Article

Fluorescein angiography of the fundus in diabetic retinopathy.

British Medical Bulletin (Impact Factor: 3.95). 06/1970; 26(2):166-70.
Source: PubMed
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    ABSTRACT: Purpose: We describe a novel approach to analyze fluorescein angiography to investigate fluorescein flow dynamics in the rat posterior retina as well as identify abnormal areas following laser photocoagulation. Methods: Experiments were undertaken in adult Long Evans rats. Using a rodent retinal camera, videos were acquired at 30 frames per second for 30 seconds following intravenous introduction of sodium fluorescein in a group of control animals (n = 14). Videos were image registered and analyzed using principle components analysis across all pixels in the field. This returns fluorescence intensity profiles from which, the half-rise (time to 50% brightness), half-fall (time for 50% decay) back to an offset (plateau level of fluorescence). We applied this analysis to video fluorescein angiography data collected 30 minutes following laser photocoagulation in a separate group of rats (n = 7). Results: Pixel-by-pixel analysis of video angiography clearly delineates differences in the temporal profiles of arteries, veins and capillaries in the posterior retina. We find no difference in half-rise, half-fall or offset amongst the four quadrants (inferior, nasal, superior, temporal). We also found little difference with eccentricity. By expressing the parameters at each pixel as a function of the number of standard deviation from the average of the entire field, we could clearly identify the spatial extent of the laser injury.
    PLoS ONE 11/2014; 9(11):e111330. DOI:10.1371/journal.pone.0111330 · 3.53 Impact Factor
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    25 Perguntas & Respostas : Retinopatia Diabética- Novo paradigma de Cuidados, GER- Grupo de Estudos da Retina Portugal edited by Henriques J, Nascimento J, Silva F, coordenadores, 11/2012: chapter 21: pages 131-139;