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Ablordeppey RK, Nieu R, Lin CR, Benavente-Perez A. Early Alterations in Inner-Retina Neural and Glial Saturated Responses in Lens-Induced Myopia. Transl Vis Sci Technol 2024; 13:16. [PMID: 38591944 PMCID: PMC11008749 DOI: 10.1167/tvst.13.4.16] [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: 07/19/2023] [Accepted: 03/11/2024] [Indexed: 04/10/2024] Open
Abstract
Purpose Myopic marmosets are known to exhibit significant inner retinal thinning compared to age-matched controls. The purpose of this study was to assess inner retinal activity in marmosets with lens-induced myopia compared to age-matched controls and evaluate its relationship with induced changes in refractive state and eye growth. Methods Cycloplegic refractive error (Rx), vitreous chamber depth (VCD), and photopic full-field electroretinogram were measured in 14 marmosets treated binocularly with negative contact lenses compared to 9 untreated controls at different stages throughout the experimental period (from 74 to 369 days of age). The implicit times of the a-, b-, d-, and photopic negative response (PhNR) waves, as well as the saturated amplitude (Vmax), semi-saturation constant (K), and slope (n) estimated from intensity-response functions fitted with Naka-Rushton equations were analyzed. Results Compared to controls, treated marmosets exhibited attenuated b-, d-, and PhNR waves Vmax amplitudes 7 to 14 days into treatment before compensatory changes in refraction and eye growth occurred. At later time points, when treated marmosets had developed axial myopia, the amplitudes and implicit times of the b-, d-, and PhNR waves were similar between groups. In controls, the PhNR wave saturated amplitude increased as the b + d-wave Vmax increased. This trend was absent in treated marmosets. Conclusions Marmosets induced with negative defocus exhibit early alterations in inner retinal saturated amplitudes compared to controls, prior to the development of compensatory myopia. These early ERG changes are independent of refraction and eye size and may reflect early changes in bipolar, ganglion, amacrine, or glial cell physiology prior to myopia development. Translational Relevance The early changes in retinal function identified in the negative lens-treated marmosets may serve as clinical biomarkers to help identify children at risk of developing myopia.
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Affiliation(s)
- Reynolds K. Ablordeppey
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
| | - Rita Nieu
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
| | - Carol R. Lin
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
| | - Alexandra Benavente-Perez
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
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Stapley V, Anderson RS, Saunders K, Mulholland PJ. Examining the concordance of retinal ganglion cell counts generated using measures of structure and function. Ophthalmic Physiol Opt 2022; 42:1338-1352. [PMID: 36065739 PMCID: PMC9826349 DOI: 10.1111/opo.13041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 01/11/2023]
Abstract
PURPOSE There are several indirect methods used to estimate retinal ganglion cell (RGC) count in an individual eye, but there is limited information as to the agreement between these methods. In this work, RGC receptive field (RGC-RF) count underlying a spot stimulus (0.43°, Goldmann III) was calculated and compared using three different methods. METHODS RGC-RF count was calculated at a retinal eccentricity of 2.32 mm for 44 healthy adult participants (aged 18-58 years, refractive error -9.75 DS to +1.75 DS) using: (i) functional measures of achromatic peripheral grating resolution acuity (PGRA), (ii) structural measures of RGC-layer thickness (OCT-model, based on the method outlined by Raza and Hood) and (iii) scaling published histology density data to simulate a global expansion in myopia (Histology-Balloon). RESULTS Whilst average RGC-RF counts from the OCT-model (median 105.3, IQR 99.6-111.0) and the Histology-Balloon model (median 107.5, IQR 97.7-114.6) were similar, PGRA estimates were approximately 65% lower (median 37.7, IQR 33.8-46.0). However, there was poor agreement between all three methods (Bland-Altman 95% limits of agreement; PGRA/OCT: 55.4; PGRA/Histology-Balloon 59.3; OCT/Histology-Balloon: 52.4). High intersubject variability in RGC-RF count was evident using all three methods. CONCLUSIONS The lower PGRA RGC-RF counts may be the result of targeting only a specific subset of functional RGCs, as opposed to the coarser approach of the OCT-model and Histology-Balloon, which include all RGCs, and also likely displaced amacrine cells. In the absence of a 'ground truth', direct measure of RGC-RF count, it is not possible to determine which method is most accurate, and each has limitations. However, what is clear is the poor agreement found between the methods prevents direct comparison of RGC-RF counts between studies utilising different methodologies and highlights the need to utilise the same method in longitudinal work.
