PURPOSE: To develop a risk score for predicting treatment-requiring retinopathy of prematurity (TR-ROP) in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study. DESIGN: Second analyses of an observational cohort study. PARTICIPANTS: Infants with birth weight (BW) <1251 g who had ≥1 imaging session by 34 weeks of postmenstrual age (PMA) and ≥1 subsequent retinopathy of prematurity (ROP) examination for determining TR-ROP by study-certified ophthalmologists. METHODS: Nonphysician trained readers evaluated wide-field retinal image sets for characteristics of ROP, pre-plus/plus disease, and retinal hemorrhage. Risk score points for predicting TR-ROP were derived from the regression coefficients of significant predictors in a multivariate logistic regression model. MAIN OUTCOME MEASURES: TR-ROP. RESULTS: Eighty-five of 771 infants (11.0%) developed TR-ROP. In a multivariate model, significant predictors for TR-ROP were gestational age (GA) (odds ratio [OR], 5.7; 95% confidence interval [CI], 1.7-18.9 for ≤25 vs. ≥28 weeks), need for respiratory support (OR, 7.0; 95% CI, 1.3-37.1 for high-frequency oscillatory ventilation vs. no respiratory support), slow weight gain (OR, 2.4; 95% CI, 1.2-4.6 for weight gain ≤12 g/day vs. >15 g/day), and image findings at the first image session including number of quadrants with pre-plus (OR, 3.8; 95% CI, 1.5-9.7 for 4 pre-plus quadrants vs. no pre-plus), stage and zone of ROP (OR, 4.7; 95% CI, 2.1-11.8 for stage 1-2 zone I, OR, 5.9; 95% CI, 2.1-16.6 for stage 3 zone I vs. no ROP), and presence of blot hemorrhage (OR, 3.1; 95% CI, 1.4-6.7). Image findings predicted TR-ROP better than GA (area under receiver operating characteristic curve [AUC] = 0.82 vs. 0.75, P = 0.03). The risk of TR-ROP steadily increased with higher risk score and predicted TR-ROP well (AUC = 0.88; 95% CI, 0.85-0.92). Risk score ≥3 points for predicting TR-ROP had a sensitivity of 98.8%, specificity of 40.1%, and positive and negative predictive values of 17.0% and 99.6%, respectively. CONCLUSIONS: Image characteristics at 34 PMA weeks or earlier independently predict TR-ROP. If externally validated in other infants, risk score, calculated from image findings, GA, weight gain, and respiratory support, enables early identification of infants in need of increased surveillance for TR-ROP.
- Home
- Retina
Retina
PURPOSE: The development of a suitable storage method for retinal pigment epithelium (RPE) is necessary in the establishment of future RPE replacement therapy, and storage temperature has proven to be pivotal for cell survival. ARPE-19, a widely used model for RPE, has been shown to yield the greatest number of viable cells when stored at 16°C compared to other storage temperatures. In this study, we analyze the gene expression profile of cultured ARPE-19 cells after seven days of storage at different temperatures in an effort to predict the gene-level consequences of storage of RPE transplants. MATERIALS AND METHODS: ARPE-19 cells were cultured until confluence and then stored in minimum essential medium at 4°C, 16°C, and 37°C for seven days. The total RNA was isolated and the gene expression profile was determined using DNA microarrays. The Results were validated using qPCR. RESULTS: Principal component and hierarchical clustering analyses show that the gene expression profiles of cell cultures stored at different temperatures cluster into separate groups. Cultures stored at 4°C cluster closest to the control cultures that were not stored and display the least change in gene expression after storage (157 differentially expressed genes). Cultures stored at 16°C and 37°C display a much larger change in differential gene expression (1787 and 1357 differentially expressed genes, respectively). At 16°C, the expression of several genes with proposed tumor suppressor functions was markedly increased. Changes in regulation of several known signaling pathways and of oxidative stress markers were discovered at both 16°C and 37°C, and activation of the angiogenesis marker vascular endothelial growth factor (VEGF) was discovered at 37°C. There was no evidence of the activation of inflammatory processes in stored cell cultures. CONCLUSION: ARPE-19 cultures stored at 16°C show the greatest propensity to modulate their gene expression profile in a manner that supports cell survival during storage.
