Inhibition of NF-κB ameliorates aberrant retinal glia activation and inflammatory responses in streptozotocin-induced diabetic rats.

Background: To determine the anti-inflammatory effects of IMD-0354, a specific NF-κB blocker, on glial cells in rats with streptozotocin (STZ)-induced diabetic retinopathy (DR). Methods: The following four groups of rats were used: control, control + IMD-0354, STZ, and STZ + IMD-0354. After six weeks of STZ injection, diabetic rats and nondiabetic control rats received IMD-0354 (30 mg/kg) or an equal volume of 4% dimethyl sulfoxide (DMSO) in phosphate-buffered saline intraperitoneally for six consecutive weeks. The following four groups of primary rat retinal microglia and Müller cells were used: control (5 mM), control + IMD-0354, high glucose (20 mM), and high glucose + IMD-0354. The effects of IMD-0354 on nuclear factor-κB (NF-κB) activation, oxidative stress strength, expression of inflammatory cytokines and VEGF (vascular endothelial growth factor), activation of glial cells, and apoptosis of neuron cells were evaluated by immunohistochemistry, oxidative stress assays, western blot, enzyme linked immunosorbent assay (ELISA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining respectively. Results: Nuclear translocation of NF-κB was markedly increased in diabetic rat retina and high glucose treated glial cells. Systemic administration of IMD-0354 significantly inhibited NF-κB activation in both diabetic rat retina and high glucose treated glial cells, ameliorated oxidative injury, inflammatory responses, VEGF production and glial cell activation, and protected neurons from apoptosis. Conclusions: Our findings indicated that NF-κB activation is acritical step in the abnormal reactivity of glial cells in STZ-induced diabetic rats. Inhibition effect of IMD-0354 on NF-κB activation may represent a promising therapeutic strategy for DR via a variety of mechanisms, including inflammation reduction and glial cells regulation.

Case report: Sympathetic ophthalmia after vitrectomies in a patient with Von Hippel-Lindau syndrome.

Background: Sympathetic ophthalmia (SO) is a rare but sight-threatening uveitis, and most observations have been made after typical manifestations occur. This report focuses on the choroidal changes detected by multimodal imaging at the presymptomatic stage of SO, which is implicated in the early recognition of SO. Case presentation: A 21-year-old woman suffered from decreased vision in the right eye and was diagnosed with retinal capillary hemangioblastomas associated with Von Hippel-Lindau syndrome. The patient underwent two 23-G pars plana vitrectomies (PPVs), soon after which typical signs of SO manifested. SO resolved quickly after the oral administration of prednisone and remained stable during the follow-up of more than 1 year. The retrospective analysis revealed preexisting bilaterally increased choroidal thickness, dots of flow void on the choroid, and choriocapillaris en-face slabs in optical coherence tomography angiography (OCTA) after the first PPV, which were all reversed by corticosteroid treatment. Conclusion: The case report highlights the involvement of the choroid and choriocapillaris at the presymptomatic stage of SO after the first inciting event. Abnormally thickened choroid and flow void dots suggested that SO had started and an ensuing surgery would run the risk of exacerbating SO. OCTA scanning of both eyes should be ordered routinely for patients with a history of trauma or intraocular surgeries, especially before the next surgical intervention. The report also suggests that non-human leukocyte antigen gene variation may also regulate the progression of SO, which requires further laboratory investigations.

SHP-1 knockdown suppresses mitochondrial biogenesis and aggravates mitochondria-dependent apoptosis induced by all trans retinal through the STING/AMPK pathways.

