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Hu J, Chen J, Ku Y, Yu M. Reduced interocular suppression after inverse patching in anisometropic amblyopia. Front Neurosci 2023; 17:1280436. [PMID: 38152718 PMCID: PMC10752599 DOI: 10.3389/fnins.2023.1280436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 11/21/2023] [Indexed: 12/29/2023] Open
Abstract
Purpose Recent investigations observed substantial enhancements in binocular balance, visual acuity, and stereovision among older children and adults with amblyopia by patching the amblyopic eye (i.e., inverse patching) for 2 h daily over 2 months. Despite these promising findings, the precise neural mechanisms underlying inverse patching remain elusive. This study endeavors to delve deeper into the neural alterations induced by inverse patching, focusing on steady-state visual evoked potentials (SSVEPs). We specifically investigate the changes in SSVEPs following monocular deprivation of either the fellow eye or the amblyopic eye in older amblyopic children and adults. Method Ten participants (17.60 ± 2.03 years old; mean ± SEM), clinically diagnosed with anisometropic amblyopia, were recruited for this study. Each participant underwent a 120 min patching session on their fellow eye on the first day, followed by a similar session on their amblyopic eye on the second day. Baseline steady-state visual evoked potentials (SSVEPs) measurements were collected each day prior to patching, with post-patching SSVEPs measurements obtained immediately after the patching session. The experimental design incorporated a binocular rivalry paradigm, utilizing SSVEPs measurements. Results The results revealed that inverse patching induced a heightened influence on neural plasticity, manifesting in a reduction of interocular suppression from the fellow eye to the amblyopic eye. In contrast, patching the fellow eye demonstrated negligible effects on the visual cortex. Furthermore, alterations in interocular suppression subsequent to inverse patching exhibited a correlation with the visual acuity of the amblyopic eye. Conclusion Inverse patching emerges as a promising therapeutic avenue for adolescents and adults grappling with severe anisometropic amblyopia that proves refractory to conventional interventions. This innovative approach exhibits the potential to induce more robust neural plasticity within the visual cortex, thereby modulating neural interactions more effectively than traditional amblyopia treatments.
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Affiliation(s)
- Jingyi Hu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Chen
- School of Psychology, Shanghai University of Sport, Shanghai, China
| | - Yixuan Ku
- Center for Brain and Mental Wellbeing, Department of Psychology, Sun Yat-sen University, Guangzhou, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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2
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Meng C, Zhang Y, Wang S. Anisometropic amblyopia: A review of functional and structural changes and treatment. Eur J Ophthalmol 2023; 33:1529-1535. [PMID: 36448184 DOI: 10.1177/11206721221143164] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Amblyopia is the decreased best-corrected visual acuity (BCVA) in one or both eyes caused by the abnormal processing of visual input during development. One common cause of amblyopia is anisometropia, which has attracted widespread attention. Many structural changes occur in the primary and extrastriate visual areas of the cerebral cortex, as well as in the eyes, in patients with anisometropic amblyopia. Understanding these mechanisms has provided a favorable theoretical basis for treating anisometropic amblyopia. This article reviews the functional and anatomical changes and progress toward the treatment of anisometropic amblyopia.
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Affiliation(s)
- Can Meng
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China
| | - Yan Zhang
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China
| | - Shurong Wang
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China
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He Y, Feng L, Zhou Y, Zhuang Y, Xu Z, Yao Y, Chen X, Jiang R, Yuan J, Ye Q, Wen Y, Jia Y, Liu J, Li J. Characteristics and predictive factors of visual function improvements after monocular perceptual learning in amblyopia. Heliyon 2023; 9:e17281. [PMID: 37416659 PMCID: PMC10320034 DOI: 10.1016/j.heliyon.2023.e17281] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 07/08/2023] Open
Abstract
Monocular perceptual learning has shown promising performance in restoring visual function in amblyopes beyond the critical period in the laboratory. However, the treatment outcome is variable and indeterminate in actual clinical and neuroscientific practice. We aimed to explore the efficacy of monocular perceptual learning in the clinical setting. By combining continuous monitoring of perceptual learning and clinical measurements, we evaluated the efficacy and characteristics of visual acuity and contrast sensitivity function improvement and further explored the individualized effect after perceptual learning. Amblyopes (average age:17 ± 7 years old) were trained in a monocular two-alternative forced choice identification task at the 50% contrast threshold of the amblyopic eye for 10-15 days. We found that monocular perceptual learning improves both visual acuity and contrast sensitivity function in amblyopia. The broader activation of spatial contrast sensitivity, with a significant improvement in lower spatial frequencies, contributed to improving visual acuity. Visual acuity changes in the early stage can predict the endpoint treatment outcomes. Our results confirm the efficacy of monocular perceptual learning and suggest potential predictors of training outcomes to assist in the future management of clinical intervention and vision neuroscience research in amblyopia beyond the critical period of visual plasticity.
