Effect of metformin on the polarization status of microglia and photoreceptor cells activity in a high glucose environment / 中华眼底病杂志

Objective:To observe the effect of metformin on the polarization state and photoreceptor cell activity of microglia (BV2 cells) in a high glucose environment.Methods:An experimental study. BV2 cells were divided into a control group, a high glucose group, and a metformin+high glucose group. The cells in the high glucose group were cultured with 75 mmol/L glucose in the medium; the cells in the metformin+high glucose group were pretreated with 2 mmol/L metformin for 12 h and then placed in 75 mmo/L glucose concentration medium. The relative expression of M1 marker inducible nitric oxide synthase (iNOS), CD86 and M2 markers arginase 1 (Arg-1), and CD206 protein were detected by Western blot. Interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-4 were detected by enzyme-linked immunosorbent assay (ELISA). BV2 cells were co-cultured with mouse retinal photoreceptor cells (661W cells) for 24 h. The proliferation rate of 661W cells in each group was measured by methyl thiazolyl tetrazolium (MTT) colorimetric assay; the apoptosis rate of 661W cells in each group was measured by flow cytometry and terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL). An independent sample t-test was used for comparison between groups. Results:Western blot assay showed that the relative expression of iNOS and CD86 protein was increased and the relative expression of Arg-1 and CD206 protein was decreased in BV2 cells in the high glucose group compared with the control group, and the differences were all statistically significant ( t=-16.783, -11.605, 4.325, 4.649; P<0.05); compared with the high glucose group, the relative expression of iNOS and CD86 protein was decreased and the relative expression of Arg-1 and CD206 protein was increased in BV2 cells in the metformin + high glucose group compared with the high glucose group, and the differences were all statistically significant ( t=7.231, 5.560, -8.035, -8.824; P<0.01). ELISA results showed that compared with the control group, the BV2 cells in the high glucose group had increased IL-6, TNF-α content and IL-4 content was decreased in BV2 cells in the high glucose group compared with the control group, and the differences were all statistically significant ( t=-64.312, -127.147, 71.547; P<0.001); compared with the high glucose group, IL-6 and TNF-α content was significantly decreased and IL-4 content was significantly increased in BV2 cells in the metformin+high glucose group, and the differences were all statistically significant ( t=44.426, 83.232,-143.115; P<0.001). After co-culture of BV2 cells with 661W cells for 24 h, the results of MTT colorimetric assay showed that compared with the control group, the activity of 661W cells in the high glucose group was significantly reduced, and the difference was statistically significant ( t=7.456, P<0.01); compared with the high glucose group, the activity of 661W cells in the metformin+high glucose group was increased ( t=-3.076, P<0.05). TUNEL method and flow cytometry showed that the apoptosis rate of 661W cells in the high glucose group was significantly higher compared with the control group, and the differences were both statistically significant ( t=-22.248, -22.628; P<0.001); compared with the high glucose group, the apoptosis rate of 661W cells in the metformin+high glucose group was significantly decreased, and the difference was statistically significant ( t=11.767, 6.906; P<0.001, 0.01). Conclusion:In the high glucose environment, metformin inhibited the inflammatory response and attenuated the apoptosis of photoreceptor cells by regulating the polarization of microglia toward the M2 type.

Retinal photoreceptor cell damage caused by diabetes through down-regulation of glutathione peroxidase 4 and its mechanism / 中华实验眼科杂志

