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Sakurai K, Chen J, Khani SC, Kefalov VJ. Regulation of Mammalian cone phototransduction by recoverin and rhodopsin kinase. J Biol Chem 2015;290(14):9239-50.Abstract

Cone photoreceptors function under daylight conditions and are essential for color perception and vision with high temporal and spatial resolution. A remarkable feature of cones is that, unlike rods, they remain responsive in bright light. In rods, light triggers a decline in intracellular calcium, which exerts a well studied negative feedback on phototransduction that includes calcium-dependent inhibition of rhodopsin kinase (GRK1) by recoverin. Rods and cones share the same isoforms of recoverin and GRK1, and photoactivation also triggers a calcium decline in cones. However, the molecular mechanisms by which calcium exerts negative feedback on cone phototransduction through recoverin and GRK1 are not well understood. Here, we examined this question using mice expressing various levels of GRK1 or lacking recoverin. We show that although GRK1 is required for the timely inactivation of mouse cone photoresponse, gradually increasing its expression progressively delays the cone response recovery. This surprising result is in contrast with the known effect of increasing GRK1 expression in rods. Notably, the kinetics of cone responses converge and become independent of GRK1 levels for flashes activating more than ∼1% of cone pigment. Thus, mouse cone response recovery in bright light is independent of pigment phosphorylation and likely reflects the spontaneous decay of photoactivated visual pigment. We also find that recoverin potentiates the sensitivity of cones in dim light conditions but does not contribute to their capacity to function in bright light.

Papavasileiou E, Sobrin L, Papaliodis GN. Ocular ischemic syndrome presenting as retinal vasculitis in a patient with moyamoya syndrome. Retin Cases Brief Rep 2015;9(2):170-2.Abstract

PURPOSE: To report a case of ocular ischemic syndrome presenting as retinal vasculitis in a patient with Moyamoya syndrome. METHODS: A retrospective chart review was conducted to record clinical data including fluorescein angiography, optical coherence tomography, and serologic testing. A review of the literature from 1969 to 2014 of ocular involvement in Moyamoya syndrome was performed. RESULTS: A 51-year-old woman with long history of bilateral retinal vasculitis and refractory cystoid macular edema was eventually diagnosed with Moyamoya syndrome after sustaining a perioperative cerebrovascular accident. Moyamoya syndrome has been associated in the literature with ocular ischemic syndrome, presenting with narrowed retinal arteries, dilated veins, and midperipheral retinal hemorrhages, but retinal vasculitis with cystoid macular edema has not been reported. CONCLUSION: Moyamoya-related ocular ischemic syndrome can present as retinal vascular leakage and macular edema. Ophthalmologists should be cognizant that signs of the disease may be first observed in the eye before manifestations in the cerebrovascular system.

Sim DA, Keane PA, Tufail A, Egan CA, Aiello LP, Silva PS. Automated retinal image analysis for diabetic retinopathy in telemedicine. Curr Diab Rep 2015;15(3):14.Abstract

There will be an estimated 552 million persons with diabetes globally by the year 2030. Over half of these individuals will develop diabetic retinopathy, representing a nearly insurmountable burden for providing diabetes eye care. Telemedicine programmes have the capability to distribute quality eye care to virtually any location and address the lack of access to ophthalmic services. In most programmes, there is currently a heavy reliance on specially trained retinal image graders, a resource in short supply worldwide. These factors necessitate an image grading automation process to increase the speed of retinal image evaluation while maintaining accuracy and cost effectiveness. Several automatic retinal image analysis systems designed for use in telemedicine have recently become commercially available. Such systems have the potential to substantially improve the manner by which diabetes eye care is delivered by providing automated real-time evaluation to expedite diagnosis and referral if required. Furthermore, integration with electronic medical records may allow a more accurate prognostication for individual patients and may provide predictive modelling of medical risk factors based on broad population data.

Mehta M, Rasheed RA, Duker J, Reichel E, Feinberg E, Husain D, Foster CS, Laver NV. Vitreous evaluation: a diagnostic challenge. Ophthalmology 2015;122(3):531-7.Abstract

