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Sorour OA, Nassar E, Sarhan N, El-Anwar N, ElKholy RA, Tahoon DM, Sweilam A, Tadros D. Chronic sildenafil citrate use decreases retinal vascular endothelial growth factor expression in diabetic rats: a pilot study. Int J Retina Vitreous 2023; 9:42. [PMID: 37460929 PMCID: PMC10351124 DOI: 10.1186/s40942-023-00480-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/01/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Sildenafil citrate (SC) attenuates endothelial dysfunction. However, its effects on diabetic retinopathy (DR), which is mainly a microvascular disease, remain unclear. Vascular endothelial growth factor (VEGF) is known to be a critical mediator of DR. Therefore, we investigated the effects of SC on diabetic retina by measuring VEGF levels. METHODS In this study, twenty-eight rats were divided into the following groups: group I, the control group; group II, rats with streptozotocin-induced diabetes; group III, rats with streptozotocin-induced diabetes receiving daily oral sildenafil at 1 mg/kg; and group IV, rats with streptozotocin-induced diabetes receiving high-dose daily sildenafil at 2.5 mg/kg. After 3 months, VEGF was measured in the retina specimen in one eye and the vitreous body in the other eye by immunohistochemistry and enzyme-linked immunosorbent assay, respectively. RESULTS We found that VEGF expression in the retina was low in all rats from groups I and IV and in 30% of rats from group III; 80% of rats in group II demonstrated high VEGF expression in the retinae (P < 0.001). VEGF concentrations in the vitreous body samples were 32 ± 2, 61 ± 4, 44 ± 5, and 36 ± 3 pg/l in groups I-IV, respectively (P < 0.001). CONCLUSION VEGF decreased significantly in the eyes of diabetic rats after chronic oral sildenafil citrate treatment. SC may have a modifying/attenuating effect on DR. However, further studies are needed to evaluate its use as an adjunctive treatment.
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Affiliation(s)
- Osama A Sorour
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt.
| | - Elsayed Nassar
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Naglaa Sarhan
- Department of Histology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Noha El-Anwar
- Department of Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Pathology, Armed Forces College of Medicine, Heliopolis, Egypt
| | - Reem A ElKholy
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Pharmacology, School of medicine, Badr University, Badr, Egypt
| | - Dina M Tahoon
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Aalaa Sweilam
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Clinical Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Dina Tadros
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt
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2
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Gao S, Zeng Y, Li Y, Cohen ED, Berkowitz BA, Qian H. Fast and slow light-induced changes in murine outer retina optical coherence tomography: complementary high spatial resolution functional biomarkers. PNAS NEXUS 2022; 1:pgac208. [PMID: 36338188 PMCID: PMC9615127 DOI: 10.1093/pnasnexus/pgac208] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/21/2022] [Indexed: 11/18/2022]
Abstract
Fast (seconds) and slow (minutes to hours) optical coherence tomography (OCT) responses to light stimulation have been developed to probe outer retinal function with higher spatial resolution than the classical full-field electroretinogram (ERG). However, the relationships between functional information revealed by OCT and ERG are largely unexplored. In this study, we directly compared the fast and slow OCT responses with the ERG. Fast responses [i.e. the optoretinogram (ORG)] are dominated by reflectance changes in the outer segment (OS) and the inner segment ellipsoid zone (ISez). The ORG OS response has faster kinetics and a higher light sensitivity than the ISez response, and both differ significantly with ERG parameters. Sildenafil-inhibition of phototransduction reduced the ORG light sensitivity, suggesting a complete phototransduction pathway is needed for ORG responses. Slower OCT responses were dominated by light-induced changes in the external limiting membrane to retinal pigment epithelium (ELM-RPE) thickness and photoreceptor-tip hyporeflective band (HB) magnitudes, with the biggest changes occurring after prolonged light stimulation. Mice with high (129S6/ev) vs. low (C57BL/6 J) ATP(adenosine triphosphate) synthesis efficiency show similar fast ORG, but dissimilar slow OCT responses. We propose that the ORG reflects passive physiology, such as water movement from photoreceptors, in response to the photocurrent response (measurable by ERG), whereas the slow OCT responses measure mitochondria-driven physiology in the outer retina, such as dark-provoked water removal from the subretinal space.