Objective:To investigate the changes of glutathione peroxidase 4 (GPX4) in retinal photoreceptor cells, and the related mechanism correlated with retinal photoreceptor cell damage.Methods:The posterior segment tissues of 8 age-matched male donors were collected from the Body (Organ) Donation Register and Corneal Receiving Station of Tongji Hospital of Wuhan Red Cross from 2018 to 2021, including 4 non-diabetic donors and 4 diabetic donors.The tissues were divided into diabetes group and control group according to their donors.A total of 14 healthy SPF 8-week-old male C57BL/6 mice were selected and randomly divided into diabetes group and control group by the random number method, with 7 mice in each group.The mice in diabetes group were intraperitoneally injected with streptozotocin at a dose of 50 mg/kg for 5 days, and no intervention was given to mice in control group.Mouse photoreceptor cells 661W were divided into advanced glycation end products (AGEs) group and control group.AGEs group was treated with 100 μg/ml AGEs for 24 hours to simulate diabetic injury, and no intervention was given to control group.The outer segment morphology of retinal photoreceptors in human and mouse retinas was observed by hematoxylin-eosin staining.The expressions of glial fibrillary acidic protein (GFAP), rhodopsin and GPX4 in human and mouse retinas were detected by immunofluorescence staining.The expressions of GFAP, rhodopsin and GPX4 in mouse retina and the expression of GPX4 in 661W cells were determined by Western blot.The activity of 661W cells was detected by cell counting kit-8 (CCK8) method.The concentration of malondialdehyde (MDA) in mouse retina and cells was detected by TBA method.The activity of superoxide dismutase (SOD) in mouse retina and cells was detected by hydroxylamine assay.The use of human tissues was approved by the Ethics Committee of Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (No.TJ-C20230301). The animal experiments were conducted with reference to the Standards Guide for the Care and Use of Laboratory Animals of the National Institutes of Health, and the study protocol was approved by the Experimental Animal Ethics Committee of Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (No.TJH-2016001).Results:Hematoxylin-eosin staining showed that retinal photoreceptor outer segments were deformed or broken in diabetic donors and diabetic mice compared with control groups.GFAP fluorescent signal mainly appeared in the inner retina of human and mice, and the stained cells were spindle or polygonal, which was consistent with the shape of glial cells.The retinal GFAP fluorescent signal of diabetic tissue and mouse groups was stronger than that of respective control groups.Rhodopsin was only expressed in the outer segment layer of photoreceptors with clear boundaries, and GPX4 was expressed in the whole retina with strong signal in the outer segment layer of photoreceptors.The fluorescent signals of rhodopsin and GPX4 in diabetic tissue and mouse groups were weaker than those in respective control groups.The relative expressions of GFAP were significantly higher and the relative expressions of rhodopsin and GPX4 were significantly lower in diabetic tissue and mouse groups than in respective control groups (all at P<0.05). The cell viability of AGEs group was significantly lower than that of control group ( t=13.490, P<0.001). The relative expression of GPX4 protein in AGEs group was 0.42±0.12, which was significantly lower than 1.00±0.04 in control group ( t=9.041, P<0.001). MDA concentration was higher and SOD activity was lower in retinal tissue of diabetic mice and AGEs group than those in respective control groups, and the differences were statistically significant (all at P<0.05). Conclusions:Diabetes can reduce the GPX4 level in retinal photoreceptor cells and cause the imbalance of oxidation-antioxidant system, which may be the mechanism of the damage to retinal photoreceptor cells caused by diabetes.

Inhibitory effect of blue light intervention on lens-induced myopia development in guinea pigs and the mechanism of cone density change / 中华实验眼科杂志