BACKGROUND: Oxidative stress-caused damage to the retinal pigment epithelium (RPE) underlies the onset and progression of age-related macular degeneration (AMD). Impaired mitochondrial biogenesis sensitizes RPE cells to mitochondrial dysfunction, energy insufficiency and death. Src-homology 2 domain-containing phosphatase (SHP)-1 is important in regulating immune responses and cell survival. However, its roles in cell survival are not always consistent. Until now, the effects of SHP-1 on RPE dysfunction, especially mitochondrial homeostasis, remain to be elucidated. We sought to clarify the effects of SHP-1 in RPE cells in response to atRAL-induced oxidative stress and determine the regulatory mechanisms involved. METHODS: In the all trans retinal (atRAL)-induced oxidative stress model, we used the vector of lentivirus to knockdown the expression of SHP-1 in ARPE-19 cells. CCK-8 assay, Annexin V/PI staining and JC-1 staining were utilized to determine the cell viability, cell apoptosis and mitochondrial membrane potential. We also used immunoprecipitation to examine the ubiquitination modification of stimulator of interferon genes (STING) and its interaction with SHP-1. The expression levels of mitochondrial marker, proteins related to mitochondrial biogenesis, and signaling molecules involved were examined by western blotting analysis. RESULTS: We found that SHP-1 knockdown predisposed RPE cells to apoptosis, aggravated mitochondrial damage, and repressed mitochondrial biogenesis after treatment with atRAL. Immunofluoresent staining and immunoprecipitation analysis confirmed that SHP-1 interacted with the endoplasmic reticulum-resident STING and suppressed K63-linked ubiquitination and activation of STING. Inhibition of STING with the specific antagonist H151 attenuated the effects of SHP-1 knockdown on mitochondrial biogenesis and oxidative damage. The adenosine monophosphate-activated protein kinase (AMPK) pathway acted as the crucial downstream target of STING and was involved in the regulatory processes. CONCLUSIONS: These findings suggest that SHP-1 knockdown potentiates STING overactivation and represses mitochondrial biogenesis and cell survival, at least in part by blocking the AMPK pathway in RPE cells. Therefore, restoring mitochondrial health by regulating SHP-1 in RPE cells may be a potential therapeutic strategy for degenerative retinal diseases including AMD.

Increased expression of TSPO-VDAC complex is correlated with NLRP3 inflammasome activation in diabetic retinopathy.

The present study aimed to investigate the level of translocator protein (TSPO) and its correlation with different inflammatory cytokines in diabetic retinopathy (DR) patients. Peripheral blood samples were obtained from 54 DR patients and 22 age-related cataract (ARC) patients. The mRNA expression of TSPO, voltage-dependent anion channel (VDAC), apoptosis-associated speck like protein with a caspase recruitment domain (ASC), NOD-like receptors pyrin domain-containing 3 (NLRP3) and caspase-1 were examined by reverse transcription-quantitative PCR. Interleukin-1ß and interleukin-18 levels were detected by enzyme-linked immunosorbent assay. The mRNA levels of TSPO, VDAC, ASC, NLRP3 and capase-1, the protein levels of IL-ß and IL-18 were all significantly higher in the DR group compared with those in the ARC group. The expression levels of those aforementioned cytokines/proteins were more significantly higher in the subgroup of active proliferative DR (PDR) compared with those in the inactive PDR group (P<0.05). Significant positive correlations between TSPO/VDAC complex and ASC, NLRP3, capase-1, IL-ß and IL-18 were found in DR patients. These outcomes suggested that TSPO/VDAC complex and NLRP3 inflammasomes may play an important role in the development and progression of DR.

Ocular Manifestations in a Chinese Pedigree of Familial Amyloidotic Polyneuropathy Carrying the Transthyretin Mutation c.401A>G (p.Tyr134Cys)

