All

Francis JH, Berry D, Abramson DH, Barker CA, Bergstrom C, Demirci H, Engelbert M, Grossniklaus H, Hubbard B, Iacob CE, Jaben K, Kurli M, Postow MA, Wolchok JD, Kim IK, Wells JR. Intravitreous Cutaneous Metastatic Melanoma in the Era of Checkpoint Inhibition: Unmasking and Masquerading. Ophthalmology 2020;127(2):240-248.Abstract
PURPOSE: Cutaneous melanoma metastatic to the vitreous is very rare. This study investigated the clinical findings, treatment, and outcome of patients with metastatic cutaneous melanoma to the vitreous. Most patients received checkpoint inhibition for the treatment of systemic disease, and the significance of this was explored. DESIGN: Multicenter, retrospective cohort study. PARTICIPANTS: Fourteen eyes of 11 patients with metastatic cutaneous melanoma to the vitreous. METHODS: Clinical records, including fundus photography and ultrasound results, were reviewed retrospectively, and relevant data were recorded for each patient eye. MAIN OUTCOME MEASURES: Clinical features at presentation, ophthalmic and systemic treatments, and outcomes. RESULTS: The median age at presentation of ophthalmic disease was 66 years (range, 23-88 years), and the median follow-up from diagnosis of ophthalmic disease was 23 months. Ten of 11 patients were treated with immune checkpoint inhibition at some point in the treatment course. The median time from starting immunotherapy to ocular symptoms was 17 months (range, 4.5-38 months). Half of eyes demonstrated amelanotic vitreous debris. Five eyes demonstrated elevated intraocular pressure, and 4 eyes demonstrated a retinal detachment. Six patients showed metastatic disease in the central nervous system. Ophthalmic treatment included external beam radiation (30-40 Gy) in 6 eyes, intravitreous melphalan (10-20 μg) in 4 eyes, enucleation of 1 eye, and local observation while receiving systemic treatment in 2 eyes. Three eyes received intravitreous bevacizumab for neovascularization. The final Snellen visual acuity ranged from 20/20 to no light perception. CONCLUSIONS: The differential diagnosis of vitreous debris in the context of metastatic cutaneous melanoma includes intravitreal metastasis, and this seems to be particularly apparent during this era of treatment with checkpoint inhibition. External beam radiation, intravitreous melphalan, and systemic checkpoint inhibition can be used in the treatment of ophthalmic disease. Neovascular glaucoma and retinal detachments may occur, and most eyes show poor visual potential. Approximately one quarter of patients demonstrated ocular disease that preceded central nervous system metastasis. Patients with visual symptoms or vitreous debris in the context of metastatic cutaneous melanoma would benefit from evaluation by an ophthalmic oncologist.
Scott HA, Place EM, Ferenchak K, Zampaglione E, Wagner NE, Chao KR, DiTroia SP, Navarro-Gomez D, Mukai S, Huckfeldt RM, Pierce EA, Bujakowska KM. Expanding the phenotypic spectrum in RDH12-associated retinal disease. Cold Spring Harb Mol Case Stud 2020;6(1)Abstract
Retinol dehydrogenase 12, RDH12, plays a pivotal role in the visual cycle to ensure the maintenance of normal vision. Alterations in activity of this protein result in photoreceptor death and decreased vision beginning at an early age and progressing to substantial vision loss later in life. Here we describe 11 patients with retinal degeneration that underwent next-generation sequencing (NGS) with a targeted panel of all currently known inherited retinal degeneration (IRD) genes and whole-exome sequencing to identify the genetic causality of their retinal disease. These patients display a range of phenotypic severity prompting clinical diagnoses of macular dystrophy, cone-rod dystrophy, retinitis pigmentosa, and early-onset severe retinal dystrophy all attributed to biallelic recessive mutations in We report 15 causal alleles and expand the repertoire of known mutations with four novel variants: c.215A > G (p.Asp72Gly); c.362T > C (p.Ile121Thr); c.440A > C (p.Asn147Thr); and c.697G > A (p.Val233Ille). The broad phenotypic spectrum observed with biallelic mutations has been observed in other genetic forms of IRDs, but the diversity is particularly notable here given the prior association of primarily with severe early-onset disease. This breadth emphasizes the importance of broad genetic testing for inherited retinal disorders and extends the pool of individuals who may benefit from imminent gene-targeted therapies.
