Fluorescein Leakage and Optical Coherence Tomography Angiography Features of Microaneurysms in Diabetic Retinopathy

Background and Objective. To correlate optical coherence tomography angiography (OCTA) characteristics of diabetic microaneurysms (MAs) with leakage status on fluorescein angiography (FA). Patients and Methods. 167 MAs from 39 diabetic eyes were analyzed using OCTA and FA simultaneously. The characteristics of MAs on OCTA en face, OCT en face, and OCT B-scan with flow overlay were evaluated and correlated with fluorescein leakage status. Results. Thirty-six, fifty-two, and seventy-nine MAs showed no, mild, and severe leakage on FA, respectively. Most MAs (61.7%) were centered in the inner nuclear layer. Cystoid spaces were observed adjacent to 60 (35.9%) MAs. MAs with severe leakage had a statistically higher flow proportion compared to MAs with no or mild leakage (both P < 0.001 ). Only 112 MAs (67.1%) were visualized in the OCTA en face images, while 165 MAs (98.8%) could be visualized in the OCT en face images. The location of MAs did not associate significantly with FA leakage status. The presence of nearby cystoid spaces and higher flow proportion by OCT B-scan with flow overlay correlated significantly with FA leakage status. Conclusion. The flow proportion of MAs observed on OCT B-scans with flow overlay might be a potential biomarker to identify leaking MAs. A combination of OCT B-scan, OCT en face, and OCTA en face images increased the detection rate of diabetic MAs in a noninvasive way.

Fingerprint sign in Vogt-Koyanagi-Harada disease: a case series

Background The tomographic finding, which has been called the "fingerprint sign" in en face reconstructions, seems to be the result of a variety of processes that cause distension of the outer plexiform layer (OPL) and the Henle fiber layer (HFL). The aim of this paper is to describe the appearance of concentric rings at the OPL/HFL interface visualized using en face reconstructions of cross-sectional optical coherence tomography images of patients with Vogt-Koyanagi-Harada disease. Methods Retrospective analysis of images of six eyes of three patients obtained by cross-sectional OCT imaging and en face reconstruction at the level of the OPL/HFL interface. Results All eyes presented with a dentate or saw-tooth pattern of the OPL/HFL interface on cross-sectional OCT with corresponding concentric rings on en face OCT reconstruction, consistent with the recently published “fingerprint sign”. Initial OPL/HFL interface changes were observed between the first and fourth months after treatment and resolution of VKHD associated serous retinal detachments. These OPL/HFL interface changes have persisted for many years following the resolution of the active inflammation. Conclusions Changes in the OPL/HFL interface can be identified following successful treatment of VKHD. These included both a dentate or saw-tooth pattern on cross-sectional imaging and concentric rings or the “fingerprint sign” on en face reconstructions. These changes persisted for many years despite disease quiescence.

Optical coherence tomography angiography for the detection of macular neovascularization—comparison of en face versus cross-sectional view

Purpose To evaluate sensitivity and specificity of swept source-optical coherence tomography angiography (SS-OCTA) en face images versus cross-sectional OCTA versus a combination of both for the detection of macular neovascularization (MNV). Design Prospective cohort study. Participants Consecutive patients with various chorioretinal diseases and subretinal hyperreflective material (SHRM) and/or pigment epithelial detachment (PED) on OCT possibly corresponding to MNV in at least one eye. Methods 102 eyes of 63 patients with fluorescein angiography (FA), OCT and SS-OCTA performed on the same day were included. FA images, the outer retina to choriocapillaris (ORCC) OCTA en face slab, a manually modified en face slab (‘custom slab’), cross-sectional OCTA and a combination of OCTA en face and cross-section were evaluated for presence of MNV. Main outcome measures Sensitivity and specificity for MNV detection, as well as the concordance was calculated using FA as the reference. Results OCTA en face imaging alone yielded a sensitivity of 46.3% (automated)/78.1% (custom) and specificity of 93.4% (automated)/88.5% (custom) for MNV detection. Cross-sectional OCTA (combination with en face) resulted in a sensitivity of 85.4% (82.9%) and specificity of 82.0% (85.3%). Concordance to FA was moderate for automated en face OCTA (κ = 0.43), and substantial for custom en face OCTA (κ = 0.67), cross-sectional OCTA (κ = 0.66) and the combination (κ = 0.68). Conclusion Segmentation errors result in decreased sensitivity for MNV detection on automatically generated OCTA en face images. Cross-sectional OCTA allows detection of MNV without manual modification of segmentation lines and should be used for evaluation of MNV on OCTA.

ETUDE DE LA CAPACITE DUNE PHOTOPILE AU SILICIUM A JONCTIONS VERTICALES SERIES SOUS ECLAIREMENT MONOCHROMATIQUE

Ce travail consiste a faire une etude de la capacite de la photopile a jonction verticale serie sous eclairement monochromatique en tenant compte de la longueur donde et de la profondeur. Lequation de continuite, traduisant, les phenomenes de generation, de diffusion et de recombinaison des porteurs de charge photogeneres dans la base de la photopile est resolue en tenant compte des vitesses de recombinaison a la jonction et en face arriere. Une etude de la capacite de diffusion en fonction des vitesses de recombinaison a la jonction base-emetteur mais aussi en fonction de la phototension a permis de determiner une capacite initiale Co, pour differentes longueurs donde de leclairement incident et pour differentes valeurs de la profondeur.