PURPOSE: To categorize vitrectomy cytologic diagnoses and ancillary tests to address appropriate processing of low-volume vitreous samples. DESIGN: Retrospective case series. PARTICIPANTS: Five thousand seven hundred thirty-six vitreous samples. METHODS: Cytologic diagnoses of therapeutic and diagnostic vitrectomy samples and their processing protocols from 3 teaching institutions were reviewed. MAIN OUTCOME MEASURES: Diagnostic results were categorized as negative for malignancy, suspicious for malignancy, and positive for malignancy. All ancillary studies performed were documented, including special stains, immunohistochemistry analysis, cytokine levels, and polymerase chain reaction (PCR) analysis. RESULTS: Of the 5736 vitreous samples analyzed, 4683 (81.64%) were from Tufts Medical Center (TMC), 955 (16.65%) were from Boston Medical Center (BMC), and 98 (1.70%) were from Massachusetts Eye Research and Surgery Institution (MERSI). Cases from TMC and BMC were therapeutic and diagnostic vitrectomies, and MERSI cases were diagnostic vitrectomies. Most vitrectomies showed negative results for malignancy: 99.47% of TMC cases, 99.89% of BMC cases, and 79.6% of MERSI cases. These included vitreous hemorrhage and inflammatory or infectious findings. Ancillary studies performed in this category included Periodic Acid-Schiff staining for fungi, PCR analysis for toxoplasmosis, cytomegalovirus, Epstein-Barr virus (EBV), herpes simplex virus I and II, and vitreous cultures for infections (coagulase-negative Staphylococcus, Candida, Fusarium, and Propionibacterium species). Interleukin (IL) 10-to-IL-6 ratios were performed on 38.7% of cases from MERSI. Fourteen cases from TMC were suspicious for malignancy based on cytologic evaluation. Eleven cases from TMC, 1 case from BMC, and 20 cases from MERSI showed positive results for malignancy and included B-cell lymphoma, retinoblastoma, melanoma, and metastatic adenocarcinoma. The ancillary testing included PCR for heavy chain immunoglobulin gene rearrangements, immunohistochemistry for EBV, in situ hybridization for κ and λ light chains, and cytogenetics. CONCLUSIONS: This is the largest data pool of reported cytologic diagnoses of diagnostic and therapeutic vitrectomy samples. Cytologic evaluation of therapeutic vitrectomy samples provides a valuable baseline of nonpathologic findings that assist in differentiation between malignancy, infections, and inflammatory conditions. Allocation of small-volume vitreous samples to select ancillary testing from the plethora of available diagnostic tests requires preoperative communication between surgeons and pathologists to ensure appropriate and timely treatment methods.

Bunker S, Holeniewska J, Vijay S, Dahlmann-Noor A, Khaw P, Ng Y-S, Shima D, Foxton R. Experimental glaucoma induced by ocular injection of magnetic microspheres. J Vis Exp 2015;(96)Abstract

Progress in understanding the pathophysiology, and providing novel treatments for glaucoma is dependent on good animal models of the disease. We present here a protocol for elevating intraocular pressure (IOP) in the rat, by injecting magnetic microspheres into the anterior chamber of the eye. The use of magnetic particles allows the user to manipulate the beads into the iridocorneal angle, thus providing a very effective blockade of fluid outflow from the trabecular meshwork. This leads to long-lasting IOP rises, and eventually neuronal death in the ganglion cell layer (GCL) as well as optic nerve pathology, as seen in patients with the disease. This method is simple to perform, as it does not require machinery, specialist surgical skills, or many hours of practice to perfect. Furthermore, the pressure elevations are very robust, and reinjection of the magnetic microspheres is not usually required unlike in some other models using plastic beads. Additionally, we believe this method is suitable for adaptation for the mouse eye.

Silva PS, Cavallerano JD, Haddad NMN, Kwak H, Dyer KH, Omar AF, Shikari H, Aiello LM, Sun JK, Aiello LP. Peripheral Lesions Identified on Ultrawide Field Imaging Predict Increased Risk of Diabetic Retinopathy Progression over 4Years. Ophthalmology 2015;122(5):949-56.Abstract