PURPOSE: To determine the feasibility and safety of bilateral simultaneous vitreoretinal surgery in pediatric patients. DESIGN: International, multicenter, interventional, retrospective case series. PARTICIPANTS: Patients 17 years of age or younger from 24 centers worldwide who underwent immediate sequential bilateral vitreoretinal surgery (ISBVS)-defined as vitrectomy, scleral buckle, or lensectomy using the vitreous cutter-performed in both eyes sequentially during the same anesthesia session. METHODS: Clinical history, surgical details and indications, time under anesthesia, and intraoperative and postoperative ophthalmic and systemic adverse events were reviewed. MAIN OUTCOME MEASURES: Ocular and systemic adverse events. RESULTS: A total of 344 surgeries from 172 ISBVS procedures in 167 patients were included in the study. The mean age of the cohort was 1.3±2.6 years. Nonexclusive indications for ISBVS were rapidly progressive disease (74.6%), systemic morbidity placing the child at high anesthesia risk (76.0%), and residence remote from surgery location (30.2%). The most common diagnoses were retinopathy of prematurity (ROP; 72.7% [P < 0.01]; stage 3, 4.8%; stage 4A, 44.4%; stage 4B, 22.4%; stage 5, 26.4%), familial exudative vitreoretinopathy (7.0%), abusive head trauma (4.1%), persistent fetal vasculature (3.5%), congenital cataract (1.7%), posterior capsular opacification (1.7%), rhegmatogenous retinal detachment (1.7%), congenital X-linked retinoschisis (1.2%), Norrie disease (2.3%), and viral retinitis (1.2%). Mean surgical time was 143±59 minutes for both eyes. Higher ROP stage correlated with longer surgical time (P = 0.02). There were no reported intraoperative ocular complications. During the immediate postoperative period, 2 eyes from different patients demonstrated unilateral vitreous hemorrhage (0.6%). No cases of endophthalmitis, choroidal hemorrhage, or hypotony occurred. Mean total anesthesia time was 203±87 minutes. There were no cases of anesthesia-related death, malignant hyperthermia, anaphylaxis, or cardiac event. There was 1 case of reintubation (0.6%) and 1 case of prolonged oxygen desaturation (0.6%). Mean follow-up after surgery was 103 weeks, and anatomic success and globe salvage rates were 89.8% and 98.0%, respectively. CONCLUSIONS: This study found ISBVS to be a feasible and safe treatment paradigm for pediatric patients with bilateral vitreoretinal pathologic features when repeated general anesthesia is undesirable or impractical.
Migraine headache is uniquely exacerbated by light. Using psychophysical assessments in patients with normal eyesight we found that green light exacerbates migraine headache significantly less than white, blue, amber or red lights. To delineate mechanisms, we used electroretinography and visual evoked potential recording in patients, and multi-unit recording of dura- and light-sensitive thalamic neurons in rats to show that green activates cone-driven retinal pathways to a lesser extent than white, blue and red; that thalamic neurons are most responsive to blue and least responsive to green; and that cortical responses to green are significantly smaller than those generated by blue, amber and red lights. These findings suggest that patients' experience with colour and migraine photophobia could originate in cone-driven retinal pathways, fine-tuned in relay thalamic neurons outside the main visual pathway, and preserved by the cortex. Additionally, the findings provide substrate for the soothing effects of green light.
