Dear Sir,I am Dr. Xiao-Qiang Liu, from the Department of Ophthalmology, Shanghai Tenth People’s Hospital,Tongji University School of Medicine, Shanghai, China. I write to report a case of malignant hypertensive retin...Dear Sir,I am Dr. Xiao-Qiang Liu, from the Department of Ophthalmology, Shanghai Tenth People’s Hospital,Tongji University School of Medicine, Shanghai, China. I write to report a case of malignant hypertensive retinopathy demonstrated by spectral domain optical coherence展开更多
AIM To investigate the effect of two ways of lipofuscin production(lipid peroxidation and glycation) on lipofuscin fluorescence characteristics and phototoxicity and to compare them with the properties of natural lipo...AIM To investigate the effect of two ways of lipofuscin production(lipid peroxidation and glycation) on lipofuscin fluorescence characteristics and phototoxicity and to compare them with the properties of natural lipofuscin.METHODS Model lipofuscins were prepared on the basis of bovine photoreceptor outer segments(POS) with bisretinoid A2 E addition. One set of samples was prepared from POS modified by lipid peroxidation,while another set from POS modified by glycation with fructose. Fluorescent properties and kinetics of photoinduced superoxide generation of model lipofuscins and human retinal pigment epithelium(RPE) lipofuscin were compared. The fluorescence spectra of samples were measured at 365 nm excitation wavelength and 380-650 emission wavelength. RESULTS The fluorescence spectra of model lipofuscins are almost the same as the spectrum of natural lipofuscin. Visible light irradiation of both model lipofuscins and natural lipofuscin isolated from RPE cells leads to decrease of a fluorescence maximum at 550 nm and to appearance of a distinct,new maximum at 445-460 nm. The rate of photogeneration of reactive oxygen forms by both model lipofuscins was almost the same and approximately two times less than that of RPE lipofuscin granules.CONCLUSION These data suggest that fluorescent characteristics and phototoxicity of lipofuscin granules depend only to an insignificant degree on the oxidative modification of POS proteins and lipids,and generally are defined by the bisretinoid fluorophores contained in them.展开更多
Retinal aging has been recognized as a significant risk factor for various retinal disorders,including diabetic retinopathy,age-related macular degeneration,and glaucoma,following a growing understanding of the molecu...Retinal aging has been recognized as a significant risk factor for various retinal disorders,including diabetic retinopathy,age-related macular degeneration,and glaucoma,following a growing understanding of the molecular underpinnings of their development.This comprehensive review explores the mechanisms of retinal aging and investigates potential neuroprotective approaches,focusing on the activation of transcription factor EB.Recent meta-analyses have demonstrated promising outcomes of transcription factor EB-targeted strategies,such as exercise,calorie restriction,rapamycin,and metformin,in patients and animal models of these common retinal diseases.The review critically assesses the role of transcription factor EB in retinal biology during aging,its neuroprotective effects,and its therapeutic potential for retinal disorders.The impact of transcription factor EB on retinal aging is cell-specific,influencing metabolic reprogramming and energy homeostasis in retinal neurons through the regulation of mitochondrial quality control and nutrient-sensing pathways.In vascular endothelial cells,transcription factor EB controls important processes,including endothelial cell proliferation,endothelial tube formation,and nitric oxide levels,thereby influencing the inner blood-retinal barrier,angiogenesis,and retinal microvasculature.Additionally,transcription factor EB affects vascular smooth muscle cells,inhibiting vascular calcification and atherogenesis.In retinal pigment epithelial cells,transcription factor EB modulates functions such as autophagy,lysosomal dynamics,and clearance of the aging pigment lipofuscin,thereby promoting photoreceptor survival and regulating vascular endothelial growth factor A expression involved in neovascularization.These cell-specific functions of transcription factor EB significantly impact retinal aging mechanisms encompassing proteostasis,neuronal synapse plasticity,energy metabolism,microvasculature,and inflammation,ultimately offering protection against retinal aging and diseases.The review emphasizes transcription factor EB as a potential therapeutic target for retinal diseases.Therefore,it is imperative to obtain well-controlled direct experimental evidence to confirm the efficacy of transcription factor EB modulation in retinal diseases while minimizing its risk of adverse effects.展开更多