Objective:To observe the effects of blue light intervention on the development of optical defocus-induced myopia in guinea pigs and investigate its underlying mechanisms.Methods:Forty-eight normal-grade two-week-old tricolor guinea pigs were randomly divided into a blue light group and a white light group, with 24 animals in each group.The right eye of guinea pigs was fitted with a -5.00 D lens to establish an optical defocus model as the experimental eye, while the left eye served as the control without any covering.Before the experiment and after 8-week intervention, the refractive power of guinea pigs was measured by streak retinoscopy.The anterior chamber depth, lens thickness, and axial length were measured by A-scan ultrasonography.Corneal curvature radius was determined using a keratometer.After 8-week intervention, the guinea pigs were euthanized through overanesthesia, and the right eyeballs were enucleated and the retinas were isolated.The density of S and M cone cells of the guinea pig retinal sections were observed via immunofluorescence staining.The expression of retinal retinoic acid was assessed by high-performance liquid chromatography.The expressions of retinoic acid receptor (RAR-β) in the retina and matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2), and type Ⅰ collagen in the sclera were detected by real-time fluorescence quantitative PCR.Changes in scleral thickness were observed through hematoxylin-eosin staining.The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.The study protocol was approved by the Ethics Committee of Eye and ENT Hospital of Fudan University (No.2022ETKLD10032).Results:After 8 weeks of intervention, guinea pigs in the blue light group showed (0.63±0.12)D of relative hyperopia and a deceleration of axial elongation by (0.08±0.00)mm compared with the white light group in the right eye.In the left eye, guinea pigs in the blue light group showed (0.42±0.09)D of relative hyperopia and a deceleration of axial elongation by (0.08±0.00)mm compared with the white light group.The guinea pigs in blue light group showed (1.52±0.09)D of myopia in the right eye compared with the left eye, with an increase in axial elongation of (0.06±0.00)mm.The guinea pigs in white light group showed (1.66±0.07)D of myopia in the right eye compared with the left eye, with an increase in axial elongation of (0.13±0.00)mm, and the differences were statistically significant (all at P<0.05). The density of M cone cells was lower and density of S cone cells was higher in the blue light group in the dorsal and ventral sides of the retinal sections compared with the white light group, showing statistically significant differences ( t=32.33, 52.23, 42.09, 25.02; all at P<0.05). The deceleration of myopia progression in the blue light group was strongly positively correlated with the increase in S cone cell density on the ventral side ( r=0.95, P<0.01). The expression levels of retinoic acid, RAR-β, and MMP-2 were decreased, and expression levels of TIMP-2 and type Ⅰ collagen were increased in blue light group compared with the white light group, showing statistically significant differences ( t=18.73, 7.45, 3.72, 6.19, 9.03; all at P<0.05). The scleral thickness in the blue light group was (125.0±7.8)μm, which was significantly thicker than (102.0±6.3)μm in the white light group ( t=26.93, P<0.05). Conclusions:Blue light intervention can inhibit the progression of defocus-induced myopia in guinea pigs.Refractive power changes in guinea pigs may be influenced by alterations in retinal cone cell density, retinoic acid expression, and scleral collagen expression.

Conception and features of bacillary layer detachment / 中华实验眼科杂志

The separation of outer retinal photoreceptors in patients with toxoplasmosis chorioretinitis was first named bacillary layer detachment (BALAD), which was manifested as a split at the level of the photoreceptor inner segment myoid creating a distinctive intraretinal cavity in optical coherence tomography.Subsequently BALAD has been reported by many researchers in different diseases.In the outer retina, the myoid is a relatively weak structure in photoreceptor inner segment.When the outward force that promotes the attachment of the photoreceptor outer segment to the retinal pigment epithelium exceeds the tensile strength of the photoreceptor inner segment myoid, the myoid zone splits and BALAD occurs.BALAD has its unique multimodal imaging characteristics, and the identification of it can provide a new idea for the diagnosis, detection and treatment of ocular diseases.This paper reviewed the development of BALAD nomenclature, its anatomical structure, pathophysiological mechanism and multimodal image features.

Photoreceptor cell replacement therapy for retinal degeneration diseases / 中国组织工程研究

BACKGROUND: There is no effective treatment for retinal degenerative diseases, among which the loss of photoreceptor cells, dysfunction and loss of photoreceptor cells are the main causes of retinal degenerative diseases. Photoreceptor cell transplantation as a promising cell replacement therapy is the main research direction today. OBJECTIVE: To review the progress of photoreceptor cell replacement in the treatment of retinal degeneration. METHODS: PubMed, CNKI and Wanfang databases were searched. The Chinese keywords were “photoreceptor cells, retina, transplantation” and the English keywords were “photoreceptors, retina, transplantation”. After preliminary screening by reading the titles and abstracts, the articles with low relevance to the subject were excluded, and a total of 62 articles were finally included for review. RESULTS AND CONCLUSION: The transplantation of exogenous cells into the retinal degeneration environment to replace the photoreceptors lost in advanced retinal degeneration has shown great advantages and provided a new therapeutic strategy for the diseases of retinal degeneration. However, standardized cell screening protocols for clinical use are still not perfect, which is an important challenge for future research.