PURPOSE: Plasma kallikrein is a serine protease and circulating component of inflammation, which exerts clinically significant effects on vasogenic edema. This study examines the role of plasma kallikrein in VEGF-induced retinal edema. METHODS: Intravitreal injections of VEGF and saline vehicle were performed in plasma prekallikrein-deficient (KLKB1-/-) and wild-type (WT) mice, and in both rats and mice receiving a selective plasma kallikrein inhibitor, VA999272. Retinal vascular permeability (RVP) and retinal thickness were measured by Evans blue permeation and optical coherence tomography, respectively. The retinal kallikrein kinin system was examined by Western blotting and immunohistochemistry. Retinal neovascularization was investigated in KLKB1-/- and WT mice subjected to oxygen-induced retinopathy. RESULTS: Vascular endothelial growth factor-induced RVP and retinal thickening were reduced in KLKB1-/- mice by 68% and 47%, respectively, compared to VEGF responses in WT mice. Plasma kallikrein also contributes to TNFα-induced retinal thickening, which was reduced by 52% in KLKB1-/- mice. Systemic administration of VA999272 reduced VEGF-induced retinal thickening by 57% (P < 0.001) in mice and 53% (P < 0.001) in rats, compared to vehicle-treated controls. Intravitreal injection of VEGF in WT mice increased plasma prekallikrein in the retina, which was diffusely distributed throughout the inner and outer retinal layers. Avascular and neovascular areas induced by oxygen-induced retinopathy were similar in WT and KLKB1-/- mice. CONCLUSIONS: Vascular endothelial growth factor increases extravasation of plasma kallikrein into the retina, and plasma kallikrein is required for the full effects of VEGF on RVP and retinal thickening in rodents. Systemic plasma kallikrein inhibition may provide a therapeutic opportunity to treat VEGF-induced retina edema.
There is increasing evidence that VEGF-A antagonists may be detrimental to neuronal health following ocular administration. Here we investigated firstly the effects of VEGF-A neutralization on retinal neuronal survival in the Ins2(Akita) diabetic and JR5558 spontaneous choroidal neovascularization (CNV) mice, and then looked at potential mechanisms contributing to cell death. We detected elevated apoptosis in the ganglion cell layer in both these models following VEGF-A antagonism, indicating that even when vascular pathologies respond to treatment, neurons are still vulnerable to reduced VEGF-A levels. We observed that retinal ganglion cells (RGCs) seemed to be the cells most susceptible to VEGF-A antagonism, so we looked at anterograde transport in these cells, due to their long axons requiring optimal protein and organelle trafficking. Using cholera toxin B-subunit tracer studies, we found a distal reduction in transport in the superior colliculus following VEGF-A neutralization, which occurred prior to net RGC loss. This phenomenon of distal transport loss has been described as a feature of early pathological changes in glaucoma, Alzheimer's and Parkinson's disease models. Furthermore, we observed increased phosphorylation of p38 MAPK and downstream Hsp27 stress pathway signaling in the retinas from these experiments, potentially providing a mechanistic explanation for our findings. These experiments further highlight the possible risks of using VEGF-A antagonists to treat ocular neovascular disease, and suggest that VEGF-A may contribute to the maintenance and function of axonal transport in neurons of the retina.
Neovascular eye diseases are a major cause of blindness including retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration in which new vessel formation is driven by hypoxia or metabolic abnormalities affecting the fuel supply. White-adipose-tissue derived adipokines such as adiponectin modulate metabolic responses. Increasing evidence shows that lack of adiponectin may result in retinal neovascularization. Activation of the adiponectin pathway may in turn restore energy metabolism, to suppress the drive for compensatory but ultimately pathological neovessels of retinopathy. In this review, we will summarize our current knowledge of the role of adiponectin in eye diseases of premature infants, diabetic patients as well as the elderly. Further investigations in this field are likely to lead to new preventative approaches for these diseases.