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Affiliation(s)
- Shasha Gao
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450001, China
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yong Zeng
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ethan D Cohen
- Division of Biomedical Physics, Office of Science and Engineering Labs, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993-0002, USA
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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3
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Sterling N, Duncan AR, Park R, Koolen DA, Shi J, Cho SH, Benke PJ, Grant PE, Genetti CA, VanNoy GE, Juusola J, McWalter K, Parboosingh JS, Lamont RE, Bernier FP, Smith C, Harris DJ, Stegmann APA, Innes AM, Kim S, Agrawal PB. De novo variants in MPP5 cause global developmental delay and behavioral changes. Hum Mol Genet 2021; 29:3388-3401. [PMID: 33073849 DOI: 10.1093/hmg/ddaa224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/27/2020] [Accepted: 10/11/2020] [Indexed: 12/13/2022] Open
Abstract
Membrane Protein Palmitoylated 5 (MPP5) is a highly conserved apical complex protein essential for cell polarity, fate and survival. Defects in cell polarity are associated with neurologic disorders including autism and microcephaly. MPP5 is essential for neurogenesis in animal models, but human variants leading to neurologic impairment have not been described. We identified three patients with heterozygous MPP5 de novo variants (DNV) and global developmental delay (GDD) and compared their phenotypes and magnetic resonance imaging (MRI) to ascertain how MPP5 DNV leads to GDD. All three patients with MPP5 DNV experienced GDD with language delay/regression and behavioral changes. MRI ranged from normal to decreased gyral folding and microcephaly. The effects of MPP5 depletion on the developing brain were assessed by creating a heterozygous conditional knock out (het CKO) murine model with central nervous system (CNS)-specific Nestin-Cre drivers. In the het CKO model, Mpp5 depletion led to microcephaly, decreased cerebellar volume and cortical thickness. Het CKO mice had decreased ependymal cells and Mpp5 at the apical surface of cortical ventricular zone compared with wild type. Het CKO mice also failed to maintain progenitor pools essential for neurogenesis. The proportion of cortical cells undergoing apoptotic cell death increased, suggesting that cell death reduces progenitor population and neuron number. Het CKO mice also showed behavioral changes, similar to our patients. To our knowledge, this is the first report to show that variants in MPP5 are associated with GDD, behavioral abnormalities and language regression/delay. Murine modeling shows that neurogenesis is likely altered in these individuals, with cell death and skewed cellular composition playing significant roles.
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Affiliation(s)
- Noelle Sterling
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine. Temple University, Philadelphia, PA, 19140, USA
| | - Anna R Duncan
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA
| | - Raehee Park
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine. Temple University, Philadelphia, PA, 19140, USA
| | - David A Koolen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Jiahai Shi
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Seo-Hee Cho
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine. Temple University, Philadelphia, PA, 19140, USA
| | - Paul J Benke
- Division of Clinical Genetics, Joe DiMaggio Children's Hospital, Hollywood, FL 33021, USA
| | - Patricia E Grant
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Radiology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Casie A Genetti
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Grace E VanNoy
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jane Juusola
- Clinical Genomics Program, GeneDx, Gaithersburg, MD 20877, USA
| | - Kirsty McWalter
- Clinical Genomics Program, GeneDx, Gaithersburg, MD 20877, USA
| | - Jillian S Parboosingh
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1A4, Canada
| | - Ryan E Lamont
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1A4, Canada
| | - Francois P Bernier
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1A4, Canada
| | - Christopher Smith
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1A4, Canada
| | - David J Harris
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA
| | - Alexander P A Stegmann
- Department of Clinical Genetics, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands.,Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - A Micheil Innes
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1A4, Canada
| | - Seonhee Kim
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine. Temple University, Philadelphia, PA, 19140, USA
| | - Pankaj B Agrawal
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA.,Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
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Arora S, Surakiatchanukul T, Arora T, Cagini C, Lupidi M, Chhablani J. Sildenafil in ophthalmology: An update. Surv Ophthalmol 2021; 67:463-487. [PMID: 34175342 DOI: 10.1016/j.survophthal.2021.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 12/14/2022]
Abstract
Sildenafil citrate, a selective oral phosphodiesterase 5 inhibitor, is a widely used drug for erectile dysfunction that acts by elevating cGMP levels and causing smooth muscle relaxation. It also has 10% activity against PDE6, a key enzyme in phototransduction cascade in the retina. Recent ocular imaging developments have further revealed the influence of sildenafil on ocular hemodynamics, particularly choroidal perfusion. Choroidal thickness is increased, and choroidal perfusion is also enhanced by autoregulatory mechanisms that are further dependent on age and microvascular abnormalities. Studies demonstrating high intraocular pressure via a "parallel pathway" from increased choroidal volume and blood flow to the ciliary body have challenged previous concepts. Another new observation is the effect of sildenafil on bipolar cells and cyclic-nucleotide gated channels. We discuss potential deleterious effects (central serous chorioretinopathy, glaucoma, ischemic optic neuropathy, and risks to recessive carriers of retinitis pigmentosa), potential beneficial effects (ameliorate choroidal ischemia, prevent thickening of Bruch membrane, and promote recovery of the ellipsoid zone) in macular degeneration, as well as potential drug interactions of sildenafil.
