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Chi J, Jiao Q, Li YZ, Zhang ZY, Li GY. Animal models as windows into the pathogenesis of myopia: Illuminating new directions for vision health. Biochem Biophys Res Commun 2024; 733:150614. [PMID: 39276692 DOI: 10.1016/j.bbrc.2024.150614] [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: 05/13/2024] [Revised: 08/10/2024] [Accepted: 08/27/2024] [Indexed: 09/17/2024]
Abstract
The incidence of myopia, particularly high myopia, is increasing annually. Myopia has gradually become one of the leading causes of global blindness and is a considerable public-health concern. However, the pathogenesis of myopia remains unclear, and exploring the mechanism underlying myopia has become an urgent scientific priority. Creating animal models of myopia is important for studying the pathogenesis of refractive errors. This approach allows researchers to study and analyze the pathogenesis of myopia from aspects such as changes in refractive development, pathological changes in eye tissue, and molecular pathways related to myopia. This review summarizes the examples of animal models, methods of inducing myopia experimentally, and molecular signaling pathways involved in developing myopia-induced animal models. This review provides solid literature for researchers in the field of myopia prevention and control. It offers guidance in selecting appropriate animal models and research methods to fit their research objectives. By providing new insights and a theoretical basis for studying mechanisms of myopia, we detail how elucidated molecular pathways can be exploited to translate into safe and effective measures for myopia prevention and control.
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Affiliation(s)
- Jing Chi
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130042, PR China
| | - Qing Jiao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130042, PR China
| | - Yun-Zhi Li
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130042, PR China
| | - Zi-Yuan Zhang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130042, PR China
| | - Guang-Yu Li
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130042, PR China.
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Thomson K, Karouta C, Ashby R. Administration of Nicotine Can Inhibit Myopic Growth in Animal Models. Invest Ophthalmol Vis Sci 2024; 65:29. [PMID: 39292451 PMCID: PMC11412605 DOI: 10.1167/iovs.65.11.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2024] Open
Abstract
Purpose While previously investigating the mechanism by which atropine inhibits ocular growth, we observed that stimulation of nicotinic receptors can inhibit experimental myopia. This study expands on that preliminary finding and investigates the safety and efficacy of nicotinic stimulation in the inhibition of ocular growth. Methods Nicotine's ability to inhibit form-deprivation myopia (FDM), following intravitreal injection (9 chicks per group) or topical application (6 chicks per group), was investigated over three doses. The ability of nicotine to inhibit lens-induced myopia (LIM) was also tested (in 12 chicks). For ocular safety, following 4 weeks of topical treatment with nicotine (n = 10), pupillary reflex, intraocular pressure, corneal curvature/thickness, lens thickness, retinal health (retinal thickness/cell apoptosis), as well as retinal function (electroretinogram recordings) were assessed. We also examined the effects of nicotine on non-ocular autonomic functions in both chicks (n = 5) and mice (n = 5). Results Nicotine was observed to significantly inhibit the development of FDM in chicks when administered as an intravitreal injection (P < 0.05) or topical eye drops (P < 0.05), albeit not in a dose-dependent manner. Nicotine also inhibited LIM (P < 0.05) to a similar degree to that seen for FDM. Although ocular health was (for the most part) unaffected by nicotine, the highest topical dose induced a temporary reduction in cardiorespiratory output (P < 0.05). Conclusions Nicotine, administered as an intravitreal injection or topical eye drop, significantly inhibits the development of experimental myopia. Although the anti-myopic effects observed presently are interesting, the well-reported side effects (expanded on presently) and addictive properties of nicotine would preclude its clinical use.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, Canberra, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, Canberra, Australia
- Research School of Biology, Australian National University, Acton, Australia
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Wilmet B, Michiels C, Zhang J, Callebert J, Sahel JA, Picaud S, Audo I, Zeitz C. Loss of ON-Pathway Function in Mice Lacking Lrit3 Decreases Recovery From Lens-Induced Myopia. Invest Ophthalmol Vis Sci 2024; 65:18. [PMID: 39250117 PMCID: PMC11385651 DOI: 10.1167/iovs.65.11.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2024] Open
Abstract
Purpose To determine whether the Lrit3-/- mouse model of complete congenital stationary night blindness with an ON-pathway defect harbors myopic features and whether the genetic defect influences the recovery from lens-induced myopia. Methods Retinal levels of dopamine (DA) and 3,4 dihydroxyphenylacetic acid (DOPAC) from adult isolated Lrit3-/- retinas were quantified using ultra performance liquid chromatography after light adaptation. Natural refractive development of Lrit3-/- mice was measured from three weeks to nine weeks of age using an infrared photorefractometer. Susceptibility to myopia induction was assessed using a lens-induced myopia protocol with -25 D lenses placed in front of the right eye of the animals for three weeks; the mean interocular shift was measured with an infrared photorefractometer after two and three weeks of goggling and after one and two weeks after removal of goggles. Results Compared to wild-type littermates (Lrit3+/+), both DA and DOPAC were drastically reduced in Lrit3-/- retinas. Natural refractive development was normal but Lrit3-/- mice showed a higher myopic shift and a lower ability to recover from induced myopia. Conclusions Our data consolidate the link between ON pathway defect altered dopaminergic signaling and myopia. We document for the first time the role of ON pathway on the recovery from myopia induction.