Choroidal caverns in pachychoroid neovasculopathy

Background. Choroid plays an important role in the pathogenesis of retinal pathology. Choroidal cavern, a recently identifi ed fi nding of optical coherent tomography (OCT), has been described in some degenerative and atrophic forms of retinal pathology. In the literature, there are only a few studies of choroidal cavers in pachychoroid neovasculopathy, newly described form of age related macular degeneration.The aim: to perform a detailed analysis of choroidal structure on OCT scans of patients with pachychoroid neovasculopathy and to reveal the frequency of choroidal caverns identifi cation.Material and methods. The data of 30 patients (30 eyes) aged 64.4 ± 5.6 years with pachychoroid neovascularization were retrospectively analyzed. The patients underwent spectral OCT and OCT-angiography (OCTA) using a Spectralis device (Heidelberg Engineering, Germany). The protocol was “Posterior Pole”, consisting of 61 scans. To assess the structure of the choroid, an enhanced image depth (EDI) module was used. OCT angiography was performed with a scan area of 6 × 6 mm. These methods were compared to identify choroidal caverns.Results. On OCT subretinal type 1 neovascularization was revealed as a fl at detachment of the pigment epithelium and visualization of blood flow on OCTA in the lesion as angled vessels (21 eyes) or a seafan (9 eyes). On OCT-EDI scans, there was diffuse or local choroidal thickening of choroid with an increase in the vessels of the Haller’s layer and thinning of the choriocapillaries. Choroidal caverns appeared on OCT and en-face OCT as areas with low optical density, round or irregular, located in different layers of the chorioid, without hyperrefl ective boundaries. A typical sign of choroidal cavern is the tail of hypertransmission after the cavern toward the sclera. Choroidal caverns were found in 4 of 30 eyes (13.3 %) and were located both near the choroidal neovascularization lesion and beyond this area.Conclusion. The prevalence of choroidal cavities, a new choroidal biomarker, in pachychoroid neovasculopathy was 13.3 %. Identification of these changes is possible with the use of modern diagnostic techniques (OCT-EDI, OCTA and en-face OCT) that allow visualization the state of the choroid. The prognostic signifi cance of choroidal cavities requires further study.

Album karikatura Osijek u karikaturi Milana Tolića

Milan Tolić (Split, 1. rujna 1899. – 20. studenoga 1990.) splitski je slikar, scenograf, pedagog i karikaturist čiji opus karikatura još nije dovoljno istražen. U članku se analizira album Tolićevih karikatura Osijek u karikaturi tiskan 1940. godine u Građanskoj tiskari u Osijeku na temelju originalnih slikarovih crteža. Tolićev je album zbirka crteža u kojoj su razvrstani u skupine: glumci, odvjetnici, liječnici, članovi Trgovačke komore, profesori, industrijalci, trgovci, obrtnici, policajci, gradski činovnici, gostioničari i bankari. Ukupno tristo lica gleda nas sa 187 stranica u petnaest skupnih i dvjesto dvadeset i osam pojedinačnih karikatura. Album Tolićevih crteža donosi karikature pretežno rađene perom te u manjoj mjeri olovkom i tušem. S tehničke strane sve su karikature izvedene na sličan način – Tolićev crtež u albumu jednostavan je, prepoznatljiv i čitljiv. Autor se predstavlja kao siguran crtač i vješt opservator koji u čistoj linearnoj tvorbi vješto grafički bilježi lakim ritmom i sumarnim zatvaranjem linija figure u pokretu. Obrisna linija crteža teče u dužim neprekinutim linijama, a strukturalna ponegdje u svojim kontrastnim odnosima očitava teksture materijala. Likovi su prikazani en face i u profilu, a karikirani likovi često su prikazani u poslu koji po svojoj profesiji obavljaju. U navedenim karikaturama likovni izričaj Tolić gradi najčešće na čitavoj figuri, ali svoju osobnu umjetničku fiksaciju usmjerava na glavu, neiscrpno bogat i zanimljiv likovni sadržaj, koji deformira, korigira i mijenja dok ne ustanovi što najbolje odgovara karakteru prikazanih modela. Tako se ironija izražena naglašenom likovnom gestom ne zaustavlja samo na vanjštini, nego i u emocionalnoj komunikaciji premda su likovi u svojoj deformiranoj potenciranosti ponajprije fizički karakterizirani. Kao i u Tolićevu slikarskom opusu, i u Tolićevoj karikaturi (što dolazi do izražaja i u ovom albumu) postoje oscilacije vidljive u likovnoj kvaliteti karikarura. Tolić, britak opservator, u nekim karikaturama postaje ilustrativan, blijed, međutim s obzirom na broj karikatura to je donekle i razumljivo. Skupne karikature u albumu komuniciraju s gledateljstvom raskošnim rječnikom crte, a sve to na smiješnoj i satiričkoj osnovi u komici crte i oblika, ali i duhovitosti gesta i grimasa. Album Osijek u karikaturi zapravo je prikaz Osijeka krajem tridesetih godina dvadesetog stoljeća u njegovim intimnim sferama u relacijama vremena, prostora i ljudi, čime autor uspješno referira osječki politički, društveni i javni život. Tolićeve karikature imponiraju svojim iskrenim laganim humorom koji dobroćudno ismijava karikirane likove. Album Osijek u karikaturi vrijedan je Tolićev prinos našoj likovnoj umjetnosti karikaturalnog izraza.