Familial amyloid polyneuropathy (FAP) caused by a genetic mutation in transthyretin (TTR) is an autosomal dominant hereditary disease. The retrospective, observational case series study presents the ocular clinicopathological findings of five cases carrying the TTR mutation c.401A>G (p.Tyr134Cys). Multimodal retinal imaging and electrophysiological examination, Congo red staining and immunohistochemical analysis of specimens, and genetic analyses were performed. Cases 1 and 2 were symptomatic with vitreous and retinal amyloid deposition and poor visual recovery. Case 3 had a symptomatic vitreous haze in the left eye with good postoperative visual recovery. The right eye of case 3 and the eyes of cases 4 and 5 were asymptomatic. Thicker retinal nerve fiber layer, retinal venous tortuosity with prolonged arteriovenous passage time on fluorescein angiography and retinal dysfunction detected by multifocal electroretinogram occurred even in asymptomatic eyes. Moreover, the internal limiting membrane from patients with FAP was stained positive for Congo red and transforming growth factor-ß1. The results highlight the amyloid deposition of mutant TTR in the optic disc and retina, even in the asymptomatic stage. The deposited amyloid leads to increased resistance to venous return and retinal functional abnormalities. Therefore, careful follow-up of structural and functional changes in the retina is needed, even in asymptomatic patients with FAP.

Pediatric open globe injury in left-behind children treated by pars plana vitrectomy in China.

BACKGROUND: To analyze the clinical features of pediatric open globe injury (OGI) in left-behind children (LBC) and in non-left-behind children (non-LBC) prospectively. METHODS: Patients diagnosed with OGI were included and divided into 2 groups: LBC and non-LBC. A complete ophthalmological examination was performed. Primary wound repair was completed within 8 hours from initial administration. Pars plana vitrectomy (PPV) was subsequently performed for retained intraocular foreign body (IOFB), endophthalmitis, retinal detachment, or non-clearing vitreous hemorrhage. RESULTS: A total of 96 patients (4 to 15 years old) were recruited, including 54 LBC and 42 non-LBC. Rupture of the eyeball (P<0.001), endophthalmitis (P<0.001), primary hospitalization time (PHT) over 24 hours (PHT >24 h) (P=0.016), traumatic cataract (P=0.013), vitreous hemorrhage (P=0.040), numbers of surgeries (P<0.001), and lower OTS scores and grades (P<0.001) predisposed patients to poorer final visual acuity (VA). Compared with non-LBC, LBC were significantly younger (P<0.001), had lower OTS scores (P=0.020), had longer PHT (P<0.001), and worse baseline (P=0.011) and final VA (P<0.001). The 3 most common injury sources were pencils (20 cases, 20.8%), knives (11 cases, 11.5%), and iron wire (7 cases, 7.3%). Pencils were the major injury source for IOFB (14 cases, 53.8%). LBC were significantly more likely to be injured by instruments which should be routinely kept away from children (P=0.009). CONCLUSIONS: The prognosis of pediatric OGI was worse in LBC than in non-LBC. It is necessary to improve the guardianship of LBC. Many tragedies may be avoided if adult instruments are properly stored and if children are educated to properly use writing devices.

All-Trans Retinoic Acid Attenuates Blue Light-Induced Apoptosis of Retinal Photoreceptors by Upregulating MKP-1 Expression.

The study investigated the antiapoptotic effects of all-trans retinoic acid (RA) on retinal degeneration caused by exposure to blue light. Sprague-Dawley rats received intraperitoneal injections of RA and, if necessary, the mitogen-activated protein kinase phosphotase-1(MKP-1) inhibitor, (E)-2-benzylidene-3-(cyclohexylamino)-2, 3-dihydro-1H-inden-1-one (BCI), or the retinoic acid receptor (RAR) antagonist, AGN 193109. Retinal damage was induced by 24 h of continuous exposure to blue light. Haematoxylin and eosin staining and electroretinography were performed to measure retinal thickness and retinal function before and at 3 days and 7 days after light exposure. The retinal protein expression levels of phosphorylated c-Jun N-terminal kinase (JNK), phosphorylated nuclear factor-κB, MKP-1, Bim, Bax, and cleaved caspase-3 were also measured. Terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) staining and immunofluorescent staining of cleaved caspase-3 were also performed to evaluate photoreceptor apoptosis. The administration of RA significantly mitigated retinal dysfunction and the decrease in the outer nuclear layer (ONL) thickness at 3 days and 7 days after light exposure. RA also reduced the percentage of TUNEL-positive nuclei in the ONL and cleaved caspase-3 immunofluorescence intensity at 3 days after light exposure. Light exposure increased the retinal expression of proapoptotic proteins (Bim, Bax, and cleaved caspase-3), which was attenuated by RA. Moreover, RA enhanced the expression of MKP-1 and inhibited the phosphorylation of JNK, which were attenuated by the inhibition of RAR. The inhibitory effects of RA on blue light-induced photoreceptor apoptosis were abrogated by the MKP-1inhibitor. Our results indicate that RA alleviates photoreceptor loss following blue light exposure, at least partly, by the MKP-1/JNK pathway, which may serve as a therapeutic target for relieving retinal degeneration.