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Affiliation(s)
- Baptiste Wilmet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - Jingyi Zhang
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Jacques Callebert
- Service of Biochemistry and Molecular Biology, INSERM U942, Hospital Lariboisière, Paris, France
| | - José Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Centre de Référence Maladies Rares REFERET and INSERM-DGOS CIC 1423, Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburg, PA, United States
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Centre de Référence Maladies Rares REFERET and INSERM-DGOS CIC 1423, Paris, France
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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Barboni MTS, Széll N, Sohajda Z, Fehér T. Pupillary Light Reflex Reveals Melanopsin System Alteration in the Background of Myopia-26, the Female Limited Form of Early-Onset High Myopia. Invest Ophthalmol Vis Sci 2024; 65:6. [PMID: 38958970 PMCID: PMC11223624 DOI: 10.1167/iovs.65.8.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 05/17/2024] [Indexed: 07/04/2024] Open
Abstract
Purpose The purpose of this study was to evaluate pupillary light reflex (PLR) to chromatic flashes in patients with early-onset high-myopia (eoHM) without (myopic controls = M-CTRL) and with (female-limited myopia-26 = MYP-26) genetic mutations in the ARR3 gene encoding the cone arrestin. Methods Participants were 26 female subjects divided into 3 groups: emmetropic controls (E-CTRL, N = 12, mean age = 28.6 ± 7.8 years) and 2 myopic (M-CTRL, N = 7, mean age = 25.7 ± 11.5 years and MYP-26, N = 7, mean age = 28.3 ± 15.4 years) groups. In addition, one hemizygous carrier and one control male subject were examined. Direct PLRs were recorded after 10-minute dark adaptation. Stimuli were 1-second red (peak wavelength = 621 nm) and blue (peak wavelength = 470 nm) flashes at photopic luminance of 250 cd/m². A 2-minute interval between the flashes was introduced. Baseline pupil diameter (BPD), peak pupil constriction (PPC), and postillumination pupillary response (PIPR) were extracted from the PLR. Group comparisons were performed with ANOVAs. Results Dark-adapted BPD was comparable among the groups, whereas PPC to the red light was slightly reduced in patients with myopia (P = 0.02). PIPR at 6 seconds elicited by the blue flash was significantly weaker (P < 0.01) in female patients with MYP-26, whereas it was normal in the M-CTRL group and the asymptomatic male carrier. Conclusions L/M-cone abnormalities due to ARR3 gene mutation is currently claimed to underlie the pathological eye growth in MYP-26. Our results suggest that malfunction of the melanopsin system of intrinsically photosensitive retinal ganglion cells (ipRGCs) is specific to patients with symptomatic MYP-26, and may therefore play an additional role in the pathological eye growth of MYP-26.
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Affiliation(s)
| | - Noémi Széll
- Department of Ophthalmology, University of Debrecen, Debrecen, Hungary
| | - Zoltán Sohajda
- Kenézy Campus Department of Ophthalmology, University of Debrecen, Debrecen, Hungary
| | - Tamás Fehér
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
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Ihesiulor CG, Alzahrani K, Rhadhakrishnan H. A review of mechanism of action of outdoor exposure in preventing myopia incidence and progression. Int J Ophthalmol 2024; 17:1144-1155. [PMID: 38895671 PMCID: PMC11144779 DOI: 10.18240/ijo.2024.06.21] [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: 03/10/2023] [Accepted: 01/30/2024] [Indexed: 06/21/2024] Open
Abstract
Various studies have suggested several environmental, pharmacological, medical, and optical interventions and some are in use but their efficacy in myopia control may be transient, and the cellular, molecular, and biochemical mechanisms involved unclear. Daylight exposure is currently regarded as an effective and enduring strategy in the control of myopia development and progression. However, the mechanism behind the effect of outdoor exposure and its association with genetic predisposition and other relatively more significant environmental factors on myopia is still a conundrum. This review focuses on survey-based and intervention-based studies carried out to propose a mechanism that accounts for myopia development and important for its control.
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Affiliation(s)
- Chikezie Grand Ihesiulor
- Division of Pharmacy & Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M139PL, United Kingdom
| | - Khaled Alzahrani
- Department of Ophthalmology, King Fahad Armed Forces Hospital, Jeddah 23311, Saudi Arabia
| | - Hema Rhadhakrishnan
- Division of Pharmacy & Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M139PL, United Kingdom
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Zhang XJ, Zaabaar E, French AN, Tang FY, Kam KW, Tham CC, Chen LJ, Pang CP, Yam JC. Advances in myopia control strategies for children. Br J Ophthalmol 2024:bjo-2023-323887. [PMID: 38777389 DOI: 10.1136/bjo-2023-323887] [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: 05/05/2023] [Accepted: 03/19/2024] [Indexed: 05/25/2024]
Abstract
Myopia has long been a global threat to public health. Timely interventions are likely to reduce the risk of vision-threatening complications. There are both established and rapidly evolving therapeutic approaches to slow myopia progression and/or delay its onset. The effective methods for slowing myopia progression include atropine eye-drops, defocus incorporated multiple segments (DIMS) spectacle lenses, spectacle lenses with highly aspherical lenslets target (HALT), diffusion optics technology (DOT) spectacle lenses, red light therapy (RLT), multifocal soft contact lenses and orthokeratology. Among these, 0.05% atropine, HALT lenses, RLT and +3.00 peripheral addition soft contact lenses yield over 60% reduction in myopia progression, whereas DIMS, DOT and MiSight contact lenses demonstrate at least 50% myopia control efficacy. 0.05% atropine demonstrates a more optimal balance of efficacy and safety than 0.01%. The efficacy of 0.01% atropine has not been consistent and requires further validation across diverse ethnicities. Combining atropine 0.01% with orthokeratology or DIMS spectacles yields better outcomes than using these interventions as monotherapies. Increased outdoor time is an effective public health strategy for myopia prevention while recent studies suggest that 0.05% low-concentration atropine and RLT therapy have promising potential as clinical myopia prevention interventions for high-risk groups. Myopia control spectacle lenses, being the least invasive, are safe for long-term use. However, when considering other approaches, it is essential to ensure proper instruction and regular follow-ups to maintain safety and monitor any potential complications. Ultimately, significant advances have been made in myopia control strategies, many of which have shown meaningful clinical outcomes. However, regular use and adequate safety monitoring over extended durations are imperative to foster confidence that can only come from extensive clinical experience.