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Affiliation(s)
- Supriya Arora
- Bahamas Vision Centre and Princess Margaret Hospital, Nassau NP, Bahamas.
| | - Thamolwan Surakiatchanukul
- Department of Ophthalmology, Jamaica Hospital Medical Center, New York Medical College, Jamaica, NY, USA
| | - Tarun Arora
- Bahamas Vision Centre and Princess Margaret Hospital, Nassau NP, Bahamas.
| | - Carlo Cagini
- Department of Biochemical and Surgical Sciences, Section of ophthalmology, University of Perugia, Perugia, Italy
| | - Marco Lupidi
- Department of Biochemical and Surgical Sciences, Section of ophthalmology, University of Perugia, Perugia, Italy
| | - Jay Chhablani
- University of Pittsburgh, UPMC Eye Center, Pittsburgh, PA, USA.
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5
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Visual Side Effects Linked to Sildenafil Consumption: An Update. Biomedicines 2021; 9:biomedicines9030291. [PMID: 33809319 PMCID: PMC7998971 DOI: 10.3390/biomedicines9030291] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 12/14/2022] Open
Abstract
Phosphodiesterase type 5 (PDE5) inhibitors such as Viagra® (sildenafil citrate) have demonstrated efficacy in the treatment of erectile dysfunction (ED) by inducing cyclic guanosine monophosphate (cGMP) elevation followed by vasodilation and increased blood flow. It also exerts minor inhibitory action against PDE6, which is present exclusively in rod and cone photoreceptors. The effects of sildenafil on the visual system have been investigated in a wide variety of clinical and preclinical studies due to the fact that a high dose of sildenafil may cause mild and transient visual symptoms in some patients. A literature review was performed using PubMed, Cochrane Library and Clinical Trials databases from 1990 up to 2020, focusing on the pathophysiology of visual disorders induced by sildenafil. The aim of this review was not only to gather and summarize the information available on sildenafil clinical trials (CTs), but also to spot subpopulations with increased risk of developing undesirable visual side effects. This PDE inhibitor has been associated with transient and reversible ocular side effects, including changes in color vision and light perception, blurred vision, photophobia, conjunctival hyperemia and keratitis, and alterations in the electroretinogram (ERG). Sildenafil may induce a reversible increase in intraocular pressure (IOP) and a few case reports suggest it is involved in the development of nonarteritic ischemic optic neuropathy (NAION). Reversible idiopathic serous macular detachment, central serous retinopathy and ERG disturbances have been related to the significant impact of sildenafil on retinal perfusion. So far, sildenafil does not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors as long as the therapeutic dose is not exceeded and is taken under a physician’s direction to treat a medical condition. However, the recreational use of sildenafil can lead to harmful side effects, including vision changes.
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6
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Sildenafil-evoked photoreceptor oxidative stress in vivo is unrelated to impaired visual performance in mice. PLoS One 2021; 16:e0245161. [PMID: 33661941 PMCID: PMC7932139 DOI: 10.1371/journal.pone.0245161] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 12/22/2020] [Indexed: 12/22/2022] Open
Abstract
Purpose The phosphodiesterase inhibitor sildenafil is a promising treatment for neurodegenerative disease, but it can cause oxidative stress in photoreceptors ex vivo and degrade visual performance in humans. Here, we test the hypotheses that in wildtype mice sildenafil causes i) wide-spread photoreceptor oxidative stress in vivo that is linked with ii) impaired vision. Methods In dark or light-adapted C57BL/6 mice ± sildenafil treatment, the presence of oxidative stress was evaluated in retina laminae in vivo by QUEnch-assiSTed (QUEST) magnetic resonance imaging, in the subretinal space in vivo by QUEST optical coherence tomography, and in freshly excised retina by a dichlorofluorescein assay. Visual performance indices were also evaluated by QUEST optokinetic tracking. Results In light-adapted mice, 1 hr post-sildenafil administration, oxidative stress was most evident in the superior peripheral outer retina on both in vivo and ex vivo examinations; little evidence was noted for central retina oxidative stress in vivo and ex vivo. In dark-adapted mice 1 hr after sildenafil, no evidence for outer retina oxidative stress was found in vivo. Evidence for sildenafil-induced central retina rod cGMP accumulation was suggested as a panretinally thinner, dark-like subretinal space thickness in light-adapted mice at 1 hr but not 5 hr post-sildenafil. Cone-based visual performance was impaired by 5 hr post-sildenafil and not corrected with anti-oxidants; vision was normal at 1 hr and 24 hr post-sildenafil. Conclusions The sildenafil-induced spatiotemporal pattern of oxidative stress in photoreceptors dominated by rods was unrelated to impairment of cone-based visual performance in wildtype mice.