SHP-1 suppresses endotoxin-induced uveitis by inhibiting the TAK1/JNK pathway.

We investigated how Src-homology 2-domain phosphatase-1 (SHP-1) regulates the inflammatory response in endotoxin-induced uveitis (EIU), and the signalling pathways involved. One week after intravitreal injection of short hairpin RNA targeting SHP-1 or SHP-1 overexpression lentivirus in rats, we induced ocular inflammation with an intravitreal injection of lipopolysaccharide (LPS). We then assessed the extent of inflammation and performed full-field electroretinography. The concentrations and retinal expression of various inflammatory mediators were examined with enzyme-linked immunosorbent assays and Western blotting, respectively. SHP-1 overexpression and knockdown were induced in Müller cells to study the role of SHP-1 in the LPS-induced inflammatory response in vitro. Retinal SHP-1 expression was up-regulated by LPS. SHP-1 knockdown exacerbated LPS-induced retinal dysfunction and increased the levels of proinflammatory mediators in the retina, which was abrogated by a c-Jun N-terminal kinase (JNK) inhibitor (SP600125). SHP-1 overexpression had the opposite effects. In Müller cells, the LPS-induced inflammatory response was enhanced by SHP-1 knockdown and suppressed by SHP-1 overexpression. SHP-1 negatively regulated the activation of the transforming growth factor-ß-activated kinase-1 (TAK1)/JNK pathway, but not the nuclear factor-κB pathway. These results indicate that SHP-1 represses EIU, at least in part, by inhibiting the TAK1/JNK pathway and suggest that SHP-1 is a potential therapeutic target for uveitis.

Effects of intravitreal conbercept before panretinal photocoagulation on lipid exudates in diabetic macular documented by optical coherence tomography.

AIM: To evaluate the effects of intravitreal conbercept (IVC) as adjunctive treatments before panretinal photocoagulation (PRP) to decrease hyperreflective dots (HRDs) in Chinese proliferative diabetic retinopathy (PDR) patients. METHODS: Fifty-nine enrolled patients were categorized into 2 groups: single dose IVC (0.5 mg/0.05 mL) 1wk before PRP (Plus group) or PRP only (PRP group). Six months later, we measured the best corrected visual acuity (BCVA), central macula thickness (CMT) by optical coherence tomography and counted the number of HRDs in different retina layers. RESULTS: The average CMT significantly decreased in Plus group but increased in PRP group. The average BCVA in the Plus group was also significantly better than that in the PRP group. Total HRDs decreased in the Plus group but increased in PRP group significantly. IVC pre-treatment has beneficial effects on reducing HRDs forming in the inner retina layer while the PRP alone increased the HRDs in the outer retina layer. CONCLUSION: IVC is a promising adjunctive treatment to PRP in the treatment of PDR. Single dose IVC one week before PRP is suggested to improve retina blood-retina barrier, decrease lipid exudate and inhibit HRDs development in PDR.

Clinical analysis of posterior segment injury in left-behind children in China.