Anti-vascular endothelial growth factor (anti-VEGF) drugs - ranibizumab, aflibercept, and off-label bevacizumab - are vital to the treatment of common retinal diseases, including exudative age-related macular degeneration (AMD), diabetic macular edema (DME), and macular edema (ME) associated with retinal vein occlusion (RVO). Given the high prevalence of AMD and retinal vascular diseases, anti-VEGF agents represent a large cost burden to the United States (US) healthcare system. Although ranibizumab and aflibercept are 30-fold more expensive per injection than bevacizumab, the two more costly medications are commonly used in the US, even though all three have been shown to be effective and safe for treatment of these retinal diseases. We investigated the availability and content of professional ophthalmic guidelines on cost consideration in the selection of anti-VEGF agents. We found that current professional guidelines were limited in availability and lacked specific guidance on cost-based anti-VEGF drug selection. This represents a missed opportunity to encourage the practice of value-based medicine. [Full article available at http://rimed.org/rimedicaljournal-2016-05.asp, free with no login].
PURPOSE: Anterior ischemic optic neuropathy (AION) is the most common cause of non-glaucomatous optic nerve head (ONH) injury among older adults. AION results from a sudden ischemic insult to the proximal portion of the optic nerve, typically leading to visual impairment. Here, we present an experimental model of photodynamically induced ONH injury that can be used to study neuroprotective modalities. METHODS: Intraperitoneal injection of mesoporphyrin IX was followed by photodynamic treatment of the ONH in one eye of Brown-Norway rats; the fellow eye received the reverse sequence as a sham control. Fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), and visual evoked potential (VEP) recordings were performed at different time points following laser treatment. Immunohistochemistry was used to monitor apoptotic cell death (TUNEL) and macrophage infiltration (CD68). Cytokine levels were evaluated using enzyme-linked immunosorbent assay (ELISA). RESULTS: FA showed early hyperfluorescence and late leakage of the ONH, while SD-OCT revealed optic nerve edema. No leakage or other abnormalities were detected in control eyes. VEPs were significantly reduced in amplitude and showed prolonged responses compared to sham eyes. The number of apoptotic retinal ganglion cells was elevated one day after laser treatment (13.77 ± 4.49, p < 0.01) and peaked on day 7 (57.22 ± 11.34, p < 0.01). ONH macrophage infiltration also peaked on day 7 (101.8 ± 9.8, p < 0.05). ELISAs performed showed upregulation of macrophage chemoattractant protein-1 and macrophage inflammatory protein-2 on days 3 and 1, respectively. CONCLUSIONS: Photodynamic treatment of the ONH after administration of mesoporphyrin IX leads to macroscopic, histologic, and physiologic evidence of ONH injury. Given the long half-life of mesoporphyrin IX and the ease of intraperitoneal injections, this new model of photodynamically induced ONH injury may be a useful tool for studying optic nerve injury and possible neuroprotective treatments.
BACKGROUND: Endothelial cells (EC) grown on collagen particles inhibit intimal hyperplasia in animal models when applied perivascularly, and this effect appears to be, at least in part, the result of EC-derived soluble factors that suppress local vascular inflammation. To elucidate the molecular basis of the therapeutic effects of EC grown on collagen particles, the anti-inflammatory activity of conditioned medium from these cells was characterized. METHODS: Human aortic EC (HAEC) and, for chromatin immunoprecipitation assays, human umbilical vein EC (HUVEC) were treated with tumor necrosis factor alpha (TNFα) in the presence of conditioned medium generated by HAEC grown on collagen particles (ECPCM), and the anti-inflammatory effects were evaluated by analysing the expression of the inflammation-related adhesion molecules E-selectin and vascular cell adhesion molecule-1 (VCAM-1). The therapeutic activity of ECPCM was studied using the mouse strain JR5558, which develops spontaneous choroidal neovascularisation (CNV) lesions driven by local inflammation. RESULTS: ECPCM significantly suppressed TNFα-induced expression of E-selectin and VCAM-1. ECPCM did not affect the mRNA stability of the two genes, but suppressed TNFα-induced binding of the p65 subunit of NF-kB transcription factor to E-selectin and VCAM-1 promoters. In vivo, systemic ECPCM treatment significantly reduced the CNV area and the recruitment of activated macrophages to the lesions. Characterization of the molecule responsible for the anti-inflammatory activity in ECPCM indicates that it is unlikely to be a protein and that it is not any of the better characterized EC-derived anti-inflammatory molecules. CONCLUSIONS: Medium conditioned by HAEC grown on collagen particles exhibits significant anti-inflammatory activity via inhibition of genes that mediate inflammatory responses in EC.