Background:Most patients of established retinitis pigmentosa(RP)have subnormal peripheral vision and heavily rely on central vision for their daily activities.Central visual acuity is dependent on photoreceptor surviv...Background:Most patients of established retinitis pigmentosa(RP)have subnormal peripheral vision and heavily rely on central vision for their daily activities.Central visual acuity is dependent on photoreceptor survival at the macula.Identification of structural changes that precede visual loss is essential.The aim of this study was to correlate the Spectral Domain-Optical Coherence Tomography(SD-OCT)characteristics with visual acuity in patients with typical RP.Methods:This was a retrospective,observational case series of 224 eyes of 113 RP patients conducted a tertiary eye care center.SD-OCT imaging was done for all eyes.Central retinal thickness(CRT),photoreceptor outer segment length(PROS),foveal outer segment pigment epithelial thickness(FOSPET)and ellipsoid zone(EZ)extent were measured.A new variable,FOSPET-PROS ratio(FPR),obtained by dividing FOSPET by PROS is defined and correlated to corrected distance visual acuity(CDVA)in logMAR using linear regression.Results:Out of 113 patients,71 were males and 42 females.Mean age of the patients was 35.4±15.1 years.Mean CDVA was 0.33±0.25 logMAR with no difference between the genders.Mean CRT(218.74±83.5μm)and FPR(1.63±0.22)significantly correlated to CDVA with a correlation coefficient of r=−0.139(p=0.048)and r=0.842(p=0.0001),respectively.FOSPET(mean=71.15±13.8μm)and PROS(mean=44.85±12.5μm)did not show a significant correlation to CDVA,independent of FPR.Conclusions:Retinal microstructural changes on SD-OCT,especially the FPR,can be used as a surrogate marker to monitor disease progression in the central retina in degenerative diseases like RP.展开更多
文摘Dear Sir,I am Dr. Xiao-Qiang Liu, from the Department of Ophthalmology, Shanghai Tenth People’s Hospital,Tongji University School of Medicine, Shanghai, China. I write to report a case of malignant hypertensive retinopathy demonstrated by spectral domain optical coherence
基金The Russian Foundation for Basic Research,No.15-29-03831
文摘AIM To investigate the effect of two ways of lipofuscin production(lipid peroxidation and glycation) on lipofuscin fluorescence characteristics and phototoxicity and to compare them with the properties of natural lipofuscin.METHODS Model lipofuscins were prepared on the basis of bovine photoreceptor outer segments(POS) with bisretinoid A2 E addition. One set of samples was prepared from POS modified by lipid peroxidation,while another set from POS modified by glycation with fructose. Fluorescent properties and kinetics of photoinduced superoxide generation of model lipofuscins and human retinal pigment epithelium(RPE) lipofuscin were compared. The fluorescence spectra of samples were measured at 365 nm excitation wavelength and 380-650 emission wavelength. RESULTS The fluorescence spectra of model lipofuscins are almost the same as the spectrum of natural lipofuscin. Visible light irradiation of both model lipofuscins and natural lipofuscin isolated from RPE cells leads to decrease of a fluorescence maximum at 550 nm and to appearance of a distinct,new maximum at 445-460 nm. The rate of photogeneration of reactive oxygen forms by both model lipofuscins was almost the same and approximately two times less than that of RPE lipofuscin granules.CONCLUSION These data suggest that fluorescent characteristics and phototoxicity of lipofuscin granules depend only to an insignificant degree on the oxidative modification of POS proteins and lipids,and generally are defined by the bisretinoid fluorophores contained in them.