BACKGROUND: We aimed to evaluate the severity and prognosis of posterior segment injury between left-behind children (LBC) and guarded children (NLBC). METHODS: A retrospective, controlled analysis of a case series was performed. Patients diagnosed with posterior segment injury in Department of vitreous and retinal, the Affiliated Ophthalmology and Otolaryngology Hospital of Fudan University were included in this study. Patients were divided into two groups, including LBC group (n = 48) and NLBC group (n = 44). All the children underwent 25G transconjunctival sutureless pars plana vitrectomy. RESULTS: Compared with NLBC, LBC had delayed treatment, worse baseline vision and visual prognosis, lower OTS rating, more times of vitrectomies, more complicated surgical procedures, and higher rate of lens removal and silicone oil tamponade. CONCLUSIONS: Due to lack of care and delayed treatment, posterior segment ocular trauma in the LBC was more severe, more common complicated with infectious endophthalmitis, and had worse visual prognosis. It was urgent to enforce the guardianship in LBC.

Diagnostic Performance of MALDI-TOF MS Compared to Conventional Microbiological Cultures in Patients with Suspected Endophthalmitis.

Purpose: To evaluate the performance and speed of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) when identifying the pathogenic microorganism of endophthalmitis compared to conventional microbiological culturing.Methods: Forty-four patients with suspected endophthalmitis who had undergone vitrectomy were enrolled. Vitreous specimen was analyzed using either conventional culturing or MALDI-TOF MS.Results: The identification rates of the conventional microbiological culture and MALDI-TOF MS were 45.5% (20/44) and 65.9% (29/44), respectively (Kappa value 0.787, P < 0.000). The mean detection times by the standard culturing method and MALDI-TOF MS were 5.39 ± 0.56d and 3.17 ± 0.40d (P < 0.001). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MALDI-TOF MS were 70.59%, 54.17%, 80.00%, and 86.67%, respectively. Polymicrobial endophthalmitis was identified in 6.82% of the patients (3/44) using conventional microbiological culturing. However, MALDI-TOF MS failed to identify any polymicrobial infection.Conclusions: With a higher sensitivity, acceptable specificity and a shorter detection time, MALDI-TOF MS was an efficient technique for the rapid identification of a pathogenic microorganism in endophthalmitis.

Long-term outcomes of patients with myopic traction maculopathy after phacoemulsification for incident cataract.

PURPOSE: To evaluate the long-term effect of cataract surgery on highly myopic patients with myopic traction maculopathy (MTM) and the risk factors associated with MTM progression. METHODS: Highly myopic patients with cataract and MTM were included. Phacoemulsification surgery was performed on patients who had vision loss below 20/63 and were willing to operation. Exclusion criteria included full thickness macular hole, foveal/retinal detachment, history of vitreoretinal surgery, myopic choroidal neovascularization, macular chorioretinal atrophy, peripheral lattice degeneration, incomplete follow up, or intraoperative complications. All patients underwent a complete ophthalmological examination. Optical coherence tomography examinations and microperimetry examinations were performed. RESULTS: A total of 229 patients (mean age: 57 ± 6 years) were recruited, including 179 operated patients and 50 unoperated patients. Both the best corrected visual acuity (BCVA) and macular sensitivity (MS) were significantly improved after cataract surgeries throughout the follow-up period (p = 0.000). No difference was found in the proportion of MTM staging and in the rate of resolving/stable or progressive MTM (p = 0.757) between the operated and the unoperated groups. Of all patients, those with S2 to S4 MTM at baseline had significantly higher risk of progressive MTM (p < 0.001). Patients with absence of posterior vitreous detachment or with longer axial length at baseline had higher risks of progressive MTM. CONCLUSION: Cataract surgery generally improves the BCVA and MS of highly myopic patients with MTM. Preoperative vitreoretinal adhesion, longer axial length, and S2 to S4 MTM are risk factors for progressive MTM. A long-term follow-up on the development of MTM is recommended.

Single-Dose Intravitreal Conbercept before Panretinal Photocoagulation as an Effective Adjunctive Treatment in Chinese Proliferative Diabetic Retinopathy.