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Affiliation(s)
- Victoria Stapley
- Centre for Optometry & Vision Science, Biomedical Sciences Research InstituteUlster UniversityColeraineUK
| | - Roger S. Anderson
- Centre for Optometry & Vision Science, Biomedical Sciences Research InstituteUlster UniversityColeraineUK,National Institute for Health Research (NIHR)Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of OphthalmologyLondonUK
| | - Kathryn Saunders
- Centre for Optometry & Vision Science, Biomedical Sciences Research InstituteUlster UniversityColeraineUK
| | - Pádraig J. Mulholland
- Centre for Optometry & Vision Science, Biomedical Sciences Research InstituteUlster UniversityColeraineUK,National Institute for Health Research (NIHR)Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of OphthalmologyLondonUK
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Barbano L, Ziccardi L, Antonelli G, Nicoletti CG, Landi D, Mataluni G, Falsini B, Marfia GA, Centonze D, Parisi V. Multifocal Electroretinogram Photopic Negative Response: A Reliable Paradigm to Detect Localized Retinal Ganglion Cells' Impairment in Retrobulbar Optic Neuritis Due to Multiple Sclerosis as a Model of Retinal Neurodegeneration. Diagnostics (Basel) 2022; 12:diagnostics12051156. [PMID: 35626311 PMCID: PMC9139610 DOI: 10.3390/diagnostics12051156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/28/2022] [Accepted: 05/05/2022] [Indexed: 11/28/2022] Open
Abstract
The measure of the full-field photopic negative response (ff-PhNR) of light-adapted full-field electroretinogram (ff-ERG) allows to evaluate the function of the innermost retinal layers (IRL) containing primarily retinal ganglion cells (RGCs) and other non-neuronal elements of the entire retina. The aim of this study was to acquire functional information of localized IRL by measuring the PhNR in response to multifocal stimuli (mfPhNR). In this case-control observational and retrospective study, we assessed mfPhNR responses from 25 healthy controls and from 20 patients with multiple sclerosis with previous history of optic neuritis (MS-ON), with full recovery of visual acuity, IRL morphological impairment, and absence of morpho-functional involvement of outer retinal layers (ORL). MfPhNR response amplitude densities (RADs) were measured from concentric rings (R) with increasing foveal eccentricity: 0−5° (R1), 5−10° (R2), 10−15° (R3), 15−20° (R4), and 20−25° (R5) from retinal sectors (superior-temporal (ST), superior-nasal (SN), inferior-nasal (IN), and inferior-temporal (IT)); between 5° and 20° and from retinal sectors (superior (S), temporal (T), inferior (I), and nasal (N)); and within 5° to 10° and within 10° and 20° from the fovea. The mfPhNR RAD values observed in all rings or sectors in MS-ON eyes were significantly reduced (p < 0.01) with respect to control ones. Our results suggest that mfPhNR recordings may detect localized IRL dysfunction in the pathologic condition of selective RGCs neurodegeneration.
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Affiliation(s)
- Lucilla Barbano
- IRCCS—Fondazione Bietti, Via Livenza 1, 00198 Rome, Italy; (L.B.); (G.A.); (V.P.)
| | - Lucia Ziccardi
- IRCCS—Fondazione Bietti, Via Livenza 1, 00198 Rome, Italy; (L.B.); (G.A.); (V.P.)
- Correspondence: ; Tel.: +39-06-85356727; Fax: +39-06-84242333
| | - Giulio Antonelli
- IRCCS—Fondazione Bietti, Via Livenza 1, 00198 Rome, Italy; (L.B.); (G.A.); (V.P.)
| | - Carolina Gabri Nicoletti
- Multiple Sclerosis Clinical and Research Unit, Department of Systems Medicine, Tor Vergata University, Via Montpellier 1, 00133 Rome, Italy; (C.G.N.); (D.L.); (G.M.); (G.A.M.); (D.C.)
| | - Doriana Landi
- Multiple Sclerosis Clinical and Research Unit, Department of Systems Medicine, Tor Vergata University, Via Montpellier 1, 00133 Rome, Italy; (C.G.N.); (D.L.); (G.M.); (G.A.M.); (D.C.)