Mutations in NOTCH 3 are the cause of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a neurological disorder characterized by stroke, and vascular cognitive impairment and dementia. Loss of vascular smooth muscle cells (VSMC) and accumulation of granular osmiophilic material (GOM) deposits are hallmarks of CADASIL. There are no therapies for CADASIL and experimental endpoints to examine the preclinical efficacy of potential drugs are lacking. This study aims to use a mouse carrying the C455R mutation in Notch 3 to identify biomarkers associated with CADASIL. Mass spectrometry and antibody arrays were used to explore the aorta and blood proteomes of CADASIL mice, ELISA assays were utilized for biomarker validation, a ligand-dependent assay was applied to examine the relationship between Notch signaling and biomarker expression, and retinal histology was performed for quantification of VSMC loss in arteries. Two-hundred day-old mice with the C455R CADASIL mutation in Notch 3 mice display robust VSMC loss in retinal arteries and had increased plasma levels of collagen18α1/endostatin (col18α1) and high-temperature requirement A serine peptidase 1 (HTRA1) and reduced levels of Notch 3 extracellular domain (N3ECD), compared to control wild type mice. Measurements of plasma endostatin, HTRA1 and N3ECD, along with VSMC quantification in retinal arteries, may serve as surrogate endpoints for assessing efficacy in preclinical therapeutic studies of CADASIL using mice.
PURPOSE: To identify prognostic factors for poor visual outcome in patients with birdshot retinochoroidopathy. METHODS: A case-control study of 98 patients with birdshot retinochoroidopathy (196 eyes) was evaluated with a follow-up period of at least 12 months. After exclusion of glaucoma, optic atrophy, and macular scar, the remaining eligible patients were categorized into two groups: poor visual outcomes and good visual outcomes. Poor visual outcome was defined as less than -6 mean deviation score on Swedish interactive threshold algorithm (SITA) short-wavelength automated perimetry (SWAP) test and abnormality (amplitude or implicit time) of 30 Hz flicker electroretinogram at 4-year follow-up and at the most recent visit for separate analysis. Potential factors between both groups were statistically analyzed by Chi-square test and logistic regression model. RESULTS: After the aforementioned exclusion, the remaining 77 patients with an average follow-up period of 52 ± 29 months (335 person-years, 36% with follow-up of more than 5 years) were divided into two groups. Sixteen patients were categorized as having poor visual outcome. Univariate analysis identified significant association of abnormal 30 Hz flicker electroretinogram amplitude (P = 0.004), implicit time (P = 0.002), and SITA SWAP mean deviation at the initial visit (P < 0.001) in the poor visual outcome group. Multivariate logistic regression analysis identified only SITA SWAP mean deviation to be associated with poor visual outcome (adjusted odds ratio, 32.50; 95% confidence interval [3.84-275.32]; P = 0.001) at the initial visit. To verify the model validity, an analysis of 42 patients at 4-year follow-up was performed and the outcome was confirmed (adjusted odds ratio, 8.80; 95% confidence interval [1.58-49.16]; P = 0.013). CONCLUSION: Worse SITA SWAP mean deviation at the initial visit is a predictor of poor visual outcome in patients with birdshot retinochoroidopathy, and may serve as a proxy marker for delayed effective steroid sparing therapy in patients with birdshot retinochoroidopathy.
A 65-year-old woman with chronic hypertension, chronic renal insufficiency, and schizophrenia self-discontinued her medications and presented complaining of decreased vision; she was found to have a blood pressure of 256/156 and visual acuity 20/70 OD. In the emergency department, her blood pressure was rapidly lowered to a nadir of 134/104. During the course of her hospitalization, her visual acuity declined from 20/70 to 20/200 OD in parallel with a decline in her renal function. Multi-modal imaging revealed simultaneous hypertensive retinopathy, choroidopathy, and optic neuropathy. Autofluorescence can play an important role in the diagnosis of hypertensive choroidopathy.