Relationship between irradiation time of riboflavin-ultraviolet A scleral collagen cross-linking and retinal injury / 中华实验眼科杂志

Objective:To investigate the effects of riboflavin-ultraviolet A scleral collagen cross-linking on the retina under different irradiation time, and to determine the safe irradiation time.Methods:Sixty healthy New Zealand white rabbits were randomly divided into control group (0 minute group), 10 minutes group, 20 minutes group, 30 minutes group and 40 minutes irradiation group according to the irradiation time, with 12 rabbits in each group.The left eye was irradiated with riboflavin-ultraviolet A scleral collagen (370 nm, 10 mW/cm 2). The histopathological change of retina was observed by light microscope and transmission electron microscope and compared among different groups.The concentration of MDA and the activities of SOD, CAT and GSH-Px in retinal tissue were detected by corresponding kits.The expression levels of SOD and CAT proteins in retinal tissue were detected by Western blot method.The study protocol was approved by the Binzhou Medical University Laboratory Animal Ethical Committee (No.2017-80). The use and care of animals complied with the statement of ARVO and the Regulation on the Management of Laboratory Animal Quality of China. Results:Under the light microscope, the structure of the retinas in the control group was orderly arranged.Under the transmission electron microscope, the lamellar structure in the inner segment and the mitochondrial structure in the outer segment of the photoreceptor cells were intact, and the mitochondrial ridge was continuous in the control group.There was no obvious difference in retinal morphology between the 10 minutes irradiation group and the control group under both the light microscope and the transmission electron microscope, and the retinal damage became more severe with the prolongation of irradiation time.The concentration of MDA in the retina of each group was elevated gradually with the increase of irradiation time, and the difference was statistically significant ( F=65.25, P<0.05). The concentration of MDA was (11.31±1.84), (14.94±1.04)and (18.25±1.42)nmol/mgprot in the 20 minutes, 30 minutes and 40 minutes irradiation groups respectively, which were significantly higher than (1.13±0.02)nmol/mgprot in the control group (all at P<0.05). The MDA concentration in 20 minutes, 30 minutes and 40 minutes irradiation groups was increased successively, showing statistically significant differences (all at P<0.05). With the prolongation of irradiation time, the activities of SOD, CAT and GSH-Px as well as the expression levels of SOD and CAT proteins were significantly decreased gradually ( F=44.09, 34.18, 35.60, 115.75, 78.86; all at P<0.05). The differences between the control group and 20 minutes, 30 minutes, 40 minutes irradiation groups, and the differences among 20 minutes, 30 minutes, 40 minutes irradiation groups were statistically significant (all at P<0.05). Conclusions:Riboflavin-ultraviolet A 10 mW/cm 2 scleral collagen cross-linking irradiation for 10 minutes is safe.Excessive irradiation time can cause damage to the retina of rabits.

Mechanism and protection of retina injured by blue light / 国际眼科杂志(Guoji Yanke Zazhi)

@#Blue light is an important part of natural light.The wavelength is mainly between 400nm and 500nm, which is a kind of short-wavelength light and a part of the high-energy visible spectrum. The damage of blue light refers to the photochemical action caused by radiation of this wavelength, resulting in damage to the retina. In the visible light, blue light has the highest sensitivity to the retina and the strongest penetrating power, so the photochemical damage is the strongest. The primary harm is to damage retinal pigment epithelium(RPE)and retinal photoreceptor cells. The research on the protection against the damage of blue light has been gradually carried out. In this paper, the research progress of its protective mechanism is discussed based on the currently study.