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7
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Progressive Effects of Sildenafil on Visual Processing in Rats. Neuroscience 2020; 441:131-141. [PMID: 32615234 DOI: 10.1016/j.neuroscience.2020.06.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/26/2020] [Accepted: 06/23/2020] [Indexed: 10/24/2022]
Abstract
Photoreceptors are light-sensitive cells in the retina converting visual stimuli into electrochemical signals. These signals are evaluated and interpreted in the visual pathway, a process referred to as visual processing. Phosphodiesterase type 5 and 6 (PDE5 and 6) are abundant enzymes in retinal vessels and notably photoreceptors where PDE6 is exclusively present. The effects of the PDE inhibitor sildenafil on the visual system, have been studied using electroretinography and a variety of clinical visual tasks. Here we evaluate effects of sildenafil administration by electrophysiological recordings of flash visual evoked potentials (VEPs) and steady-state visual evoked potentials (SSVEPs) from key regions in the rodent visual pathway. Progressive changes were investigated in female Sprague-Dawley rats at 10 timepoints from 30 min to 28 h after peroral administration of sildenafil (50 mg/kg). Sildenafil caused a significant reduction in the amplitude of VEPs in both visual cortex and superior colliculus, and a significant delay of the VEPs as demonstrated by increased latency of several VEP peaks. Also, sildenafil-treatment significantly reduced the signal-to-noise ratio of SSVEPs. The effects of sildenafil were dependent on the wavelength condition in both assays. Our results support the observation that while PDE6 is a key player in phototransduction, near full inhibition of PDE6 is not enough to abolish the complex process of visual processing. Taken together, VEPs and SSVEPs are effective in demonstrating progressive effects of drug-induced changes in visual processing in rats and as the same paradigms may be applied in humans, representing a promising tool for translational research.
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Defining the Efficacy and Safety of Phosphodiesterase Type 5 Inhibitors with Tamsulosin for the Treatment of Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia with or without Erectile Dysfunction: A Network Meta-Analysis. BIOMED RESEARCH INTERNATIONAL 2020; 2020:1419520. [PMID: 32309423 PMCID: PMC7140123 DOI: 10.1155/2020/1419520] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/19/2020] [Indexed: 01/19/2023]
Abstract
Purpose The purpose of this study was to compare the relative safety and efficacy of different types of phosphodiesterase type 5 inhibitors (PDE5-Is) with tamsulosin for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostate hyperplasia (BPH) (BPH-LUTS) with or without erectile dysfunction (ED). Methods We use the Stata version 13.0 to conduct the network meta-analysis (NMA) with a random effects model of the Bayesian framework. The International Prostate Symptom Score (IPSS), Maximum Urinary Flow Fate (Qmax), International Index of Erectile Function (IIEF), and their credible intervals (CI) were used to compare the efficacy and safety of every medical intervention, including sildenafil plus tamsulosin, tadalafil plus tamsulosin, and vardenafil plus tamsulosin. Results Seven RCTs including 531 participants with seven interventions were analyzed. The results of NMA SUCRA showed that compared with different doses or types of PDE5-Is combined with tamsulosin (0.4 mg qd), the sildenafil (25 mg qd) combined with tamsulosin (0.4 mg qd) group had the greatest probabilities of being the best in the achievement of improving IIEF. The sildenafil (25 mg 4 days per week) combined with tamsulosin (0.4 mg qd) group had the greatest probabilities of being the best in the achievement of improving Qmax, whereas sildenafil (25 mg qd) combined with tamsulosin (0.4 mg qd) ranked the best for the safety outcomes. Conclusions This meta-analysis indicates that sildenafil combined with tamsulosin is the best effective and tolerated treatment option for BPH-LUTS with or without ED. Further RCTs are strongly required to provide more direct evidence.
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9
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Brader HS, Athappilly GK, Loewenstein J. Retinal Toxicity Associated With Excessive Sildenafil Ingestion. JAMA Ophthalmol 2019; 137:326-328. [PMID: 30629106 DOI: 10.1001/jamaophthalmol.2018.3652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abstract
INTRODUCTION In men, lower urinary tract symptoms (LUTS) are primarily attributed to benign prostatic hyperplasia (BPH). Therapeutic options are targeted to relax prostate smooth muscle and/or reduce prostate enlargement. Areas covered: This article reviews the major preclinical and clinical data on PDE5 inhibitors with a specific focus on tadalafil. It includes details of the role of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) - PDE5 pathway in the LUT organs (bladder and prostate) in addition to the available data on tadalafil in patients with LUTS secondary to BPH with or without erectile dysfunction (ED). Expert opinion: Preclinical and clinical data have clearly demonstrated that PDE5 inhibitors induce bladder and prostate relaxation, which contributes to the improvement seen in storage symptoms in both animal models of bladder and prostate hypercontractility. Tadalafil is effective both as a monotherapy and add-on therapy in patients with LUTS secondary to BPH. Furthermore, as LUTS-BPH and ED are urological disorders that commonly coexist in aging men, tadalafil is more advantageous than α1-adrenoceptors and should be used as the first option. Tadalafil is a safe and tolerable therapy and unlike α1- adrenoceptors and 5-alpha reductase inhibitors, which can cause sexual dysfunctions, tadalafil improves sexual function.
