Characteristics of Eyes With CRB1-Associated EOSRD/LCA: Age-Related Changes.

PURPOSE: To evaluate ocular and retinal features of CRB1-associated early onset severe retinal dystrophy/Leber congenital amaurosis (EOSRD/LCA) for age-related changes. DESIGN: Retrospective cohort study. METHODS: Sixteen pediatric patients with biallelic CRB1 EOSRD/LCA who had been followed for up to 18 years were reviewed. Results of comprehensive ophthalmic examinations-including visual acuity, refractive error, dark-adapted visual threshold, Goldmann perimetry, and macular optical coherence tomography (OCT)-were analyzed for significant age-related changes using mixed-effects models. RESULTS: Visual acuity dark-adapted visual sensitivity, and area of seeing visual field (all subnormal from the earliest ages recorded) declined with increasing age. Hyperopia was stable through childhood and adolescence. In CRB1 EOSRD/LCA, OCT extrafoveal inner and outer laminar thicknesses exceeded those in controls but varied little with age, and foveal metrics (depth, breadth, thickness at rim) differed significantly from those in controls, but variations in foveal metrics were not associated with declines in acuity. CONCLUSIONS: From the youngest ages, retinal and visual function is significantly subnormal and becomes progressively compromized. A goal of future therapies should be intervention at young ages, when there is more function to be rescued.

The Impact of Field of View on Understanding of a Movie Is Reduced by Magnifying Around the Center of Interest.

Purpose: Magnification is commonly used to reduce the impact of impaired central vision. However, magnification limits the field of view (FoV) which may make it difficult to follow the story. Most people with normal vision look in about the same place at about the same time, the center of interest (COI), when watching "Hollywood" movies. We hypothesized that if the FoV was centered at the COI, then this view would provide more useful information than either the original image center or an unrelated view location (the COI locations from a different video clip) as the FoV reduced. Methods: The FoV was varied between 100% (original) and 3%. To measure video comprehension as the FoV reduced, subjects described 30-second video clips in response to two open-ended questions. A computational, natural-language approach was used to provide an information acquisition (IA) score. Results: The IA scores reduced as the FoV decreased. When the FoV was around the COI, subjects were better able to understand the content of the video clips (higher IA scores) as the FoV decreased than the other conditions. Thus, magnification around the COI may serve as a better video enhancement approach than simple magnification of the image center. Conclusions: These results have implications for future image processing and scene viewing, which may help people with central vision loss view directed dynamic visual content ("Hollywood" movies). Translational Relevance: Our results are promising for the use of magnification around the COI as a vision rehabilitation aid for people with central vision loss.

Evaluation of choroidal lesions with swept-source optical coherence tomography.

AIMS: The aim of our study was to image choroidal lesions with swept-source optical coherence tomography (SS-OCT) and to identify the morphological characteristics associated with optimal visualisation. METHODS: This was a prospective, cross-sectional study. Patients with choroidal melanocytic lesions <3 mm in thickness on B-scan ultrasonography were recruited. All participants underwent SS-OCT. On SS-OCT we evaluated qualitative (eg, lesion outline, detection of scleral-choroidal interface and quality of the image) and quantitative (measurement of maximum lesion thickness and the largest basal diameter) parameters. Probability of optimal image quality was examined using ordered logistic regression models. The main outcome measure was quality of the choroidal lesion images on SS-OCT, defined as: optimal, suboptimal or poor. RESULTS: We included 85 choroidal lesions of 82 patients. There were 24 choroidal lesions (29%) for which image quality was classified as optimal, 31 lesions (37%) as suboptimal and 30 lesions (36%) as poor. The factors associated with optimal image quality were distance closer to the fovea (OR 0.76, p<0.001), posterior pole location (OR 3.87, p=0.05), lower ultrasonography thickness (OR 0.44, p=0.04), lighter lesion pigmentation (OR 0.12, p=0.003) and smaller lesion diameter (OR 0.73, p<0.001). In the multivariable analysis, closer distance to the fovea (OR 0.81, p=0.005), lighter lesion pigmentation (OR 0.11, p=0.01) and smaller lesion diameter (OR 0.76, p=0.006) remained statistically significant. CONCLUSION: SS-OCT is useful in imaging most choroidal melanocytic lesions. Image quality is best when the choroidal lesion is closer to the fovea, has a smaller diameter and a lighter choroidal pigmentation.

