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UNRAVELED FRINGE-LIKE MARGINS AND BIPHASIC AUTOFLUORESCENCE OF UNILATERAL RETINAL PIGMENT EPITHELIUM DYSGENESIS
摘要： To illustrate the features of unilateral retinal pigment epithelium dysgenesis (URPED) in an African-American male patient. A 47-year-old asymptomatic African-American man was referred for an atypical subretinal pigmented mass in the left eye. On examination, visual acuity was 20/20 in both eyes. The right eye was unremarkable. The left eye revealed a darkly pigmented grey-black lesion at the level of the RPE with irregular, unraveled fringe-like margins, consistent with URPED. The lesion measured 5 mm in basal dimension and was located 400 mm from the foveola. The dark portion of the lesion was grey-black and demonstrated homogeneous hypoauto?uorescence, particularly at the site of grey-white peripheral fringe of ?brous metaplasia. By contrast, there was an additional, subtle lacey arrangement of normal-appearing RPE traversing over the entire lesion demonstrating isoauto?uorescence. On ?uorescein angiography, the lesion was generally hypo?uorescent, particularly in the dark portion of the lesion, but the peripheral fringe of ?brous metaplasia displayed angiographic hyper?uorescent staining, and the subtle lacey normal RPE showed iso?uorescence. Optical coherence tomography demonstrated RPE hyperplasia and shallow RPE detachment interspersed with normal-appearing RPE and thinning of outer retina and preservation of the foveola and choroid. In this case, URPED demonstrated biphasic auto?uorescence implying RPE dysfunction in the hypoauto?uorescent area and partial RPE function in the lacey isoauto?uorescent region.
关键词： optical coherence tomography,African-American,retinal pigment epithelium,auto?uorescence,race,dysgenesis
更新于2025-09-12 10:27:22
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Longitudinal Assessment of Progressive Retinal Pigment Epithelium Disruption in a 26 Year Old A MultiSpectral Imaging Case Study
摘要： Background: Progressive retinal pigment epithelium (RPE) disruption in the absence of drusen or visual disturbances in young people is rarely reported in the literature, except for cases of juvenile macular degenerative diseases, pattern dystrophies or white dot syndromes. In age-related macular degeneration (AMD), RPE disruption typically does not become manifest clinically before age 55. This case report presents a young, healthy 26 year old Caucasian male with asymptomatic progressive RPE disruption in the absence of drusen, as detected by multi-spectral imaging (MSI) technology. Methods: A 26 year old Caucasian male was followed for progressive changes in RPE atrophy and melanin clumping over three visits in a three year period. His dilated fundus examination, fundus photography and optical coherence tomography were within normal limits. Long wavelength MSI revealed progressive RPE changes in the form of RPE atrophy and melanin clumping. MSI fundus auto-fluorescence (FAF) showed corresponding hyperautofluorescence and hypoautofluorescence in the left. Findings: Macular RPE changes can result from phototoxic effects and vary by ethnicity. Functional biomarkers to determine the risk of future vision loss with AMD are frequently sought and include complement factor H and Age-Related Maculopathy Susceptibility 2. FAF, for example is highly indicative of RPE dysfunction and progression. Long wavelength MSI, 620 nm to 740 nm, enhances visualization of the RPE, more specifically atrophy and melanin clumping, which may be indicative of asymptomatic progressive early AMD or retinal dystrophies. Conclusion: This case shows a longitudinal example of progressive RPE disruption in a 26 year old male. This is only one example, but multiple cases of RPE disruption in young people exist. Using MSI to further investigate RPE disruption and progression in a young population may provide a potential biomarker for early AMD, photo toxicity or other retinal dystrophies and degenerations.
关键词： Retinal Pigment Epithelium,Fundus Autofluorescence,Age-related Macular Degeneration,Multi-Spectral Imaging,Progressive retinal pigment epithelium disruption
更新于2025-09-11 14:15:04
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Nanosekundenlaserbehandlung bei Chorioretinopathia centralis serosa ohne RPE-Defekte: eine retrospektive Fallserie
摘要： Background Chorioretinopathia centralis serosa (CCS) is a uni- or bilateral disease of the macula which is characterized by detachment of the neuro-sensory retina. The spontaneous resolution rate is 68 % after four months and 84 % after six months. Purpose To investigate the efficacy of subthreshold nanopulse laser treatment for central serous chorioretinopathy (CCS) in the absence of any atrophy in the retinal pigment epithelium (RPE). Methods This retrospective study comprised 23 eyes of 23 patients without previous treatment. Patients were followed up to 12 months. Laser treatment was performed with the 2RT? nanolaser using a grid stimulation. Changes in corrected visual acuity (VA), microperimetry and subretinal fluid height in optical coherence tomographic images were measured. Saliences in autofluorescence images and angiographic images were observed. All results were documented 1, 3, 6 and 12 months after the first treatment. Patients did not receive any supplementary treatment. Results Two months after the first treatment, 74 % of the patients showed complete SRF resolution and 91 % of the patients within 6 months had complete resorption of the SRF. Central visual acuity and macula sensitivity significantly improved from 0.18 ± 0.16 logMAR to 0.09 ± 0.17 logMAR and 24.19 ± 3.96 dB to 27.59 ± 2.89 dB. The SRF decreased within one month significantly. No CNV was documented during the observation time. The baseline subretinal fluid height is a predictive factor of faster resolution. Conclusion The evaluation of our treatment results shows that the therapy is a safe and promising method. Patients with a CCS without existing RPE defects benefit from the treatment with the 2RT? nanolaser, which is associated with an improvement of the macula function.
