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To demonstrate efficacy and safety of an ophthalmic hydrogel formulation of netilmicin/dexamethasone, containing xanthan gum twice a day (b.i.d.) versus netilmicin/dexamethasone eye drops four times a day (q.i.d) to treat inflammation and prevention of infection after cataract surgery.Patients undergoing phacoemulsification with intraocular lens implantation (IOL) were randomised in two groups: group 1, twice daily (b.i.d.) dexamethasone 0.1%/netilmicin 0.3% (Netildex) ophthalmic gel; group 2, four times daily (q.i.d.) dexamethasone 0.1%/netilmicin 0.3% (Netildex) eye drops. Both treatments were administered for 14 days after surgery. Patients were evaluated before surgery, on the day of surgery and at 1, 7, 15 and 60 postoperative days. The primary efficacy endpoint was evaluation of cellularity and flare in the anterior chamber through slit-lamp biomicroscopy 7 days after surgery. Secondary endpoints included: presence of signs/symptoms of postoperative ocular inflammation and incidence of infection.One hundred seventy-three patients were randomised and 168 were evaluable. Flare and cellularity were resolved at day 7 in 92.5% of patients and almost completely by day 15. In both intent to treat (ITT) and per-protocol (PP) populations, the efficacy analysis demonstrated that the gel formulation administered twice a day was non-inferior to the eye drops administered four times a day. For ITT analysis, the lower limit of the 97.5% confidence interval (- 0.0535) was greater than the non-inferiority limit of -0.10. For the PP analysis, the lower limit of the 97.5% confidence interval (- 0.0526) was greater than the non-inferiority limit of - 0.10. The patient's global tolerability and reported symptoms were similar between treatment groups. No microbial load and no safety events were observed.Efficacy of the gel reduced posology (twice a day) is not inferior to four times a day eye drops. Both treatments were well tolerated and efficacious. The new reduced posology hydrogel formulation may improve patient compliance and quality of life.Eudract: 2016-0021138-63; ClinicalTrial.gov: NCT029738880.

Background Pigment epithelial detachments (PEDs) occur in association with various chorioretinal diseases. With respect to the broad clinical spectrum of PEDs we describe fundus autofluorescence (FAF) characteristics of PEDs. Methods Ninety-three eyes of 66 patients (mean age 71.9 ± 11.1) with uni- or bilateral PED ( ≥ 350 µm) were included in a retrospective cross-sectional study. PEDs were secondary to age-related macular degeneration (n = 79), central serous chorioretinopathy (n = 7), polypoidal choroidal vasculopathy (n = 2), pattern dystrophy (n = 3) or idiopathic PED (n = 2). FAF images were recorded using confocal scanning laser ophthalmoscopy (488 nm excitation wavelength, detection of emission >500 nm). Diagnosis of PED was confirmed using spectral-domain optical coherence tomography. A qualitative FAF grading system was established, and grading was performed by two independent readers. Results PEDs showed highly variable characteristics on FAF imaging. FAF within the area of PED was found to be irregular/granular (n = 59, 63.4%), increased (n = 28, 30.1%), decreased (n = 3, 3.2 %), or normal (n = 3, 3.2%). Accompanying FAF changes included condensation of macular pigment (n = 67, 72.0%), focally increased FAF at the PED apex (n = 14, 15.1%) or elsewhere (n = 52, 55.9%), focally decreased FAF (n = 23, 24.7%), a cartwheel-like pattern (n = 10, 10.8%), a doughnut sign (n = 6, 6.5%), and a halo of decreased FAF encircling the PED (completely n = 20, 21.5% or incompletely n = 20, 21.5%). Conclusions PEDs show a variety of abnormal patterns on FAF imaging. These changes in FAF signals may be secondary to morphological and metabolic alterations within corresponding retinal layers and do not necessarily correspond with the underlying PED subtype or a specific pathology.

To reduce treatment burden and optimise patient outcomes in diabetic macular oedema, we present 1-year results from two phase 3 trials of faricimab, a novel angiopoietin-2 and vascular endothelial growth factor-A bispecific antibody.YOSEMITE and RHINE were randomised, double-masked, non-inferiority trials across 353 sites worldwide. Adults with vision loss due to centre-involving diabetic macular oedema were randomly assigned (1:1:1) to intravitreal faricimab 6·0 mg every 8 weeks, faricimab 6·0 mg per personalised treatment interval (PTI), or aflibercept 2·0 mg every 8 weeks up to week 100. PTI dosing intervals were extended, maintained, or reduced (every 4 weeks up to every 16 weeks) based on disease activity at active dosing visits. The primary endpoint was mean change in best-corrected visual acuity at 1 year, averaged over weeks 48, 52, and 56. Efficacy analyses included the intention-to-treat population (non-inferiority margin 4 Early Treatment Diabetic Retinopathy Study [ETDRS] letters); safety analyses included patients with at least one dose of study treatment. These trials are registered with ClinicalTrials.gov (YOSEMITE NCT03622580 and RHINE NCT03622593).3247 patients were screened for eligibility in YOSEMITE (n=1532) and RHINE (n=1715). After exclusions, 940 patients were enrolled into YOSEMITE between Sept 5, 2018, and Sept 19, 2019, and 951 patients were enrolled into RHINE between Oct 9, 2018, and Sept 20, 2019. These 1891 patients were randomly assigned to faricimab every 8 weeks (YOSEMITE n=315, RHINE n=317), faricimab PTI (n=313, n=319), or aflibercept every 8 weeks (n=312, n=315). Non-inferiority for the primary endpoint was achieved with faricimab every 8 weeks (adjusted mean vs aflibercept every 8 weeks in YOSEMITE 10·7 ETDRS letters [97·52% CI 9·4 to 12·0] vs 10·9 ETDRS letters [9·6 to 12·2], difference -0·2 ETDRS letters [-2·0 to 1·6]; RHINE 11·8 ETDRS letters [10·6 to 13·0] vs 10·3 ETDRS letters [9·1 to 11·4] letters, difference 1·5 ETDRS letters [-0·1 to 3·2]) and faricimab PTI (YOSEMITE 11·6 ETDRS letters [10·3 to 12·9], difference 0·7 ETDRS letters [-1·1 to 2·5]; RHINE 10·8 ETDRS letters [9·6 to 11·9], difference 0·5 ETDRS letters [-1·1 to 2·1]). Incidence of ocular adverse events was comparable between faricimab every 8 weeks (YOSEMITE n=98 [31%], RHINE n=137 [43%]), faricimab PTI (n=106 [34%], n=119 [37%]), and aflibercept every 8 weeks (n=102 [33%], n=113 [36%]).Robust vision gains and anatomical improvements with faricimab were achieved with adjustable dosing up to every 16 weeks, demonstrating the potential for faricimab to extend the durability of treatment for patients with diabetic macular oedema.F Hoffmann-La Roche.