PURPOSE: This study evaluates the efficacy and patient satisfaction of intravitreal conbercept (IVC) as adjunctive treatment before panretinal photocoagulation (PRP) for Chinese proliferative diabetic retinopathy (PDR) with or without clinically significant macular edema. METHODS: We enrolled 94 patients and categorized them into 2 groups: eyes that received PRP with single-dose IVC (0.5 mg/0.05 mL) 1 week before PRP (Plus group) or PRP only (PRP group). We measured the central macular thickness (CMT) by optical coherence tomography and best-corrected visual acuity. Satisfaction of PRP after 3 months was evaluated by a satisfaction questionnaire. RESULTS: Single-dose IVC 1 week before PRP significantly increased the PRP completion rate and satisfaction of treatment after 3 months in PDR patients. The average CMT significantly decreased in the Plus group but increased in the PRP group. No average visual changes were detected in the Plus group, but significant average visual loss was detected in the PPR group. The most important factors that determined satisfaction were the PRP completion rate in the short term and better vision gain after PRP. CONCLUSIONS: IVC is a promising adjunctive treatment to PRP in the treatment of PDR. Single-dose IVC 1 week before PRP was suggested to improve PRP completion rate and patient satisfaction in the short term.

RAPID PROGRESSION OF FOVEOMACULAR RETINOSCHISIS IN YOUNG MYOPICS.

PURPOSE: To describe a foveomacular retinoschisis that has not been described. METHODS: Patients with foveomacular retinoschisis were included. Exclusion criteria included refractive error over -6.00 diopters, presence of posterior staphyloma, positive RS1-gene mutation, family history of retinoschisis, optic disk abnormalities, or glaucoma. Vitrectomy was performed on eyes with functional or structural deterioration. RESULTS: Seventeen eyes from 10 patients (15-30 years old, 8 females and 2 males) with foveoschisis were recruited, with bilateral involvement in 7 patients and unilateral in 3 patients. Vitrectomy was performed in 13 eyes (13/17, 76.5%). Seven eyes (6 patients) were operated soon after the first presentation because of poor vision and severe foveoschisis. Six eyes (6 patients) were operated 2 weeks to 13 months later because of deterioration of vision and foveoschisis. Preoperative vision was 20/134 ± 20/165, and postoperative vision was 20/25 ± 20/57, with visual improvement of 6.9 (4-14) lines. The mean postoperative follow-up period was 36.5 (15-69) months. Four eyes (4 patients) were asymptomatic, despite progression of foveoschisis. Three eyes (3 patients) maintained normal macula structures. CONCLUSION: We report a foveomacular retinoschisis characterized by young age of onset, female predominant, no highly myopia, mostly bilateral involvement, and rapid progression of foveoschisis and visual acuity. Vitrectomy is effective in restoring anatomical structure and stabilize vision.

Risk factors for and diagnosis of pseudophakic cystoid macular edema after cataract surgery in diabetic patients.

PURPOSE: To evaluate the risk factors and potential diagnostic criteria for pseudophakic cystoid macular edema (CME) in diabetic patients after phacoemulsification. SETTING: Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China. DESIGN: Prospective nonrandomized study. METHODS: Diabetic patients were followed for up to 6 months after cataract surgery and examined to evaluate their foveal thickness, macular sensitivity, and corrected distance visual acuity. Multiple statistical analyses were performed to determine risk factors and diagnostic criteria for pseudophakic CME. RESULTS: The duration, type of diabetes, stage of diabetic retinopathy, nuclear opalescence grading, glycosylated hemoglobin A1c (HbA1c), and ultrasound time were correlated with the change in foveal thickness and macular sensitivity after cataract surgery. Unsupervised data analysis showed 3 groups of patients as follows: nonpseudophakic CME, level 1 pseudophakic CME, and level 2 pseudophakic CME. Subclinical level 1 patients had a 30% to 40% increase in foveal thickness 1 month postoperatively, while level 2 patients had at least a 40% increase in foveal thickness and a 20% decrease in macular sensitivity. The incidence of clinical pseudophakic CME was 3.2% in diabetic patients as per the diagnostic criteria. The change in macular sensitivity was more consistent and correlated with foveal thickness. CONCLUSIONS: The duration, severity, type of diabetes, hardness of the lens, and HbA1c were risks for pseudophakic CME in diabetic patients after cataract surgery. A 40% or more increase in foveal thickness and 20% or more decrease in macular sensitivity offer an objective and reliable diagnostic standard to report pseudophakic CME in diabetics.