关键词： Retina,central serous chorioretinopathy,Nanolaser,microperimetry,retinal pigment epithelium,Subthreshold?Laser,Chorioretinopathia centralis serosa,subthreshold nanopulse laser,subretinal fluid,Mikroperimetrie,subretinale Flüssigkeit
更新于2025-09-11 14:15:04
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Fabrication of Optimized Eco-friendly Dye-Sensitized Solar Cells by Extracting Pigments from Low-Cost Native Wild Plants
摘要： The major proportion of dye-sensitized solar cells (DSSCs) fabrication cost is attributed to the pigments. In this study, to increase the performance/cost ratio of DSSCs, we used several wild regional plants of Persian Gulf zone for natural pigment production. At first, the optimum conditions for pigment extraction were obtained for all plants using response surface methodology. The results showed that increasing temperature, as well as extraction time, increased the pigment extraction efficiency while the pH of the solution did not exert a significant effect on the extraction process. Besides, the microwave-assisted method and pure ethanol have the highest extraction efficiency compared to ordinary solvent extraction and water as the extraction method and solvent, respectively. Moreover, all pigments were characterized using circular dichroism, dynamic light scattering, and zeta potential techniques. The results showed that the extracted pigments from Malva verticillata have the highest optical activity while all kinds of pigments tend to make aggregates 12 h after the extraction. Finally, the effectiveness of each pigment was evaluated as a sensitizer in natural DSSCs that fabricated using the doctor blade technique. Based on the photovoltaic results of the DSSCs sensitized with extracted pigments, the open circuit voltage and short circuit current ranged from 0.35 to 0.542 ??and 0.802 to 1.702 ????, respectively. The Microwave-assisted Malva verticillata-DSSC owned the highest energy conversion efficiency of 1.702% as well as the comparable open circuit voltage to that of the reference DSSC that made using synthetic sensitizer. This superiority could be attributed to the highest pigments concentration as well as the highest pigments optical activity of Malva verticillata. Moreover, the results showed that the LUMO energy level and the band gap of the extracted pigments from Malva verticillata are better than the other natural pigments for DSSC fabrication. Besides, due to the presence of carbonyl and hydroxyl groups in chemical structures of extracted pigment from Malva verticillata, an effective bond between the pigment and TiO2 surface might be achieved and thereby increasing the energy conversion efficiency.
关键词： solar cell,sensitizer,natural,Algae,pigment,Malva verticillata
更新于2025-09-11 14:15:04
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Self-Formation of RPE Spheroids Facilitates Enrichment and Expansion of hiPSC-Derived RPE Generated on Retinal Organoid Induction Platform
摘要： PURPOSE. Retinal pigment epithelium (RPE) and neural retina could be generated concurrently through retinal organoid induction approaches using human induced pluripotent stem cells (hiPSCs), providing valuable sources for cell therapy of retinal degenerations. This study aims to enrich and expand hiPSC-RPE acquired with this platform and explore characteristics of serially passaged RPE cells. METHODS. RPE has been differentiated from hiPSCs with a published retinal organoid induction method. After detachment of neural retina on the 4th week, the remaining mixture was scraped from the dish and subjected to suspension culture for the formation of RPE spheroids. RPE sheets were isolated and digested for expansion. The cellular, molecular, and functional features of expanded RPE cells were evaluated by different assays. RESULTS. Under suspension culture, hiPSC-RPE spheroids with pigmentation self-formed were readily enriched by removing the non-retinal tissues. RPE sheets were further dissected and purified from the spheroids. The individualized RPE cells could be passaged every week for at least 5 times in serum medium, yielding large numbers of cells with high quality in a short period. In addition, when switched to a serum-free medium, the passaged RPE cells could mature in cellular, molecular, and physiological levels, including repigmentation, markers expression, and phagocytosis. CONCLUSIONS. We developed a simple and novel RPE spheroids formation approach to enrich and expand hiPSC-RPE cells generated along with retinal neurons on a universal retinal organoid induction platform. This achievement will reduce the cost and time in producing retinal cells for basic and translational researches, in particular for retinal cell therapy.
