1
|
Parthasarathi P, Moss HE. Review of evidence for treatments of acute non arteritic anterior ischemic optic neuropathy. Eye (Lond) 2024:10.1038/s41433-024-03136-8. [PMID: 38778140 DOI: 10.1038/s41433-024-03136-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/08/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
OBJECTIVE To review treatment modalities that have been studied in acute non arteritic anterior ischemic optic neuropathy (NAION). METHODS We performed a comprehensive literature search of English language publications in the last 5 years, with human species and NAION. Articles were reviewed to identify those that described original research on treatment of acute NAION. Study type, setting, duration, interventions, and results were extracted and articles were reviewed for biases and limitations. RESULTS We identified 22 kinds of treatment varying by compound and modality. These include topical, intravitreal, and systemic drugs as well as surgical approaches. Evidence for efficacy ranges from expert opinion to randomized control trials. CONCLUSIONS Although several treatments are utilized in practice, none of these have high quality evidence of efficacy to improve visual outcomes. Continued collaborative research is necessary to complete high quality studies in order identify effective therapies for this rare and blinding disease.
Collapse
Affiliation(s)
- Pooja Parthasarathi
- Department of Ophthalmology, Stanford University, Palo Alto, CA, 94303, USA.
| | - Heather E Moss
- Department of Ophthalmology, Stanford University, Palo Alto, CA, 94303, USA
- Department of Neurology & Neurological Sciences, Stanford University, Palo Alto, CA, 94303, USA
| |
Collapse
|
2
|
Lantos K, Dömötör ZR, Farkas N, Kiss S, Szakács Z, Garami A, Varga G, Lujber L, Kanaan R, Hegyi P, Fehér G, Gaál V. Efficacy of Treatments in Nonarteritic Ischemic Optic Neuropathy: A Systematic Review and Meta-Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19052718. [PMID: 35270411 PMCID: PMC8910678 DOI: 10.3390/ijerph19052718] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 02/04/2023]
Abstract
Background: Nonarteritic Anterior Ischemic Optic Neuropathy (NAION) is the second most common cause of optic nerve-related permanent visual loss in adults. Aim: We aimed to analyze the efficacy of the noninvasive and minimally invasive therapeutic options of NAION. Methods: We performed a systematic literature search in MEDLINE, EMBASE, and CENTRAL from inception to 10 June 2019 to identify the studies that report on the effect of different therapies on visual acuity (VA) and visual field (VF). Weighted mean difference (WMD) with 95% confidence interval (CI) was calculated for these outcomes. The efficacy of steroids was investigated in quantitative, oxygen, steroid plus erythropoietin (EPO), levodopa/carbidopa, memantine, and heparin-induced extracorporeal LDL/fibrinogen precipitation (HELP) therapies and other therapeutic modalities in qualitative synthesis. Results: Thirty-two studies were found to be eligible. We found that steroid therapy compared to control did not improve VA (p = 0.182, WMD = 0.14, 95% CI: −0.07, 0.35) or VF (p = 0.853, WMD = 0.16, 95% CI: −1.54, 1.86). Qualitative analysis could be performed for oxygen, steroid plus EPO, and HELP as well, however, none of them showed VA and VF benefit. Two individual studies found memantine and levodopa beneficial regarding VA. Conclusion: Our systematic review did not reveal any effective treatment. Further investigations are needed to find therapy for NAION.
Collapse
Affiliation(s)
- Krisztina Lantos
- Department of Ophthalmology, Medical School, University of Pécs, 7632 Pécs, Hungary;
| | - Zsuzsa Réka Dömötör
- Department of Ophthalmology, Medical School, University of Debrecen, 4032 Debrecen, Hungary;
| | - Nelli Farkas
- Institute of Bioanalysis, Medical School, University of Pécs, 7624 Pécs, Hungary;
| | - Szabolcs Kiss
- Doctoral School of Clinical Medicine, University of Szeged, 6720 Szeged, Hungary;
- Institute for Translational Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary; (Z.S.); (A.G.); (P.H.)
| | - Zsolt Szakács
- Institute for Translational Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary; (Z.S.); (A.G.); (P.H.)
| | - András Garami
- Institute for Translational Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary; (Z.S.); (A.G.); (P.H.)
| | - Gábor Varga
- Department of Oral Biology, Faculty of Dentistry, Semmelweis University, 1089 Budapest, Hungary;
| | - László Lujber
- Department of Otorhinolaryngology, Medical School, University of Pécs, 7621 Pécs, Hungary;
| | - Reem Kanaan
- Department of Public Health Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary;
| | - Péter Hegyi
- Institute for Translational Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary; (Z.S.); (A.G.); (P.H.)