Tribulus terrestris L protects the photoreceptors against light-induced degeneration in part through suppression of retinal inflammation and oxidative stress / 眼科新进展

Objective To investigate the protective effects of tribulus terrestris L (TTL) against light-induced photoreceptor degeneration and its underlying mechanisms.Methods BALB/c mice were randomly divided into normal control group,light exposure group and TTL administration group,with 12 mice in each group,and then exposed to light at the intensity of 10,000 lux for 30 min for the establishment of a retinal damage model of BALB/C mice.And 100 μL TTL decoction was intraperitoneally administered into mice of TTL administration group 30 min prior to illumination.Saline vehicle was administrated into the mice of normal control group and light exposure group.Next,intraperitoneal injection of dihydroethidium (DHE) was performed 22 h after illumination,and the eyes were enucleated 2 h later and subjected to cryosectioning for microscopic detection of the in situ retinal oxidative stress.Then,retinas were dissected 6 and 24 h after illumination,which was followed by total RNA extraction,reverse transcription and RT-PCR to assess the expression level of proinflammatory cytokines.Meanwhile,the expression levels of interleukin-β (IL-1 β),chemokine (Ccl2),cyclooxygenase-2 (COX-2),tumor necrosis factor-α (TNF-α),cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) mRNA were determined.Results Prominent oxidative stress was observed in retinal pigment epithelial cells and photoreceptor cells in the light exposure group when compared with the normal control group and TTL administration group,with significant difference (both P ＜ 0.001).Moreover,results of RT-PCR revealed that the expression of IL-1β,Ccl2,COX-2,TNF-α,ICAM-1 and VCAM-1 mRNA was significantly elevated as a result of light exposure compared to those from vehicle-treated normal controls with a significant difference (all P ＜ 0.01).TTL treatment resulted in significantly decreased expression of IL-1β,Ccl2,COX-2,TNF-α,ICAM-1 and VCAM-1 mRNA compared to those from light-exposed vehicle-treated controls with significant differences (all P ＜0.01).Conclusion In the retinal degeneration model,TTL protects the photoreceptor cells against fight-induced degeneration in part through suppressing light-induced retinal oxidative stress and inflammatory responses.

Structure-functional correlation using adaptive optics, OCT, and microperimetry in a case of occult macular dystrophy / Correlação de estrutura e função da retina utilizando óptica adaptativa, OCT e microperimetria em um caso de distrofia macular oculta

ABSTRACT We report retinal functional and structural changes of a 40-year-old man diagnosed with occult macular dystrophy. Comprehensive ophthalmological evaluation was performed, followed by spectral-domain optical coherence tomography (SD-OC - Heidelberg) and image acquisition using an adaptive optics (AO) camera (RTX1, Imagine Eyes) for photoreceptor density analysis. Functional tests included full-field ERG (ERG) and multifocal electroretinography (mfERG) (Diagnosys, LLC) and microperimetry with scanning laser ophthalmoscope (SLO) fixation controlled (MAIA, CenterVUE). OCT revealed a line of discontinuity corresponding to cone outer-segment photoreceptors associated with a loss of cone density, highlighted by a dark blue spot on the AO co ne-density map on the fovea in both eyes. Loss of central sensitivity was revealed using microperimetry; ERG was within the normal range, although the mfERG showed a reduced central response amplitude.

RESUMO Relatamos exames de função e estrutura retiniana de paciente masculino, de 40 anos, com diagnóstico clínico de Distrofia Macular Oculta (DMO). Avaliação oftalmológica completa foi seguida por tomografia de Coerência Óptica (SD-OCT - Heidelberg) e exame com câmara de fundo de olho com tecnologia "Adaptive Optics" (AO - RTX1, Imagine Eyes) para análise da densidade de fotorreceptores. Os exames funcionais incluíram: Eletroretinografia de campo total (ERG) e multifocal (mfERG) (Diagnosys - LLC) e microperimetria com controle de fixação (MAIA - CenterVUE). Os exames revelam descontinuidade da camada de fotorreceptores na região central da fóvea em ambos os olhos pelo SD-OCT em associação com perda de densidade no mosaico cones, representado por mancha azulada no mapa do AO. Os exames de função apresentam diminuição da acuidade visual (20/80; 20/50), redução de sensibilidade central na microperimetria. Como esperado, o ERG está dentro da normalidade, mas há redução da amplitude das respostas centrais do mfERG em ambos os olhos.