OBJECTIVE: To determine whether peripheral diabetic retinopathy (DR) lesions identified on ultrawide field (UWF) imaging are associated with increased DR progression. DESIGN: Prospective, longitudinal cohort. PARTICIPANTS: Two hundred eyes of 100 participants previously enrolled in a comparative instrument validation study. METHODS: Baseline mydriatic 7-standard field Early Treatment Diabetic Retinopathy Study (ETDRS) photographs and UWF images were obtained. On UWF images, DR lesions with a greater extent outside versus inside standard ETDRS fields were defined as predominantly peripheral lesions (PPLs). Follow-up ETDRS photographs were obtained 4.2±0.3 years after baseline. Baseline and follow-up DR severity were graded from ETDRS photographs. MAIN OUTCOME MEASURES: Rates of 2-step or more progression and progression to proliferative DR (PDR) in eyes with PPLs compared with eyes without PPLs identified on UWF imaging at baseline. RESULTS: In eyes without PDR (n = 109) at baseline, 56 (51%) had at least 1 field with PPLs and 43 (39%) had DR progression. Compared with eyes without PPLs, eyes with PPLs had a 3.2-fold increased risk of 2-step or more DR progression (6 [11%] vs. 19 [34%]; P = 0.005) and a 4.7-fold increased risk for progression to PDR (3 [6%] vs. 14 [25%]; P = 0.005). These findings remained statistically significant after adjusting for gender, diabetes type, diabetes duration, hemoglobin A1c (HbA1c) levels, and baseline DR severity. Increasing extent of fields with PPLs increased the risk for 2-step or more DR progression (P = 0.004) and progression to PDR (P = 0.009). CONCLUSIONS: Presence and increasing extent of PPLs were associated with increased risk of DR progression over 4 years, independent of baseline DR severity and HbA1c levels. Increasing extent of PPLs substantially increased the risk of DR progression and progression to PDR, especially with less severe DR at baseline. These findings demonstrate that detailed peripheral retinal evaluation provides important information that is necessary to assess completely the risk of DR progression.

Kekunnaya R, Kraft S, Rao VB, Velez FG, Sachdeva V, Hunter DG. Surgical management of strabismus in Duane retraction syndrome. J AAPOS 2015;19(1):63-9.Abstract

SUMMARY: While Duane retraction syndrome (DRS) is relatively common, surgical management of the associated strabismus can be challenging because of the lack of abduction/adduction, the variable severity of muscle contracture, and the variety of clinical presentations. In this workshop a panel of experienced surgeons provide their perspective and practical tips on the management of strabismus in patients with DRS.

Farkas MH, Au ED, Sousa ME, Pierce EA. RNA-Seq: Improving Our Understanding of Retinal Biology and Disease. Cold Spring Harb Perspect Med 2015;Abstract

Over the past several years, rapid technological advances have allowed for a dramatic increase in our knowledge and understanding of the transcriptional landscape, because of the ability to study gene expression in greater depth and with more detail than previously possible. To this end, RNA-Seq has quickly become one of the most widely used methods for studying transcriptomes of tissues and individual cells. Unlike previously favored analysis methods, RNA-Seq is extremely high-throughput, and is not dependent on an annotated transcriptome, laying the foundation for novel genetic discovery. Additionally, RNA-Seq derived transcriptomes provide a basis for widening the scope of research to identify potential targets in the treatment of retinal disease.

Wang Z, Cheng R, Lee K, Tyagi P, Ding L, Kompella UB, Chen J, Xu X, Ma J-X. Nanoparticle-mediated expression of a wnt pathway inhibitor ameliorates ocular neovascularization. Arterioscler Thromb Vasc Biol 2015;35(4):855-64.Abstract

OBJECTIVE: The deficiency of very low-density lipoprotein receptor resulted in Wnt signaling activation and neovascularization in the retina. The present study sought to determine whether the very low-density lipoprotein receptor extracellular domain (VLN) is responsible for the inhibition of Wnt signaling in ocular tissues. APPROACH AND RESULTS: A plasmid expressing the soluble VLN was encapsulated with poly(lactide-co-glycolide acid) to form VLN nanoparticles (VLN-NP). Nanoparticles containing a plasmid expressing the low-density lipoprotein receptor extracellular domain nanoparticle were used as negative control. MTT, modified Boyden chamber, and Matrigel (™) assays were used to evaluate the inhibitory effect of VLN-NP on Wnt3a-stimulated endothelial cell proliferation, migration, and tube formation. Vldlr(-/-) mice, oxygen-induced retinopathy, and alkali burn-induced corneal neovascularization models were used to evaluate the effect of VLN-NP on ocular neovascularization. Wnt reporter mice (BAT-gal), Western blotting, and luciferase assay were used to evaluate Wnt pathway activity. Our results showed that VLN-NP specifically inhibited Wnt3a-induced endothelial cell proliferation, migration, and tube formation. Intravitreal injection of VLN-NP inhibited abnormal neovascularization in Vldlr(-/-), oxygen-induced retinopathy, and alkali burn-induced corneal neovascularization models, compared with low-density lipoprotein receptor extracellular domain nanoparticle. VLN-NP significantly inhibited the phosphorylation of low-density lipoprotein receptor-related protein 6, the accumulation of β-catenin, and the expression of vascular endothelial growth factor in vivo and in vitro. CONCLUSIONS: Taken together, these results suggest that the soluble VLN is a negative regulator of the Wnt pathway and has antiangiogenic activities. Nanoparticle-mediated expression of VLN may thus represent a novel therapeutic approach to treat pathological ocular angiogenesis and potentially other vascular diseases affected by Wnt signaling.