| | - Gergely Fehér
- Department of Primary Health Care, Medical School, University of Pécs, 7624 Pécs, Hungary;
| | - Valéria Gaál
- Department of Ophthalmology, Medical School, University of Pécs, 7632 Pécs, Hungary;
- Correspondence: ; Tel.: +36-72-504-210
| |
Collapse
|
3
|
Randomized Controlled Phase 2a Study of RPh201 in Previous Nonarteritic Anterior Ischemic Optic Neuropathy. J Neuroophthalmol 2020; 39:291-298. [PMID: 31430268 DOI: 10.1097/wno.0000000000000786] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND No proven treatment exists for nonarteritic anterior ischemic optic neuropathy (NAION), either in the acute or late phase. OBJECTIVE To assess safety and changes in visual function and structure after RPh201/placebo treatment in participants with previous NAION. DESIGN AND SETTING Phase 2a, single-site, prospective, randomized, placebo-controlled, double-masked trial (registration NCT02045212). MAIN OUTCOMES MEASURES Early Treatment Diabetic Retinopathy Study best-corrected visual acuity (BCVA), visual fields, retinal nerve fiber layer, and visual evoked potential at weeks 13, 26, and after a 13-week wash-out ("off-drug") period; and safety. STUDY POPULATION Twenty-two participants aged 18 years or older with previous NAION. INTERVENTION(S) RPh201 (20 mg) or placebo (cottonseed oil vehicle) administered subcutaneously twice weekly at the study site. RESULTS Thirteen men and 9 women were randomized, of which 20 completed all visits. The mean (±SD) age was 61.0 ± 7.6 years. In a post hoc analysis, after 26 weeks of treatment, BCVA improved by ≥15 letters in 4/11 (36.4%) eyes with RPh201, compared to 1/8 (12.5%) eyes with placebo (P = 0.24). Overall, 7/11 (63.6%) of participants on RPh201 showed some improvement in BCVA, compared with 3/8 (37.5%) on placebo (P = 0.26). Improvement in BCVA from a calculated baseline was 14.8 ± 15.8 letters for RPh201 and 6.6 ± 15.3 for placebo (P = 0.27). Of the 154 adverse effects (AEs), 52 were considered related to the study procedures/treatment. Across the study and 1,017 injections, the most frequently reported AE was injection site pain (23 events in 5 participants). There were no clinically significant changes in vital signs or laboratory values. CONCLUSIONS This Phase 2a was designed to assess safety, feasibility, and explore potential efficacy signals in treating previous NAION with RPh201. No safety concerns were raised. The results support a larger trial in patients with previous NAION.
Collapse
|
4
|
Hayreh SS. Controversies on neuroprotection therapy in non-arteritic anterior ischaemic optic neuropathy. Br J Ophthalmol 2019; 104:153-156. [PMID: 31488431 DOI: 10.1136/bjophthalmol-2019-314656] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/14/2019] [Accepted: 08/20/2019] [Indexed: 12/24/2022]
Abstract
OBJECTIVE There has long been a great interest in neuroprotection therapy for ischaemic stroke and various types of optic neuropathies. In view of that, I reviewed the literature on the role of neuroprotection for non-arteritic anterior ischaemic optic neuropathy (NA-AION). METHODS The review is based on a PubMed search of literature about the use of neuroprotectors in stroke and optic neuropathies and about current clinical trials of RPh201 and QPI-1007 in NA-AION. RESULTS Several neuroprotection agents for ischaemic stroke and various types of optic neuropathies have been evaluated extensively in experimental studies in animals and benefits claimed. However, translation of therapeutic strategies for neuroprotection from experimental research to humans has invariably been fraught with failure. Two currently ongoing studies dealing with neuroprotection by RPh201 and QPI-1007 in NA-AION may have limitations in their rationale and study designs. CONCLUSIONS Unfortunately, in spite of all the experimental and clinical research on neuroprotection agents in NA-AION so far, we have no scientifically proven evidence of neuroprotection agents showing any benefit in the human clinical studies so far.
Collapse
|
5
|
Treatment of Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION). Neuroophthalmology 2019. [DOI: 10.1007/978-3-319-98455-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
6
|
Gossman CA, Linn DM, Linn C. Glaucoma-inducing Procedure in an In Vivo Rat Model and Whole-mount Retina Preparation. J Vis Exp 2016. [PMID: 27023167 DOI: 10.3791/53831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glaucoma is a disease of the central nervous system affecting retinal ganglion cells (RGCs). RGC axons making up the optic nerve carry visual input to the brain for visual perception. Damage to RGCs and their axons leads to vision loss and/or blindness. Although the specific cause of glaucoma is unknown, the primary risk factor for the disease is an elevated intraocular pressure. Glaucoma-inducing procedures in animal models are a valuable tool to researchers studying the mechanism of RGC death. Such information can lead to the development of effective neuroprotective treatments that could aid in the prevention of vision loss. The protocol in this paper describes a method of inducing glaucoma - like conditions in an in vivo rat model where 50 µl of 2 M hypertonic saline is injected into the episcleral venous plexus. Blanching of the vessels indicates successful injection. This procedure causes loss of RGCs to simulate glaucoma. One month following injection, animals are sacrificed and eyes are removed. Next, the cornea, lens, and vitreous are removed to make an eyecup. The retina is then peeled from the back of the eye and pinned onto sylgard dishes using cactus needles. At this point, neurons in the retina can be stained for analysis. Results from this lab show that approximately 25% of RGCs are lost within one month of the procedure when compared to internal controls. This procedure allows for quantitative analysis of retinal ganglion cell death in an in vivo rat glaucoma model.