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Affiliation(s)
- Xiu Juan Zhang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ebenezer Zaabaar
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Amanda Nicole French
- Discipline of Orthoptics, University of Sydney, Sydney, New South Wales, Australia
| | - Fang Yao Tang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ka Wai Kam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Ophthalmology and Visual Sciences, The Prince of Wales Hospital, Hong Kong SAR, China
| | - Clement C Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Ophthalmology and Visual Sciences, The Prince of Wales Hospital, Hong Kong SAR, China
- Hong Kong Eye Hospital, Hong Kong SAR, China
- Lam Kin Chung. Jet King-Shing Ho Glaucoma Treatment and Research Centre, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Ophthalmology, Hong Kong Children Hospital, Hong Kong SAR, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Ophthalmology and Visual Sciences, The Prince of Wales Hospital, Hong Kong SAR, China
- Hong Kong Eye Hospital, Hong Kong SAR, China
- Lam Kin Chung. Jet King-Shing Ho Glaucoma Treatment and Research Centre, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Lam Kin Chung. Jet King-Shing Ho Glaucoma Treatment and Research Centre, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jason C Yam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Ophthalmology and Visual Sciences, The Prince of Wales Hospital, Hong Kong SAR, China
- Hong Kong Eye Hospital, Hong Kong SAR, China
- Department of Ophthalmology, Hong Kong Children Hospital, Hong Kong SAR, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
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Thomson K, Karouta C, Weber D, Hoffmann N, Morgan I, Kelly T, Ashby R. The role of the serotonergic system in atropine's anti-myopic effects. Biomed Pharmacother 2023; 167:115542. [PMID: 37742601 DOI: 10.1016/j.biopha.2023.115542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/11/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023] Open
Abstract
The muscarinic cholinergic antagonist atropine is the most widely used pharmacological treatment for the visual disorder myopia (short-sightedness), the leading cause of low-vision worldwide. This study sought to better define the mechanism by which atropine inhibits myopic growth. Although classified as a muscarinic-cholinergic antagonist, atropine has been found to bind and modulate the activity of several non-cholinergic systems (e.g., serotonin). Thus, this study investigated whether the serotonergic system could underly atropine's anti-myopic effects. Using a chick model of myopia, we report that atropine's growth-inhibitory effects can be attenuated by pharmacological stimulation of the serotonin system. This may suggest that atropine can slow the development of myopia through inhibiting serotonergic receptor activity. We also observed that pharmacological antagonism of serotonergic receptors inhibits the development of experimental myopia in a dose-dependent manner, further demonstrating that modulation of serotonergic receptor activity can alter ocular growth rates. Finally, we found that neither experimental myopia, nor atropine treatment, induced a significant change in retinal serotonergic output (i.e., synthesis, transport, release and catabolism). This may suggest that, although myopic growth can be inhibited through modulation of serotonergic receptor activity (by atropine or serotonergic antagonists), this does not require a change in serotonin levels. These findings regarding a serotonergic mechanism for atropine may have significant ramifications for the treatment of human myopia. This includes assessing the use of atropine in patients who are also undergoing treatment to upregulate serotonergic signaling (e.g., serotonergic anti-depressants).
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia.
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Daniel Weber
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Nichola Hoffmann
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Ian Morgan
- Research School of Biology, Australian National University, Australia
| | - Tamsin Kelly
- Faculty of Science and Technology, University of Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia; Research School of Biology, Australian National University, Australia
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Sankaridurg P, Berntsen DA, Bullimore MA, Cho P, Flitcroft I, Gawne TJ, Gifford KL, Jong M, Kang P, Ostrin LA, Santodomingo-Rubido J, Wildsoet C, Wolffsohn JS. IMI 2023 Digest. Invest Ophthalmol Vis Sci 2023; 64:7. [PMID: 37126356 PMCID: PMC10155872 DOI: 10.1167/iovs.64.6.7] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Myopia is a dynamic and rapidly moving field, with ongoing research providing a better understanding of the etiology leading to novel myopia control strategies. In 2019, the International Myopia Institute (IMI) assembled and published a series of white papers across relevant topics and updated the evidence with a digest in 2021. Here, we summarize findings across key topics from the previous 2 years. Studies in animal models have continued to explore how wavelength and intensity of light influence eye growth and have examined new pharmacologic agents and scleral cross-linking as potential strategies for slowing myopia. In children, the term premyopia is gaining interest with increased attention to early implementation of myopia control. Most studies use the IMI definitions of ≤-0.5 diopters (D) for myopia and ≤-6.0 D for high myopia, although categorization and definitions for structural consequences of high myopia remain an issue. Clinical trials have demonstrated that newer spectacle lens designs incorporating multiple segments, lenslets, or diffusion optics exhibit good efficacy. Clinical considerations and factors influencing efficacy for soft multifocal contact lenses and orthokeratology are discussed. Topical atropine remains the only widely accessible pharmacologic treatment. Rebound observed with higher concentration of atropine is not evident with lower concentrations or optical interventions. Overall, myopia control treatments show little adverse effect on visual function and appear generally safe, with longer wear times and combination therapies maximizing outcomes. An emerging category of light-based therapies for children requires comprehensive safety data to enable risk versus benefit analysis. Given the success of myopia control strategies, the ethics of including a control arm in clinical trials is heavily debated. IMI recommendations for clinical trial protocols are discussed.
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Affiliation(s)
- Padmaja Sankaridurg
- Brien Holden Vision Institute, Sydney, Australia
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - David A Berntsen
- University of Houston, College of Optometry, Houston, Texas, United States
| | - Mark A Bullimore
- University of Houston, College of Optometry, Houston, Texas, United States
| | - Pauline Cho
- West China Hospital, Sichuan University, Sichuan, China
- Eye & ENT Hospital of Fudan University, Shanghai, China
- Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, China
| | - Ian Flitcroft
- Centre for Eye Research Ireland, School of Physics and Clinical and Optometric Sciences, Technological University Dublin, Dublin, Ireland
- Department of Ophthalmology, Children's Health Ireland at Temple Street Hospital, Dublin, Ireland
| | - Timothy J Gawne
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Kate L Gifford
- Queensland University of Technology, Brisbane, Australia
| | - Monica Jong
- Johnson & Johnson Vision, Jacksonville, Florida, United States
| | - Pauline Kang
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Lisa A Ostrin
- University of Houston, College of Optometry, Houston, Texas, United States
| | | | - Christine Wildsoet
- UC Berkeley Wertheim School Optometry & Vision Science, Berkeley, California, United States
| | - James S Wolffsohn
- College of Health & Life Sciences, Aston University, Birmingham, United Kingdom
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Wilmet B, Callebert J, Duvoisin R, Goulet R, Tourain C, Michiels C, Frederiksen H, Schaeffel F, Marre O, Sahel JA, Audo I, Picaud S, Zeitz C. Mice Lacking Gpr179 with Complete Congenital Stationary Night Blindness Are a Good Model for Myopia. Int J Mol Sci 2022; 24:ijms24010219. [PMID: 36613663 PMCID: PMC9820543 DOI: 10.3390/ijms24010219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/25/2022] Open
Abstract
Mutations in GPR179 are one of the most common causes of autosomal recessive complete congenital stationary night blindness (cCSNB). This retinal disease is characterized in patients by impaired dim and night vision, associated with other ocular symptoms, including high myopia. cCSNB is caused by a complete loss of signal transmission from photoreceptors to ON-bipolar cells. In this study, we hypothesized that the lack of Gpr179 and the subsequent impaired ON-pathway could lead to myopic features in a mouse model of cCSNB. Using ultra performance liquid chromatography, we show that adult Gpr179-/- mice have a significant decrease in both retinal dopamine and 3,4-dihydroxyphenylacetic acid, compared to Gpr179+/+ mice. This alteration of the dopaminergic system is thought to be correlated with an increased susceptibility to lens-induced myopia but does not affect the natural refractive development. Altogether, our data added a novel myopia model, which could be used to identify therapeutic interventions.