Photoreceptor IRBP prevents light induced injury.

Interphotoreceptor retinoid-binding protein (IRBP) is a classic inducer of experimental autoimmune uveoretinitis (EAU). Although IRBP causes neuronal loss in susceptible animals, resistant animals such as Sprague-Dawley (SPD) rats can benefit from the evoked protective autoimmune responses. The aim of the present study was to analyze the neuroprotective effects of IRBP against light-induced photoreceptor degeneration. We immunized 75 male SPD rats with IRBP and the rats were then exposed to blue light for 24 hours (IRBP group). Seventy five rats were included in the control group. We found that the number of apoptotic cells in the outer nuclear layer (ONL) peaked on 1 day after light exposure, and the ONL thickness decreased significantly on day 3. OX42-positive cells appeared in the ONL immediately after light exposure, and their number peaked on day 3, and changed from resting ramified cells to activated amoeboid cells. Compared with the control group (n=75), the IRBP group showed less apoptotic cells, a thicker ONL, and reduced expression of tumor necrosis factor-alpha. These outcomes indicate the IRPB might protect retinal photoreceptors against light-induced injury.

Correlation between Retinal Changes and Visual Function in Late-Stage Vogt-Koyanagi-Harada Disease: An Optical Coherence Tomography Study.

Purpose. To characterize the optical coherence tomography (OCT) findings in late-stage Vogt-Koyanagi-Harada (VKH) disease and its correlation with visual function. Methods. The records of patients with late-stage VKH disease (defined as ≥12 months from disease onset) were retrospectively reviewed. The analysis focused on the OCT findings and microperimetry, in addition to the possible correlation between morphology and functional findings. Results. Twenty-nine patients (58 eyes) were included. Mean age at onset was 34.24 ± 10.67 years. The OCT revealed that the outer retina and retinal pigment epithelium (RPE) were mainly affected. These effects included RPE thickening and breakage or disappearance of the cone outer segment tip (COST) line and/or inner segment/outer segment (IS/OS) junction. The COST line and IS/OS results were related to macular function and the interval between symptom onset and initiation of high-dose corticosteroid treatment (all P < 0.01). Eyes with intact COST lines demonstrated intact IS/OS and normal RPE layers as well as better visual function and normal retinal sensitivity. Conclusions. The OCT findings are strongly correlated with macular function, as well as other clinical findings in late-stage VKH. With respect to the COST line and retinal sensitivity especially, the OCT and microperimetry findings may be useful for evaluating later-stage VKH.

Ras homolog enriched in the brain is linked to retinal ganglion cell apoptosis after light injury in rats.

Ras homolog enriched in the brain (Rheb) is a small GTPase of the Ras family. It has been confirmed that Rheb activation not only regulates cell growth and migration but also induces neuron apoptosis after toxic stimuli. However, the function of Rheb in the retina is still not fully understood. To find out whether Rheb was involved in retinal neuron death, the expression profile of Rheb in light-damaged retinal ganglion cells (RGCs) of adult rats was investigated. Western blotting showed the expression of Rheb was significantly upregulated in the injured retina. Rheb was mainly detected in apoptotic RGCs by using double immunofluorescent staining. Active caspase-3 was upregulated and co-labeled with Rheb. Meanwhile, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that Rheb-positive RGCs underwent apoptosis after light exposure, which suggested that Rheb might be relevant to RGC apoptosis following phototoxicity. Furthermore, Western blotting and immunofluorescence showed that the expression profiles of CyclinD1 and cyclin-dependent kinase 4 (CDK4) were parallel with that of Rheb in a time-space dependent manner. Based on this study, it is speculated that Rheb might play an important role in physiological and pathological process in light-induced retina damage, which might provide a potential therapeutic avenue of retinal degeneration.