Tissues with high metabolic rates often use lipids, as well as glucose, for energy, conferring a survival advantage during feast and famine. Current dogma suggests that high-energy-consuming photoreceptors depend on glucose. Here we show that the retina also uses fatty acid β-oxidation for energy. Moreover, we identify a lipid sensor, free fatty acid receptor 1 (Ffar1), that curbs glucose uptake when fatty acids are available. Very-low-density lipoprotein receptor (Vldlr), which is present in photoreceptors and is expressed in other tissues with a high metabolic rate, facilitates the uptake of triglyceride-derived fatty acid. In the retinas of Vldlr(-/-) mice with low fatty acid uptake but high circulating lipid levels, we found that Ffar1 suppresses expression of the glucose transporter Glut1. Impaired glucose entry into photoreceptors results in a dual (lipid and glucose) fuel shortage and a reduction in the levels of the Krebs cycle intermediate α-ketoglutarate (α-KG). Low α-KG levels promotes stabilization of hypoxia-induced factor 1a (Hif1a) and secretion of vascular endothelial growth factor A (Vegfa) by starved Vldlr(-/-) photoreceptors, leading to neovascularization. The aberrant vessels in the Vldlr(-/-) retinas, which invade normally avascular photoreceptors, are reminiscent of the vascular defects in retinal angiomatous proliferation, a subset of neovascular age-related macular degeneration (AMD), which is associated with high vitreous VEGFA levels in humans. Dysregulated lipid and glucose photoreceptor energy metabolism may therefore be a driving force in macular telangiectasia, neovascular AMD and other retinal diseases.
PURPOSE: Intraocular vascular diseases are leading causes of adult vision loss, and in the mid-1900s, I. C. Michaelson postulated that the retina releases a soluble, diffusible factor that causes abnormal vascular growth and leakage. What became known as "Factor X" eluded investigators for decades. METHODS: The field of cancer research, where Judah Folkman pioneered the concept of angiogenesis, provided the inspiration for the work honored by the 2014 Champalimaud Vision Award. Recognizing that tumors recruit their own blood supply to achieve critical mass, Dr Folkman proposed that angiogenic factors could be therapeutic targets in cancer. Napoleone Ferrara identified vascular endothelial growth factor (VEGF) as such an angiogenic agent: stimulated by hypoxic tumor tissue, secreted, and able to induce neovascularization. VEGF also was a candidate for Factor X, and the 2014 Champalimaud Laureates and colleagues worked individually and collaboratively to identify the role of VEGF in ocular disease. RESULTS: The Champalimaud Laureates correlated VEGF with ocular neovascularization in animal models and in patients. Moreover, they showed that VEGF not only was sufficient, but it also was required to induce neovascularization in normal animal eyes, as VEGF inhibition abolished ocular neovascularization in key animal models. CONCLUSIONS: The identification of VEGF as Factor X altered the therapeutic paradigms for age-related macular degeneration (AMD), diabetic retinopathy, retinal vein occlusion, and other retinal disorders. TRANSLATIONAL RELEVANCE: The translation of VEGF from discovery to therapy resulted in the most successful applications of antiangiogenic therapy to date. Annually, over one million patients with eye disease are treated with anti-VEGF agents.
