Diffuse laser illumination for Maxwellian view Doppler holography of the retina

We describe the advantages of diffuse illumination in laser holography for ophthalmology. The presence of a diffusing element introduces an angular diversity of the optical radiation and reduces its spatial coherence, which spreads out the energy distribution of the illumination beam in the focal plane of the eyepiece. The field of view of digitally computed retinal images can easily be increased as the eyepiece can be moved closer to the cornea to obtain a Maxwellian view of the retina without compromising ocular safety. Compliance with American and European safety standards for ophthalmic devices is more easily obtained by preventing the presence of a laser hot spot observed in front of the cornea in the absence of a scattering element. Diffuse laser illumination does not introduce any adverse effects on digitally computed laser Doppler images.Comment: 9 page

International comparisons of behavioral and emotional problems in preschool children: parents’ reports from 24 societies

International comparisons were conducted of preschool children’s behavioral and emotional problems as reported on the Child Behavior Checklist for Ages 1½–5 by parents in 24 societies (N¼19,850). Item ratings were aggregated into scores on syndromes; Diagnostic and Statistical Manual of Mental Disorders–oriented scales; a Stress Problems scale; and Internalizing, Externalizing, and Total Problems scales. Effect sizes for scale score differences among the 24 societies ranged from small to medium (3–12%). Although societies differed greatly in language, culture, and other characteristics, Total Problems scores for 18 of the 24 societies were within 7.1 points of the omnicultural mean of 33.3 (on a scale of 0–198). Gender and age differences, as well as gender and age interactions with society, were all very small (effect sizes<1%). Across all pairs of societies, correlations between mean item ratings averaged .78, and correlations between internal consistency alphas for the scales averaged .92, indicating that the rank orders of mean item ratings and internal consistencies of scales were very similar across diverse societies

Segmentation of OCT images of retina for the quantitative study of retinal variability

Nous proposons une méthode de segmentation d'images de la rétine, acquises par tomographie de cohérence optique (OCT), en haute résolution. Elle permet d'extraire automatiquement huit couches rétiniennes, avec une bonne précision autour de la fovéola. Les résultats ont été évalués et validés par comparaison avec les segmentations manuelles faites par cinq médecins différents. Les mesures effectuées à partir des segmentations automatiques ont également été comparées aux mesures faites manuellement par les experts, pour validation. Ainsi, des études quantitatives de variabilités rétiniennes ont pu être menées, sur une base de données de 72 images segmentées automatiquement par la méthode proposée

AUTOMATED SEGMENTATION OF RETINAL LAYERS IN OCT IMAGING AND DERIVED OPHTHALMIC MEASURES

International audienceThis paper proposes an automated method for the segmentation of eight retinal layers in high resolution OCT images. It has been evaluated based on comparison with manual segmentation performed by five different experts. The method has been successfully applied on a database of 72 images. Quantitative measures are then derived as an aid to ophthalmic diagnosis. A good agreement with measures derived from manual segmentation is obtained which allows us to use the proposed method for retinal variability studies

Automated segmentation of macular layers in OCT images and quantitative evaluation of performances

International audienceOptical coherence tomography (OCT) allows high-resolution and noninvasive imaging of the structure of the retina in humans. This technique revolutionized the diagnosis of retinal diseases in routine clinical practice. Nevertheless, quantitative analysis of OCT scans is yet limited to retinal thickness measurements. We propose a novel automated method for the segmentation of eight retinal layers in these images. Our approach is based on global segmentation algorithms, such as active contours and Markov random fields. Moreover, a Kalman filter is designed in order to model the approximate parallelism between the photoreceptor segments and detect them. The performance of the algorithm was tested on a set of retinal images acquired in-vivo from healthy subjects. Results have been compared with manual segmentations performed by five different experts, and intra and inter-physician variability has been evaluated as well. These comparisons have been carried out directly via the computation of the root mean squared error between the segmented interfaces, region-oriented analysis, and retrospectively on the thickness measures derived from the segmentations. This study was performed on a large database including more than seven hundred images acquired from more than one hundred healthy subjects

High-resolution spectral-domain optical coherence tomography (SD OCT) features in adult onset foveomacular vitelliform dystrophy

International audiencePurpose: To describe the different morphological features in adult onset foveomacular vittelliform dystrophy (AOFVD) using high-resolution spectral-domain optical coherence tomography (SD OCT). Design: Prospective observational cases series. Methods: Complete ophthalmologic examination, including SD OCT, was performed in 49 consecutive AOFVD patients (60 eyes). Results: In 28/60 eyes, SD OCT showed hyperreflective clumps within the outer plexiform and outer nuclear layers. In 9/60 eyes, the photoreceptors inner /outer segments (IS/OS) interface appeared highly reflective like a shell all around the vitelliform material, and appeared irregular and discontinued in 27/60 eyes. The Verhoeff membrane (VM) was clearly visible at the border of the lesion, disappeared over the vitelliform lesion in 20/60 eyes, became thickened and less defined on the outer aspect of the lesion in 11/60 eyes, appeared without noticeable alterations in 10/60 eyes, and not well defined in 19/60 eyes. The vitelliform material appeared as a highly reflective dome-shaped lesion (homogeneous in 14/60 eyes and heterogeneous in 36/60 eyes) located between the photoreceptor layer and the retinal pigment epithelium (RPE). In 10/60 eyes the macular lesion appeared hypo/a-reflective. The RPE appeared irregular in 14/60 eyes, with hyperreflective mottling on its inner aspect. We observed discrete RPE detachments in 29/60 eyes. Conclusions: We hypothesize that early changes involve the layer between RPE and IS/OS interface, first with vitelliform material accumulation beneath the sensory retina, and then with IS/OS alterations, pigments migration towards inner layers, and fluid accumulation. These changes come with RPE alterations such as hypertrophy or sub-RPE deposits