Collapse
Affiliation(s)
| | - David M Linn
- Department of Biomedical Sciences, Grand Valley State University
| | - Cindy Linn
- Department of Biological Sciences, Western Michigan University;
| |
Collapse
|
7
|
Allen RS, Olsen TW, Sayeed I, Cale HA, Morrison KC, Oumarbaeva Y, Lucaciu I, Boatright JH, Pardue MT, Stein DG. Progesterone treatment in two rat models of ocular ischemia. Invest Ophthalmol Vis Sci 2015; 56:2880-91. [PMID: 26024074 DOI: 10.1167/iovs.14-16070] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE To determine whether the neurosteroid progesterone, shown to have protective effects in animal models of traumatic brain injury, stroke, and spinal cord injury, is also protective in ocular ischemia animal models. METHODS Progesterone treatment was tested in two ocular ischemia models in rats: a rodent anterior ischemic optic neuropathy (rAION) model, which induces permanent monocular optic nerve stroke, and the middle cerebral artery occlusion (MCAO) model, which causes transient ischemia in both the retina and brain due to an intraluminal filament that blocks the ophthalmic and middle cerebral arteries. Visual function and retinal histology were assessed to determine whether progesterone attenuated retinal injury in these models. Additionally, behavioral testing and 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining in brains were used to compare progesterone's neuroprotective effects in both retina and brain using the MCAO model. RESULTS Progesterone treatment showed no effect on visual evoked potential (VEP) reduction and retinal ganglion cell loss in the permanent rAION model. In the transient MCAO model, progesterone treatment reduced (1) electroretinogram (ERG) deficits, (2) MCAO-induced upregulation of glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP), and (3) retinal ganglion cell loss. As expected, progesterone treatment also had significant protective effects in behavioral tests and a reduction in infarct size in the brain. CONCLUSIONS Progesterone treatment showed protective effects in the retina following MCAO but not rAION injury, which may result from mechanistic differences with injury type and the therapeutic action of progesterone.
Collapse
Affiliation(s)
- Rachael S Allen
- Emergency Medicine Emory University, Atlanta, Georgia, United States 2Department of Ophthalmology, Emory University, Atlanta, Georgia, United States 3Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
| | - Timothy W Olsen
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Iqbal Sayeed
- Emergency Medicine Emory University, Atlanta, Georgia, United States
| | - Heather A Cale
- Emergency Medicine Emory University, Atlanta, Georgia, United States
| | | | - Yuliya Oumarbaeva
- Emergency Medicine Emory University, Atlanta, Georgia, United States
| | - Irina Lucaciu
- Emergency Medicine Emory University, Atlanta, Georgia, United States
| | - Jeffrey H Boatright
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States 3Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
| | - Machelle T Pardue
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States 3Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
| | - Donald G Stein
- Emergency Medicine Emory University, Atlanta, Georgia, United States
| |
Collapse
|
8
|
Huang SP, Tsai RK. Efficacy of granulocyte-colony stimulating factor treatment in a rat model of anterior ischemic optic neuropathy. Neural Regen Res 2014; 9:1502-5. [PMID: 25317164 PMCID: PMC4192964 DOI: 10.4103/1673-5374.139472] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2014] [Indexed: 01/12/2023] Open
Abstract
Non-arteritic anterior ischemic optic neuropathy (NA-AION) is the most common cause of acute ischemic damage to the optic nerve (ON), and the leading cause of seriously impaired vision in people over 55 years of age. It demonstrated that subcutaneous administration of Granulocyte colony-stimulating factor (G-CSF) reduces RGC death in an ON crush model in rats, and that the neuroprotective effects may involve both anti-apoptotic and anti-inflammatory processes. Our recent work shows that the protective actions of G-CSF in rAION models may involve both anti-apoptotic and anti-inflammatory processes. However, the exact rescuing mechanisms involved in the administration of G-CSF in rAION models need further investigation. In addition, further studies on the administration of G-CSF at different time intervals after the induction of rAION may be able to illustrate whether treatment given at a later time is still neuroprotective. Further, it is unknown whether treatment using G-CSF combined with other drugs will result in a synergistic effect in a rAION model. Inflammation induced by ischemia plays an essential role on the ON head in NA-AION, which can result in disc edema and compartment changes. Therefore, it is reasonable that adding an anti-inflammatory drug may enhance the therapeutic effects of G-CSF. An ongoing goal is to evaluate the novel sites of action of both G-CSF and other anti-inflammatory drugs, and to identify the functionally protective pathways to enhance RGC survival. These investigations may open up new therapeutic avenues for the treatment of ischemic optic neuropathy.