Light has a crucial role in the visual process. For nonvisible radiation in the short-wave spectrum, there are natural mechanisms that protect the human retina from damaging ultraviolet (UV) radiation. Here, the dose (= energy) makes the poison. Damage caused by UV light mainly affects the outer retina, particularly the photoreceptors and the retinal pigment epithelium. While retinal damage due to increased UV radiation exposure can potentially still occur up to the age of 20, in adulthood, exposure of the retina to UV radiation can no longer be assumed, due to decreasing transmission properties of the natural lens. The natural lens, modern intraocular lenses, and wearing of sunglasses with appropriate filter function, particularly in childhood and adolescence, provide a relevant reduction in UV radiation exposure of the retina.

Fur das pathologische Verstandnis retinaler Veranderungen sind direkte Vergleiche von hochaufgeloster In-vivo-Bildgebung und histologischer Darstellung wunschenswert. Dargestellt wird der methodische Aufbau zur multimodalen In-vivo- und Ex-vivo-Bildgebung eines Spenderauges mit sekundaren Veranderungen nach einem retinalen Zentralarterienverschluss. Die sich anschliesende Korrelation mit der Histologie erfolgt an identischen Gewebelokalisationen. Mit entsprechenden Vorrichtungen lassen sich In-vivo- und Ex-vivo-Bildgebung korrelieren und an den herkommlichen Geraten zur retinalen Bildgebung – wie am Beispiel des SD-OCTs („spectral domain“ optische Koharenztomographie) gezeigt – aufnehmen. Die prazise Ausrichtung des Gewebes ermoglicht eine histologische Analyse an identischen Aufnahmeorten. Durch die direkte Korrelation von klinischer Bildgebung mit Ex-vivo-Darstellung und Histologie lassen sich Erkenntnisse zur Pathogenese unterschiedlicher ophthalmologischer Krankheiten gewinnen. Die groste Herausforderung ist derzeit die eingeschrankte Verfugbarkeit von Spendergewebe.

Choroidal melanocytic lesions require reliable and precise clinical examination and diagnosis to differentiate benign choroidal nevi from choroidal melanoma, as the latter may become life-threatening through metastatic disease. To come to an accurate diagnosis, as well as for monitoring, and to assess the efficacy of therapy, various imaging modalities may be used, one of which is non-invasive fundus autofluorescence (FAF) imaging using novel high-resolution digital imaging technology. FAF imaging is based on the visualization of intrinsic fluorophores in the ocular fundus. Lipofuscin and melanolipofuscin within the postmitotic retinal pigment epithelium (RPE) cells represent the major fluorophores that contribute to the FAF signal. In addition, the presence or loss of absorbing molecular constituents may have an impact on the FAF signal. A choroidal melanoma can cause secondary retinal and RPE alterations that affect the FAF signal (e.g., occurrence of orange pigment). Therefore, FAF imaging supports multimodal imaging and gives additional information over and above conventional imaging modalities regarding retinal metabolism and RPE health status. This article summarises the features of FAF imaging and the role of FAF imaging in the context of choroidal melanoma, both before and following therapeutic intervention.

Light has a crucial role in the visual process. For nonvisible radiation in the short-wave spectrum, there are natural mechanisms that protect the human retina from damaging ultraviolet (UV) radiation. Here, the dose (= energy) makes the poison. Damage caused by UV light mainly affects the outer retina, particularly the photoreceptors and the retinal pigment epithelium. While retinal damage due to increased UV radiation exposure can potentially still occur up to the age of 20, in adulthood, exposure of the retina to UV radiation can no longer be assumed, due to decreasing transmission properties of the natural lens. The natural lens, modern intraocular lenses, and wearing of sunglasses with appropriate filter function, particularly in childhood and adolescence, provide a relevant reduction in UV radiation exposure of the retina.Licht spielt für den Sehvorgang eine entscheidende Rolle. Für die nicht sichtbare Strahlung im kurzwelligen Spektrum gibt es natürliche Mechanismen, die die Netzhaut des Menschen vor schädigender ultravioletter (UV-)Strahlung schützt. Auch hier macht die Dosis (Energie) das Gift. Durch UV-Strahlung bedingte Schädigungen betreffen v. a. die äußere Netzhaut, insbesondere die Photorezeptoren und das retinale Pigmentepithel. Während es bis zum 20. Lebensjahr noch zu einem potenziellen Netzhauschaden aufgrund einer erhöhten UV-Strahlenexposition kommen kann, ist im Erwachsenenalter aufgrund abnehmender Transmissionseigenschaften der natürlichen Linse von praktisch keiner nennenswerten Exposition der Netzhaut gegenüber UV-Strahlen mehr auszugehen. Sowohl die natürliche Linse, moderne Intraokularlinsen als auch das Tragen von Sonnenbrillen mit entsprechender Filterfunktion, insbesondere im Kindes- und Jugendalter, sorgen für eine relevante Reduktion der UV-Strahlenbelastung der Netzhaut.