The effects of Crumbs proteins on zebrafish photoreceptors / 中华眼底病杂志

Objective To observe the effects of Crumbs (Crb) proteins on different types ofzebrafish photoreceptors.Methods The retinal cell population dynamics of adult wild-type zebrafish and Tg (RH22:Crb2b-sfEX/RH2-2:GFP)pt108b transgenic zebrafish (called pt108b zebrafish for short) were evaluated by monitoring the densities of three categories of retinal photoreceptors (rod cells,UV cone cells and RGB cone cells) in different retinal regions,which were visualized by Feulgen nuclear staining histology technique.Results The wild-type zebrafish retinal photoreceptor cell densities are generally higher in the central region than the peripheral regions.Compared with wild-type zebrafish,pt108b zebrafish had much less RGB cone cells at the top of outer nuclear layer,and no RGB cone ceils at the central and intermediate regions of retina.While pt108b zebrafish had normal density of UV cone cells at the top of rods and the bottom of outer limiting membrane,they had much higher density of rods.Conclusions Crb proteins may affect the zebrafish retinal cell densities of different photoreceptor types.

Cyclic nucleotide-gated channels and retinal cone photoreceptor cells function / 中华实验眼科杂志

Cyclic nucleotide-gated (CNG) channels are ion channels which are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP),they play a central role in the signal transduction pathways of vision and olfaction.Six different genes encode CNG protein,containing four A subunits (A1-A4) and two B subunits (B1 and B3).CNGA3 and CNGB3 have been found to be implicated in achromatopsia-associated mutations.Recently,a huge amount of researches showed the good responses to gene therapy in achromatopsia animal models.This article briefly reviewed the physiological roles of CNG channel in retinal cone photoreceptor cells and the recent research achievements of gene therapy in CNG channel-deficient mouse models with achromatopsia.

The effects of FTY720 on retinal photoreceptor cells and microglial following light-induced degeneration in rat retina / 中华眼底病杂志

Objective To investigate the effects of FTY720 on retinal photoreceptor cells and microglial following light-induced degeneration in rat retina.Methods 120 Sprague-Dawley rats were randomly divided into four groups including FTY720 group,solvent control group,model group and normal group.The rats of normal group were not intervened.The FTY720 group,solvent control group and model group establish retinal light injury mode.FTY720 was injected into abdominal cavity of the rats in FTY720 group 0.5 hours before light exposure.50％ dimethylsulfoxide was injected into abdominal cavity of the rats in solvent control group.The expressions of microglial cells in rat retinal were quantified using flow cytometry,the expressions of interleukin (IL)-1β were examined by enzyme-linked immuno sorbent assay at 6 hours,1 day,3 days,7 days after light exposure.The apoptosis of retinal photoreceptor cells were measured by terminal-deoxynucleoitidyl transferase mediated nick end labeling at 1 day after light exposure.The morphological change of retinal were viewed by haematoxylin and eosin staining at 7 days after light exposure.Results The expressions of microgilal and IL-1β began to rise at 1 day after light exposure,reached at peak at 3 days and decreased at 7 days.The expressions of IL-1βand microglial in FTY720 group were significantly lower than solvent control group and model group,but higher than normal group (P＜0.05).One day after exposure to light,the apoptosis cell ratio in normal group,model group,solvent control group and FTY720 group were 0,(87.66 ± 2.50) ％,(86.00 ± 2.44) ％,(49.66 ± 2.80) ％.The apoptosis cell in FTY720 group were higher than normal group,lower than solvent control group and model group (P＜0.05).Seven days after exposure to light,the retinal in normal group was structured and the cell was arranged well,the cell in solvent control group and model group was irregular arrangement and the outer nuclear layer (ONL) was thin after light exposure.The thickness of the ONL in FTY720 group was significantly higher than solvent control group and model group,below normal group.Conclusion FTY720 can prevents retinal photoreceptor cells from apoptosis and inhibits activation of microglial.