基金supported by the Start-up Fund for new faculty from the Hong Kong Polytechnic University(PolyU)(A0043215)(to SA)the General Research Fund and Research Impact Fund from the Hong Kong Research Grants Council(15106018,R5032-18)(to DYT)+1 种基金the Research Center for SHARP Vision in PolyU(P0045843)(to SA)the InnoHK scheme from the Hong Kong Special Administrative Region Government(to DYT).
文摘Retinal aging has been recognized as a significant risk factor for various retinal disorders,including diabetic retinopathy,age-related macular degeneration,and glaucoma,following a growing understanding of the molecular underpinnings of their development.This comprehensive review explores the mechanisms of retinal aging and investigates potential neuroprotective approaches,focusing on the activation of transcription factor EB.Recent meta-analyses have demonstrated promising outcomes of transcription factor EB-targeted strategies,such as exercise,calorie restriction,rapamycin,and metformin,in patients and animal models of these common retinal diseases.The review critically assesses the role of transcription factor EB in retinal biology during aging,its neuroprotective effects,and its therapeutic potential for retinal disorders.The impact of transcription factor EB on retinal aging is cell-specific,influencing metabolic reprogramming and energy homeostasis in retinal neurons through the regulation of mitochondrial quality control and nutrient-sensing pathways.In vascular endothelial cells,transcription factor EB controls important processes,including endothelial cell proliferation,endothelial tube formation,and nitric oxide levels,thereby influencing the inner blood-retinal barrier,angiogenesis,and retinal microvasculature.Additionally,transcription factor EB affects vascular smooth muscle cells,inhibiting vascular calcification and atherogenesis.In retinal pigment epithelial cells,transcription factor EB modulates functions such as autophagy,lysosomal dynamics,and clearance of the aging pigment lipofuscin,thereby promoting photoreceptor survival and regulating vascular endothelial growth factor A expression involved in neovascularization.These cell-specific functions of transcription factor EB significantly impact retinal aging mechanisms encompassing proteostasis,neuronal synapse plasticity,energy metabolism,microvasculature,and inflammation,ultimately offering protection against retinal aging and diseases.The review emphasizes transcription factor EB as a potential therapeutic target for retinal diseases.Therefore,it is imperative to obtain well-controlled direct experimental evidence to confirm the efficacy of transcription factor EB modulation in retinal diseases while minimizing its risk of adverse effects.
文摘Background:Most patients of established retinitis pigmentosa(RP)have subnormal peripheral vision and heavily rely on central vision for their daily activities.Central visual acuity is dependent on photoreceptor survival at the macula.Identification of structural changes that precede visual loss is essential.The aim of this study was to correlate the Spectral Domain-Optical Coherence Tomography(SD-OCT)characteristics with visual acuity in patients with typical RP.Methods:This was a retrospective,observational case series of 224 eyes of 113 RP patients conducted a tertiary eye care center.SD-OCT imaging was done for all eyes.Central retinal thickness(CRT),photoreceptor outer segment length(PROS),foveal outer segment pigment epithelial thickness(FOSPET)and ellipsoid zone(EZ)extent were measured.A new variable,FOSPET-PROS ratio(FPR),obtained by dividing FOSPET by PROS is defined and correlated to corrected distance visual acuity(CDVA)in logMAR using linear regression.Results:Out of 113 patients,71 were males and 42 females.Mean age of the patients was 35.4±15.1 years.Mean CDVA was 0.33±0.25 logMAR with no difference between the genders.Mean CRT(218.74±83.5μm)and FPR(1.63±0.22)significantly correlated to CDVA with a correlation coefficient of r=−0.139(p=0.048)and r=0.842(p=0.0001),respectively.FOSPET(mean=71.15±13.8μm)and PROS(mean=44.85±12.5μm)did not show a significant correlation to CDVA,independent of FPR.Conclusions:Retinal microstructural changes on SD-OCT,especially the FPR,can be used as a surrogate marker to monitor disease progression in the central retina in degenerative diseases like RP.