关键词： differentiation,human induced pluripotent stem cells,retinal pigment epithelium,retinal degenerations,organoids
更新于2025-09-11 14:15:04
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Quantitative Fundus Autofluorescence and Optical Coherence Tomography in <i>PRPH2/RDS</i> - and <i>ABCA4</i> -Associated Disease Exhibiting Phenotypic Overlap
摘要： PURPOSE. To assess whether quantitative fundus autofluorescence (qAF), a measure of RPE lipofuscin, and spectral-domain optical coherence tomography (SD-OCT) can aid in the differentiation of patients with fundus features that could either be related to ABCA4 mutations or be part of the phenotypic spectrum of pattern dystrophies. METHODS. Autofluorescence images (308, 488-nm excitation) from 39 patients (67 eyes) were acquired with a confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference and were quantified as previously described. In addition, horizontal SD-OCT images through the fovea were obtained. Patients were screened for ABCA4 and PRPH2/RDS mutations. RESULTS. ABCA4 mutations were identified in 19 patients (mean age, 37 ± 12 years) and PRPH2/RDS mutations in 8 patients (mean age, 48 ± 13 years); no known ABCA4 or PRPH2/RDS mutations were found in 12 patients (mean age, 48 ± 9 years). Differentiation of the groups using phenotypic SD-OCT and AF features (e.g., peripapillary sparing, foveal sparing) was not reliable. However, patients with ABCA4 mutations could be discriminated reasonably well from other patients when qAF values were corrected for age and race. In general, ABCA4 patients had higher qAF values than PRPH2/RDS patients, while most patients without mutations in PRPH2/RDS or ABCA4 had qAF levels within the normal range. CONCLUSIONS. The high qAF levels of ABCA4-positive patients are a hallmark of ABCA4-related disease. The reason for high qAF among many PRPH2/RDS-positive patients is not known; higher RPE lipofuscin accumulation may be a primary or secondary effect of the PRPH2/RDS mutation.
关键词： scanning laser ophthalmoscope,PRPH2/RDS,optical coherence tomography,quantitative fundus autofluorescence,retinal pigment epithelium,lipofuscin,recessive Stargardt disease,ABCA4,pattern dystrophy
更新于2025-09-11 14:15:04
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Cool and photocatalytic yellow ceramic pigments; from lead-tin to Cr doped scheelite pigments
摘要： The historical lead based pigments (XVII-XVIII century), the modern Ni,Sb-rutile (1939) and Pr-zircon (1961) yellow pigments as well as the novel yellow pigments based on Cr-scheelite and Mo-yttrium cerate pigments were synthesised and compared as semiconductors of high NIR reflectance (cool pigments) and with photocatalytic activity. All powders are wide band gap semiconductors (Eg=2.1-3.1 eV) with high NIR reflectance, ranging from 80% for Cr-Scheelite to 86% of Naples yellow, except Ni,Sb-rutile pigment that shows 55%. The low color performance of lead based pigments in alkyd paint and lead-free glazes along with its toxicity, discard these pigments as cool eco-friendly pigments. The Pr-zircon, Cr-scheelite and Mo-yttrium cerate pigments exhibit high NIR reflectance (RNIR=80-83%) and yellow coloration (b*=57.6-45.3) but only Pr-zircon and Cr-scheelite show colour stability in alkyd paint and lead free glaze applications. Regarding to results of Orange II photodegradation test, lead based and Ni,Sb-rutile pigments inhibits the photolysis of the UV irradiation, acting as protecting agents from irradiation. The Mo-cerate shows a slight photocatalytic activity (t1/2 =301 min) and both Cr-scheelite and Pr-zircon pigments show a moderate activity (t1/2 =198 and 184 min respectively). Looking at a possible industrial application, the leaching test shows that the fluorides released by Pr-zircon (16.8 mg/g) as well as the Cr(VI) of Cr-scheelite (6 mg/g) should be treated and controlled. The Cr-scheelite solid solution Ca(CrxW1-x)O4 is stable to x=0.2 but its pigmenting capacity saturates at x=0.1.