Jacobi A, van Zyl T. [Recent Research Efforts to Achieve Neuroprotection, Progression and Treatment of Glaucoma]. Klin Monbl Augenheilkd 2020;237(2):133-139.Abstract
Glaucoma is a neurodegenerative disease that leads to irreversible blindness over time. Its defining feature is the loss of retinal ganglion cells (RGCs) in the eye and their axons in the optic nerve. Increased intraocular pressure (IOP) is a major risk factor for the development of glaucoma, but is neither necessary nor sufficient for the disease and its progression; this motivates research and development of new strategies for the detection and treatment of glaucoma that focus on neuroprotection - protection of RGCs from dying. In addition, for diagnosis and treatment by reducing IOP, new approaches have been developed in recent years. This article reviews current theories of pathophysiological mechanisms underlying glaucoma and recent research - with a focus on neuroprotection and current preclinical and clinical studies to improve the diagnosis and treatment of glaucoma.
Feldstein IT, Dyszak GN. Road crossing decisions in real and virtual environments: A comparative study on simulator validity. Accid Anal Prev 2020;137:105356.Abstract
Virtual reality (VR) is a valuable tool for the assessment of human perception and behavior in a risk-free environment. Investigators should, however, ensure that the used virtual environment is validated in accordance with the experiment's intended research question since behavior in virtual environments has been shown to differ to behavior in real environments. This article presents the street crossing decisions of 30 participants who were facing an approaching vehicle and had to decide at what moment it was no longer safe to cross, applying the step-back method. The participants executed the task in a real environment and also within a highly immersive VR setup involving a head-mounted display (HMD). The results indicate significant differences between the two settings regarding the participants' behaviors. The time-to-contact of approaching vehicles was significantly lower for crossing decisions in the virtual environment than for crossing decisions in the real one. Additionally, it was demonstrated that participants based their crossing decisions in the real environment on the temporal distance of the approaching vehicle (i.e., time-to-contact), whereas the crossing decisions in the virtual environment seemed to depend on the vehicle's spatial distance, neglecting the vehicle's velocity. Furthermore, a deeper analysis suggests that crossing decisions were not affected by factors such as the participant's gender or the order in which they faced the real and the virtual environment.
Tomita Y, Fu Z, Wang Z, Cakir B, Cho SS, Britton W, Sun Y, Hellström A, Talukdar S, Smith LEH. Long-Acting FGF21 Inhibits Retinal Vascular Leakage in In Vivo and In Vitro Models. Int J Mol Sci 2020;21(4)Abstract
The aim of the current study was to investigate the impact of long-acting fibroblast growth factor 21 (FGF21) on retinal vascular leakage utilizing machine learning and to clarify the mechanism underlying the protection. To assess the effect on retinal vascular leakage, C57BL/6J mice were pre-treated with long-acting FGF21 analog or vehicle (Phosphate Buffered Saline; PBS) intraperitoneally (i.p.) before induction of retinal vascular leakage with intravitreal injection of mouse (m) vascular endothelial growth factor 164 (VEGF164) or PBS control. Five hours after mVEGF164 injection, we retro-orbitally injected Fluorescein isothiocyanate (FITC) -dextran and quantified fluorescence intensity as a readout of vascular leakage, using the Image Analysis Module with a machine learning algorithm. In FGF21- or vehicle-treated primary human retinal microvascular endothelial cells (HRMECs), cell permeability was induced with human (h) VEGF165 and evaluated using FITC-dextran and trans-endothelial electrical resistance (TEER). Western blots for tight junction markers were performed. Retinal vascular leakage in vivo was reduced in the FGF21 versus vehicle- treated mice. In HRMECs in vitro, FGF21 versus vehicle prevented hVEGF-induced increase in cell permeability, identified with FITC-dextran. FGF21 significantly preserved TEER compared to hVEGF. Taken together, FGF21 regulates permeability through tight junctions; in particular, FGF21 increases Claudin-1 protein levels in hVEGF-induced HRMECs. Long-acting FGF21 may help reduce retinal vascular leakage in retinal disorders and machine learning assessment can help to standardize vascular leakage quantification.