For an understanding of the pathology of retinal diseases, direct comparisons of high-resolution in vivo retinal imaging and ex vivo histological preparations are desirable.Multimodal in vivo and ex vivo imaging of a human donor eye with secondary alterations showing atrophic retina due to central retinal arterial occlusion. The subsequent correlation with the histological examination was carried out on identical tissue localizations.Appropriate custom-built retinal imaging devices facilitate in vivo and ex vivo correlations and the examination of human eye tissue and acquisition of retinal images, e.g. SD-OCT. The precise alignment of the tissue enables a histological analysis on identical sites.The direct correlation of clinical in vivo imaging with ex vivo imaging including histopathology can further enhance our understanding in the pathogenesis of retinal diseases; however, the proposed method is currently limited due to restricted availability of human donor tissue.HINTERGRUND: Für das pathologische Verständnis retinaler Veränderungen sind direkte Vergleiche von hochaufgelöster In-vivo-Bildgebung und histologischer Darstellung wünschenswert.Dargestellt wird der methodische Aufbau zur multimodalen In-vivo- und Ex-vivo-Bildgebung eines Spenderauges mit sekundären Veränderungen nach einem retinalen Zentralarterienverschluss. Die sich anschließende Korrelation mit der Histologie erfolgt an identischen Gewebelokalisationen.Mit entsprechenden Vorrichtungen lassen sich In-vivo- und Ex-vivo-Bildgebung korrelieren und an den herkömmlichen Geräten zur retinalen Bildgebung – wie am Beispiel des SD-OCTs („spectral domain“ optische Kohärenztomographie) gezeigt – aufnehmen. Die präzise Ausrichtung des Gewebes ermöglicht eine histologische Analyse an identischen Aufnahmeorten.Durch die direkte Korrelation von klinischer Bildgebung mit Ex-vivo-Darstellung und Histologie lassen sich Erkenntnisse zur Pathogenese unterschiedlicher ophthalmologischer Krankheiten gewinnen. Die größte Herausforderung ist derzeit die eingeschränkte Verfügbarkeit von Spendergewebe.

Purpose Lipofuscin and melanolipofuscin organelles in retinal pigment epithelium (RPE) cells are signal sources for clinical fundus autofluorescence (AF). To elucidate the subcellular basis of AF imaging, we identified, characterized, and quantified the frequency of RPE morphology and AF phenotypes in donor eyes with age-related macular degeneration (AMD). Methods In 25 RPE-Bruch's membrane flat mounts from 25 eyes, we analyzed 0.4-μm z-stack epifluorescence images of RPE stained with phalloidin for actin cytoskeleton. Using a custom ImageJ plugin, we classified cells selected in a systematic unbiased fashion in six phenotypes representing increasing degrees of pathology. For each cell, area, AF intensity, and number of Voronoi neighbors were compared with phenotype 1 (uniform AF, polygonal morphology) via generalized estimating equations. We also analyzed each cell's neighborhood. Results In 29,323 cells, compared with phenotype 1, all other phenotypes, in order of increasing pathology, had significantly larger area, reduced AF, and more variable number of neighbors. Neighborhood area and AF showed similar, but subtler, trends. Cells with highly autofluorescent granule aggregates are no more autofluorescent than others and are in fact lower overall in AF. Pre-aggregates were found in phenotype 1. Phenotype 2, which exhibited degranulation despite normal cytoskeleton, was the most numerous nonhealthy phenotype (16.23%). Conclusions Despite aggregation of granules that created hyperAF aggregates within cells, overall AF on a per cell basis decreased with increasing severity of dysmorphia (abnormal shape). Data motivate further development of subcellular resolution in clinical fundus AF imaging and inform an ongoing reexamination of the role of lipofuscin in AMD.

Journal of Clinical Medicine (17), 5101 (2022). doi:10.3390/jcm11175101, Published by MDPI, Basel

Purpose: Phenotype alterations of the retinal pigment epithelium (RPE) are a main characteristic of age-related macular degeneration (AMD). Individual RPE cell shape descriptors may help to delineate healthy from AMD-affected cells in early disease stages. Methods: Twenty-two human RPE flatmounts (7 eyes with AMD [early, 3; geographic atrophy, 1; neovascular, 3); 15 unaffected eyes [8 aged ≤51 years; 7 aged >80 years)] were imaged at the fovea, perifovea, and near periphery (predefined sample locations) using a laser-scanning confocal fluorescence microscope. RPE cell boundaries were manually marked with computer assistance. For each cell, 11 shape descriptors were calculated and correlated with donor age, cell autofluorescence (AF) intensity, and retinal location. Statistical analysis was performed using an ensemble classifier based on logistic regression. Results: In AMD, RPE was altered at all locations (most pronounced at the fovea), with area, solidity, and form factor being the most discriminatory descriptors. In the unaffected macula, aging had no significant effect on cell shape factors; however, with increasing distance to the fovea, area, solidity, and convexity increased while form factor decreased. Reduced AF in AMD was significantly associated with decreased roundness and solidity. Conclusions: AMD results in an altered RPE with enlarged and deformed cells that could precede clinically visible lesions and thus serve as early biomarkers for AMD onset. Our data may also help guide the interpretation of RPE morphology in in vivo studies utilizing high-resolution single-cell imaging. Translational Relevance: Our histologic RPE cell shape data have the ability to identify robust biomarkers for the early detection of AMD-affected cells, which also could serve as a basis for automated segmentation of RPE sheets.