Rodriguez-Galindo C, Orbach DB, Vanderveen D. Retinoblastoma. Pediatr Clin North Am 2015;62(1):201-23.Abstract

Retinoblastoma is the most common neoplasm of the eye in childhood, and represents 3% of all childhood malignancies. Retinoblastoma is a cancer of the very young; two-thirds are diagnosed before 2 years of age and 95% before 5 years. Retinoblastoma presents in 2 distinct clinical forms: (1) a bilateral or multifocal, heritable form (25% of all cases), characterized by the presence of germline mutations of the RB1 gene; and (2) a unilateral or unifocal form (75% of all cases), 90% of which are nonhereditary. The treatment of retinoblastoma is multidisciplinary and is designed primarily to save life and preserve vision.

Jakobiec FA, Kool M, Stagner AM, Pfister SM, Eagle RC, Proia AD, Korshunov A. Intraocular Medulloepitheliomas and Embryonal Tumors with Multilayered Rosettes of the Brain: Comparative Roles of LIN28A and C19MC. Am J Ophthalmol 2015;Abstract

PURPOSE: To compare immunohistochemical and genetic overlaps and differences between intraocular medulloepitheliomas and embryonal tumors with multilayered rosettes of the brain. DESIGN: Retrospective histopathologic, immunohistochemical and genetic analysis of 20 intraocular medulloepitheliomas. METHODS: 1) Review of clinical data and hematoxylin and eosin stained sections with 2) immunohistochemical staining of paraffin sections using a polyclonal antibody against the protein LIN28A, and 3) FISH testing for the amplification of the genetic locus 19q13.42 involving the C19MC cluster of miRNA. Ten retinoblastomas served as controls and to determine the specificity of these biomarkers for intraocular medulloepitheliomas. RESULTS: Nineteen of the 20 intraocular medulloepitheliomas were either diffusely or focally LIN28A positive (weak, moderate or strong). The most intense positivity correlated with aggressive behavior such as intraocular tissue invasion or extraocular extension. None of the cases studied by fluorescence in situ hybridization (FISH) harbored an amplicon for C19MC. The ten retinoblastomas were LIN28A and C19MC negative. CONCLUSION: LIN28A has a putative role in oncogenesis and is found only in embryonic cells and malignancies. Intraocular medulloepitheliomas and embryonal tumors with multilayered rosettes of the brain both display LIN28A positivity. Only the latter, however, display amplification of the 19q13.42 locus involving C19MC, implying that other causative factors are at play in intraocular medulloepitheliomas. More aggressive tumor behavior within the eye can be partially predicted by LIN28A staining intensity.

Stacy RC, Gilbert AL, Rizzo JF. Correlation of clinical profile and specific histopathological features of temporal artery biopsies. J Neuroophthalmol 2015;35(2):127-33.Abstract

BACKGROUND: This study sought to correlate the clinical features of patients with giant cell arteritis (GCA) who present with ophthalmic symptoms and signs, with 2 specific histopathological findings-the presence of giant cells and arterial wall neoangiogenesis. The goal was to assess if these pathological features might be useful in guiding the approach to patient management. METHODS: Medical charts were retrospectively reviewed from 58 patients who underwent a temporal artery biopsy at a single institution. Detailed information was collected about the clinical presentation and course, with an emphasis on visual function. Histopathological and immunohistochemical techniques were used to examine temporal artery biopsies for evidence of inflammation. Correlations were made between the clinical data and the presence of giant cells and neoangiogenesis. RESULTS: Twenty-one (34%) biopsies were positive for inflammation consistent with GCA. Although the percentage of positive biopsies with giant cells was high, neither the presence of giant cells nor neoangiogenesis was predictive of a patient's presenting visual symptoms, severity and bilaterality of vision loss, other ophthalmic manifestations of GCA, presence of headache or jaw claudication, or erythrocyte sedimentation rate. Giant cells were more common in patients with recent weight loss. Immunohistochemistry confirmed diagnoses but did not alter the clinical course or treatment plan. CONCLUSIONS: There was no correlation between the clinical, specifically visual, features of GCA and the presence or absence of giant cells or neoangiogenesis in temporal artery biopsy specimens. Although the presence of neoangiogenesis may be important in the pathogenesis of GCA, our study showed no correlation between this finding and the clinical course.