| | - Giorgia Mataluni
- Multiple Sclerosis Clinical and Research Unit, Department of Systems Medicine, Tor Vergata University, Via Montpellier 1, 00133 Rome, Italy; (C.G.N.); (D.L.); (G.M.); (G.A.M.); (D.C.)
| | - Benedetto Falsini
- Ophthalmology Department, IRCCS—Fondazione Policlinico Universitario A. Gemelli, Catholic University, Largo F. Vito 1, 00168 Rome, Italy;
| | - Girolama Alessandra Marfia
- Multiple Sclerosis Clinical and Research Unit, Department of Systems Medicine, Tor Vergata University, Via Montpellier 1, 00133 Rome, Italy; (C.G.N.); (D.L.); (G.M.); (G.A.M.); (D.C.)
| | - Diego Centonze
- Multiple Sclerosis Clinical and Research Unit, Department of Systems Medicine, Tor Vergata University, Via Montpellier 1, 00133 Rome, Italy; (C.G.N.); (D.L.); (G.M.); (G.A.M.); (D.C.)
- Unit of Neurology and Neurorehabilitation, IRCCS—Neuromed, Via Atinense 18, 86077 Pozzilli, Italy
| | - Vincenzo Parisi
- IRCCS—Fondazione Bietti, Via Livenza 1, 00198 Rome, Italy; (L.B.); (G.A.); (V.P.)
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Saurabh K, Roy R. Commentary: From diabetic retinopathy toward diabetic retinal disease. Indian J Ophthalmol 2021; 69:3248-3249. [PMID: 34708781 PMCID: PMC8725101 DOI: 10.4103/ijo.ijo_2131_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Kumar Saurabh
- Retina Services, Kamalnayan Bajaj Sankara Nethralaya, Kolkata, West Bengal, India
| | - Rupak Roy
- Retina Services, Aditya Birla Sankara Nethralaya, Kolkata, West Bengal, India
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Lazzara F, Amato R, Platania CBM, Conti F, Chou TH, Porciatti V, Drago F, Bucolo C. 1α,25-dihydroxyvitamin D 3 protects retinal ganglion cells in glaucomatous mice. J Neuroinflammation 2021; 18:206. [PMID: 34530842 PMCID: PMC8444391 DOI: 10.1186/s12974-021-02263-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Glaucoma is an optic neuropathy characterized by loss of function and death of retinal ganglion cells (RGCs), leading to irreversible vision loss. Neuroinflammation is recognized as one of the causes of glaucoma, and currently no treatment is addressing this mechanism. We aimed to investigate the anti-inflammatory and neuroprotective effects of 1,25(OH)2D3 (1α,25-dihydroxyvitamin D3, calcitriol), in a genetic model of age-related glaucomatous neurodegeneration (DBA/2J mice). METHODS DBA/2J mice were randomized to 1,25(OH)2D3 or vehicle treatment groups. Pattern electroretinogram, flash electroretinogram, and intraocular pressure were recorded weekly. Immunostaining for RBPMS, Iba-1, and GFAP was carried out on retinal flat mounts to assess retinal ganglion cell density and quantify microglial and astrocyte activation, respectively. Molecular biology analyses were carried out to evaluate retinal expression of pro-inflammatory cytokines, pNFκB-p65, and neuroprotective factors. Investigators that analysed the data were blind to experimental groups, which were unveiled after graph design and statistical analysis, that were carried out with GraphPad Prism. Several statistical tests and approaches were used: the generalized estimated equations (GEE) analysis, t-test, and one-way ANOVA. RESULTS DBA/2J mice treated with 1,25(OH)2D3 for 5 weeks showed improved PERG and FERG amplitudes and reduced RGCs death, compared to vehicle-treated age-matched controls. 1,25(OH)2D3 treatment decreased microglial and astrocyte activation, as well as expression of inflammatory cytokines and pNF-κB-p65 (p < 0.05). Moreover, 1,25(OH)2D3-treated DBA/2J mice displayed increased mRNA levels of neuroprotective factors (p < 0.05), such as BDNF. CONCLUSIONS 1,25(OH)2D3 protected RGCs preserving retinal function, reducing inflammatory cytokines, and increasing expression of neuroprotective factors. Therefore, 1,25(OH)2D3 could attenuate the retinal damage in glaucomatous patients and warrants further clinical evaluation for the treatment of optic neuropathies.