Lu Y, Wang JC, Zeng R, Nagata T, Katz R, Mukai S, Miller JB. Detection of retinal microvascular changes in von Hippel-Lindau disease using optical coherence tomography angiography. PLoS One 2020;15(2):e0229213.Abstract
PURPOSE: Von Hippel-Lindau (VHL) disease is a hereditary disorder that can lead to ophthalmic manifestations, including retinal capillary hemangioma (RCH). The diagnosis of RCH is often guided by wide-field fluorescein angiography. In some cases, optical coherence tomography angiography (OCT-A) serves as a non-invasive alternative to FA. Herein, we used OCT-A to examine the macular microvasculature in patients with VHL disease. SUBJECTS: Subjects were selected from patients with a diagnosis of VHL. The control group included eyes without retinal diagnosis from patients with an episode of unilateral retinal detachment or trauma and age ≤ 50 years old. METHODS: Subjects were scanned on the Optovue RTVue-XR device to acquire 3mm x 3mm OCT-A images of the superficial (SCP) and deep capillary plexus (DCP). SCP and DCP vessel density (VD) were calculated after the images were binarized. Furthermore, for subjects with RCH, each OCT-A image was divided equally into four quadrants. SCP and DCP VD of quadrants with RCH were compared to those without RCH. T-tests were performed for statistical analysis. RESULTS: 67 eyes with a history of VHL disease were included as study subjects, while 16 eyes were included as controls. Significant increases in VD were found in patients with VHL disease for both the SCP (p = 0.0441) and DCP (p = 0.0344). When comparing quadrants with associated RCH development to those without, we found no significant difference in SCP VD (p = 0.160) or DCP VD (p = 0.484). CONCLUSIONS: OCT-A can detect changes in the retinal microvasculature in the macula of patients with VHL disease. OCT-A imaging may be an additional tool for screening and early detection of patients at risk of developing ocular complications of VHL disease. Future studies should explore subtle progression on OCT-A associated with the pathogenesis and development of RCH, particularly with larger scan patterns.
Ung C, Stryjewski TP, Eliott D. Indications, Findings, and Outcomes of Pars Plana Vitrectomy after Open Globe Injury. Ophthalmol Retina 2020;4(2):216-223.Abstract
PURPOSE: To determine the indications, findings, and outcomes of patients with open globe injury (OGI) requiring pars plana vitrectomy (PPV). DESIGN: Retrospective, single-vitreoretinal surgeon case series. PARTICIPANTS: Sixty-one consecutive eyes with OGI that required PPV. METHODS: Retrospective chart review of consecutive patients who underwent PPV after OGI between March 1, 2011, and August 1, 2017, at Massachusetts Eye and Ear by 1 surgeon. MAIN OUTCOME MEASURES: Final visual acuity and rates of recurrent retinal detachment (RD) and proliferative vitreoretinopathy (PVR). RESULTS: Sixty-one eyes of 61 consecutive patients underwent PPV after sustaining OGI. Mean follow-up