Collapse
Affiliation(s)
- Shun-Ping Huang
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97002, Taiwan, China
| | - Rong-Kung Tsai
- Institute of Eye Research, Buddhist Tzu Chi General Hospital, Hualien 97002, Taiwan, China ; Institute of Medical Sciences, Tzu Chi University, Hualien 97002, Taiwan, China
| |
Collapse
|
9
|
Nicholson JD, Leiba H, Goldenberg-Cohen N. Translational Preclinical Research may Lead to Improved Medical Management of Non-Arteritic Anterior Ischemic Optic Neuropathy. Front Neurol 2014; 5:122. [PMID: 25071709 PMCID: PMC4092366 DOI: 10.3389/fneur.2014.00122] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/25/2014] [Indexed: 12/23/2022] Open
Affiliation(s)
- James D Nicholson
- The Krieger Eye Research Laboratory, Felsenstein Medical Research Center , Petach Tikva , Israel ; Sackler Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel
| | - Hana Leiba
- Department of Ophthalmology, Kaplan Medical Center , Rehovot , Israel ; Hebrew University Hadassah Medical Center , Jerusalem , Israel
| | - Nitza Goldenberg-Cohen
- The Krieger Eye Research Laboratory, Felsenstein Medical Research Center , Petach Tikva , Israel ; Sackler Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel ; Pediatric Ophthalmology Unit, Schneider Children's Medical Center of Israel , Petach Tikva , Israel
| |
Collapse
|
10
|
Kinori M, Ben-Bassat I, Wasserzug Y, Chetrit A, Huna-Baron R. Visual outcome of mega-dose intravenous corticosteroid treatment in non-arteritic anterior ischemic optic neuropathy - retrospective analysis. BMC Ophthalmol 2014. [PMID: 24886579 PMCID: PMC4017224 DOI: 10.1186/1471-2415-14-62|] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND To date, non arteritic anterior ischemic optic neuropathy (NAION) is still incurable. We wish to evaluate the effect of intravenous (IV) corticosteroids on the visual outcome of NAION patients. METHODS Visual parameters were retrospectively compared between NAION patients treated with IV corticosteroids and untreated NAION patients (control). Visual acuity (VA) and Humphrey automated static perimetry visual field (VF) defects of the affected eye were compared between groups at baseline, 1, 3, 6 months, and end of follow-up visits. The VF analysis consisted of number of quadrant involvements and mean deviation (MD). RESULTS Each group comprised 23 patients (24 eyes). Mean initial VA was similar in the control and treatment groups (p = 0.8). VA at end of follow-up did not improve in either groups (p = 0.8 treated group, p = 0.1 control group). No improvement and no difference in VF defects were found by either quadrant analysis (p = 0.1 treated group, p = 0.5 control group) or MD analysis (p = 0.2, treated group, p = 0.9 control group). VA and VF parameters tended to be worse in the treated group, although without statistical significance. CONCLUSIONS Our results suggest that IV corticosteroids may not improve the visual outcome of NAION patients. Since intravenous corticosteroids could potentially cause serious adverse effects, this treatment for NAION is questionable.
Collapse
Affiliation(s)
- Michael Kinori
- Neuro-Ophthalmology unit, The Goldschleger Eye Institute, Sheba Medical Center, Tel- Hashomer, Israel affiliated to the Sackler school of medicine, Tel Aviv university, Tel Aviv, Israel.
| | - Iris Ben-Bassat
- Neuro-Ophthalmology unit, The Goldschleger Eye Institute, Sheba Medical Center, Tel- Hashomer, Israel affiliated to the Sackler school of medicine, Tel Aviv university, Tel Aviv, Israel
| | - Yael Wasserzug
- Neuro-Ophthalmology unit, The Goldschleger Eye Institute, Sheba Medical Center, Tel- Hashomer, Israel affiliated to the Sackler school of medicine, Tel Aviv university, Tel Aviv, Israel
| | - Angela Chetrit
- Gertner Institute for Research and Epidemiology, Sheba Medical Center, Tel Hashomer, Ramat Gan Israel
| | - Ruth Huna-Baron
- Neuro-Ophthalmology unit, The Goldschleger Eye Institute, Sheba Medical Center, Tel- Hashomer, Israel affiliated to the Sackler school of medicine, Tel Aviv university, Tel Aviv, Israel
| |
Collapse
|
11
|
Kinori M, Ben-Bassat I, Wasserzug Y, Chetrit A, Huna-Baron R. Visual outcome of mega-dose intravenous corticosteroid treatment in non-arteritic anterior ischemic optic neuropathy - retrospective analysis. BMC Ophthalmol 2014; 14:62. [PMID: 24886579 PMCID: PMC4017224 DOI: 10.1186/1471-2415-14-62] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 04/28/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To date, non arteritic anterior ischemic optic neuropathy (NAION) is still incurable. We wish to evaluate the effect of intravenous (IV) corticosteroids on the visual outcome of NAION patients. METHODS Visual parameters were retrospectively compared between NAION patients treated with IV corticosteroids and untreated NAION patients (control). Visual acuity (VA) and Humphrey automated static perimetry visual field (VF) defects of the affected eye were compared between groups at baseline, 1, 3, 6 months, and end of follow-up visits. The VF analysis consisted of number of quadrant involvements and mean deviation (MD). RESULTS Each group comprised 23 patients (24 eyes). Mean initial VA was similar in the control and treatment groups (p = 0.8). VA at end of follow-up did not improve in either groups (p = 0.8 treated group, p = 0.1 control group). No improvement and no difference in VF defects were found by either quadrant analysis (p = 0.1 treated group, p = 0.5 control group) or MD analysis (p = 0.2, treated group, p = 0.9 control group). VA and VF parameters tended to be worse in the treated group, although without statistical significance. CONCLUSIONS Our results suggest that IV corticosteroids may not improve the visual outcome of NAION patients. Since intravenous corticosteroids could potentially cause serious adverse effects, this treatment for NAION is questionable.