PurposeBy optical coherence tomography (OCT) imaging, hyperreflective foci (HRF) indicate progression risk for advanced age-related macular degeneration (AMD) and are in part attributable to ectopic retinal pigment epithelium (RPE). We hypothesized that ectopic RPE are molecularly distinct from in-layer cells and that their cross-retinal course follows Müller glia.MethodIn clinical OCT (61 eyes, 44 AMD patients, 79.4 ± 7.7 years; 29 female; follow-up = 4.7 ± 0.9 years) one HRF type, RPE plume, was reviewed. Twenty eyes of 20 donors characterized by ex vivo OCT were analyzed by histology (normal, 4; early/intermediate AMD, 7; geographic atrophy (GA), 6; 3 neovascular AMD (nvAMD). Cryosections were stained with antibodies to retinoid (RPE65, CRALPB) and immune (CD68, CD163) markers. In published RPE cellular phenotypes, red immunoreactivity was assessed semi-quantitatively by one observer (none, some cells, all cells).ResultsTrajectories of RPE plume and cellular debris paralleled Müller glia, whether ordered or subsident, near atrophy borders. RPE corresponding to HRF lost immunoreactivity for retinoid markers and gained immunoreactivity for immune markers. Aberrant immunoreactivity appeared in individual in-layer RPE cells and extended to all abnormal phenotypes. Müller glia remained CRALBP-positive. Plume cells approached and contacted retinal capillaries.ConclusionGain- and loss-of-function starts with individual in-layer RPE cells and extends to all abnormal phenotypes. Down-regulated RPE retinoid handling may impair rod vision while Müller glia sustain cone vision. Evidence for RPE transdifferentiation, possibly due to ischemia, supports a proposed process of epithelial-mesenchyme transition. Data can propel new biomarkers and therapeutic strategies for AMD.PrécisHyperreflective foci (HRF) are OCT progression risk indicators in age-related macular degeneration. Abnormal RPE cells including some that correspond to HRF lose immunoreactivity for retinoid markers and gain immunoreactivity for immune markers, indicating molecular transdifferentiation.

Annotation is a major hurdle in the semantic segmentation of microscopy images and volumes due to its prerequisite expertise and effort. This work enables the training of semantic segmentation networks on images with only a single point for training per instance, an extreme case of weak supervision which drastically reduces the burden of annotation. Our approach has two key aspects: (1) we construct a graph-theoretic soft-segmentation using individual seeds to be used within a regularizer during training and (2) we use an objective function that enables learning from the constructed soft-labels. We achieve competitive results against the state-of-the-art in point-supervised semantic segmentation on challenging datasets in digital pathology. Finally, we scale our methodology to point-supervised segmentation in 3D fluorescence microscopy volumes, obviating the need for arduous manual volumetric delineation. Our code is freely available., Accepted to IEEE ISBI 2021. Code available at https://github.com/CJLee94/Point-Supervised-Segmentation

Purpose The human retinal pigment epithelium (RPE) accumulates granules significant for autofluorescence imaging. Knowledge of intracellular accumulation and distribution is limited. Using high-resolution microscopy techniques, we determined the total number of granules per cell, intracellular distribution, and changes related to retinal topography and age. Methods RPE cells from the fovea, perifovea, and near-periphery of 15 human RPE flat mounts were imaged using structured illumination microscopy (SIM) and confocal fluorescence microscopy in young (≤51 years, n = 8) and older (>80 years, n = 7) donors. Using custom FIJI plugins, granules were marked with computer assistance, classified based on morphological and autofluorescence properties, and analyzed with regard to intracellular distribution, total number per cell, and granule density. Results A total of 193,096 granules in 450 RPE cell bodies were analyzed. Based on autofluorescence properties, size, and composition, the RPE granules exhibited nine different phenotypes (lipofuscin, two; melanolipofuscin, five; melanosomes, two), distinguishable by SIM. Overall, lipofuscin (low at the fovea but increases with eccentricity and age) and melanolipofuscin (equally distributed at all three locations with no age-related changes) were the major granule types. Melanosomes were under-represented due to suboptimal visualization of apical processes in flat mounts. Conclusions Low lipofuscin and high melanolipofuscin content within foveal RPE cell bodies and abundant lipofuscin at the perifovea suggest a different genesis, plausibly related to the population of overlying photoreceptors (fovea, cones only; perifovea, highest rod density). This systematic analysis provides further insight into RPE cell and granule physiology and links granule load to cell autofluorescence, providing a subcellular basis for the interpretation of clinical fundus autofluorescence.

PurposeEvaluated the safety and efficacy of an integrative surgical approach to neovascular glaucoma (NVG).MethodsConsecutive interventional case series of NVG with one-year follow-up. Eyes underwent pars plana vitrectomy, near-confluent panretinal photocoagulation, intravitreal bevacizumab, and transscleral cyclophotocoagulation. Phakic eyes underwent concomitant cataract surgery. Best-corrected visual acuity (BCVA, logMAR), intraocular pressure (IOP, mmHg), glaucoma medication score (GMS), visual analog pain scale (VAPS, 0-10) were recorded at baseline, and 1, 3, 6 and 12 months. Blind eyes were excluded.Results83 eyes of 83 patients (53 male, 30 female, mean age 74.6±11.6 years) were included and 53 completed a one-year follow-up. NVG underlying conditions included retinal vein occlusion (n=41), proliferative diabetic retinopathy (n=25), central retinal artery occlusion (n=10), and ocular ischemic syndrome (n=6). Mean IOP decreased postoperatively from 46.0±10.3 mmHg to 14.2±8.9 mmHg (pConclusionsA single, comprehensive surgery session was able to significantly lower IOP, reduce GMS and control pain.

The retinal pigment epithelium (RPE) is a monolayer between photoreceptor and Bruch membrane/choriocapillaris. It has multiple functions in the homeostasis of the outer retina. As many other tissues, also RPE cells pass through different parts of a life cycle: from development to maturation to aging. Based on its prominent location, RPE cells are also often involved in diseases of the outer retina, e.g., age-related macular degeneration.