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Affiliation(s)
- Baptiste Wilmet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
- Correspondence: (B.W.); (C.Z.); Tel.: +33-1-53-46-25-26 (B.W.); +33-1-53-46-25-40 (C.Z.)
| | - Jacques Callebert
- Service of Biochemistry and Molecular Biology, INSERM U942, Hospital Lariboisière, AP-HP, 75010 Paris, France
| | - Robert Duvoisin
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ruben Goulet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Christophe Tourain
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
- Wavefront-Engineering Microscopy Group, Neurophotonics Laboratory, CNRS UMR8250, Paris Descartes University, 75270 Paris, France
| | - Christelle Michiels
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Helen Frederiksen
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Frank Schaeffel
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4056 Basel, Switzerland
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, 72076 Tuebingen, Germany
- Zeiss Vision Lab, Ophthalmic Research Institute, University of Tuebingen, 72076 Tuebingen, Germany
| | - Olivier Marre
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - José Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, INSERM-DGOS CIC 1423, 75012 Paris, France
- Fondation Ophtalmologique Adolphe de Rothschild, 75019 Paris, France
- Académie des Sciences, Institut de France, 75006 Paris, France
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
- Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, INSERM-DGOS CIC 1423, 75012 Paris, France
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
- Correspondence: (B.W.); (C.Z.); Tel.: +33-1-53-46-25-26 (B.W.); +33-1-53-46-25-40 (C.Z.)
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Thomson K, Karouta C, Sabeti F, Anstice N, Leung M, Jong T, Maddess T, Morgan IG, Game J, Ashby R. The safety and tolerability of levodopa eye drops for the treatment of ocular disorders: A randomized first-in-human study. Clin Transl Sci 2022; 15:2673-2684. [PMID: 36221799 PMCID: PMC9652433 DOI: 10.1111/cts.13392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/20/2022] [Accepted: 08/17/2022] [Indexed: 01/25/2023] Open
Abstract
Myopia is the leading cause of low vision worldwide and can lead to significant pathological complications. Therefore, to improve patient outcomes, the field continues to develop novel interventions for this visual disorder. Accordingly, this first-in-human study reports on the safety profile of a novel dopamine-based ophthalmic treatment for myopia, levodopa/carbidopa eye drops. This phase I, first-in-human, monocenter, placebo-controlled, double-blind, paired-eye, multidose, randomized clinical trial was undertaken in healthy adult males aged 18-30 years (mean age 24.9 ± 2.7) at the University of Canberra Eye Clinic, Australia. Participants were randomly assigned to receive either a low (1.4 levodopa:0.34 carbidopa [μmoles/day], n = 14) or standard dose (2.7 levodopa:0.68 carbidopa [μmoles/day], n = 15) of levodopa/carbidopa eye drops in one eye and placebo in the fellow eye once daily for 4 weeks (28 days). Over this 4-week trial, and after a 4-month follow-up visit, levodopa/carbidopa treatment had no significant effect on ocular tolerability and anterior surface integrity, visual function, ocular health, refraction/ocular biometry, and did not induce any non-ocular adverse events. These results indicate that topical levodopa/carbidopa is safe and tolerable to the eye, paving the way for future studies on the efficacy of this novel ophthalmic formulation in the treatment of human myopia. The findings of this study have implications not only for the treatment of myopia, but in a number of other visual disorders (i.e., amblyopia, diabetic retinopathy, and age-related macular degeneration) in which levodopa has been identified as a potential clinical intervention.
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Affiliation(s)
- Kate Thomson
- Faculty of Science and TechnologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Cindy Karouta
- Faculty of Science and TechnologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Faran Sabeti
- Discipline of Optometry, Faculty of HealthUniversity of CanberraCanberraAustralian Capital TerritoryAustralia,John Curtin School of Medical Research (JCSMR)The Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Nicola Anstice
- Optometry & Vision Science, College of Nursing and Health SciencesFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Myra Leung
- Discipline of Optometry, Faculty of HealthUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Tina Jong
- Discipline of Optometry, Faculty of HealthUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Ted Maddess
- John Curtin School of Medical Research (JCSMR)The Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Ian G. Morgan
- Research School of BiologyThe Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Jeremy Game
- Faculty of Science and TechnologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Regan Ashby
- Faculty of Science and TechnologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
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11
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Yuan T, Zou H. Effects of air pollution on myopia: an update on clinical evidence and biological mechanisms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:70674-70685. [PMID: 36031679 PMCID: PMC9515022 DOI: 10.1007/s11356-022-22764-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/24/2022] [Indexed: 05/06/2023]
Abstract
Myopia is one of the most common forms of refractive eye disease and considered as a worldwide pandemic experienced by half of the global population by 2050. During the past several decades, myopia has become a leading cause of visual impairment, whereas several factors are believed to be associated with its occurrence and development. In terms of environmental factors, air pollution has gained more attention in recent years, as exposure to ambient air pollution seems to increase peripheral hyperopia defocus, affect the dopamine pathways, and cause retinal ischemia. In this review, we highlight epidemiological evidence and potential biological mechanisms that may link exposure to air pollutants to myopia. A thorough understanding of these mechanisms is a key for establishing and implementing targeting strategies. Regulatory efforts to control air pollution through effective policies and limit individual exposure to preventable risks are required in reducing this global public health burden.
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Affiliation(s)
- Tianyi Yuan
- Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, Shanghai, China.
- National Clinical Research Center for Eye Diseases, Shanghai, China.
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China.
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12
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Brown DM, Mazade R, Clarkson-Townsend D, Hogan K, Datta Roy PM, Pardue MT. Candidate pathways for retina to scleral signaling in refractive eye growth. Exp Eye Res 2022; 219:109071. [PMID: 35447101 PMCID: PMC9701099 DOI: 10.1016/j.exer.2022.109071] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 12/22/2022]
Abstract
The global prevalence of myopia, or nearsightedness, has increased at an alarming rate over the last few decades. An eye is myopic if incoming light focuses prior to reaching the retinal photoreceptors, which indicates a mismatch in its shape and optical power. This mismatch commonly results from excessive axial elongation. Important drivers of the myopia epidemic include environmental factors, genetic factors, and their interactions, e.g., genetic factors influencing the effects of environmental factors. One factor often hypothesized to be a driver of the myopia epidemic is environmental light, which has changed drastically and rapidly on a global scale. In support of this, it is well established that eye size is regulated by a homeostatic process that incorporates visual cues (emmetropization). This process allows the eye to detect and minimize refractive errors quite accurately and locally over time by modulating the rate of elongation of the eye via remodeling its outermost coat, the sclera. Critically, emmetropization is not dependent on post-retinal processing. Thus, visual cues appear to influence axial elongation through a retina-to-sclera, or retinoscleral, signaling cascade, capable of transmitting information from the innermost layer of the eye to the outermost layer. Despite significant global research interest, the specifics of retinoscleral signaling pathways remain elusive. While a few pharmacological treatments have proven to be effective in slowing axial elongation (most notably topical atropine), the mechanisms behind these treatments are still not fully understood. Additionally, several retinal neuromodulators, neurotransmitters, and other small molecules have been found to influence axial length and/or refractive error or be influenced by myopigenic cues, yet little progress has been made explaining how the signal that originates in the retina crosses the highly vascular choroid to affect the sclera. Here, we compile and synthesize the evidence surrounding three of the major candidate pathways receiving significant research attention - dopamine, retinoic acid, and adenosine. All three candidates have both correlational and causal evidence backing their involvement in axial elongation and have been implicated by multiple independent research groups across diverse species. Two hypothesized mechanisms are presented for how a retina-originating signal crosses the choroid - via 1) all-trans retinoic acid or 2) choroidal blood flow influencing scleral oxygenation. Evidence of crosstalk between the pathways is discussed in the context of these two mechanisms.