Foveal Shape and Structure in a Normal Population

International audiencePURPOSE: The shape of the human fovea presents important but still poorly characterized variations. In this study, the variability of the shape and structure of normal foveae were examined. METHODS: In a group of 110 eyes of 57 healthy adults, the shape and structure of the fovea were analyzed by automated segmentation of retinal layer on high-resolution optical coherence tomography scans. In an additional group of 10 normal eyes of 10 patients undergoing fluorescein angiography, the size of the foveal avascular zone (FAZ) was correlated to foveal shape. RESULTS: From the thickest to the thinnest fovea, there was a structural continuum ranging from a shallow pit with continuity of the inner nuclear layer (INL) over the center (seven eyes; 6.7%), to a complete separation of inner layers overlying a flat and thinner central outer nuclear layer (ONL; eight eyes; 7.3%). Central foveal thickness correlated inversely to the degree of inner layer separation and to the surface of the FAZ. CONCLUSIONS: Foveal structure strongly correlates with its neurovascular organization. The findings support a developmental model in which the size of the FAZ determines the extent of centrifugal migration of inner retinal layers, which counteracts in some way the centripetal packing of cone photoreceptors

Identification and characterization of novel TRPM1 autoantibodies from serum of patients with melanoma-associated retinopathy

Melanoma-associated retinopathy (MAR) is a rare paraneoplastic retinal disorder usually occurring in the context of metastatic melanoma. Patients present with night blindness, photopsias and a constriction of the visual field. MAR is an auto-immune disorder characterized by the production of autoantibodies targeting retinal proteins, especially autoantibodies reacting to the cation channel TRPM1 produced in melanocytes and ON-bipolar cells. TRPM1 has at least three different isoforms which vary in the N-terminal region of the protein. In this study, we report the case of three new MAR patients presenting different anti-TRPM1 autoantibodies reacting to the three isoforms of TRPM1 with variable binding affinity. Two sera recognized all isoforms of TRPM1, while one recognized only the two longest isoforms upon immunolocalization studies on overexpressing cells. Similarly, the former two sera reacted with all TRPM1 isoforms on western blot, but an immunoprecipitation enrichment step was necessary to detect all isoforms with the latter serum. In contrast, all sera labelled ON-bipolar cells on Tprm1+/+ but not on Trpm1-/- mouse retina as shown by co-immunolocalization. This confirms that the MAR sera specifically detect TRPM1. Most likely, the anti-TRPM1 autoantibodies of different patients vary in affinity and concentration. In addition, the binding of autoantibodies to TRPM1 may be conformation-dependent, with epitopes being inaccessible in some constructs (truncated polypeptides versus full-length TRPM1) or applications (western blotting versus immunohistochemistry). Therefore, we propose that a combination of different methods should be used to test for the presence of anti-TRPM1 autoantibodies in the sera of MAR patients

Morphological Predictive Features on Spectral-Domain Optical Coherence Tomography for Visual Outcomes in Neovascular Age-Related Macular Degeneration Treated with Ranibizumab

Purpose. To identify spectral-domain optical coherence tomography (SD-OCT) predictive morphological features for the outcome of Ranibizumab therapy for neovascular age-related macular degeneration (AMD). Methods. This is a retrospective multicentric study that involved 64 eyes with naïve AMD. Patients who received three monthly intravitreal injections of Ranibizumab were stratified into (1) “responders” [≥ 5 letters gain on Early Treatment Diabetic Retinopathy Study (ETDRS) scale] and (2) “nonresponders” ( 250 μm at baseline were two independent prognostic indicators of final BCVA. No other SD-OCT morphological studied features seem to affect final BCVA after Ranibizumab treatment. Conclusion. SFCT and the presence of PED > 250 μm are two significant biomarkers that may predict improvement after Ranibizumab therapy for AMD. These markers may guide ophthalmologists' treatment decision under financial constraints and limited time

Adding the third dimension on adaptive optics retina imager thanks to full-field optical coherence tomography

International audienceRetinal pathologies, like ARMD or glaucoma, need to be early detected, requiring imaging instruments with resolution at a cellular scale. However, in vivo retinal cells studies and early diagnoses are severely limited by the lack of resolution on eye-fundus images from classical ophthalmologic instruments. We built a 2D retina imager using Adaptive Optics to improve lateral resolution. This imager is currently used in clinical environment. We are currently developing a time domain full-field optical coherence tomograph. The first step was to conceive the images reconstruction algorithms and validation was realized on non-biological samples. Ex vivo retina are currently being imaged. The final step will consist in coupling both setups to acquire high resolution retina cross-sections