PURPOSE: Melanotic cells with large spherical melanosomes, thought to originate from retinal pigment epithelium (RPE), are found in eyes with neovascular age-related macular degeneration (nvAMD). To generate hypotheses about RPE participation in fibrosis, we correlate histology to clinical imaging in an eye with prominent black pigment in fibrotic scar secondary to nvAMD. METHODS: Macular findings in a white woman with untreated inactive subretinal fibrosis due to nvAMD in her right eye were documented over 9 years with color fundus photography (CFP), fundus autofluorescence (FAF) imaging, and optical coherence tomography (OCT). After death (age 90 years), this index eye was prepared for light and electron microscopy to analyze 7 discrete zones of pigmentation in the fibrotic scar. In additional donor eyes with nvAMD, we determined the frequency of black pigment (n = 36 eyes) and immuno-labeled for retinoid, immunologic, and microglial markers (RPE65, CD68, Iba1, TMEM119; n = 3 eyes). RESULTS: During follow-up of the index eye, black pigment appeared and expanded within a hypoautofluorescent fibrotic scar. The blackest areas correlated to melanotic cells (containing large spherical melanosomes), some in multiple layers. Pale areas had sparse pigmented cells. Gray areas correlated to cells with RPE organelles entombed in the scar and multinucleate cells containing sparse large spherical melanosomes. In 94% of nvAMD donor eyes, hyperpigmentation was visible. Certain melanotic cells expressed some RPE65 and mostly CD68. Iba1 and TMEM119 immunoreactivity, found both in retina and scar, did not co-localize with melanotic cells. CONCLUSION: Hyperpigmentation in CFP results from both organelle content and optical superimposition effects. Black fundus pigment in nvAMD is common and corresponds to cells containing numerous large spherical melanosomes and superimposition of cells containing sparse large melanosomes, respectively. Melanotic cells are molecularly distinct from RPE, consistent with a process of transdifferentiation. The subcellular source of spherical melanosomes remains to be determined. Detailed histology of nvAMD eyes will inform future studies using technologies for spatially resolved molecular discovery to generate new therapies for fibrosis. The potential of black pigment as a biomarker for fibrosis can be investigated in clinical multimodal imaging datasets.

Purpose By optical coherence tomography (OCT) imaging, hyperreflective foci (HRF) indicate progression risk for advanced age-related macular degeneration (AMD) and are in part attributable to ectopic retinal pigment epithelium (RPE). We hypothesized that ectopic RPE are molecularly distinct from in-layer cells and that their cross-retinal course follows Muller glia. Methods In clinical OCT (61 eyes, 44 patients with AMD, 79.4 ± 7.7 years; 29 female; follow-up = 4.7 ± 0.9 years), one HRF type, RPE plume (n = 129 in 4 morphologies), was reviewed. Twenty eyes of 20 donors characterized by ex vivo OCT were analyzed by histology (normal, 4; early/intermediate AMD, 7; geographic atrophy, 6; neovascular AMD, 3). Cryosections were stained with antibodies to retinoid (RPE65, CRALPB) and immune (CD68, CD163) markers. In published RPE cellular phenotypes, red immunoreactivity was assessed semiquantitatively by one observer (none, some cells, all cells). Results Plume morphology evolved over time and many resolved (40%). Trajectories of RPE plume and cellular debris paralleled Muller glia, including near atrophy borders. RPE corresponding to HRF lost immunoreactivity for retinoid markers and gained immunoreactivity for immune markers. Aberrant immunoreactivity appeared in individual in-layer RPE cells and extended to all abnormal phenotypes. Muller glia remained CRALBP positive. Plume cells approached and contacted retinal capillaries. Conclusions HRF are indicators not predictors of overall disease activity. Gain and loss of function starts with individual in-layer RPE cells and extends to all abnormal phenotypes. Evidence for RPE transdifferentiation, possibly due to ischemia, supports a proposed process of epithelial-mesenchyme transition. Data can propel new biomarkers and therapeutic strategies for AMD.

ZusammenfassungFundusautofluoreszenz(FAF)-Aufnahmen zählen seit beinahe 2 Jahrzehnten zur Routinediagnostik des menschlichen Augenhintergrunds. Die stetigen Weiterentwicklungen der Aufnahmetechniken ermöglichen heute eine sichere, nicht invasive, einfach durchführbare und reproduzierbare Darstellung des Augenhintergrunds. Die zugrunde liegende Technik macht sich die autofluoreszierenden Eigenschaften von Geweben, insbesondere des retinalen Pigmentepithels (RPE) und dessen Fluorophore, zunutze. Dadurch können FAF-Aufnahmen in hervorragender Weise Phänomene der normalen Alterung sowie krankheitsbedingte Veränderungen des Augenhintergrunds aufzeigen, aber auch Informationen zu Krankheitsverlauf und Therapiekontrolle liefern. In dieser Übersichtsarbeit sollen nach einer kurzen Einführung in die Basis der Fundusautofluoreszenz neueste grundlagenwissenschaftliche Kenntnisse zur Histologie im Hinblick auf altersbedingte und pathologische Veränderungen des RPE zusammengefasst werden, um so eine bessere Interpretation von FAF-Aufnahmen zu ermöglichen. Der Darstellung altersbedingter Veränderungen werden hierbei die pathologischen Veränderungen im Rahmen einer altersbedingten Makuladegeneration sowohl klinisch als auch auf histologischer Ebene gegenübergestellt.