was 12.8±12.1 months (range, 0.5-65 months). At the time of presentation after OGI, 64% of eyes showed light perception or worse vision. The indications for PPV, which was performed on average of 15 days after injury, included RD without retinal incarceration (39%), RD with retinal incarceration in the scleral or corneal wound or both (13%), media opacity without RD (28%), vitreous traction without RD (11%), intraocular foreign body (5%), and endophthalmitis (3%). At the time of PPV, substantial comorbidities were noted, including corneal trauma (20%), hyphema (41%), iris trauma (62%), lens expulsion (54%), subretinal hemorrhage (51%), and choroidal hemorrhage (30%). Using multivariate analysis, factors associated with RD after initial PPV were preoperative subretinal hemorrhage (odds ratio [OR], 5.73; P = 0.03), PVR found at initial PPV (OR, 11.94; P = 0.021), and retinectomy (OR, 17.88; P = 0.003). No patients were inoperable, because all patients left the operating room with complete retinal reattachment. Of 35 eyes that showed RD, 19 (54%) redetached as a result of PVR. In 80% of eyes with RD at initial presentation (28/35 eyes), the retina remained completely attached at last follow-up, and 5 additional eyes remained partially attached (33/35 [94%]). Of 61 total eyes included in this study, 89% remained completely attached, and 42 (69%) achieved visual acuity of 20/200 or better at last follow-up. CONCLUSIONS: Despite substantial ocular comorbidities, PPV can result in retinal reattachment in even the most severe cases. Good visual outcomes can be achieved for most patients who undergo vitreoretinal surgery after open globe trauma.
Pamir Z, Canoluk UM, Jung J-H, Peli E. Poor resolution at the back of the tongue is the bottleneck for spatial pattern recognition. Sci Rep 2020;10(1):2435.Abstract
Spatial patterns presented on the tongue using electro-tactile sensory substitution devices (SSDs) have been suggested to be recognized better by tracing the pattern with the tip of the tongue. We examined if the functional benefit of tracing is overcoming the poor sensitivity or low spatial resolution at the back of the tongue or alternatively compensating for limited information processing capacity by fixating on a segment of the spatial pattern at a time. Using a commercially available SSD, the BrainPort, we compared letter recognition performance in three presentation modes; tracing, static, and drawing. Stimulation intensity was either constant or increased from the tip to the back of the tongue to partially compensate for the decreasing sensitivity. Recognition was significantly better for tracing, compared to static and drawing conditions. Confusion analyses showed that letters were confused based on their characteristics presented near the tip in static and drawing conditions. The results suggest that recognition performance is limited by the poor spatial resolution at the back of the tongue, and tracing seems to be an effective strategy to overcome this. Compensating for limited information processing capacity or poor sensitivity by drawing or increasing intensity at the back, respectively, does not improve the performance.