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Affiliation(s)
- Fabiola Zakia Mónica
- a Department of Pharmacology, Faculty of Medical Sciences , University of Campinas , Campinas , Sao Paulo , Brazil
| | - Gilberto De Nucci
- a Department of Pharmacology, Faculty of Medical Sciences , University of Campinas , Campinas , Sao Paulo , Brazil
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Roessler G, Vobig M, Walter P, Mazinani BA. Ocular side effects of Levitra ® (vardenafil) - results of a double-blind crossover study in healthy male subjects. DRUG DESIGN DEVELOPMENT AND THERAPY 2018; 13:37-43. [PMID: 30587926 PMCID: PMC6305137 DOI: 10.2147/dddt.s186633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Purpose To determine ocular side effects of vardenafil with special regard to color vision and retinal function. Methods This was a single center, randomized, double-blind, placebo-controlled, twofold crossover study with an administration of a single oral dose of two 20 mg tablets of BAY 38–9456 (vardenafil hydrochloride) or corresponding placebo in 24 healthy male subjects. Ocular investigations included Farnsworth–Munsell D100 color vision test, electroretinogram, and basic ophthalmological examinations like visual acuity, visual field, and slit-lamp of anterior segment and fundus. Results Compared to placebo, administration of vardenafil hydrochloride lead to a temporary significant increase of Farnsworth–Munsell D100 total error score after 1 and 6 hours as well as in error lines 3 and 4 after 1 hour. Twenty-four hours after administration there was no significant alteration of total error score or of any error line. While latency of electroretinogram b-wave remained unaffected, amplitudes showed a significant decrease compared to placebo 1 hour following administration. While other ocular examinations did not reveal any differences in general some mild to moderate but no serious adverse events have been reported. Conclusion Despite temporary changes in retinal function our study reports good tolerability of vardenafil in regard to ocular side effects.
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Affiliation(s)
- Gernot Roessler
- Department of Ophthalmology, RWTH Aachen University, D-52057 Aachen, Germany,
| | - Michael Vobig
- Department of Ophthalmology, RWTH Aachen University, D-52057 Aachen, Germany,
| | - Peter Walter
- Department of Ophthalmology, RWTH Aachen University, D-52057 Aachen, Germany,
| | - Babac Ae Mazinani
- Department of Ophthalmology, RWTH Aachen University, D-52057 Aachen, Germany,
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Yanoga F, Gentile RC, Chui TYP, Freund KB, Fell M, Dolz-Marco R, Rosen RB. SILDENAFIL CITRATE INDUCED RETINAL TOXICITY-ELECTRORETINOGRAM, OPTICAL COHERENCE TOMOGRAPHY, AND ADAPTIVE OPTICS FINDINGS. Retin Cases Brief Rep 2018; 12 Suppl 1:S33-S40. [PMID: 29489563 PMCID: PMC6110976 DOI: 10.1097/icb.0000000000000708] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND/PURPOSE To report a case of persistent retinal toxicity associated with a high dose of sildenafil citrate intake. METHODS Single retrospective case report. RESULTS A 31-year-old white man with no medical history presented with complaints of bilateral multicolored photopsias and erythropsia (red-tinted vision), shortly after taking sildenafil citrate-purchased through the internet. Patient was found to have cone photoreceptor damage, demonstrated using electroretinogram, optical coherence tomography, and adaptive optics imaging. The patient's symptoms and the photoreceptor structural changes persisted for several months. CONCLUSION Sildenafil citrate is a widely used erectile dysfunction medication that is typically associated with transient visual symptoms in normal dosage. At high dosage, sildenafil citrate can lead to persistent retinal toxicity in certain individuals.