The placenta controls the physiology of pregnancy by increasing the half-life in blood and receptor activity of its secreted peptide hormones.

An efficient functioning placenta is essential for a healthy pregnancy and yet the way this is achieved has been the subject of much discussion and confusion, particularly with the occurrence of pathological conditions such as preeclampsia, morning sickness and hyperemesis/ptyalism gravidarum. We will attempt to explain the underlying physiology and the potential roles played by the placental tachykinins, neurokinin B and endokinin.

Quantitative fundus autofluorescence in healthy eyes.

PURPOSE: Fundus autofluorescence was quantified (qAF) in subjects with healthy retinae using a standardized approach. The objective was to establish normative data and identify factors that influence the accumulation of RPE lipofuscin and/or modulate the observed AF signal in fundus images. METHODS: AF images were acquired from 277 healthy subjects (age range: 5-60 years) by employing a Spectralis confocal scanning laser ophthalmoscope (cSLO; 488-nm excitation; 30°) equipped with an internal fluorescent reference. For each image, mean gray level was calculated as the average of eight preset regions, and was calibrated to the reference, zero-laser light, magnification, and optical media density from normative data on lens transmission spectra. Relationships between qAF and age, sex, race/ethnicity, eye color, refraction/axial length, and smoking status were evaluated as was measurement repeatability and the qAF spatial distribution. RESULTS: qAF levels exhibited a significant increase with age. qAF increased with increasing eccentricity up to 10° to 15° from the fovea and was highest superotemporally. qAF values were significantly greater in females, and, compared with Hispanics, qAF was significantly higher in whites and lower in blacks and Asians. No associations with axial length and smoking were observed. For two operators, between-session repeatability was ± 9% and ± 12%. Agreement between the operators was ± 13%. CONCLUSIONS: Normative qAF data are a reference tool essential to the interpretation of qAF measurements in ocular disease.

Identification of a novel mammalian post-translational modification, phosphocholine, on placental secretory polypeptides.

Placental neurokinin B appears to be post-translationally modified by phosphocholine (PC) attached to the aspartyl side chain at residue 4 of the mature peptide. Corticotrophin releasing factor (CRF) was found to be expressed by the rat placenta with the main secreted forms being phosphocholinated proCRF+/- one or two polysaccharide moieties. A combination of high-pressure liquid chromatography (HPLC) and two-site immunometric analysis suggested that PC was also attached to the placental precursors of adrenocorticotrophin, hemokinin, activin and follistatin. However, the fully processed forms of rat placental activin and CRF were free of PC. Formerly, the parasitic filarial nematodes have used PC as a post-translational modification, attached via the polysaccharide moiety of certain secretory glycoproteins to attenuate the host immune system allowing parasite survival, but it is the PC group itself which endows the carrier with the biological activity. The fact that treatment of proCRF peptides with phospholipase C but not endoglycosidase destroyed PC immunoreactivity suggested a simpler mode of attachment of PC to placental peptides than that used by nematodes. Thus, it is possible that by analogy the placenta uses its secreted phosphocholinated hormones to modulate the mother's immune system and help protect the placenta from rejection.

Critical behavior of the banded-unbanded spherulite transition in a mixture of ethylene carbonate with polyacrylonitrile.

We investigate the transition from unbanded to banded spherulitic growth in mixtures of ethylene carbonate with polyacrylonitrile. By carefully considering systematic errors, we show that the band spacing diverges with a power-law form showing scaling over nearly two decades. We also observe that the bands disorder as the transition point is approached. The critical exponent is nonclassical. One possible explanation is that the nonequilibrium transition is actually weakly first order (subcritical).