Collapse
Affiliation(s)
- Michael Kinori
- Neuro-Ophthalmology unit, The Goldschleger Eye Institute, Sheba Medical Center, Tel- Hashomer, Israel affiliated to the Sackler school of medicine, Tel Aviv university, Tel Aviv, Israel.
| | | | | | | | | |
Collapse
|
12
|
Grove K, Dobish J, Harth E, Ingram MC, Galloway RL, Mawn LA. Trans-meningeal drug delivery to optic nerve ganglion cell axons using a nanoparticle drug delivery system. Exp Eye Res 2013; 118:42-5. [PMID: 24184721 DOI: 10.1016/j.exer.2013.10.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 12/01/2022]
Abstract
The purpose of this study was to investigate if neuroprotective drugs can cross the optic nerve sheath in vitro. Four optic nerves were used for this study. Two porcine nerves were harvested at the time of euthanasia and two human nerves were obtained at the time of therapeutic globe enucleation. The optic nerve sheaths were dissected and placed as a membrane in a two chamber diffusion cell to test meningeal penetration by both brimonidine alone and brimonidine encapsulated in nanoparticle (NP-brimonidine). Brimonidine concentration was assayed by UV-vis spectrometer measurement of absorbance at 389 nm. Increasing concentration of brimonidine on the receiver side of the chamber was measured in both the brimonidine alone and the brimonidine encapsulated experiments. The human data were fitted with a two parameter exponential regression analysis (brimonidine alone donor r(2) = 0.87 and receiver r(2) = 0.80, NP-brimonidine donor r(2) = 0.79 and receiver r(2) = 0.84). Time constant (τ) was 10.2 h (donor) and 13.1 h (receiver) in the brimonidine study, and 24.0 h (donor) and 15.9 h (receiver) in the NP-brimonidine study. Encapsulated brimonidine had a longer time to reach equilibrium. Passage of brimonidine through the optic nerve sheath was demonstrated in the experiments. Increase in time constants when comparing the NP-brimonidine with the brimonidine curves in the human studiesindicates that diffusion is delayed by the initial parameter of drug being loaded in NP. Direct treatment of injured optic nerve axons may be possible by trans-meningeal drug diffusion.
Collapse
Affiliation(s)
- Karen Grove
- Vanderbilt Eye Institute, 2311 Pierce Avenue, Nashville, TN 37232-8808, USA.
| | - Julia Dobish
- Chemistry Department, 7619 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Eva Harth
- Chemistry Department, 7619 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Martha-Conley Ingram
- Biomedical Engineering, 5824 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Robert L Galloway
- Biomedical Engineering, 5824 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Louise A Mawn
- Vanderbilt Eye Institute, 2311 Pierce Avenue, Nashville, TN 37232-8808, USA.
| |
Collapse
|
13
|
Mackay DD, Atkins EJ, Newman NJ, Biousse V. Nonarteritic anterior ischemic optic neuropathy: untreatable at present? EXPERT REVIEW OF OPHTHALMOLOGY 2013. [DOI: 10.1586/17469899.2013.817720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
14
|
Establishing an experimental model of photodynamically induced anterior ischemic optic neuropathy. Vis Neurosci 2011; 28:155-62. [PMID: 21356144 DOI: 10.1017/s0952523810000398] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Numerous methods and drugs have been used to treat anterior ischemic optic neuropathy (AION); however, further investigations to determine the value of treatments for AION have been impeded by the lack of appropriate animal models of AION, significantly impacting on in-depth study of the disease. A rat model of AION was established, and corresponding functional changes of the fundus were observed using fundus fluorescein angiography (FFA), optical coherence tomography (OCT), and flash visual-evoked potential (F-VEP) in order to confirm the reliability of the AION model histopathologically. One day after model establishment, histopathology demonstrated that portions of the optic disc were highly edematous, with edema of nerve fibers and loose tissue, accompanied by displacement of the surrounding retina. At 23 days, the optic disc and surrounding nerve fiber layers had become thinner. None of the above-mentioned changes was observed in the laser, hematoporphyrin derivative (HPD), or naive groups. The results of fundus, FFA, F-VEP, and OCT-within 90 days after model establishment-confirmed that krypton red laser irradiation (647 nm), applied 2 h after HPD injection, can establish an ideal animal model of AION.
Collapse
|
15
|
Bosley TM, Abu-Amero KK. Assessing mitochondrial DNA nucleotide changes in spontaneous optic neuropathies. Ophthalmic Genet 2010; 31:163-72. [DOI: 10.3109/13816810.2010.514015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
16
|
Nelson K, Singh G, Boyer S, Gay D. Two presentations of nonarteritic ischemic optic neuropathy. OPTOMETRY (ST. LOUIS, MO.) 2010; 81:587-597. [PMID: 21035747 DOI: 10.1016/j.optm.2010.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 01/23/2010] [Accepted: 02/05/2010] [Indexed: 05/30/2023]
Abstract
BACKGROUND Nonarteritic ischemic optic neuropathy (NAION) is the most common acute optic neuropathy in adults over the age of 50. Patients affected notice sudden and painless loss of vision in 1 eye, often upon awaking. Studies have found that the opposite eye may be affected in approximately 15% to 20% of cases within a 5-year period. NAION vision loss results from an ischemic event often affecting the short posterior ciliary arteries. This results in optic nerve pallor, nerve fiber layer defects, and corresponding visual field defects. CASE REPORTS Two cases of NAION are discussed here. The first patient, a 57-year-old woman, had a 10-year history of visual symptoms, and the second, a 66-year-old man, presented in less than a week after first noticing symptoms. Both had predisposing systemic risk factors and resultant visual field loss and decreased visual acuity. CONCLUSIONS Predisposing factors for NAION include small cup-to-disc ratios of the optic nerve, obstructive sleep apnea, nocturnal hypotension, diabetes, and other vascular diseases. The vision loss is irreversible, and there is no known effective treatment to prevent subsequent disc atrophy or recurring episodes.