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Affiliation(s)
- Dillon M Brown
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Reece Mazade
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Danielle Clarkson-Townsend
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA; Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115, USA; Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02115, USA; Gangarosa Department of Environmental Health, Emory University, 1518 Clifton Rd, Atlanta, GA, 30322, USA
| | - Kelleigh Hogan
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Pooja M Datta Roy
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Machelle T Pardue
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA.
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13
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Zhou Y, Huang XB, Cao X, Wang M, Jin NX, Gong YX, Xiong YJ, Cai Q, Zhu Y, Song Y, Sun ZM. Prevalence of Myopia and Influencing Factors among High School Students in Nantong, China: A Cross-Sectional Study. Ophthalmic Res 2022; 66:27-38. [PMID: 35500560 DOI: 10.1159/000524293] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 03/22/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Myopia is an increasingly serious health problem in China. The aim of this study was to investigate the prevalence of myopia and the factors associated with it among students in Nantong, China, to show the current status of myopia prevention. METHODS This school-based, cross-sectional study examined students from all high schools in an urban area of Nantong, China. At least two classes were randomly selected from each grade of each school. A self-reported questionnaire was used to collect the required information. Univariate analyses were performed to identify associations between myopia and various parameters. Noncycloplegic autorefraction and visual acuity were assessed for each student. Factors that were statistically significant in univariate analyses were selected for multivariate analyses. Myopia was defined as a spherical equivalent refraction of ≤-0.5 diopters. RESULTS The completion percentage of students out of the whole high school was 6.5%. The overall prevalence of myopia was 94%. The response percentage of the number of validated questionnaires was 90.2%, of which 50.2% (n = 1,466) were from male participants, and 49.8% (n = 1,452) were from female participants. The mean (SD) of age was 15.22 ± 1.75 years, ranging from 12 to 18 years. Factors such as female sex, older age, parental myopia, sitting in the back of the classroom, increased homework time, and minimal outdoor activity were significantly associated with a higher risk of myopia (p < 0.05). In the myopic population, most students (67.9%) did not take measures to prevent further progression of myopia. CONCLUSION The prevalence of myopia among high school students was 94%. Female sex, older age, parental myopia, sitting in the back of the classroom, increased homework time, and minimal outdoor activity were significantly associated with a higher risk of myopia. Most students with myopia (67.9%) did not take measures to prevent further progression of myopia.
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Affiliation(s)
- Yue Zhou
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Xiao Bo Huang
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Xin Cao
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Min Wang
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Nan Xi Jin
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Ye Xun Gong
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Yao Jia Xiong
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Qi Cai
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Yan Zhu
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Yu Song
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
| | - Zhi Min Sun
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, China
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14
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Huang F, Shu Z, Huang Q, Chen K, Yan W, Wu W, Yang J, Wang Q, Wang F, Zhang C, Qu J, Zhou X. Retinal Dopamine D2 Receptors Participate in the Development of Myopia in Mice. Invest Ophthalmol Vis Sci 2022; 63:24. [PMID: 35050306 PMCID: PMC8787610 DOI: 10.1167/iovs.63.1.24] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose To learn more about the locations of dopamine D2 receptors (D2Rs) that regulate form-deprivation myopia (FDM), using different transgenic mouse models. Methods One eye of D2R-knockout (KO) mice and wild-type littermates was subjected to four weeks of monocular FDM, whereas the fellow eye served as control. Mice in both groups received daily intraperitoneal injections of either the D2R antagonist sulpiride (8 µg/g) or vehicle alone. FDM was also induced in retina- (Six3creD2Rfl/fl) or fibroblast-specific (S100a4creD2Rfl/fl) D2R-KO mice. A subset of retina-specific D2R-KO mice and D2Rfl/fl littermates were also given sulpiride or vehicle injections. Refraction was measured with an eccentric infrared photorefractor, and other biometric parameters were measured by optical coherence tomography (n ≈ 20 for each group). Results FDM development was attenuated in wild-type littermates treated with sulpiride. However, this inhibitory effect disappeared in the D2R-KO mice, suggesting that antagonizing D2Rs suppressed myopia development. Similarly, the development of myopia was partially inhibited by retina-specific (deletion efficiency: 94.7%) but not fibroblast-specific (66.9%) D2R-KO. The sulpiride-mediated inhibitory effects on FDM also disappeared with retinal D2R-KO, suggesting that antagonizing D2Rs outside the retina may not attenuate myopia. Changes in axial length were less marked than changes in refraction, but in general the two were correlated. Conclusions This study demonstrates that D2Rs located in the retina participate in dopaminergic regulation of FDM in mice. These findings provide an important and fundamental basis for further exploring the retinal mechanism(s) involved in dopamine signaling and myopia development.