An association between subclinical familial exudative vitreoretinopathy and rod-cone dystrophy / Associação entre vitreorretinopatia exsudativa familiar subclínica e distrofia de cones e bastonetes

A 21-year-old Caucasian man presented with a complaint of nyctalopia. Visual acuity in both eyes was 20/20 and anterior segment biomicroscopy results were unremarkable. Fundoscopy revealed peripheral avascular zones, minimal peripheral retinal exudation from the retinal vessels, peripheral retinal telangiectasias and anastomosis in both eyes, and retinal vascular dragging toward the temporal periphery in both eyes. Full field electroretinography showed that rod responses were almost absent and that cone responses were reduced. Macular optical coherence tomography showed normal structure in both eyes. Vascular changes were attributed to a subclinical form of familial exudative vitreoretinopathy. This was an interesting case due to the association of familial exudative vitreoretinopathy with rod-cone dystrophy.

Um homem caucasiano de 21 anos foi avaliado com queixa de nictalopia. A acuidade visual era 20/20 em ambos os olhos. Biomicroscopia do segmento anterior era normal. A fundoscopia revelava zonas avasculares periféricas, exsudação mínima dos vasos retinianos periféricos da retina, telangiectasias da retina periférica com anastomoses em ambos os olhos e deslocamento vascular da retina em direção a periferia temporal em ambos os olhos. O eletrorretinograma (ERG) de campo total apresentava respostas de bastonetes praticamente indetectáveis e redução das respostas de cones. A tomografia de coerência óptica (OCT) macular mostrava estrutura normal em AO. As alterações vasculares foram atribuídas à forma subclínica da vitreorretinopatia exsudativa familiar. Este é um caso interessante com a associação de vitreoretinopatia exsudativa familiar e distrofia de cones e bastonetes (RCD).

Morphologic Characteristics of the Outer Retina in Cone Dystrophy on Spectral-domain Optical Coherence Tomography

PURPOSE: To investigate the morphologic changes in the outer retina of patients with cone dystrophy, using spectral-domain optical coherence tomography (SD-OCT). METHODS: The medical records of 15 cone dystrophy patients examined from January 2007 to January 2012 were reviewed retrospectively. All patients underwent ophthalmic evaluation including best-corrected visual acuity (BCVA), color vision testing, fundus examination, full-field standard electroretinography (ERG), multifocal (mf) ERG, and SD-OCT. Qualitative and quantitative SD-OCT data and ERG responses were analyzed and compared among the patient categories and the normal control group. RESULTS: There were 4 major categories of SD-OCT findings, based on the status of the ellipsoid portion of the photoreceptor inner segment (ISe), outer segment (OS) contact cylinder, and retinal pigment epithelium (RPE) layer. Category 0 showed no structural abnormalities. Category 1 showed foveal ISe loss and obscurity of the border between the ISe band and the external limiting membrane (ELM). Category 2 showed foveal thinning and focal foveal ISe disruption with an intact ELM. Category 3 showed foveal thickening and perifoveal disruption of the ISe layer. Category 1 to 3 showed OS contact cylinder layer absence and RPE thickening. The patients in category 0 tended to be younger (mean, 10.0 years) than those in categories 1 to 3 (mean, 17.6 years), although this difference was not statistically significant. Category 1 to 3 patients exhibited statistically significant thinning of the central retina and outer nuclear layer and thickening of the RPE layer relative to the category 0 and normal control group. There was a significant correlation between the central foveal thickness and BCVA in the patients with cone dystrophy. ERG and mfERG responses did not differ significantly among the different cone dystrophy categories. CONCLUSIONS: The morphologic features of cone dystrophy as revealed by SD-OCT, could be categorized as either normal or 1 of 3 different types of outer retinal changes. The presence of normal retinal structures in young cone dystrophy patients with functional impairment (category 0) indicates that electrophysiologic studies are superior to current imaging modalities for the early diagnosis of cone dystrophy. The characteristic SD-OCT findings in cone dystrophy patients may aid in differential diagnosis and be useful for future research on the pathology of cone dystrophy.