, Fabian ID, Abdallah E, Abdullahi SU, Abdulqader RA, Adamou Boubacar S, Ademola-Popoola DS, Adio A, Afshar AR, Aggarwal P, Aghaji AE, Ahmad A, Akib MNR, Al Harby L, Al Ani MH, Alakbarova A, Portabella SA, Al-Badri SAF, Alcasabas APA, Al-Dahmash SA, Alejos A, Alemany-Rubio E, Alfa Bio AI, Alfonso Carreras Y, Al-Haddad C, Al-Hussaini HHY, Ali AM, Alia DB, Al-Jadiry MF, Al-Jumaly U, Alkatan HM, All-Eriksson C, Al-Mafrachi AARM, Almeida AA, Alsawidi KM, Al-Shaheen AASM, Al-Shammary EH, Amiruddin PO, Antonino R, Astbury NJ, Atalay HT, Atchaneeyasakul L-O, Atsiaya R, Attaseth T, Aung TH, Ayala S, Baizakova B, Balaguer J, Balayeva R, Balwierz W, Barranco H, Bascaran C, Beck Popovic M, Benavides R, Benmiloud S, Bennani Guebessi N, Berete RC, Berry JL, Bhaduri A, Bhat S, Biddulph SJ, Biewald EM, Bobrova N, Boehme M, Boldt HC, Bonanomi MTBC, Bornfeld N, Bouda GC, Bouguila H, Boumedane A, Brennan RC, Brichard BG, Buaboonnam J, Calderón-Sotelo P, Calle Jara DA, Camuglia JE, Cano MR, Capra M, Cassoux N, Castela G, Castillo L, Català-Mora J, Chantada GL, Chaudhry S, Chaugule SS, Chauhan A, Chawla B, Chernodrinska VS, Chiwanga FS, Chuluunbat T, Cieslik K, Cockcroft RL, Comsa C, Correa ZM, Correa Llano MG, Corson TW, Cowan-Lyn KE, Csóka M, Cui X, Da Gama IV, Dangboon W, Das A, Das S, Davanzo JM, Davidson A, De Potter P, Delgado KQ, Demirci H, Desjardins L, Diaz Coronado RY, Dimaras H, Dodgshun AJ, Donaldson C, Donato Macedo CR, Dragomir MD, Du Y, Du Bruyn M, Edison KS, Eka Sutyawan WI, El Kettani A, Elbahi AM, Elder JE, Elgalaly D, Elhaddad AM, Elhassan MAM, Elzembely MM, Essuman VA, Evina TGA, Fadoo Z, Fandiño AC, Faranoush M, Fasina O, Fernández DDPG, Fernández-Teijeiro A, Foster A, Frenkel S, Fu LD, Fuentes-Alabi SL, Gallie BL, Gandiwa M, Garcia JL, García Aldana D, Gassant PY, Geel JA, Ghassemi F, Girón AV, Gizachew Z, Goenz MA, Gold AS, Goldberg-Lavid M, Gole GA, Gomel N, Gonzalez E, Gonzalez Perez G, González-Rodríguez L, Garcia Pacheco HN, Graells J, Green L, Gregersen PA, Grigorovski NDAK, Guedenon KM, Gunasekera SD, Gündüz AK, Gupta H, Gupta S, Hadjistilianou T, Hamel P, Hamid SA, Hamzah N, Hansen ED, Harbour WJ, Hartnett EM, Hasanreisoglu M, Hassan S, Hassan S, Hederova S, Hernandez J, Hernandez LMC, Hessissen L, Hordofa DF, Huang LC, Hubbard GB, Hummlen M, Husakova K, Hussein Al-Janabi AN, Ida R, Ilic VR, Jairaj V, Jeeva I, Jenkinson H, Ji X, Jo DH, Johnson KP, Johnson WJ, Jones MM, Kabesha TAB, Kabore RL, Kaliki S, Kalinaki A, Kantar M, Kao L-Y, Kardava T, Kebudi R, Kepak T, Keren-Froim N, Khan ZJ, Khaqan HA, Khauv P, Kheir WJ, Khetan V, Khodabande A, Khotenashvili Z, Kim JW, Kim JH, Kiratli H, Kivelä TT, Klett A, Komba Palet JEK, Krivaitiene D, Kruger M, Kulvichit K, Kuntorini MW, Kyara A, Lachmann ES, Lam CPS, Lam GC, Larson SA, Latinovic