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Affiliation(s)
- Furong Huang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Ziheng Shu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Qin Huang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Kaijie Chen
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Wenjun Yan
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Wenjing Wu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Jinglei Yang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Qiongsi Wang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Fengjiao Wang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Chunlan Zhang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China
| | - Jia Qu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China.,Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, China
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health P. R. China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China.,Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, China.,Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences (2019RU025), Wenzhou, Zhejiang, China
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15
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Chakraborty R, Landis EG, Mazade R, Yang V, Strickland R, Hattar S, Stone RA, Iuvone PM, Pardue MT. Melanopsin modulates refractive development and myopia. Exp Eye Res 2022; 214:108866. [PMID: 34838844 PMCID: PMC8792255 DOI: 10.1016/j.exer.2021.108866] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Myopia, or nearsightedness, is the most common form of refractive abnormality and is characterized by excessive ocular elongation in relation to ocular power. Retinal neurotransmitter signaling, including dopamine, is implicated in myopic ocular growth, but the visual pathways that initiate and sustain myopia remain unclear. Melanopsin-expressing retinal ganglion cells (mRGCs), which detect light, are important for visual function, and have connections with retinal dopamine cells. Here, we investigated how mRGCs influence normal and myopic refractive development using two mutant mouse models: Opn4-/- mice that lack functional melanopsin photopigments and intrinsic mRGC responses but still receive other photoreceptor-mediated input to these cells; and Opn4DTA/DTA mice that lack intrinsic and photoreceptor-mediated mRGC responses due to mRGC cell death. In mice with intact vision or form-deprivation, we measured refractive error, ocular properties including axial length and corneal curvature, and the levels of retinal dopamine and its primary metabolite, L-3,4-dihydroxyphenylalanine (DOPAC). Myopia was measured as a myopic shift, or the difference in refractive error between the form-deprived and contralateral eyes. We found that Opn4-/- mice had altered normal refractive development compared to Opn4+/+ wildtype mice, starting ∼4D more myopic but developing ∼2D greater hyperopia by 16 weeks of age. Consistent with hyperopia at older ages, 16 week-old Opn4-/- mice also had shorter eyes compared to Opn4+/+ mice (3.34 vs 3.42 mm). Opn4DTA/DTA mice, however, were more hyperopic than both Opn4+/+ and Opn4-/- mice across development ending with even shorter axial lengths. Despite these differences, both Opn4-/- and Opn4DTA/DTA mice had ∼2D greater myopic shifts in response to form-deprivation compared to Opn4+/+ mice. Furthermore, when vision was intact, dopamine and DOPAC levels were similar between Opn4-/- and Opn4+/+ mice, but higher in Opn4DTA/DTA mice, which differed with age. However, form-deprivation reduced retinal dopamine and DOAPC by ∼20% in Opn4-/- compared to Opn4+/+ mice but did not affect retinal dopamine and DOPAC in Opn4DTA/DTA mice. Lastly, systemically treating Opn4-/- mice with the dopamine precursor L-DOPA reduced their form-deprivation myopia by half compared to non-treated mice. Collectively our findings show that disruption of retinal melanopsin signaling alters the rate and magnitude of normal refractive development, yields greater susceptibility to form-deprivation myopia, and changes dopamine signaling. Our results suggest that mRGCs participate in the eye's response to myopigenic stimuli, acting partly through dopaminergic mechanisms, and provide a potential therapeutic target underling myopia progression. We conclude that proper mRGC function is necessary for correct refractive development and protection from myopia progression.
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Affiliation(s)
- Ranjay Chakraborty
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, United States; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, United States; College of Nursing and Health Sciences, Optometry and Vision Science, Flinders University, Bedford Park, SA, 5001, Adelaide, Australia; Caring Futures Institute, Flinders University, Bedford Park, SA, 5042, Adelaide, Australia
| | - Erica G Landis
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, United States; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, United States; Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, United States
| | - Reece Mazade
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, United States; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA, 30332, United States
| | - Victoria Yang
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, United States; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA, 30332, United States
| | - Ryan Strickland
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, United States; Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, United States
| | - Samer Hattar
- Section on Light and Circadian Rhythms, NIMH, NIH, 9000 Rockville Pike, Bethesda, MD, USA, 20892
| | - Richard A Stone
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, United States; Department of Pharmacology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, United States
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, United States; Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, United States; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA, 30332, United States.
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16
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Thomson K, Game J, Karouta C, Morgan IG, Ashby R. Correlation between small-scale methylation changes and gene expression during the development of myopia. FASEB J 2021; 36:e22129. [PMID: 34958689 DOI: 10.1096/fj.202101487r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/07/2021] [Accepted: 12/16/2021] [Indexed: 12/11/2022]
Abstract
Visually induced changes in the expression of early growth response-1 (EGR1), FBJ osteosarcoma oncogene (FOS), and NGFI-A binding protein-2 (NAB2) appear to form a part of a retinal network fundamental to ocular growth regulation, and thus, the development of myopia (short-sightedness). However, it is unclear how environmental (visual) cues are translated into these molecular changes. One possibility is through epigenetic modifications such as DNA methylation, a known regulator of such processes. By sequencing bisulfite-converted DNA amplicons, this study examined whether changes in DNA methylation occur within specific regulatory and promoter regions of EGR1, FOS, and NAB2 during the periods of increased and decreased ocular growth in chicks. Visually induced changes in ocular growth rates were associated with single-point, but not large-scale, shifts in methylation levels within the investigated regions. Analysis of methylation pattern variability (entropy) demonstrated that the observed methylation changes are occurring within small subpopulations of retinal cells. This concurs with previous observations that EGR1 and FOS are differentially regulated at the peptide level within specific retinal cell types. Together, the findings of this study support a potential role for DNA methylation in the translation of external visual cues into molecular changes critical for ocular growth regulation and myopia development.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Jeremy Game
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Ian G Morgan
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia.,Research School of Biology, Australian National University, Canberra, ACT, Australia
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17
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Yang J, Ouyang X, Fu H, Hou X, Liu Y, Xie Y, Yu H, Wang G. Advances in biomedical study of the myopia-related signaling pathways and mechanisms. Biomed Pharmacother 2021; 145:112472. [PMID: 34861634 DOI: 10.1016/j.biopha.2021.112472] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022] Open
Abstract
Myopia has become one of the most critical health problems in the world with the increasing time spent indoors and increasing close work. Pathological myopia may have multiple complications, such as myopic macular degeneration, retinal detachment, cataracts, open-angle glaucoma, and severe cases that can cause blindness. Mounting evidence suggests that the cause of myopia can be attributed to the complex interaction of environmental exposure and genetic susceptibility. An increasing number of researchers have focused on the genetic pathogenesis of myopia in recent years. Scleral remodeling and excessive axial elongating induced retina thinning and even retinal detachment are myopia's most important pathological manifestations. The related signaling pathways are indispensable in myopia occurrence and development, such as dopamine, nitric oxide, TGF-β, HIF-1α, etc. We review the current major and recent progress of biomedicine on myopia-related signaling pathways and mechanisms.
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Affiliation(s)
- Jing Yang
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Xinli Ouyang
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Hong Fu
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Xinyu Hou
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Yan Liu
- Department of Ophthalmology, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Yongfang Xie
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China.
| | - Haiqun Yu
- Department of Ophthalmology, Affiliated Hospital of Weifang Medical University, Weifang 261031, China.
| | - Guohui Wang
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China.