Damage of photoreceptor cells by N-methyl-N-nitrosourea in cats / 中华实验眼科杂志

Background To establish the ideal animal model of retinitis pigmentosa (RP) is very important for onward relevant study.Previous research determined that N-methyl-N-nitrosourea (MNU) can selectively damage photoreceptors via intravenous injection in mammal.However,whether MNU can be used to create an RP model needs to be investigated.Objective This experiment was designed to evaluate the toxic effect of MNU on photoreceptor cells of cats.Methods MNU was injected into 20 2-year-old cats via femoral vein and randomized into 20mg/kg, 25mg/kg, 30mg/kg, 35mg/kg and 40mg/kg MNU groups,and equal amount of normal saline solution was used in the same way in 4 normal cats as the control group.The activity,pupil size and light reflex were observed after injection of MNU.The cats were sacrificed and eyeballs were enucleated for histological examination to evaluate the structural and morphological changes of photoreceptors at 24 hours,72 hours,7 days and 14 days after the administration of MNU.This experimental study complied with the Statement for the Use of Animals in Ophthalmic and Vision Research.Results Dilated pupil and inertia of light reaction were found in experimental cats on the 7th days in the various groups.In 24 hours after MNU injection,the damage of photoreceptors was primarily characterized by pyknosis and disorder.In 72 hours after MNU injection,attenuation of the outer nuclear layer and disruption of cells were seen.Loss of photoreceptors and disappearance of the outer nuclear layer were observed on the 7th and 14th day.The extent of retinal photoreceptor cell damage was dependent on the dose of MNU.Conclusion MNU can selectively induce serious damage of the photoreceptor cells in cats retina in a time- and dose-dependent manner.

Photoreceptor Disruption Related to Persistent Submacular Fluid after Successful Scleral Buckle Surgery

PURPOSE: To investigate serial changes in photoreceptor status and associated visual outcome in patients with persistent submacular fluid after successful scleral buckle surgery for macula-off rhegmatogenous retinal detachment. METHODS: This was a prospective observational case series including 76 consecutive patients who underwent successful scleral buckle surgery for macula-off rhegmatogenous retinal detachment with symptom duration < or =90 days at a single tertiary hospital. Optical coherence tomography (OCT) and visual acuity examination were performed at one month and three months postoperatively and at three-month intervals until the submacular fluid disappeared. Main outcome measures were postoperative photoreceptor status on OCT and visual acuity. RESULTS: Forty-two patients (55.3%) showed persistent submacular fluid at postoperative one month. Of 42 patients with persistent submacular fluid, three (7.1%) showed photoreceptor disruption on OCT. None of the 34 patients without persistent submacular fluid showed photoreceptor disruption. Two patients (4.8%) had progressive photoreceptor disruption, and one patient (2.4%) had early photoreceptor disruption. All three patients showed photoreceptor reappearance and limited visual restoration after absorption of submacular fluid. Final visual acuities were significantly worse in these three patients (20 / 1000, 20 / 133, and 20 / 133) compared to those of the other patients (mean, 20 / 30) with persistent submacular fluid and intact photoreceptors. CONCLUSIONS: Even after successful scleral buckle surgery for rhegmatogenous retinal detachment, photoreceptor disruption can occur related to persistent submacular fluid and may be a cause of poor visual outcome.