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Affiliation(s)
- Fatoumata Yanoga
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA
| | - Ronald C. Gentile
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA
| | - Toco YP Chui
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA
| | - K. Bailey Freund
- Vitreous Retina Macula Consultants of New York, NY, USA
- LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear and Throat Hospital, New York, NY, USA
- Department of Ophthalmology, Edward S Harkness Eye Institute, Columbia University College of Physicians and Surgeons, New York, NY, USA
- Department of Ophthalmology, New York University School of Medicine, New York, NY, USA
| | | | - Rosa Dolz-Marco
- Vitreous Retina Macula Consultants of New York, NY, USA
- LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear and Throat Hospital, New York, NY, USA
| | - Richard B. Rosen
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA
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Tu L, Wang JH, Barathi VA, Prea SM, He Z, Lee JH, Bender J, King AE, Logan GJ, Alexander IE, Bee YS, Tai MH, Dusting GJ, Bui BV, Zhong J, Liu GS. AAV-mediated gene delivery of the calreticulin anti-angiogenic domain inhibits ocular neovascularization. Angiogenesis 2018; 21:95-109. [PMID: 29318471 DOI: 10.1007/s10456-017-9591-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 12/23/2017] [Indexed: 12/20/2022]
Abstract
Ocular neovascularization is a common pathological feature in diabetic retinopathy and neovascular age-related macular degeneration that can lead to severe vision loss. We evaluated the therapeutic efficacy of a novel endogenous inhibitor of angiogenesis, the calreticulin anti-angiogenic domain (CAD180), and its functional 112-residue fragment, CAD-like peptide 112 (CAD112), delivered using a self-complementary adeno-associated virus serotype 2 (scAAV2) in rodent models of oxygen-induced retinopathy and laser-induced choroidal neovascularization. The expression of CAD180 and CAD112 was elevated in human umbilical vein endothelial cells transduced with scAAV2-CAD180 or scAAV2-CAD112, respectively, and both inhibited angiogenic activity in vitro. Intravitreal gene delivery of scAAV2-CAD180 or scAAV2-CAD112 significantly inhibited ischemia-induced retinal neovascularization in rat eyes (CAD180: 52.7% reduction; CAD112: 49.2% reduction) compared to scAAV2-mCherry, as measured in retinal flatmounts stained with isolectin B4. Moreover, the retinal structure and function were unaffected by scAAV2-CAD180 or scAAV2-CAD112, as measured by optical coherence tomography and electroretinography. Moreover, subretinal delivery of scAAV2-CAD180 or scAAV2-CAD112 significantly attenuated laser-induced choroidal neovascularization in mouse eyes compared to scAAV2-mCherry, as measured by fundus fluorescein angiography (CAD180: 62.4% reduction; CAD112: 57.5% reduction) and choroidal flatmounts (CAD180: 40.21% reduction; CAD112: 43.03% reduction). Gene delivery using scAAV2-CAD180 or scAAV2-CAD112 has significant potential as a therapeutic option for the management of ocular neovascularization.
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Affiliation(s)
- Leilei Tu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Veluchamy A Barathi
- Translational Pre-clinical Model Platform, Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, DUKE-NUS Graduate Medical School, Singapore, Singapore
| | - Selwyn M Prea
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Jia Hui Lee
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - James Bender
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS, Australia
| | - Anna E King
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS, Australia
| | - Grant J Logan
- Gene Therapy Research Unit, Children's Medical Research Institute and Sydney Children's Hospitals Network, University of Sydney, Sydney, NSW, Australia
| | - Ian E Alexander
- Gene Therapy Research Unit, Children's Medical Research Institute and Sydney Children's Hospitals Network, University of Sydney, Sydney, NSW, Australia
- Discipline of Child and Adolescent Health, University of Sydney, Westmead, NSW, Australia
| | - Youn-Shen Bee
- Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Ming-Hong Tai
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Gregory J Dusting
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Jingxiang Zhong
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China.
| | - Guei-Sheung Liu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China.
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia.
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.
- , Liverpool St, Hobart, TAS, 7000, Australia.