OBJECTIVE: To provide artificially-elicited vision that is temporally dynamic, retinal prosthetic devices will need to repeatedly stimulate retinal neurons. However, given the diversity of physiological types of retinal ganglion cells (RGCs) as well as the heterogeneity of their responses to electric stimulation, temporal properties of RGC responses have not been adequately investigated. Here, we explored the cell type dependence of network-mediated RGC responses to repetitive electric stimulation at various stimulation rates. APPROACH: We examined responses of ON and OFF types of RGCs in the rabbit retinal explant to five consecutive stimuli with varying inter-stimulus intervals (10-1000 ms). Each stimulus was a 4 ms long monophasic sinusoidal cathodal current, which was applied epiretinally via a conical electrode. Spiking activity of targeted RGCs was recorded using a cell-attached patch electrode. MAIN RESULTS: ON and OFF cells had distinct responses to repetitive stimuli. Consistent with earlier studies, OFF cells always generated reduced responses to subsequent stimuli compared to responses to the first stimulus. In contrast, a new stimulus to ON cells suppressed all pending/ongoing responses from previous stimuli and initiated its own response that was remarkably similar to the response from a single stimulus in isolation. This previously unreported 'reset' behavior was observed exclusively and consistently in ON cells. These contrasts between ON and OFF cells created a range of stimulation rates (4-7 Hz) that maximized the ratio of the responses arising in ON versus OFF cells. SIGNIFICANCE: Previous clinical testing reported that subjects perceive bright phosphenes (ON responses) and also prefer stimulation rates of 5-7 Hz. Our results suggest that responses of ON cells are weak at high rates of stimulation (> ∼7 Hz) due to the reset while responses of OFF cells are strong at low rates (< ∼4 Hz) due to reduced desensitization, both reducing the ratio of ON to OFF responses. In combination with previous results indicating that responses in ON cells more closely match physiological patterns (Im and Fried 2015 J. Physiol. 593 3577-96), our results offer a potential reason for the user preference of intermediate rates (5-7 Hz).
IMPORTANCE: Ultrawide field imaging (UWFI) is increasingly being used in teleophthalmology settings. Given the greater area of the retina imaged, we evaluated the ability of UWFI vs nonmydriatic fundus photography (NMFP) to detect nondiabetic retinal findings in a teleophthalmology program. OBSERVATION: We conducted a retrospective single-center comparative cohort study from January 1, 2011, to June 30, 2013, imaging 3864 and 3971 consecutive teleophthalmology patients (7728 and 7942 eyes) using NMFP and UWFI, respectively. Standard diabetic retinopathy evaluation and nondiabetic findings were compared between the 2 imaging modalities. In patients without diabetic retinopathy (2243 by NMFP and 2252 by UWFI), the rate of identification of nondiabetic findings by NMFP (451 patients [20.1%]) and UWFI (490 [21.8%]) were comparable (P = .19). Ultrawide field imaging increased the identification of choroidal nevi by 27% (406 eyes [5.3%] by NMFP vs 545 eyes [6.9%] by UWFI; P < .001) and chorioretinal atrophy or scarring by 116% (50 eyes [0.6%] by NMFP vs 101 eyes [1.3%] by UWFI; P < .001). No peripheral retinal findings were identified with NMFP, while UWFI detected 25 retinal tears (0.3%; P < .001), 54 lattice and peripheral degenerations (0.7%; P < .001), and 142 cases of vitreous detachment or floaters (1.8%; P < .001). Data analysis was performed from November 1, 2013, to May 1, 2014. CONCLUSIONS AND RELEVANCE: In eyes without diabetic retinopathy, approximately 20% may have ocular findings identified on retinal imaging, which emphasizes the role of retinal imaging in patients with diabetes mellitus type 1 and type 2 regardless of the severity of retinopathy. In this cohort, UWFI increased the identification of peripheral retinal and vitreous pathologic findings.