关键词： cool pigment,ceramic pigment,environment,photocatalysis
更新于2025-09-10 09:29:36
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From nano-structured polycrystalline spheres with Zn1-xCoxO composition to core-shell Zn1-xCoxO@SiO2 as green pigments
摘要： ZnO doped with Co2+, a well-known green pigment which is an alternative to the chromium based inorganic pigments, has been prepared by a polyol process and investigated in terms of crystallographic structure and UV?visible properties. Thanks to the obtaining of nanometric crystallite size from our process, the incorporation of a very high concentration of Co2+ in the ZnO matrix is achieved. Thus, different grades of more or less deep green pigments can be produced. Furthermore, the obtaining of spherical aggregates allows the easy preparation of ZnO:Co@SiO2 core-shells, minimizing hence the problems linked to the zinc oxide high solubility into slightly acidic conditions acidic conditions and the metal cation’s toxicity.
关键词： Core-shell,Zinc-Cobalt oxide,Green Pigment,Polyol synthesis
更新于2025-09-10 09:29:36
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Novel Protective Effects of Cistanche Tubulosa Extract Against Low-Luminance Blue Light-Induced Degenerative Retinopathy
摘要： Background/Aims: Blue light-emitting diode light (BLL)-induced phototoxicity plays an important role in ocular diseases and causes retinal degeneration and apoptosis in human retinal pigment epithelial (RPE) cells. Cistanche tubulosa extract (CTE) is a traditional Chinese medicine with many beneficial protective properties; however, few studies have examined the ocular protective roles of CTE. In this study, we investigated the mechanisms underlying the effects of CTE on BLL-induced apoptosis in vitro and in vivo. Methods: RPE cells were applied in the current in vitro study and cell viability was determined by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis-related protein expression was determined by western blot analysis and immunofluorescence staining. Brown Norway rats were used to examine exposure to commercially available BLL in vivo. Hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and western blot assays were used to examine retinal morphological deformation. Results: CTE significantly inhibited hydrogen peroxide-, tert-butyl hydroperoxide-, sodium azide-, and BLL-induced RPE damage. Further, CTE reduced the expression of apoptotic markers such as cleaved caspase-3 and TUNEL staining after BLL exposure by inactivating apoptotic pathways, as shown via immunofluorescent staining. In addition, CTE inhibited the BLL-induced phosphorylation of c-Jun N-terminal kinase, extra signal-related kinases 1/2, and p38 in RPE cells. In vivo, the oral administration of CTE rescued 60-day periodic BLL exposure-induced decrements in retinal thickness and reduced the number of TUNEL-positive cells in the brown Norway rat model. Conclusion: CTE is a potential prophylactic agent against BLL-induced phototoxicity.
关键词： Cistanche tubulosa extract,Blue light,Retinal pigment epithelial cells,Apoptosis
更新于2025-09-10 09:29:36
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Light-Induced Thickening of Photoreceptor Outer Segment Layer Detected by Ultra-High Resolution OCT Imaging
摘要： PURPOSE. We examined if light induces changes in the retinal structure that can be observed using optical coherence tomography (OCT). METHODS. Normal C57BL/6J mice (age 3–6 months) adapted to either room light (15 minutes to ~5 hours, 50–500 lux) or darkness (overnight) were imaged using a Bioptigen UHR-OCT system. Confocal histologic images were obtained from mice killed under light- or dark-adapted conditions. RESULTS. The OCT image of eyes adapted to room light exhibited signi?cant increases (6.1 6 0.8 lm, n ? 13) in total retina thickness compared to the same eyes after overnight dark adaptation. These light-adapted retinal thickness changes occurred mainly in the outer retina, with the development of a hypore?ective band between the RPE and photoreceptor-tip layers. Histologic analysis revealed a light-evoked elongation between the outer limiting membrane and Bruch’s membrane from 45.8 6 1.7 lm in the dark (n ? 5) to 52.1 6 3.7 lm (n ? 5) in the light. Light-adapted retinas showed an increase of actin staining in RPE apical microvilli at the same location as the hypore?ective band observed in OCT images. Elongation of the outer retina could be detected even with brief light exposures, increasing 2.1 6 0.3 lm after 15 minutes (n ? 9), and 4.1 6 1.0 lm after 2 hours (n ? 6). Conversely, dark-adaptation caused outer retinal shortening of 1.4 6 0.4 lm (n ? 7) and 3.0 6 0.5 lm (n ? 8) after 15 minutes and 2 hours, respectively. CONCLUSIONS. Light-adaption induces an increase in the thickness of the outer retina and the appearance of a hypore?ective band in the OCT image. This is consistent with previous reports of light-induced ?uid accumulation in the subretinal space.
关键词： optical coherence tomography,subretinal space,retinal pigment epithelium,light/dark adaptation,outer segments
更新于2025-09-10 09:29:36