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VISION LOSS IN A PATIENT WITH PRIMARY PULMONARY HYPERTENSION AND LONG-TERM USE OF SILDENAFIL. Retin Cases Brief Rep 2018; 11:325-328. [PMID: 27355186 DOI: 10.1097/icb.0000000000000355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe a case of bilateral, asymmetrical outer macular atrophy in a patient with pulmonary hypertension treated with long-term sildenafil (Revatio). METHODS Case report with fundus photography, spectral domain optical coherence tomography, fundus autofluorescence, and fluorescein angiography imaging. RESULTS A 32-year-old African American woman with a history of primary pulmonary hypertension and 5-year history of oral sildenafil (Revatio) use presented with decreasing central vision in her left eye. She reported a decline in central vision in the left eye that started 1 month after treatment initiation and progressed until discontinuation 5 years later. Visual acuity was 20/20 in the right eye and 20/100 in the left eye. Fundus photography revealed retinal pigment epithelial mottling and atrophy in the right eye and parafoveal retinal pigment epithelial mottling and atrophy in a ring-like configuration of the left eye. Optical coherence tomography demonstrated outer retinal irregularity in the right eye and disrupted outer retina involving the external limiting membrane, inner segment/outer segment junction, and the retinal pigment epithelium in the left eye; no choroidal thickening was observed. Fundus autofluorescence showed mild hypoautofluorescence in the foveal center with an irregular autofluorescence pattern in the parafovea of the left eye. Fluorescein angiography revealed capillary dropout with pinpoint hyperfluorescence and leakage in the far periphery bilaterally. A window defect was also observed in the foveal center of the left eye. CONCLUSION Sildenafil and other PDE5 inhibitors have been associated with several ocular side effects. However, this is the first report in the literature of outer macular atrophy in a patient with pulmonary hypertension and long-term use of oral sildenafil. All patients with long-term use of sildenafil should be educated on the risk of potential visual adverse effects.
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Campbell LJ, Jensen AM. Phosphodiesterase Inhibitors Sildenafil and Vardenafil Reduce Zebrafish Rod Photoreceptor Outer Segment Shedding. Invest Ophthalmol Vis Sci 2017; 58:5604-5615. [PMID: 29094165 PMCID: PMC5667398 DOI: 10.1167/iovs.17-21958] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Purpose The vertebrate rod photoreceptor undergoes daily growth and shedding to renew the rod outer segment (ROS), a modified cilium that contains the phototransduction machinery. It has been demonstrated that ROS shedding is regulated by the light–dark cycle; however, we do not yet have a satisfactory understanding of the molecular mechanisms that underlie this regulation. Given that phototransduction relies on the hydrolysis of cGMP via phosphodiesterase 6 (PDE6), we examined ROS growth and shedding in zebrafish treated with cGMP-specific PDE inhibitors. Methods We used transgenic zebrafish that express an inducible, transmembrane-bound mCherry protein, which forms a stripe in the ROS following a heat shock pulse and serves as a marker of ROS renewal. Zebrafish were reared in constant darkness or treated with PDE inhibitors following heat shock. Measurements of growth and shedding were analyzed in confocal z-stacks collected from treated retinas. Results As in dark-reared zebrafish, shedding was reduced in larvae and adults treated with the PDE5/6 inhibitors sildenafil and vardenafil but not with the PDE5 inhibitor tadalafil. In addition, vardenafil noticeably affected rod inner segment morphology. The inhibitory effect of sildenafil on shedding was reversible with drug removal. Finally, cones were more sensitive than rods to the toxic effects of sildenafil and vardenafil. Conclusions We show that pharmacologic inhibition of PDE6 mimics the inhibition of shedding by prolonged constant darkness. The data show that the influence of the light–dark cycle on ROS renewal is regulated, in part, by initiating the shedding process through activation of the phototransduction machinery.
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Affiliation(s)
- Leah J Campbell
- Biology Department, University of Massachusetts, Amherst, Massachusetts, United States
| | - Abbie M Jensen
- Biology Department, University of Massachusetts, Amherst, Massachusetts, United States.,Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, United States
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16
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Bee YS, Tu L, Sheu SJ, Lin HC, Tang JH, Wang JH, Prea SM, Dusting GJ, Wu DC, Zhong J, Bui BV, Tai MH, Liu GS. Gene Delivery of Calreticulin Anti-Angiogenic Domain Attenuates the Development of Choroidal Neovascularization in Rats. Hum Gene Ther 2017; 28:403-414. [DOI: 10.1089/hum.2016.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Youn-Shen Bee
- Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
- Yuh-Ing Junior College of Health Care and Management, Kaohsiung, Taiwan
- National Defense Medical Center, Taipei, Taiwan
| | - Leilei Tu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Ophthalmology, the First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Shwu-Jiuan Sheu
- Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Hsiu-Chen Lin
- Department of Ophthalmology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Jia-Hua Tang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Australia
| | - Selwyn M. Prea
- Department of Optometry and Vision Sciences, University of Melbourne, East Melbourne, Australia
| | - Gregory J. Dusting
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Australia
| | - Deng-Chyang Wu
- Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung, Taiwan
- Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jingxiang Zhong
- Department of Ophthalmology, the First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, University of Melbourne, East Melbourne, Australia
| | - Ming-Hong Tai
- Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
- Center for Neuroscience, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Guei-Sheung Liu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Australia
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17
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Nguyen CTO, Hui F, Charng J, Velaedan S, van Koeverden AK, Lim JKH, He Z, Wong VHY, Vingrys AJ, Bui BV, Ivarsson M. Retinal biomarkers provide "insight" into cortical pharmacology and disease. Pharmacol Ther 2017; 175:151-177. [PMID: 28174096 DOI: 10.1016/j.pharmthera.2017.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The retina is an easily accessible out-pouching of the central nervous system (CNS) and thus lends itself to being a biomarker of the brain. More specifically, the presence of neuronal, vascular and blood-neural barrier parallels in the eye and brain coupled with fast and inexpensive methods to quantify retinal changes make ocular biomarkers an attractive option. This includes its utility as a biomarker for a number of cerebrovascular diseases as well as a drug pharmacology and safety biomarker for the CNS. It is a rapidly emerging field, with some areas well established, such as stroke risk and multiple sclerosis, whereas others are still in development (Alzheimer's, Parkinson's, psychological disease and cortical diabetic dysfunction). The current applications and future potential of retinal biomarkers, including potential ways to improve their sensitivity and specificity are discussed. This review summarises the existing literature and provides a perspective on the strength of current retinal biomarkers and their future potential.