Purpose To inform the interpretation of clinical optical coherence tomography and fundus autofluorescence imaging in geographic atrophy (GA) of age-related macular degeneration by determining the distribution of retinal pigment epithelium (RPE) phenotypes in the transition from health to atrophy in donor eyes. Methods In RPE-Bruch membrane flat mounts of two GA eyes, the terminations of organized RPE cytoskeleton and autofluorescent material were compared. In high-resolution histological sections of 13 GA eyes, RPE phenotypes were assessed at ±500 and ±100 μm from the descent of the external limiting membrane (ELM) toward Bruch membrane. The ELM descent was defined as curved, reflected, or oblique in shape. Thicknesses of RPE, basal laminar deposit (BLamD), and RPE plus BLamD were measured. Results A border of atrophy that can be precisely delimited is the ELM descent, as opposed to the termination of the RPE layer itself, because of dissociated RPE in the atrophic area. Approaching the ELM descent, the percentage of abnormal RPE morphologies increases, the percentage of age-normal cells decreases, overall RPE thickens, and BLamD does not thin. The combination of RPE plus BLamD is 19.7% thicker at -100 μm from the ELM descent than that at -500 μm (23.1 ± 10.7 μm vs. 19.3 ± 8.2 μm; P = 0.05). Conclusion The distribution of RPE phenotypes at the GA transition supports the idea that these morphologies represent defined stages of a degeneration sequence. The idea that RPE dysmorphia including rounding and stacking helps explain variable autofluorescence patterns in GA is supported. The ELM descent and RPE plus BLamD thickness profile may have utility as spectral domain optical coherence tomography metrics in clinical trials.

Purpose To elucidate the molecular pathogenesis of age-related macular degeneration (AMD) and interpretation of fundus autofluorescence imaging, the authors identified spectral autofluorescence characteristics of drusen and retinal pigment epithelium (RPE) in donor eyes with AMD. Methods Macular RPE/Bruch membrane flat mounts were prepared from 5 donor eyes with AMD. In 12 locations (1-3 per eye), hyperspectral autofluorescence images in 10-nm-wavelength steps were acquired at 2 excitation wavelengths (λex 436, 480 nm). A nonnegative tensor factorization algorithm was used to recover 5 abundant emission spectra and their corresponding spatial localizations. Results At λex 436 nm, the authors consistently localized a novel spectrum (SDr) with a peak emission near 510 nm in drusen and sub-RPE deposits. Abundant emission spectra seen previously (S0 in Bruch membrane and S1, S2, and S3 in RPE lipofuscin/melanolipofuscin, respectively) also appeared in AMD eyes, with the same shapes and peak wavelengths as in normal tissue. Lipofuscin/melanolipofuscin spectra localizations in AMD eyes varied widely in their overlap with drusen, ranging from none to complete. Conclusion An emission spectrum peaking at ∼510 nm (λex 436 nm) appears to be sensitive and specific for drusen and sub-RPE deposits. One or more abundant spectra from RPE organelles exhibit characteristic relationships with drusen.

To enable future studies of retinal pigment epithelium (RPE) fate in the macular atrophy occurring in eyes with neovascular age-related macular degeneration (nvAMD), the authors determined how RPE morphology changes across the transition from health to atrophy in donor eyes with nvAMD.In RPE-Bruch membrane flat mounts of 5 nvAMD eyes, the terminations of organized RPE cytoskeleton and autofluorescent material were compared. In high-resolution histologic sections of 27 nvAMD eyes, RPE phenotypes were assessed at ±500 μm and ±100 μm from the descent of the external limiting membrane (ELM) toward the Bruch membrane. Thicknesses of RPE, basal laminar deposit (BLamD), and RPE + BLamD were determined. Shapes of the ELM descent were recorded.Approaching the ELM descent, the percentage of different RPE phenotypes and the thickness of RPE, BLamD, and RPE + BLamD each stayed roughly constant. Compared with a separately described cohort of eyes with geographic atrophy, eyes with nvAMD were more likely to have RPE dysmorphia that did not worsen toward the atrophy border, thinner BLamD overall (3.25 ± 3.46 μm vs. 7.99 ± 7.49 μm for geographic atrophy), and a higher proportion of oblique ELM descents (47.9 vs. 31.9%).The distribution of RPE phenotypes at the transition to macular atrophy in eyes with nvAMD differs from that in primary geographic atrophy, likely reflecting greater photoreceptor loss and the effects of exudation in nvAMD. This distribution, the shape of ELM descents, and thickness profiles may be useful metrics in clinical studies of macular atrophy using optical coherence tomography and fundus autofluorescence.

Purpose To use multimodal retinal images (including quantitative fundus autofluorescence [QAF]) for spectral-domain optical coherence tomography (SD-OCT)-based image registration and alignment. For each age decade of healthy adults, normative fine-grained QAF retinal maps are generated and advanced methods for QAF image analysis are applied. Methods Multimodal retinal images were obtained from 103 healthy subjects (age 19-77 years; unremarkable retina/macula, age-appropriate clear optic media). Custom written FIJI plugins enabled: (1) determination of the fovea in SD-OCT and the edge of the optic disc in infrared (IR) images; (2) alignment and superimposition of multimodal retinal images based on foveal and optic disc position; (3) plotting of normative QAF retinal maps for each decade; and (4) comparison of individual retinas with normative retinas of different decades using newly introduced analysis patterns (QAF97, freehand tool). Results SD-OCT based image registration enables easy image registration, alignment, and analysis of different modalities (QAF, IR, and SD-OCT here reported). In QAF, intensities significantly increase with age with two major inclines between the third/fourth and seventh/eighth decades. With aging, the parafoveal area of maximum QAF intensity slightly shifts from temporal-superior to temporal. Compared with standard QAF analysis, refined QAF analysis patterns reveal a more detailed analysis of QAF, especially in the diseased retina. Conclusions Age-related QAF normative retinal maps can be used to directly compare and classify individual's QAF intensities. Advanced QAF analysis tools will further help to interpret autofluorescence changes in normal aging and in the diseased retina in a multimodal imaging setting. Translational relevance Advanced methods for QAF analysis link basic findings with clinical observations in normal aging and in the diseased macula.