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Affiliation(s)
- Francesca Lazzara
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Rosario Amato
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
- Department of Biology, University of Pisa, Pisa, Italy
| | - Chiara Bianca Maria Platania
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
| | - Federica Conti
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
- Center for Research in Ocular Pharmacology - CERFO, University of Catania, Catania, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy.
- Center for Research in Ocular Pharmacology - CERFO, University of Catania, Catania, Italy.
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Naguib S, Backstrom JR, Gil M, Calkins DJ, Rex TS. Retinal oxidative stress activates the NRF2/ARE pathway: An early endogenous protective response to ocular hypertension. Redox Biol 2021; 42:101883. [PMID: 33579667 PMCID: PMC8113046 DOI: 10.1016/j.redox.2021.101883] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 01/27/2023] Open
Abstract
Oxidative stress contributes to degeneration of retinal ganglion cells and their axons in glaucoma, a leading cause of irreversible blindness worldwide, through sensitivity to intraocular pressure (IOP). Here, we investigated early elevations in reactive oxygen species (ROS) and a role for the NRF2-KEAP1-ARE endogenous antioxidant response pathway using microbead occlusion to elevate IOP in mice. ROS levels peaked in the retina at 1- and 2-wks following IOP elevation and remained elevated out to 5-wks. Phosphorylation of NRF2 and antioxidant gene transcription and protein levels increased concomitantly at 2-wks after IOP elevation, along with phosphorylation of PI3K and AKT. Inhibiting PI3K or AKT signaling prevented NRF2 phosphorylation and reduced transcription of antioxidant-regulated genes. Ocular hypertensive mice lacking Nrf2 had elevated ROS and a diminished increase in antioxidant gene expression. They also exhibited earlier axon degeneration and loss of visual function. In conclusion, the NRF2-KEAP1-ARE pathway is endogenously activated early in ocular hypertension due to phosphorylation of NRF2 by the PI3K/AKT pathway and serves to slow the onset of axon degeneration and vision loss in glaucoma. These data suggest that exogenous activation of this pathway might further slow glaucomatous neurodegeneration.
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Affiliation(s)
- Sarah Naguib
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - Jon R Backstrom
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Melanie Gil
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - David J Calkins
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Tonia S Rex
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, USA.
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Relationship between stimulus size and different components of the electroretinogram (ERG) elicited by flashed stimuli. Doc Ophthalmol 2020; 142:213-231. [PMID: 33063285 DOI: 10.1007/s10633-020-09797-6] [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: 04/21/2020] [Accepted: 10/01/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate how light stimulus conditions of varying spatial sizes affect components of the flash and long-flash electroretinogram (ERG) in normal subjects. METHOD Three stimulus conditions were generated by a Ganzfeld stimulator: a white flash on white background (WoW), a red flash on a blue background (RoB) and an L+M-cone isolating on-off (long flash) stimulus (Cone Iso). ERGs were recorded from six subjects (5 M, 1 F) with DTL electrodes to full-field (FF), 70°, 60°, 50°, 40°, 30° and 20° diameter circular stimuli. Amplitudes and peak times for a-, b-, d- and i-wave, and PhNR were examined. PhNR amplitudes were estimated in two different ways: from baseline (fB) and from preceding b-wave peak (fP). RESULTS With decreasing stimulus size, amplitudes for all ERG waveform components attenuated and peak times increased, although the effect varied across different components. An exponential fit described the relationship between amplitudes and size of stimulated retinal area well for most components and conditions (R2= 0.75-0.99), except for PhNR(fB) (R2= - 0.16-0.88). For peak times, an exponential decay function also fitted the data well (R2= 0.81-0.97), except in a few cases where the exponential constant was too small and a linear regression function was applied instead (a-wave Cone Iso, b- and i-wave WoW). The exponential constants for RoB amplitudes (b-wave, PhNR(fB), PhNR(fP)) were larger compared to their counterparts under WoW (p < 0.05), while there was no difference between the constants for a-wave amplitudes and peak times and for PhNR peak times. The exponential constants of amplitudes vs. area under WoW and Cone Iso were remarkably similar, while under RoB PhNR(fB) showed larger constants compared to either a- or b-wave (p < 0.05). CONCLUSION ERG components change in a predictable way with stimulus size and spectral characteristics of the stimulus under these conditions. This predictability could allow a modified version of these sets of stimuli to be tested for clinical applicability.
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