Collapse
Affiliation(s)
- Kiersten Nelson
- Veterans Affairs Illiana Health Care System, Danville, Illinois, USA
| | | | | | | |
Collapse
|
17
|
Atkins EJ, Bruce BB, Newman NJ, Biousse V. Treatment of nonarteritic anterior ischemic optic neuropathy. Surv Ophthalmol 2010; 55:47-63. [PMID: 20006051 PMCID: PMC3721361 DOI: 10.1016/j.survophthal.2009.06.008] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 06/12/2009] [Accepted: 06/17/2009] [Indexed: 11/26/2022]
Abstract
Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common clinical presentation of acute ischemic damage to the optic nerve. Most treatments proposed for NAION are empirical and include a wide range of agents presumed to act on thrombosis, on the blood vessels, or on the disk edema itself. Others are presumed to have a neuroprotective effect. Although there have been multiple therapies attempted, most have not been adequately studied, and animal models of NAION have only recently emerged. The Ischemic Optic Neuropathy Decompression Trial, the only class I large multicenter prospective treatment trial for nonarteritic anterior ischemic optic neuropathy, found no benefit from surgical intervention. One recent large, nonrandomized controlled study suggested that oral steroids might be helpful for acute NAION. Others recently proposed interventions are intravitreal injections of steroids or anti-vascular endothelial growth factor (anti-VEGF) agents. There are no class I studies showing benefit from either medical or surgical treatments. Most of the literature on the treatment of NAION consists of retrospective or prospective case series and anecdotal case reports. Similarly, therapies aimed at secondary prevention of fellow eye involvement in NAION remain of unproven benefit.
Collapse
Affiliation(s)
- Edward J. Atkins
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA
| | - Beau B. Bruce
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA
- Department of Neurology, Emory University School of Medicine, Atlanta GA, USA
| | - Nancy J. Newman
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA
- Department of Neurology, Emory University School of Medicine, Atlanta GA, USA
- Department of Neurological Surgery, Emory University School of Medicine, Atlanta GA, USA
| | - Valérie Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA
- Department of Neurology, Emory University School of Medicine, Atlanta GA, USA
| |
Collapse
|
18
|
Atkins EJ, Bruce BB, Newman NJ, Biousse V. Treatment of nonarteritic anterior ischemic optic neuropathy. Surv Ophthalmol 2010. [PMID: 20006051 PMCID: PMC3721361 DOI: 10.1016/j.survophthal.2009.06.008|] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common clinical presentation of acute ischemic damage to the optic nerve. Most treatments proposed for NAION are empirical and include a wide range of agents presumed to act on thrombosis, on the blood vessels, or on the disk edema itself. Others are presumed to have a neuroprotective effect. Although there have been multiple therapies attempted, most have not been adequately studied, and animal models of NAION have only recently emerged. The Ischemic Optic Neuropathy Decompression Trial, the only class I large multicenter prospective treatment trial for nonarteritic anterior ischemic optic neuropathy, found no benefit from surgical intervention. One recent large, nonrandomized controlled study suggested that oral steroids might be helpful for acute NAION. Others recently proposed interventions are intravitreal injections of steroids or anti-vascular endothelial growth factor (anti-VEGF) agents. There are no class I studies showing benefit from either medical or surgical treatments. Most of the literature on the treatment of NAION consists of retrospective or prospective case series and anecdotal case reports. Similarly, therapies aimed at secondary prevention of fellow eye involvement in NAION remain of unproven benefit.
Collapse
Affiliation(s)
- Edward J. Atkins
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA
| | - Beau B. Bruce
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA,Department of Neurology, Emory University School of Medicine, Atlanta GA, USA
| | - Nancy J. Newman
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA,Department of Neurology, Emory University School of Medicine, Atlanta GA, USA,Department of Neurological Surgery, Emory University School of Medicine, Atlanta GA, USA
| | - Valérie Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta GA, USA,Department of Neurology, Emory University School of Medicine, Atlanta GA, USA
| |
Collapse
|
19
|
Goldenberg-Cohen N, Dadon-Bar-El S, Hasanreisoglu M, Avraham-Lubin BCR, Dratviman-Storobinsky O, Cohen Y, Weinberger D. Possible neuroprotective effect of brimonidine in a mouse model of ischaemic optic neuropathy. Clin Exp Ophthalmol 2009; 37:718-29. [DOI: 10.1111/j.1442-9071.2009.02108.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
Non-arteritic anterior ischaemic optic neuropathy: A review and update. J Clin Neurosci 2009; 16:994-1000. [DOI: 10.1016/j.jocn.2009.04.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 04/04/2009] [Accepted: 04/05/2009] [Indexed: 11/20/2022]
|
21
|
Abstract
Anterior ischemic optic neuropathy (AION) is the most common cause of acute optic neuropathy after age 50, but may also occur in younger patients. The diagnosis is clinical and includes painless visual loss associated with a relative afferent pupillary defect and disc edema. In almost all cases, there is an underlying crowded optic nerve with a small cup-to-disc ratio. The visual prognosis is usually poor, although up to 43% of patients may improve over time. The fellow eye is involved in up to 15% of patients within 5 years, but the risk of recurrence in the same eye is less than 5%. There is no treatment for acute nonarteritic AION but it is essential to evaluate these patients for underlying treatable atheromatous vascular risk factors. A coagulation workup should also be considered in younger patients. It is essential to rule out giant cell arteritis in all patients over the age of 50 with ischemic optic neuropathies. Posterior ischemic neuropathy (in which the optic nerve is normal acutely) is rare and should be considered a diagnosis of exclusion.