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Affiliation(s)
- Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia.
| | - Flora Hui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Jason Charng
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Shajan Velaedan
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Anna K van Koeverden
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Magnus Ivarsson
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
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Kalloniatis M, Nivison-Smith L, Chua J, Acosta ML, Fletcher EL. Using the rd1 mouse to understand functional and anatomical retinal remodelling and treatment implications in retinitis pigmentosa: A review. Exp Eye Res 2015; 150:106-21. [PMID: 26521764 DOI: 10.1016/j.exer.2015.10.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 12/31/2022]
Abstract
Retinitis Pigmentosa (RP) reflects a range of inherited retinal disorders which involve photoreceptor degeneration and retinal pigmented epithelium dysfunction. Despite the multitude of genetic mutations being associated with the RP phenotype, the clinical and functional manifestations of the disease remain the same: nyctalopia, visual field constriction (tunnel vision), photopsias and pigment proliferation. In this review, we describe the typical clinical phenotype of human RP and review the anatomical and functional remodelling which occurs in RP determined from studies in the rd/rd (rd1) mouse. We also review studies that report a slowing down or show an acceleration of retinal degeneration and finally we provide insights on the impact retinal remodelling may have in vision restoration strategies.
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Affiliation(s)
- M Kalloniatis
- Centre for Eye Health, University of New South Wales, Kensington, NSW, Australia; School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand; Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia.
| | - L Nivison-Smith
- Centre for Eye Health, University of New South Wales, Kensington, NSW, Australia; School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia
| | - J Chua
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - M L Acosta
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - E L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia
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19
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Cavero I. 14th Annual Meeting of the Safety Pharmacology Society: threading through scientific sessions for originality and novelty. Expert Opin Drug Saf 2015; 14:999-1008. [DOI: 10.1517/14740338.2015.1034104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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Nivison-Smith L, O'Brien BJ, Truong M, Guo CX, Kalloniatis M, Acosta ML. Vinpocetine modulates metabolic activity and function during retinal ischemia. Am J Physiol Cell Physiol 2015; 308:C737-49. [PMID: 25696811 DOI: 10.1152/ajpcell.00291.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 02/17/2015] [Indexed: 12/18/2022]
Abstract
Vinpocetine protects against a range of degenerative conditions and insults of the central nervous system via multiple modes of action. Little is known, however, of its effects on metabolism. This may be highly relevant, as vinpocetine is highly protective against ischemia, a process that inhibits normal metabolic function. This study uses the ischemic retina as a model to characterize vinpocetine's effects on metabolism. Vinpocetine reduced the metabolic demand of the retina following ex vivo hypoxia and ischemia to normal levels based on lactate dehydrogenase activity. Vinpocetine delivered similar effects in an in vivo model of retinal ischemia-reperfusion, possibly through increasing glucose availability. Vinpocetine's effects on glucose also appeared to improve glutamate homeostasis in ischemic Müller cells. Other actions of vinpocetine following ischemia-reperfusion, such as reduced cell death and improved retinal function, were possibly a combination of the drug's actions on metabolism and other retinal pathways. Vinpocetine's metabolic effects appeared independent of its other known actions in ischemia, as it recovered retinal function in a separate metabolic model where the glutamate-to-glutamine metabolic pathway was inhibited in Müller cells. The results of this study indicate that vinpocetine mediates ischemic damage partly through altered metabolism and has potential beneficial effects as a treatment for ischemia of neuronal tissues.
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Affiliation(s)
- Lisa Nivison-Smith
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Brendan J O'Brien
- Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - Mai Truong
- Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - Cindy X Guo
- Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - Michael Kalloniatis
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia; Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand; Centre for Eye Health, University of New South Wales, Sydney, Australia; and
| | - Monica L Acosta
- Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
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