S, Laurenti KD, Le BHA, Lecuona K, Leverant AA, Li C, Limbu B, Long QB, López JP, Lukamba RM, Lumbroso L, Luna-Fineman S, Lutfi D, Lysytsia L, Magrath GN, Mahajan A, Majeed AR, Maka E, Makan M, Makimbetov EK, Manda C, Martín Begue N, Mason L, Mason JO, Matende IO, Materin M, Mattosinho CCDS, Matua M, Mayet I, Mbumba FB, McKenzie JD, Medina-Sanson A, Mehrvar A, Mengesha AA, Menon V, Mercado GJVD, Mets MB, Midena E, Mishra DKC, Mndeme FG, Mohamedani AA, Mohammad MT, Moll AC, Montero MM, Morales RA, Moreira C, Mruthyunjaya P, Msina MS, Msukwa G, Mudaliar SS, Muma KI, Munier FL, Murgoi G, Murray TG, Musa KO, Mushtaq A, Mustak H, Muyen OM, Naidu G, Nair AG, Naumenko L, Ndoye Roth PA, Nency YM, Neroev V, Ngo H, Nieves RM, Nikitovic M, Nkanga ED, Nkumbe H, Nuruddin M, Nyaywa M, Obono-Obiang G, Oguego NC, Olechowski A, Oliver SCN, Osei-Bonsu P, Ossandon D, Paez-Escamilla MA, Pagarra H, Painter SL, Paintsil V, Paiva L, Pal BP, Palanivelu MS, Papyan R, Parrozzani R, Parulekar M, Pascual Morales CR, Paton KE, Pawinska-Wasikowska K, Pe'er J, Peña A, Peric S, Pham CTM, Philbert R, Plager DA, Pochop P, Polania RA, Polyakov VG, Pompe MT, Pons JJ, Prat D, Prom V, Purwanto I, Qadir AO, Qayyum S, Qian J, Rahman A, Rahman S, Rahmat J, Rajkarnikar P, Ramanjulu R, Ramasubramanian A, Ramirez-Ortiz MA, Raobela Léa, Rashid R, Reddy AM, Reich E, Renner LA, Reynders D, Ribadu D, Riheia MM, Ritter-Sovinz P, Rojanaporn D, Romero L, Roy SR, Saab RH, Saakyan S, Sabhan AH, Sagoo MS, Said AMA, Saiju R, Salas B, San Román Pacheco S, Sánchez GL, Sayalith P, Scanlan TA, Schefler AC, Schoeman J, Sedaghat A, Seregard S, Seth R, Shah AS, Shakoor SA, Sharma MK, Sherief ST, Shetye NG, Shields CL, Siddiqui SN, Sidi Cheikh S, Silva S, Singh AD, Singh N, Singh U, Singha P, Sitorus RS, Skalet AH, Soebagjo HD, Sorochynska T, Ssali G, Stacey AW, Staffieri SE, Stahl ED, Stathopoulos C, Stirn Kranjc B, Stones DK, Strahlendorf C, Suarez MEC, Sultana S, Sun X, Sundy M, Superstein R, Supriyadi E, Surukrattanaskul S, Suzuki S, Svojgr K, Sylla F, Tamamyan G, Tan D, Tandili A, Tarrillo Leiva FF, Tashvighi M, Tateshi B, Tehuteru ES, Teixeira LF, Teh KH, Theophile T, Toledano H, Trang DL, Traoré F, Trichaiyaporn S, Tuncer S, Tyau-Tyau H, Umar AB, Unal E, Uner OE, Urbak SF, Ushakova TL, Usmanov RH, Valeina S, van Hoefen Wijsard M, Varadisai A, Vasquez L, Vaughan LO, Veleva-Krasteva NV, Verma N, Victor AA, Viksnins M, Villacís Chafla EG, Vishnevskia-Dai V, Vora T, Wachtel AE, Wackernagel W, Waddell K, Wade PD, Wali AH, Wang Y-Z, Weiss A, Wilson MW, Wime ADC, Wiwatwongwana A, Wiwatwongwana D, Wolley Dod C, Wongwai P, Xiang D, Xiao Y, Yam JC, Yang H, Yanga JM, Yaqub MA, Yarovaya VA, Yarovoy AA, Ye H, Yousef YA, Yuliawati P, Zapata López AM, Zein E, Zhang C, Zhang Y, Zhao J, Zheng X, Zhilyaeva K, Zia N, Ziko OAO, Zondervan M, Bowman R. Global Retinoblastoma Presentation and Analysis by National Income Level. JAMA Oncol 2020;Abstract
Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs.