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18
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Gao Q, Ludwig CA, Smith SJ, Schachar IH. Ocular Penetrance and Safety of the Dopaminergic Prodrug Etilevodopa. Transl Vis Sci Technol 2021; 10:5. [PMID: 34609478 PMCID: PMC8496415 DOI: 10.1167/tvst.10.12.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Animal models have demonstrated the role of dopamine in regulating axial elongation, the critical feature of myopia. Because frequent delivery of dopaminergic agents via peribulbar, intravitreal, or intraperitoneal injections is not clinically viable, we sought to evaluate ocular penetration and safety of the topically applied dopaminergic prodrug etilevodopa. Methods The ocular penetration of dopamine and dopaminergic prodrugs (levodopa and etilevodopa) were quantified using an enzyme-linked immunosorbent assay in enucleated porcine eyes after a single topical administration. The pharmacokinetic profile of the etilevodopa was then assessed in rats. A four-week once-daily application of etilevodopa as a topical eye drop was conducted to establish its safety profile. Results At 24 hours, the studied prodrugs showed increased dopaminergic derivatives in the vitreous of porcine eyes. Dopamine 0.5% (P = 0.0123) and etilevodopa 10% (p = 0.370) achieved significant vitreous concentrations. Etilevodopa 10% was able to enter the posterior segment of the eye after topical administration in rats with an intravitreal half-life of eight hours after single topical administration. Monthly application of topical etilevodopa showed no alterations in retinal ocular coherence tomography, electroretinography, caspase staining, or TUNEL staining. Conclusions At similar concentrations, no difference in ocular penetration of levodopa and etilevodopa was observed. However, etilevodopa was highly soluble and able to be applied at higher topical concentrations. Dopamine exhibited both high solubility and enhanced penetration into the vitreous as compared to other dopaminergic prodrugs. Translational Relevance These findings indicate the potential of topical etilevodopa and dopamine for further study as a therapeutic treatment for myopia.
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Affiliation(s)
- Quanqing Gao
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, USA
| | - Cassie A Ludwig
- Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Stephen J Smith
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, USA
| | - Ira H Schachar
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, USA.,North Bay Vitreoretinal Consultants, Santa Rosa, California, USA
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19
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Karouta C, Kucharski R, Hardy K, Thomson K, Maleszka R, Morgan I, Ashby R. Transcriptome-based insights into gene networks controlling myopia prevention. FASEB J 2021; 35:e21846. [PMID: 34405458 DOI: 10.1096/fj.202100350rr] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 11/11/2022]
Abstract
Myopia (short-sightedness), usually caused by excessive elongation of the eye during development, has reached epidemic proportions worldwide. In animal systems including the chicken model, several treatments have been shown to inhibit ocular elongation and experimental myopia. Although diverse in their apparent mechanism of action, each one leads to a reduction in the rate of ocular growth. We hypothesize that a defined set of retinal molecular changes may underlie growth inhibition, irrespective of the treatment agent used. Accordingly, across five well-established but diverse methods of inhibiting myopia, significant overlap is seen in the retinal transcriptome profile (transcript levels and alternative splicing events) in chicks when analyzed by RNA-seq. Within the two major pathway networks enriched during growth inhibition, that of cell signaling and circadian entrainment, transcription factors form the largest functional grouping. Importantly, a large percentage of those genes forming the defined retinal response are downstream targets of the transcription factor EGR1 which itself shows a universal response to all five growth-inhibitory treatments. This supports EGR1's previously implicated role in ocular growth regulation. Finally, by contrasting our data with human linkage and GWAS studies on refractive error, we confirm the applicability of our study to the human condition. Together, these findings suggest that a universal set of transcriptome changes, which sit within a well-defined retinal network that cannot be bypassed, is fundamental to growth regulation, thus paving a way for designing novel targets for myopia therapies.
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Affiliation(s)
- Cindy Karouta
- Centre for Research in Therapeutic Solutions, Biomedical Sciences, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Robert Kucharski
- Centre for Research in Therapeutic Solutions, Biomedical Sciences, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia.,Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Kristine Hardy
- Centre for Research in Therapeutic Solutions, Biomedical Sciences, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Kate Thomson
- Centre for Research in Therapeutic Solutions, Biomedical Sciences, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Ryszard Maleszka
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Ian Morgan
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Biomedical Sciences, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia.,Research School of Biology, Australian National University, Canberra, ACT, Australia
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20
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Thomson K, Kelly T, Karouta C, Morgan I, Ashby R. Insights into the mechanism of atropine's anti-myopia effects: evidence against cholinergic hyperactivity and modulation of dopamine release. Br J Pharmacol 2021; 178:4501-4517. [PMID: 34302355 PMCID: PMC9293064 DOI: 10.1111/bph.15629] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 04/29/2021] [Accepted: 06/25/2021] [Indexed: 11/27/2022] Open
Abstract
Background and Purpose The ability of the muscarinic cholinergic antagonist atropine to inhibit myopia development in humans and animal models would suggest that cholinergic hyperactivity may underlie myopic growth. To test this, we investigated whether cholinergic agonists accelerate ocular growth rates in chickens. Furthermore, we investigated whether atropine alters ocular growth by downstream modulation of dopamine levels, a mechanism postulated to underlie its antimyopic effects. Experimental Approach Muscarinic (muscarine and pilocarpine), nicotinic (nicotine) and non‐specific (oxotremorine and carbachol) cholinergic agonists were administered to chicks developing form‐deprivation myopia (FDM) or chicks that were otherwise untreated. Vitreal levels of dopamine and its primary metabolite 3,4‐dihydroxyphenylacetic acid (DOPAC) were examined using mass spectrometry MS in form‐deprived chicks treated with atropine (360, 15 or 0.15 nmol). Further, we investigated whether dopamine antagonists block atropine's antimyopic effects. Key Results Unexpectedly, administration of each cholinergic agonist inhibited FDM but did not affect normal ocular development. Atropine only affected dopamine and DOPAC levels at its highest dose. Dopamine antagonists did not alter the antimyopia effects of atropine. Conclusion and Implications Muscarinic, nicotinic and non‐specific cholinergic agonists inhibited FDM development. This indicates that cholinergic hyperactivity does not underlie myopic growth and questions whether atropine inhibits myopia via cholinergic antagonism. This study also demonstrates that changes in retinal dopamine release are not required for atropine's antimyopic effects. Finally, nicotinic agonists may represent a novel and more targeted approach for the cholinergic control of myopia as they are unlikely to cause the anterior segment side effects associated with muscarinic treatment.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Tamsin Kelly