C-C chemokine receptor 2 (Ccr2) is a key pro-inflammatory marker of classic (M1) macrophage activation. Although Ccr2 is known to be expressed both constitutively and inductively, the full regulatory mechanism of its expression remains unclear. AMP-activated protein kinase (AMPK) is not only a master regulator of energy homeostasis but also a central regulator of inflammation. In this study, we sought to assess AMPK's role in regulating RAW264.7 macrophage Ccr2 protein levels in resting (M0) or LPS-induced M1 states. In both M0 and M1 RAW264.7 macrophages, knockdown of the AMPKα1 subunit by siRNA led to increased Ccr2 levels whereas pharmacologic (A769662) activation of AMPK, attenuated LPS-induced increases in Ccr2 expression in an AMPK dependent fashion. The increases in Ccr2 levels by AMPK downregulation were partially reversed by NF-κB inhibition whereas TNF-a inhibition had minimal effects. Our results indicate that AMPK is a negative regulator of Ccr2 expression in RAW264.7 macrophages, and that the mechanism of action of AMPK inhibition of Ccr2 is mediated, in part, through the NF-κB pathway.
OPINION STATEMENT: Susac syndrome is a microangiopathy of the brain, retina, and cochlea. Several lines of evidence support the concept that this disease is an acquired autoimmune disorder. Prospective, randomized, controlled studies of treatments are not available because the disease is rare. Furthermore, the average period of follow-up in reported cases is short, limiting a complete understanding of the natural history of the disease. Empirical treatment strategies are therefore based upon expert recommendations and anecdotal reports of response to various immunomodulators, and the appropriate duration of therapy is not known. In our opinion, the encephalopathic form of Susac syndrome should be treated early and aggressively to avoid cognitive dysfunction and disability. Induction therapy with pulse methylprednisolone frequently proves to be inadequate. Additional agents, including intravenous immunoglobulins, intravenous cyclophosphamide, or rituximab are often necessary to induce a sustained remission. Maintenance therapy with oral glucocorticoids combined with intravenous immunoglobulins, mycophenolate mofetil, methotrexate, azathioprine, cyclophosphamide, or rituximab is typically necessary to achieve a sustained remission. Aspirin may be used as an adjunctive agent, although evidence showing efficacy is scant. The response to treatment should be closely monitored by frequent clinical examinations, brain MRI, and fluorescein angiography. Once disease remission has been established, it appears prudent to continue maintenance treatment for at least two additional years, although the real long-term risk of future relapses remains unknown. Establishing a multicenter patient registry and biorepository is essential to study the pathogenesis of the disease, further define the duration of disease, identify reliable biomarkers that aid early diagnosis and assess risk of relapse, and develop effective disease-specific therapies.
The photoreceptor is a complex specialized cell in which a major component responsible for visual transduction is the photoreceptor sensory cilium (PSC). Building and maintenance of the PSC requires the transport of large proteins along microtubules that extend from the inner segments to the outer segments. A key process, termed intraflagellar transport (IFT), has been recognized as an essential phenomenon for photoreceptor development and maintenance, and exciting new studies have highlighted its importance in retinal and cilia related diseases. This review focuses on the important roles of IFT players, including motor proteins, IFT proteins, and photoreceptor-specific cargos in photoreceptor sensory cilium. In addition, specific IFT components that are involved in inherited human diseases are discussed.
Since the lipofuscin of retinal pigment epithelial (RPE) cells has been implicated in the pathogenesis of Best vitelliform macular dystrophy, we quantified fundus autofluorescence (quantitative fundus autofluorescence, qAF) as an indirect measure of RPE lipofuscin levels. Mean non-lesion qAF was found to be within normal limits for age. By spectral domain optical coherence tomography (SD-OCT) vitelliform lesions presented as fluid-filled subretinal detachments containing reflective material. We discuss photoreceptor outer segment debris as the source of the intense fluorescence of these lesions and loss of anion channel functioning as an explanation for the bullous photoreceptor-RPE detachment. Unexplained is the propensity of the disease for central retina.
Colour vision is only achieved in the presence of healthy and functional cone photoreceptors found in the retina. It is an essential component of human vision and usually the first complaint patients undergoing vision degeneration have is the loss of daylight colour vision. Therefore, an understanding of the biology and basic mechanisms behind cone death under the degenerative state of retinal dystrophies and how the activation of the apoptotic pathway is triggered will provide valuable knowledge. It will also have broader applications for a spectrum of visual disorders and will be critical for future advances in translational research.