Prahst C, Ashrafzadeh P, Mead T, Figueiredo A, Chang K, Richardson D, Venkaraman L, Richards M, Russo AM, Harrington K, Ouarné M, Pena A, Chen DF, Claesson-Welsh L, Cho K-S, Franco CA, Bentley K. Mouse retinal cell behaviour in space and time using light sheet fluorescence microscopy. Elife 2020;9Abstract
As the general population ages, more people are affected by eye diseases, such as retinopathies. It is therefore critical to improve imaging of eye disease mouse models. Here, we demonstrate that 1) rapid, quantitative 3D and 4D (time lapse) imaging of cellular and subcellular processes in the mouse eye is feasible, with and without tissue clearing, using light-sheet fluorescent microscopy (LSFM); 2) flat-mounting retinas for confocal microscopy significantly distorts tissue morphology, confirmed by quantitative correlative LSFM-Confocal imaging of vessels; 3) LSFM readily reveals new features of even well-studied eye disease mouse models, such as the oxygen-induced retinopathy (OIR) model, including a previously unappreciated 'knotted' morphology to pathological vascular tufts, abnormal cell motility and altered filopodia dynamics when live-imaged. We conclude that quantitative 3D/4D LSFM imaging and analysis has the potential to advance our understanding of the eye, in particular pathological, neuro-vascular, degenerative processes.
Ashraf M, Sampani K, AbdelAl O, Fleming A, Cavallerano J, Souka A, El Baha SM, Silva PS, Sun J, Aiello LP. Disparity of microaneurysm count between ultrawide field colour imaging and ultrawide field fluorescein angiography in eyes with diabetic retinopathy. Br J Ophthalmol 2020;104(12):1762-1767.Abstract
AIMS: To compare microaneurysm (MA) counts using ultrawide field colour images (UWF-CI) and ultrawide field fluorescein angiography (UWF-FA). METHODS: Retrospective study including patients with type 1 or 2 diabetes mellitus receiving UWF-FA and UWF-CI within 2 weeks. MAs were manually counted in individual Early Treatment Diabetic Retinopathy Study (ETDRS) and extended UWF zones. Fields with MAs ≥20 determined diabetic retinopathy (DR) severity (0 fields=mild, 1-3=moderate, ≥4=severe). UWF-FA and UWF-CI agreement was determined and UWF-CI DR severity sensitivity analysis adjusting for UWF-FA MA counts performed. RESULTS: In 193 patients (288 eyes), 2.4% had no DR, 29.9% mild non-proliferative DR (NPDR), 32.6% moderate (NPDR), 22.9% severe NPDR and 12.2% proliferative DR. UWF-FA MA counts were 3.5-fold higher (p<0.001) than UWF-CI counts overall, 3.2x-fold higher in ETDRS fields (p<0.001) and 5.3-fold higher in extended ETDRS fields (p<0.001) and higher in type 1 versus type 2 diabetes (p<0.001). In eyes with NPDR on UWF-CI (n=246), UWF-FA images had 1.6x-3.5x more fields with ≥20 MAs (p<0.001). Fair agreement existed between imaging modalities (k=0.221-0.416). In ETDRS fields, DR severity agreement increased from k=0.346 to 0.600 when dividing UWF-FA counts by a factor of 3, followed by rapid decline in agreement thereafter. Total UWF area agreement increased from k=0.317 to 0.565 with an adjustment factor of either 4 or 5. CONCLUSIONS: UWF-FA detects threefold to fivefold more MAs than UWF-CI and identifies 1.6-3.5-fold more fields affecting DR severity. Differences exist at all DR severity levels, thus limiting direct comparison between the modalities. However, correcting UWF-FA MA counts substantially improves DR severity agreement between the modalities.