Background Soft drusen and basal linear deposit (BLinD) are two forms of the same extracellular lipid rich material that together make up an Oil Spill on Bruch's membrane (BrM). Drusen are focal and can be recognized clinically. In contrast BLinD is thin and diffusely distributed, and invisible clinically, even on highest resolution OCT, but has been detected on en face hyperspectral autofluorescence (AF) imaging ex vivo. We sought to optimize histologic hyperspectral AF imaging and image analysis for recognition of drusen and sub-RPE deposits (including BLinD and basal laminar deposit), for potential clinical application. Methods Twenty locations specifically with drusen and 12 additional locations specifically from fovea, perifovea and mid-periphery from RPE/BrM flatmounts from 4 AMD donors underwent hyperspectral AF imaging with 4 excitation wavelengths (λex 436, 450, 480 and 505 nm), and the resulting image cubes were simultaneously decomposed with our published non-negative matrix factorization (NMF). Rank 4 recovery of 4 emission spectra was chosen for each excitation wavelength. Results A composite emission spectrum, sensitive and specific for drusen and presumed sub-RPE deposits (the SDr spectrum) was recovered with peak at 510-520 nm in all tissues with drusen, with greatest amplitudes at excitations λex 436, 450 and 480 nm. The RPE spectra of combined sources Lipofuscin (LF)/Melanolipofuscin (MLF) were of comparable amplitude and consistently recapitulated the spectra S1, S2 and S3 previously reported from all tissues: tissues with drusen, foveal and extra-foveal locations. Conclusions A clinical hyperspectral AF camera, with properly chosen excitation wavelengths in the blue range and a hyperspectral AF detector, should be capable of detecting and quantifying drusen and sub-RPE deposits, the earliest known lesions of AMD, before any other currently available imaging modality.

Background: Cells of the retinal pigment epithelium (RPE) accumulate different kinds of granules (lipofuscin, melanolipofuscin, melanosomes) within their cell bodies, with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation. High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration (AMD); however, this has not been confirmed in histology so far. Here, based on our previous dataset of RPE granule characteristics, we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence (AF) intensities. Methods: RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy (HR-SIM) and laser scanning microscopy (LSM). Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules. In addition, total AF intensity per cell and granule density (number of granules per cell area) were determined. For the final analysis, RPE cells with total granule number below 5th or above the 95th percentile, or a total AF intensity ± 1.5 standard deviations above or below the mean were included, and compared to the average RPE cell at the same location. Data are presented as mean ± standard deviation. Results: Within 420 RPE cells examined, 42 cells were further analyzed due to extremes regarding total granule numbers. In addition, 20 RPE cells had AF 1.5 standard deviations below, 28 RPE cells above the mean local AF intensity. Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity. RPE cells with high granule content have nearly twice (1.8 times) as many granules as an average RPE cell. Conclusions: In normal eyes, outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells, suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level. The AF of a cell is related to the composition of intracellular granule types. Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscin´s role in aging and AMD further into perspective.

Purpose Quantitative fundus autofluorescence (QAF) enables comparisons of autofluorescence intensities among participants. While clinical QAF reports mostly focused on the healthy and diseased adult retina, only very limited data of QAF in the maturing eye are available. Here, we report QAF in a large cohort of healthy children. Methods In this prospective monocentric cross-sectional study, 70 healthy Caucasian children (5–18 years) were multimodal imaged, including QAF and spectral domain optical coherence tomography. QAF and retinal thicknesses were measured at predefined locations (along horizontal meridian; Early Treatment Diabetic Retinopathy Study [ETDRS] grid) and correlated using custom written Fiji plugins. Standard retinae for different age groups were generated. Results Fifty-three participants were included. QAF was low in childhood but increased steadily (P < 0.001), also at the fovea (P < 0.001), with no gender differences (P = 0.61). The QAF distribution was similar to adults showing highest values superior-temporally. At individual points, retinal thickness remained stable, while using the ETDRS pattern, the retinal pigment epithelium (RPE) thickness increased significantly with aging. Standard QAF retinae of age groups also showed an increase with aging. Conclusions QAF can be reliably performed in young children. Function–structure correlation showed a thickening of the RPE and an increasing QAF with aging, probably related to the histologic low number of RPE autofluorescent granules at a younger age but further deposition of these granules during maturation. Standard retinae help to distinguish abnormal QAF in the diseased retina of age-matched patients. Translational Relevance Our data bridge the gap between preclinical QAF and clinical data application and structural OCT correlation in children.

Purpose To investigate the effect of systemic chloroquine/hydroxychloroquine (CQ/HCQ) on outer retinal health using quantitative fundus autofluorescence (QAF) imaging. Methods For this prospective, cross-sectional study, 44 CQ/HCQ patients and 25 age-matched controls underwent multimodal retinal imaging including QAF (488 nm) and spectral-domain optical coherence tomography (SD-OCT) in addition to the recommended CQ/HCQ screening procedures. Custom written FIJI plugins enabled detailed QAF analysis and correlation with retinal thickness and comparison to the healthy controls. Results Out of 44 patients, 29 (mean age 43.5 ± 12.2, range 22-59 years) exposed to CQ/HCQ (mean cumulative dose 724.2 ± 610.4 g, median 608.0 g, range 18.6-2171.0 g) met eligibility criteria. Four of these 29 patients had bull's-eye maculopathy (BEM). Mean QAF values were significantly higher in CQ/HCQ patients than in healthy controls. QAF increase started early after treatment onset, remained high even years after treatment cessation, and was not accompanied by pathologies in the other screening methods, including retinal thicknesses (except in BEM patients). Conclusions QAF might be a useful tool in retinal imaging and in verifying systemic CQ/HCQ intake. The early onset and preserved high levels of QAF parallel findings of CQ deposition in the retina in animal models. Whether QAF can be used as a screening tool to detect early CQ/HCQ related maculopathy is the subject of long-term ongoing studies. Translation relevance Experimental QAF imaging in systemic CQ/HCQ therapy monitoring might be a useful tool to indicate the drug or its metabolites and to detect metabolic retinal changes.

