all evaluated parameters (P < 0.001). Mean FAF wavelength of both MNV with SRF and intrareti-nal fluid (IRF) was lower versus inactive MNV (P < 0.001 and P = 0.005). MNV with SRF (P < 0.001) had higher values of GEFC and REFC versus inactive MNV (P < 0.001). MNV with IRF had higher values of GEFC versus inactive MNV (P = 0.05). Conclusions: Quantitative color FAF can differentiate active versus inactive MNV, whereas no differences were found between type 1 and type 2 MNV. If these data can be further confirmed, color FAF may be useful for automatic detection of active MNV in AMD and as a guide for treatment. Translational Relevance: Automatic quantitative evaluation of green and red emission components of FAF in AMD can help determine the activity of MNV and guide the treatment

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

Relationship between the morphology of the foveal avascular zone, retinal structure, and macular circulation in patients with diabetes mellitus

Diabetic Retinopathy (DR) is an extremely severe and common degenerative disease. The purpose of this study was to quantify the relationship between various parameters including the Foveal Avascular Zone (FAZ) morphology, retinal layer thickness, and retinal hemodynamic properties in healthy controls and patients with diabetes mellitus (DM) with and with no mild DR (MDR) using Spectral-Domain Optical Coherence Tomography (Spectralis SDOCT, Heidelberg Engineering GmbH, Germany) and the Retinal Function Imager (Optical Imaging, Ltd., Rehovot, Israel). Our results showed a higher FAZ area and diameter in MDR patients. Blood flow analysis also showed that there is a significantly smaller venous blood flow velocity in MDR patients. Also, a significant difference in roundness was observed between DM and MDR groups supporting the development of asymmetrical FAZ expansion with worsening DR. Our results suggest a potential anisotropy in the mechanical properties of the diabetic retina with no retinopathy that may trigger the FAZ elongation in a preferred direction resulting in either thinning or thickening of intraretinal layers in the inner and outer segments of the retina as a result of autoregulation. A detailed understanding of these relationships may facilitate earlier detection of DR, allowing for preservation of vision and better clinical outcomes

Gravity-driven instabilities: interplay between state-and-velocity dependent frictional sliding and stress corrosion damage cracking

We model the progressive maturation of a heterogeneous mass towards a gravity-driven instability, characterized by the competition between frictional sliding and tension cracking, using array of slider blocks on an inclined basal surface, which interact via elastic-brittle springs. A realistic state- and rate-dependent friction law describes the block-surface interaction. The inner material damage occurs via stress corrosion. Three regimes, controlling the mass instability and its precursory behavior, are classified as a function of the ratio $T_c/T_f$ of two characteristic time scales associated with internal damage/creep and with frictional sliding. For $T_c/T_f \gg 1$, the whole mass undergoes a series of internal stick and slip events, associated with an initial slow average downward motion of the whole mass, and progressively accelerates until a global coherent runaway is observed. For $T_c/T_f \ll 1$, creep/damage occurs sufficiently fast compared with nucleation of sliding, causing bonds to break, and the bottom part of the mass undergoes a fragmentation process with the creation of a heterogeneous population of sliding blocks. For the intermediate regime $T_c/T_f \sim 1$, a macroscopic crack nucleates and propagates along the location of the largest curvature associated with the change of slope from the stable frictional state in the upper part to the unstable frictional sliding state in the lower part. The other important parameter is the Young modulus $Y$ which controls the correlation length of displacements in the system.Comment: 40 pages, 13 figure

Prevalence of Age-Related Macular Degeneration in Europe: The Past and the Future

Purpose Age-related macular degeneration (AMD) is a frequent, complex disorder in elderly of European ancestry. Risk profiles and treatment options have changed considerably over the years, which may have affected disease prevalence and outcome. We determined the prevalence of early and late AMD in Europe from 1990 to 2013 using the European Eye Epidemiology (E3) consortium, and made projections for the future. Design Meta-analysis of prevalence data. Participants A total of 42 080 individuals 40 years of age and older participating in 14 population-based cohorts from 10 countries in Europe. Methods AMD was diagnosed based on fundus photographs using the Rotterdam Classification. Prevalence of early and late AMD was calculated using random-effects meta-analysis stratified for age, birth cohort, gender, geographic region, and time period of the study. Best-corrected visual acuity (BCVA) was compared between late AMD subtypes; geographic atrophy (GA) and choroidal neovascularization (CNV). Main Outcome Measures Prevalence of early and late AMD, BCVA, and number of AMD cases. Results Prevalence of early AMD increased from 3.5% (95% confidence interval [CI] 2.1%–5.0%) in those aged 55–59 years to 17.6% (95%

Patterns of G- and C-bands distribution on chromosomes of three Apodemus species

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Pegylated interferon-associated retinopathy is frequent in HCV patients with hypertension and justifies ophthalmologic screening.

Treatment with pegylated interferon alpha (PegIFN\u3b1) and ribavirin is still regarded as the standard of care for chronic hepatitis C. Retinopathy has been occasionally described but prospective, longitudinal data are lacking. We have investigated the frequency and clinical significance of retinopathy during therapy with PegIFN\u3b1 and ribavirin in 97 consecutive HCV patients. 54 (55.7%) and 43 (44.3%) patients were treated with PegIFN\u3b1 2a and PegIFN\u3b1 2b, respectively. Ophthalmologic examination was performed before therapy (baseline), at 3 and 6 months (3T and 6T, respectively) of therapy and 3 months after the end of therapy (3ET). All patients underwent the baseline and 3T examination, 90.7% underwent 6T and 3ET examination. Overall, 30.9% of patients developed retinopathy, as defined by the presence of cotton wool spots and/or retinal haemorrhages. Variables significantly associated with retinopathy during treatment were age (p=0.004), metabolic syndrome (p=0.05), hypertension (p<0.0001), cryoglobulinaemia (p=0.05) and preexisting intraocular lesions at baseline (p=0.05). By multivariate analysis, the only variable independently associated with PegIFN\u3b1-associated retinopathy was hypertension (HR=4.99, 95% CI 2.29-10.89). The frequency of retinopathy was significantly higher in hypertensive patients vs. those without hypertension at all time points (18.5% vs. 5.7% at baseline, p=0.05; 48.1% vs. 15.7% at 3T, p=0.0009; 68.0% vs. 19.1% at 6T, p<0.0001; 32.0% vs. 6.2%, p=0.0005 at 3ET). In one (1.1%) hypertensive patient, who developed bilateral branch retinal vein occlusion at 6T, the therapy was discontinued. A cost-analysis showed that screening for PegIFN\u3b1-associated retinopathy was cost-effective as compared to thyroid screening by TSH. Conclusion: Retinopathy is frequent during treatment with PegIFN\u3b1 and ribavirin, especially in hypertensive patients, who may develop serious complications. Screening for PegIFN\u3b1-associated retinopathy should be recommended for HCV patients with hypertension