Collapse
|
22
|
Affiliation(s)
- Derek W DelMonte
- Department of Medicine, Duke University Eye Center, DUMC 3802, Durham, NC 27710, USA
| | | |
Collapse
|
23
|
|
24
|
Bernstein SL, Mehrabyan Z, Guo Y, Moianie N. Estrogen is not neuroprotective in a rodent model of optic nerve stroke. Mol Vis 2007; 13:1920-5. [PMID: 17982415 PMCID: PMC2185481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Accepted: 09/20/2007] [Indexed: 11/13/2022] Open
Abstract
PURPOSE Nonarteritic anterior ischemic optic neuropathy (NAION) is an optic nerve (ON) infarct of retinal ganglion cell (RGC) axons, and the most common cause of ON-related sudden vision loss. Estrogen has been previously proposed as a neuroprotective treatment for central nervous system ischemia. We evaluated estrogen's potential in post-ON infarct treatment to reduce neuronal loss following a model of NAION, rodent anterior ischemic optic neuropathy (rAION). METHODS We used the rat rAION model, coupled to array and northern analyses, to evaluate estrogen-associated, early post-infarct retinal gene expression changes. rAION was induced in ovariectomized female rats, which were then treated with either estrogen or vehicle. Stereological analysis of post-rAION RGC numbers was performed, using retrograde RGC fill-labeling with fluorogold. RESULTS rAION induces an early increase in estrogen expressed transcript-1 (EET-1), but EET-1 expression is not affected by systemic estrogen pretreatment. Post-rAION, there is no significant increase in RGC numbers in estrogen treated animals compared with vehicle-treated controls. Estrogen treatment following stroke does not increase preservation of ON structure, compared with vehicle controls. CONCLUSIONS While the rAION-axonal stroke model is a useful adjunct for evaluating potential AION neuroprotective treatments, post-stroke estrogen administration does not appear neuroprotective in this form of central nervous system insult. Similarly, estrogen is likely to be ineffective in improving ON structural integrity following an ischemic infarct.
Collapse
Affiliation(s)
- Steven L. Bernstein
- Department of Ophthalmology,,Anatomy and Neurobiology,,Genetics, University of Maryland School of Medicine, Baltimore, MD
| | - Zara Mehrabyan
- Department of Ophthalmology,,Department of Anesthesiology, University of Maryland School of Medicine
| | | | | |
Collapse
|
25
|
Danylkova NO, Alcala SR, Pomeranz HD, McLoon LK. Neuroprotective effects of brimonidine treatment in a rodent model of ischemic optic neuropathy. Exp Eye Res 2006; 84:293-301. [PMID: 17113077 DOI: 10.1016/j.exer.2006.10.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 09/05/2006] [Accepted: 10/02/2006] [Indexed: 01/26/2023]
Abstract
Ischemic optic neuropathy (ION) is a common disorder caused by disruption of the arterial blood supply to the optic nerve. It can result in significant loss of visual acuity and/or visual field. An ischemic optic nerve injury was produced in rats by intravenous injection of Rose Bengal dye followed by argon green laser application to the retinal arteries overlying the optic nerve, causing a coagulopathy within the blood vessels and disruption of optic nerve and retinal perfusion. The effect of brimonidine tartrate eye drops on survival of retinal ganglion cell axons in this experimental paradigm was studied. One eye was treated and the contralateral eye served as a control. Four groups of animals were used for this study. Group 1 received 7 days of treatment with 0.15% brimonidine tartrate eye drops twice a day prior to the ischemic injury. Group 2 animals received 0.15% brimonidine tartrate eye drops twice a day for 14 days after photocoagulation injury. Animal groups 3 and 4 received eye drops of 0.9% NaCl twice a day either daily for 7 days before injury or daily for 14 days, respectively. All rats were sacrificed 5 months after the injury to ascertain long-term optic axon survival. Coagulopathy-induced optic nerve ischemia resulted in a 71% loss of optic axons. Treatment with brimonidine daily for the 7 days prior to the injury resulted in a greater survival of optic axons, with only a 56.1% loss compared to control. Brimonidine treatment every day for 14 days after the ischemic injury did not result in a significant rescue of optic axons compared to injury alone. In summary, the application of brimonidine eye drops for one week prior to an ischemic injury resulted in a statistically significant increase in survival of optic axons within the injured optic nerves. Brimonidine treatment of the eye after the ischemic injury did not result in axon rescue, and axon loss was similar to the injured optic nerves treated with saline only. These results suggest that brimonidine may have potential use for prevention of ION in at-risk patients.