Machiela MJ, Zhou W, Sampson JN, Dean MC, Jacobs KB, Black A, Brinton LA, Chang I-S, Chen C, Chen C, Chen K, Cook LS, Crous Bou M, De Vivo I, Doherty J, Friedenreich CM, Gaudet MM, Haiman CA, Hankinson SE, Hartge P, Henderson BE, Hong Y-C, Hosgood DH, Hsiung CA, Hu W, Hunter DJ, Jessop L, Kim HN, Kim YH, Kim YT, Klein R, Kraft P, Lan Q, Lin D, Liu J, Le Marchand L, Liang X, Lissowska J, Lu L, Magliocco AM, Matsuo K, Olson SH, Orlow I, Park JY, Pooler L, Prescott J, Rastogi R, Risch HA, Schumacher F, Seow A, Setiawan VW, Shen H, Sheng X, Shin M-H, Shu X-O, Van Den Berg D, Wang J-C, Wentzensen N, Wong MP, Wu C, Wu T, Wu Y-L, Xia L, Yang HP, Yang P-C, Zheng W, Zhou B, Abnet CC, Albanes D, Aldrich MC, Amos C, Amundadottir LT, Berndt SI, Blot WJ, Bock CH, Bracci PM, Burdett L, Buring JE, Butler MA, Carreón T, Chatterjee N, Chung CC, Cook MB, Cullen M, Davis FG, Ding T, Duell EJ, Epstein CG, Fan J-H, Figueroa JD, Fraumeni JF, Freedman ND, Fuchs CS, Gao Y-T, Gapstur SM, Patiño-Garcia A, Garcia-Closas M, Gaziano MJ, Giles GG, Gillanders EM, Giovannucci EL, Goldin L, Goldstein AM, Greene MH, Hallmans G, Harris CC, Henriksson R, Holly EA, Hoover RN, Hu N, Hutchinson A, Jenab M, Johansen C, Khaw K-T, Koh W-P, Kolonel LN, Kooperberg C, Krogh V, Kurtz RC, LaCroix A, Landgren A, Landi MT, Li D, Liao LM, Malats N, McGlynn KA, McNeill LH, McWilliams RR, Melin BS, Mirabello L, Peplonska B, Peters U, Petersen GM, Prokunina-Olsson L, Purdue M, Qiao Y-L, Rabe KG, Rajaraman P, Real FX, Riboli E, Rodríguez-Santiago B, Rothman N, Ruder AM, Savage SA, Schwartz AG, Schwartz KL, Sesso HD, Severi G, Silverman DT, Spitz MR, Stevens VL, Stolzenberg-Solomon R, Stram D, Tang Z-Z, Taylor PR, Teras LR, Tobias GS, Viswanathan K, Wacholder S, Wang Z, Weinstein SJ, Wheeler W, White E, Wiencke JK, Wolpin BM, Wu X, Wunder JS, Yu K, Zanetti KA, Zeleniuch-Jacquotte A, Ziegler RG, deAndrade M, Barnes KC, Beaty TH, Bierut LJ, Desch KC, Doheny KF, Feenstra B, Ginsburg D, Heit JA, Kang JH, Laurie CA, Li JZ, Lowe WL, Marazita ML, Melbye M, Mirel DB, Murray JC, Nelson SC, Pasquale LR, Rice K, Wiggs JL, Wise A, Tucker M, Pérez-Jurado LA, Laurie CC, Caporaso NE, Yeager M, Chanock SJ. Characterization of large structural genetic mosaicism in human autosomes. Am J Hum Genet 2015;96(3):487-97.Abstract

Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 × 10(-31)) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population.

Jacobo SMP, Kazlauskas A. Insulin-like Growth Factor 1 (IGF-1) Stabilizes Nascent Blood Vessels. J Biol Chem 2015;290(10):6349-60.Abstract

Here we report that VEGF-A and IGF-1 differ in their ability to stabilize newly formed blood vessels and endothelial cell tubes. Although VEGF-A failed to support an enduring vascular response, IGF-1 stabilized neovessels generated from primary endothelial cells derived from various vascular beds and mouse retinal explants. In these experimental systems, destabilization/regression was driven by lysophosphatidic acid (LPA). Because previous studies have established that Erk antagonizes LPA-mediated regression, we considered whether Erk was an essential component of IGF-dependent stabilization. Indeed, IGF-1 lost its ability to stabilize neovessels when the Erk pathway was inhibited pharmacologically. Furthermore, stabilization was associated with prolonged Erk activity. In the presence of IGF-1, Erk activity persisted longer than in the presence of VEGF or LPA alone. These studies reveal that VEGF and IGF-1 can have distinct inputs in the angiogenic process. In contrast to VEGF, IGF-1 stabilizes neovessels, which is dependent on Erk activity and associated with prolonged activation.

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