Gene expression changes under cyclic mechanical stretching in rat retinal glial (Müller) cells.

OBJECTIVE: The retina is subjected to tractional forces in various conditions. As the predominant glial element in the retina, Müller cells are active players in all forms of retinal injury and disease. In this study, we aim to identify patterns of gene expression changes induced by cyclic mechanical stretching in Müller cells. METHODS: Rat Müller cells were seeded onto flexible bottom culture plates and subjected to a cyclic stretching regimen of 15% equibiaxial stretching for 1 and 24 h. RNA was extracted and amplified, labeled, and hybridized to rat genome microarrays. The expression profiles were analyzed using GeneSpring software, and gene ontology analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to select, annotate, and visualize genes by function and pathway. The selected genes of interest were further validated by Quantitative Real-time PCR (qPCR). RESULTS: Microarray data analysis showed that at 1 and 24 h, the expression of 532 and 991 genes in the Müller cells significantly (t-test, p<0.05) differed between the mechanically stretched and unstretched groups. Of these genes, 56 genes at 1 h and 62 genes at 24 h showed more than a twofold change in expression. Several genes related to response to stimulus (e.g., Egr2, IL6), cell proliferation (e.g., Areg, Atf3), tissue remodeling (e.g., PVR, Loxl2), and vasculogenesis (e.g., Epha2, Nrn1) were selected and validated by qPCR. KEGG pathway analysis showed significant changes in MAPK signaling at both time points. CONCLUSIONS: Cyclic mechanical strain induces extensive changes in the gene expression in Müller cells through multiple molecular pathways. These results indicate the complex mechanoresponsive nature of Müller cells, and they provide novel insights into possible molecular mechanisms that would account for many retinal diseases in which the retina is often subjected to mechanical forces, such as pathological myopia and proliferative vitreoretinopathy.

Supplementation with antioxidants attenuates transient worsening of retinopathy in diabetes caused by acute intensive insulin therapy.

BACKGROUND: To investigate whether insulin can increase the production of reactive oxygen species (ROS) in bovine retinal microvascular endothelial cells (BRECs), the role of antioxidants in the insulin-induced exacerbation of diabetic retinopathy and the related mechanisms. METHODS: BRECs were cultured in either 5 or 30 mM glucose for 3 days before stimulation with 100 nM insulin for 24 h or incubated with 1 mM apocynin, 100 µM LY294002, 50 µM U0126, 2 µM GF109203X, 250 U/ml catalase, 100 µg/ml ascorbic acid, 100 µM α-lipoic acid and 50 µM α-tocopherol before stimulation with 100 nM insulin. H(2)O(2) (200 µM) was added to cells to measure the VEGF protein expression. Intracellular ROS was measured by immunofluorescence and flow cytometry, superoxide anion measurement was done by cytochrome c reduction, and VEGF protein was measured by ELISA analysis. RESULTS: Insulin or (and) high glucose significantly increased intracellular ROS production in BRECs, and pretreatment of the cells with apocynin and LY294002 decreased insulin-induced superoxide anion production. Neither pretreatment with GF109203X nor U0126 showed an effect on the superoxide anion production. Ascorbic acid, α-lipoic acid, and α-tocopherol also decreased superoxide anion production. Furthermore, H(2)O(2) increased VEGF protein expression in BRECs and catalase suppressed insulin-induced VEGF protein expression. CONCLUSIONS: Insulin can increase ROS production through an NAD(P)H, phosphatidylinositol 3´-kinase-dependent mechanism in bovine retinal microvascular endothelial cells ex vivo. ROS can regulate insulin-induced VEGF expression. Supplementation with antioxidants may help to attenuate the transient worsening of retinopathy in diabetes caused by acute intensive insulin therapy.