Kallman A, Capowski EE, Wang J, Kaushik AM, Jansen AD, Edwards KL, Chen L, Berlinicke CA, Joseph Phillips M, Pierce EA, Qian J, Wang T-H, Gamm DM, Zack DJ. Investigating cone photoreceptor development using patient-derived NRL null retinal organoids. Commun Biol 2020;3(1):82.Abstract
Photoreceptor loss is a leading cause of blindness, but mechanisms underlying photoreceptor degeneration are not well understood. Treatment strategies would benefit from improved understanding of gene-expression patterns directing photoreceptor development, as many genes are implicated in both development and degeneration. Neural retina leucine zipper (NRL) is critical for rod photoreceptor genesis and degeneration, with NRL mutations known to cause enhanced S-cone syndrome and retinitis pigmentosa. While murine Nrl loss has been characterized, studies of human NRL can identify important insights for human retinal development and disease. We utilized iPSC organoid models of retinal development to molecularly define developmental alterations in a human model of NRL loss. Consistent with the function of NRL in rod fate specification, human retinal organoids lacking NRL develop S-opsin dominant photoreceptor populations. We report generation of two distinct S-opsin expressing populations in NRL null retinal organoids and identify MEF2C as a candidate regulator of cone development.
Woodward AM, Di Zazzo A, Bonini S, Argüeso P. Endoplasmic reticulum stress promotes inflammation-mediated proteolytic activity at the ocular surface. Sci Rep 2020;10(1):2216.Abstract
A growing body of evidence implicates endoplasmic reticulum (ER) stress in the pathogenesis of chronic inflammatory and autoimmune disorders. Here, we demonstrate that the proinflammatory cytokine TNFα stimulates matrix metalloproteinase 9 (MMP9) at the ocular surface through a c-Fos-dependent mechanism of ER stress. We found positive reactivity of the molecular chaperone BiP/GRP78 in conjunctival epithelium of patients with ocular cicatricial pemphigoid and increased levels of BiP/GRP78, sXBP1 and GRP94 in human corneal epithelial cells treated with TNFα. Pharmacological blockade of ER stress in vitro using dexamethasone or the chemical chaperones TUDCA and 4PBA attenuated MMP9 expression and secretion in the presence of TNFα. Moreover, expression analysis of genes associated with inflammation and autoimmunity identified the c-Fos proto-oncogene as a mediator of ER stress responses in epithelial cells. Substantially less TNFα-induced MMP9 expression occurred when c-Fos signaling was suppressed with a function-blocking antibody. Taken together, these results indicate that activation of ER stress contributes to promote inflammation-mediated proteolytic activity and uncovers a target for restoring tissue homeostasis in ocular autoimmune disease.
Kang J, Cho SS, Kim HY, Lee BH, Cho HJ, Gwak YS. Regional Hyperexcitability and Chronic Neuropathic Pain Following Spinal Cord Injury. Cell Mol Neurobiol 2020;40(6):861-878.Abstract
Spinal cord injury (SCI) causes maladaptive changes to nociceptive synaptic circuits within the injured spinal cord. Changes also occur at remote regions including the brain stem, limbic system, cortex, and dorsal root ganglia. These maladaptive nociceptive synaptic circuits frequently cause neuronal hyperexcitability in the entire nervous system and enhance nociceptive transmission, resulting in chronic central neuropathic pain following SCI. The underlying mechanism of chronic neuropathic pain depends on the neuroanatomical structures and electrochemical communication between pre- and postsynaptic neuronal membranes, and propagation of synaptic transmission in the ascending pain pathways. In the nervous system, neurons are the only cell type that transmits nociceptive signals from peripheral receptors to supraspinal systems due to their neuroanatomical and electrophysiological properties. However, the entire range of nociceptive signaling is not mediated by any single neuron. Current literature describes regional studies of electrophysiological or neurochemical mechanisms for enhanced nociceptive transmission post-SCI, but few studies report the electrophysiological, neurochemical, and neuroanatomical changes across the entire nervous system following a regional SCI. We, along with others, have continuously described the enhanced nociceptive transmission in the spinal dorsal horn, brain stem, thalamus, and cortex in SCI-induced chronic central neuropathic pain condition, respectively. Thus, this review summarizes the current understanding of SCI-induced neuronal hyperexcitability and maladaptive nociceptive transmission in the entire nervous system that contributes to chronic central neuropathic pain.

Pages