To characterize fluorophore signals from drusen and retinal pigment epithelium (RPE) and their changes in age related macular degeneration (AMD), the authors describe advances in ex vivo hyperspectral autofluorescence (AF) imaging of human eye tissue. Ten RPE flatmounts from eyes with AMD and 10 from eyes without AMD underwent 40&times, hyperspectral AF microscopic imaging. The number of excitation wavelengths tested was initially two (436 nm and 480 nm), then increased to three (436 nm, 480 nm, and 505 nm). Emission spectra were collected at 10 nm intervals from 420 nm to 720 nm. Non-negative matrix factorization (NMF) algorithms decomposed the hyperspectral images into individual emission spectra and their spatial abundances. These include three distinguishable spectra for RPE fluorophores (S1, S2, and S3) in both AMD and non-AMD eyes, a spectrum for drusen (SDr) only in AMD eyes, and a Bruch&rsquo, s membrane spectrum that was detectable in normal eyes. Simultaneous analysis of datacubes excited atthree excitation wavelengths revealed more detailed spatial localization of the RPE spectra and SDr within drusen than exciting only at two wavelengths. Within AMD and non-AMD groups, two different NMF initialization methods were tested on each group and converged to qualitatively similar spectra. In AMD, the peaks of the SDr at ~510 nm (436 nm excitation) were particularly consistent. Between AMD and non-AMD groups, corresponding spectra in common, S1, S2, and S3, also had similar peak locations and shapes, but with some differences and further characterization warranted.

Autofluorescence is the emission of light by naturally occurring tissue components on the absorption of incident light. Autofluorescence within the eye is associated with several disorders, such as Age-related Macular Degeneration (AMD) which is a leading cause of central vision loss. Its pathogenesis is incompletely understood, but endogenous fluorophores in retinal tissue might play a role. Hyperspectral fluorescence microscopy of ex-vivo retinal tissue can be used to determine the fluorescence emission spectra of these fluorophores. Comparisons of spectra in healthy and diseased tissues can provide important insights into the pathogenesis of AMD. However, the spectrum from each pixel of the hyperspectral image is a superposition of spectra from multiple overlapping tissue components. As spectra cannot be negative, there is a need for a non-negative blind source separation model to isolate individual spectra. We propose a tensor formulation by leveraging multiple excitation wavelengths to excite the tissue sample. Arranging images from different excitation wavelengths as a tensor, a non-negative tensor decomposition can be performed to recover a provably unique low-rank model with factors representing emission and excitation spectra of these materials and corresponding abundance maps of autofluorescent substances in the tissue sample. We iteratively impute missing values common in fluorescence measurements using Expectation-Maximization and use L2 regularization to reduce ill-posedness. Further, we present a framework for performing group hypothesis testing on hyperspectral images, finding significant differences in spectra between AMD and control groups in the peripheral macula. In the absence of ground truth, i.e. molecular identification of fluorophores, we provide a rigorous validation of chosen methods on both synthetic and real images where fluorescence spectra are known. These methodologies can be applied to the study of other pathologies presenting autofluorescence that can be captured by hyperspectral imaging.

Age-related macular degeneration (AMD) is a chronic degenerative disease of the central retina and a major cause of vision impairment and blindness with millions of people affected in the elderly population. In recent years, considerable efforts have been made to understand disease pathology with the long-term goal of designing novel and effective treatment options for this devastating disease. Although striking advances in treating the neovascular stage of late AMD have occurred, no therapy is available for almost half of all AMD patients, specifically those who are affected by the atrophic form of the disease. This review highlights current knowledge on the genetic factors associated with early- and late-stage forms of the disease. It also summarizes the findings regarding the extent to which these factors may play a role in the transition from one disease stage to another, and it emphasizes the need to explore further the underlying mechanisms for both development and progression of this disease as a starting point for designing innovative therapies for it.

Autofluorescence images of the fundus have been part of the routine diagnostics of the human eye for almost two decades. Further development of imaging techniques makes fundus autofluorescence (FAF) imaging a safe, non-invasive, easy-to-perform and reproducible diagnostic tool. FAF uses the autofluorescent properties of tissues, in particular the retinal pigment epithelium (RPE) and its fluorophores. FAF images display phenomena of normal aging as well as disease-related changes of the fundus, but also can be used for monitoring retinal diseases and therapy. After a short introduction into the basics of FAF, the results of the latest histology studies regarding age-related and pathological changes of the human RPE will be summarized for a better understanding and interpretation of FAF images. The normal age-related changes of the RPE are contrasted with the pathological changes in age-related macular degeneration, both clinically and histologically.Fundusautofluoreszenz(FAF)-Aufnahmen zählen seit beinahe 2 Jahrzehnten zur Routinediagnostik des menschlichen Augenhintergrunds. Die stetigen Weiterentwicklungen der Aufnahmetechniken ermöglichen heute eine sichere, nicht invasive, einfach durchführbare und reproduzierbare Darstellung des Augenhintergrunds. Die zugrunde liegende Technik macht sich die autofluoreszierenden Eigenschaften von Geweben, insbesondere des retinalen Pigmentepithels (RPE) und dessen Fluorophore, zunutze. Dadurch können FAF-Aufnahmen in hervorragender Weise Phänomene der normalen Alterung sowie krankheitsbedingte Veränderungen des Augenhintergrunds aufzeigen, aber auch Informationen zu Krankheitsverlauf und Therapiekontrolle liefern. In dieser Übersichtsarbeit sollen nach einer kurzen Einführung in die Basis der Fundusautofluoreszenz neueste grundlagenwissenschaftliche Kenntnisse zur Histologie im Hinblick auf altersbedingte und pathologische Veränderungen des RPE zusammengefasst werden, um so eine bessere Interpretation von FAF-Aufnahmen zu ermöglichen. Der Darstellung altersbedingter Veränderungen werden hierbei die pathologischen Veränderungen im Rahmen einer altersbedingten Makuladegeneration sowohl klinisch als auch auf histologischer Ebene gegenübergestellt.