Collapse
Affiliation(s)
- Nataliya O Danylkova
- Department of Ophthalmology, University of Minnesota, Minneapolis, MN 55455, USA
| | | | | | | |
Collapse
|
26
|
Abu-Amero KK, Bosley TM. Increased relative mitochondrial DNA content in leucocytes of patients with NAION. Br J Ophthalmol 2006; 90:823-5. [PMID: 16540486 PMCID: PMC1857173 DOI: 10.1136/bjo.2006.090332] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To investigate possible changes in relative mitochondrial DNA (mtDNA) content in patients with non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS 19 patients with NAION were compared to 32 controls matched for age, sex distribution, and ethnicity. DNA was extracted from leucocytes and competitive multiplex polymerase chain reaction was carried out with two primer pairs (one pair for mtDNA ND1 gene and the other pair for beta actin nuclear gene) in the presence of a fluorescent dye. RESULTS The mean relative mtDNA content in controls (0.93 (SD 0.11); 95% CI 0.89 to 0.97) was significantly less than in NAION patients (2.40 (1.05); 95% CI 1.90 to 2.91; p < 0.001). Relative mtDNA content was negatively correlated with Snellen visual acuity (Spearman's rho; r = -0.37; p = 0.022). CONCLUSION Increased relative mtDNA content in NAION patients may imply a response to oxidative stress, possibly in part because of mitochondrial respiratory chain defects. Significantly more non-synonymous mtDNA nucleotide changes, significantly increased relative mtDNA content, and a significant association between relative mtDNA content and visual acuity all imply that mitochondrial abnormalities may be a risk factor for NAION.
Collapse
Affiliation(s)
- K K Abu-Amero
- Mitochondrial Research Laboratory, Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
| | | |
Collapse
|
27
|
Wilhelm B, Lüdtke H, Wilhelm H. Efficacy and tolerability of 0.2% brimonidine tartrate for the treatment of acute non-arteritic anterior ischemic optic neuropathy (NAION): a 3-month, double-masked, randomised, placebo-controlled trial. Graefes Arch Clin Exp Ophthalmol 2005; 244:551-8. [PMID: 16151785 DOI: 10.1007/s00417-005-0102-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2005] [Revised: 06/12/2005] [Accepted: 07/23/2005] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION Neuroprotection may be an option in ischemic optic nerve disease. There have been promising reports about the neuroprotective ability of topical brimonidine in animal studies. Therefore, we tested whether 0.2% brimonidine tartrate could improve the outcome of patients with non-arteritic anterior ischemic optic neuropathy (NAION). The study was stopped after an interim analysis, having not proven its feasibility within practicable time frame. METHODS A 3-month, double-masked, placebo-controlled, randomised European multicenter trial conducted according to good clinical practice rules. Thirty-six patients (22 m, 14 f), older than 40 years with first eye involvement and typical signs of NAION were included in the study within the 1st week after visual loss (VA 0.05-1.0) and were randomized to treatment with either brimonidine 0.2% (Alphagan) or placebo. Visual acuity (VA, primary endpoint), visual field (VF, Humphrey 30-2 and Goldmann, quantified by a modified Esterman grid) and automated swinging flashlight test (SWIFT) were performed at baseline, 2 weeks, 4 weeks and 12 weeks after first visit. Primary analysis aimed at intention-to-treat group (ITT, n=29), secondary analysis to the per protocol population (PP, n=25). Tolerability and safety were tested in the safety group (n=36). A two-sample two-sided t-test was used for statistical analysis (alpha level at 0.05). RESULTS VA did not show statistically significant difference by treatment. There were non-significant trends for better visual field results in the brimonidine group. Adverse events consisting of local irritation were observed six times in the verum and three times in the placebo group. No serious adverse events occurred. CONCLUSION In contradiction to an open-labeled, retrospective study published by Fazzone et al., the results of this trial did not indicate any harmful effect of brimonidine in patients suffering from NAION. However, a statistically significant advantage for the patients receiving brimonidine tartrate could not be shown.
Collapse
Affiliation(s)
- Barbara Wilhelm
- Steinbeis Transfer Centre for Biomedical Optics and Function Testing Tübingen, Tübingen, Germany.
| | | | | |
Collapse
|
28
|
Abstract
A variety of acute neurologic disorders present with visual signs and symptoms. In this review the authors focus on those disorders in which the clinical outcome is dependent on timely and accurate diagnosis. The first section deals with acute visual loss, specifically optic neuritis, ischemic optic neuropathy (ION), retinal artery occlusion, and homonymous hemianopia. The authors include a discussion of those clinical features that are helpful in distinguishing between inflammatory and ischemic optic nerve disease and between arteritic and nonarteritic ION. The second section concerns disc edema with an emphasis on the prevention of visual loss in patients with increased intracranial pressure. The third section deals with abnormal ocular motility, and includes orbital inflammatory disease, carotid-cavernous fistulas, painful ophthalmoplegia, conjugate gaze palsies, and neuromuscular junction disorders. The final section concerns pupillary abnormalities, with a particular emphasis on the dilated pupil and on carotid artery dissection. Throughout there are specific guidelines for the management of these disorders, and areas are highlighted in which there is ongoing controversy.
Collapse
Affiliation(s)
- Valerie Purvin
- Indiana University Medical Center, Department of Ophthalmology, Indianapolis, IN 46280, USA.
| | | |
Collapse
|