- National Centre for Forensic Studies, Faculty of Science and Technology, University of Canberra, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Ian Morgan
- Research School of Biology, Australian National University, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia.,Research School of Biology, Australian National University, Australia
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21
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Thomson K, Karouta C, Ashby R. Form-Deprivation and Lens-Induced Myopia Are Similarly Affected by Pharmacological Manipulation of the Dopaminergic System in Chicks. Invest Ophthalmol Vis Sci 2021; 61:4. [PMID: 33016984 PMCID: PMC7545069 DOI: 10.1167/iovs.61.12.4] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose Animal models have demonstrated a link between decreases in retinal dopamine levels and the development of form-deprivation myopia (FDM). However, the consistency of dopamine's role in the other major form of experimental myopia, that of lens-induced myopia (LIM), is less clear, raising the question as to what extent dopamine plays a role in human myopia. Therefore, to better define the role of dopamine in both forms of experimental myopia, we examined how consistent the protection afforded by dopamine and the dopamine agonist 6-amino-5,6,7,8-tetrahydronaphthalene-2,3-diol hydrobromide (ADTN) is between FDM and LIM. Methods Intravitreal injections of dopamine (0.002, 0.015, 0.150, 1.500 µmol) or ADTN (0.001, 0.010, 0.100, 1.000 µmol) were administered daily to chicks developing FDM or LIM. Axial length and refraction were measured following 4 days of treatment. To determine the receptor subtype by which dopamine and ADTN inhibit FDM and LIM, both compounds were coadministered with either the dopamine D2-like antagonist spiperone (0.005 µmol) or the D1-like antagonist SCH-23390 (0.005 µmol). Results Intravitreal administration of dopamine or ADTN inhibited the development of FDM (ED50 = 0.003 µmol and ED50 = 0.011 µmol, respectively) and LIM (ED50 = 0.002 µmol and ED50 = 0.010 µmol, respectively) in a dose-dependent manner, with a similar degree of protection observed in both paradigms (P = 0.471 and P = 0.969, respectively). Coadministration with spiperone, but not SCH-23390, inhibited the protective effects of dopamine and ADTN against the development of both FDM (P = 0.214 and P = 0.138, respectively) and LIM (P = 0.116 and P = 0.100, respectively). Conclusions pharmacological targeting of the retinal dopamine system inhibits FDM and LIM in a similar dose-dependent manner through a D2-like mechanism.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia.,Research School of Biology, Australian National University, Canberra, Australia
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Thomson K, Morgan I, Kelly T, Karouta C, Ashby R. Coadministration With Carbidopa Enhances the Antimyopic Effects of Levodopa in Chickens. Invest Ophthalmol Vis Sci 2021; 62:25. [PMID: 33877264 PMCID: PMC8083087 DOI: 10.1167/iovs.62.4.25] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Purpose Topical application of levodopa inhibits the development of form-deprivation myopia (FDM) and lens-induced myopia (LIM) in chicks. Here we examine whether coadministration with carbidopa enhances this protection and compare the effectiveness of topical versus systemic administration. We also investigate the degree to which topical and systemic administration of these compounds alters retinal dopamine release and examine whether this is the mechanism by which they inhibit experimental myopia. Methods Levodopa and levodopa:carbidopa (at a 4:1 ratio) were administered as twice-daily eye drops or once-daily intraperitoneal injections to chicks developing FDM or LIM over an ascending dose range. Axial length and refraction were measured following 4 days of treatment. Dopamine levels in the vitreous and blood were analyzed using liquid chromatography-mass spectrometry following topical or systemic administration of levodopa or levodopa:carbidopa. Finally, chicks receiving topical or systemic levodopa or levodopa:carbidopa were cotreated with the dopamine antagonist spiperone. Results Levodopa:carbidopa inhibited the development of FDM and LIM to a greater extent than levodopa alone (P < 0.05). Topical application was more effective than systemic administration (P < 0.001). Vitreal dopamine levels were increased to the greatest extent by topical application of levodopa:carbidopa (P < 0.001). Systemic but not topical administration significantly increased dopamine levels within the blood (P < 0.01). Cotreatment with spiperone inhibited the antimyopic effects (P < 0.05) of levodopa and levodopa:carbidopa. Conclusions The presence of carbidopa increases the bioavailability of levodopa within the eye, enhancing its antimyopic effects, with topical application showing the greatest efficacy. Thus levodopa:carbidopa may be a promising treatment for controlling the progression of human myopia.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia
| | - Ian Morgan
- Research School of Biology, Australian National University, Canberra, Australia
| | - Tamsin Kelly
- National Centre for Forensic Studies, Faculty of Science and Technology, University of Canberra, Canberra, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia.,Research School of Biology, Australian National University, Canberra, Australia
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23
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Thomson K, Karouta C, Ashby R. Topical application of dopaminergic compounds can inhibit deprivation myopia in chicks. Exp Eye Res 2020; 200:108233. [PMID: 32919992 DOI: 10.1016/j.exer.2020.108233] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 12/19/2022]
Abstract
PURPOSE Animal models have demonstrated a link between dysregulation of the retinal dopamine system and the development of experimental myopia (short-sightedness). However, pharmacological investigations of dopamine in animal models rely heavily on intravitreal or systemic administration, which have several limitations for longer-term experiments. We therefore investigated whether administration of dopamine as a topical eye drop can inhibit the development of form-deprivation myopia (FDM) in chicks. We also examined whether chemical modification of dopamine through deuterium substitution, which might enhance stability and bioavailability, can increase dopamine's effectiveness against FDM when given topically. METHODS Dopamine or deuterated dopamine (Dopamine-1,1,2,2-d4 hydrochloride) was administered as a daily intravitreal injection or as daily topical eye drops to chicks developing FDM over an ascending dose range (min. n = 6 per group). Axial length and refraction were measured following 4 days of treatment. RESULTS Both intravitreal (ED50 = 0.002μmoles) and topical application (ED50 = 6.10μmoles) of dopamine inhibited the development of FDM in a dose-dependent manner. Intravitreal injections, however, elicited a significantly higher level of protection relative to topical eye drops (p < 0.01). Deuterated dopamine inhibited FDM to a similar extent as unmodified dopamine when administered as intravitreal injections (p = 0.897) or topical eye drops (p = 0.921). CONCLUSIONS Both intravitreal and topical application of dopamine inhibit the development of FDM in a dose-dependent manner, indicating that topical administration may be an effective avenue for longer-term dopamine experiments. Deuterium substitution does not alter the protection afforded by dopamine against FDM when given as either an intravitreal injection or topical eye drop.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia.
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
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