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Chaturvedi I, Jamil R, Sharma P. Binocular vision therapy for the treatment of Amblyopia-A review. Indian J Ophthalmol 2023; 71:1797-1803. [PMID: 37203032 PMCID: PMC10391509 DOI: 10.4103/ijo.ijo_3098_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Amblyopia is a monocular or binocular reduction in visual acuity that results from prolonged visual deprivation in the early years of life. It is second only to refractive error as a cause of poor vision in children. The gold standard treatment of amblyopia includes patching and, less commonly, atropine penalization and filters. These therapies are aimed at improvements in the visual acuity of the amblyopic eye alone. They have compliance and psychosocial issues and gains are accrued after prolonged periods. Experimental studies have demonstrated the presence of binocular cortical communication even in amblyopes and neural plasticity in late childhood as well as adulthood. On this basis, binocular vision therapy aimed at the stimulation of both eyes rather than forced use of the amblyopic eye was developed. Such therapies involve visual tasks designed in such a way that they can be completed only by binocular viewing. These tasks vary from simple game play using red-green glasses, to engaging 3D games and movie viewing. Preliminary data suggest that binocular vision therapy has led to lasting improvements in visual acuity and can be a useful adjunct, if not replacement, to the conventional treatment of amblyopia. In this article, we aim to describe the various binocular vision therapies and review the available literature on the same.
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Affiliation(s)
- Isha Chaturvedi
- Comprehensive Services, Centre for Sight Eye Institute, Dwarka, New Delhi, India
| | - Rana Jamil
- Comprehensive Services, Centre for Sight Eye Institute, Dwarka, New Delhi, India
| | - Pradeep Sharma
- Strabismus Pediatric and Neuro-Ophthalmology Services, Centre for Sight, Safdarjung Enclave, New Delhi, India
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Rodán A, Candela Marroquín E, Jara García LC. An updated review about perceptual learning as a treatment for amblyopia. JOURNAL OF OPTOMETRY 2022; 15:3-34. [PMID: 33243673 PMCID: PMC8712591 DOI: 10.1016/j.optom.2020.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/16/2020] [Accepted: 08/16/2020] [Indexed: 05/31/2023]
Abstract
The purpose of our work is to do an update of recent investigations about amblyopia treatment based on perceptual learning, dichoptic training and videogames. Therefore, we conducted a search of the studies published about this subject in the last six years. The review shows that the investigations during that period have used several kinds of treatments regarding their design (e.g., type of stimulus and context used, duration of the training), and in a wider range of age that also include adults. Most of the studies have found an improvement in some mono and binocular visual functions, such as visual acuity, contrast sensitivity and stereopsis, which for now, it seems advisable that these processes could be used, as an alternative or a complement of the traditional passive therapy. Nevertheless, it would be plausible to conduct additional, controlled and random, clinical trials in order to discover in a more deeply way which perceptive learning method of treatment is more effective for the improvement of visual functions and for how long the effects of the treatment could persist.
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Cai X, Chen Z, Liu Y, Deng D, Yu M. A Dichoptic Optokinetic Nystagmus Paradigm for Interocular Suppression Quantification in Intermittent Exotropia. Front Neurosci 2021; 15:772341. [PMID: 34924941 PMCID: PMC8678071 DOI: 10.3389/fnins.2021.772341] [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: 09/08/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Purposes: To investigate the effectiveness of a dichoptic optokinetic nystagmus (dOKN) test to objectively quantify interocular suppression in intermittent exotropia (IXT) patients during the states of orthotropia and exodeviation. Methods: The OKN motion in subjects (15 controls and 59 IXT subjects) who viewed dichoptic oppositely moving gratings with different contrast ratios was monitored and recorded by an eye tracker. Interocular suppression in control subjects was induced using neutral density (ND) filters. The OKN direction ratios were fitted to examine the changes of interocular suppression in subjects under different viewing states. Two established interocular suppression tests (phase and motion) were conducted for a comparative study. Results: The dOKN test, which requires a minimal response from subjects, could accurately quantify the interocular suppression in both IXT and control subjects, which is in line with the established interocular suppression tests. Overall, although comparative, the strength of interocular suppression detected by the dOKN test (0.171 ± 0.088) was stronger than those of the phase (0.293 ± 0.081) and the motion tests (0.212 ± 0.068) in the control subjects with 1.5 ND filters. In IXT patients, when their eyes kept aligned, the dOKN test (0.58 ± 0.09) measured deeper visual suppression compared with the phase (0.73 ± 0.17) or the motion test (0.65 ± 0.14). Interestingly, strong interocular suppression (dOKN: 0.15 ± 0.12) was observed in IXT subjects during the periods of exodeviation, irrespective of their binocular visual function as measured by synoptophore. Conclusion: The dOKN test provides efficient and objective quantification of interocular suppression in IXT, and demonstrates how it fluctuates under different eye positions.
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Affiliation(s)
- Xiaoxiao Cai
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zidong Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yanping Liu
- Guangdong Provincial Key Laboratory of Social Cognitive Neuroscience and Mental Health, Department of Psychology, Sun Yat-sen University, Guangzhou, China
| | - Daming Deng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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7
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Efficacy of Perceptual Learning-Based Vision Training as an Adjuvant to Occlusion Therapy in the Management of Amblyopia: A Pilot Study. Vision (Basel) 2021; 5:vision5010015. [PMID: 33807038 PMCID: PMC8006050 DOI: 10.3390/vision5010015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 11/26/2022] Open
Abstract
A retrospective study was conducted to evaluate preliminarily the efficacy of perceptual learning (PL) visual training in medium-term follow-up with a specific software (Amblyopia iNET, Home Therapy Systems Inc., Gold Canyon, AZ, USA) for visual acuity (VA) and contrast sensitivity (CS) recovering in a sample of 14 moderate to severe amblyopic subjects with a previously unsuccessful outcome or failure with patching (PL Group). This efficacy was compared with that achieved in a patching control group (13 subjects, Patching 2). At one-month follow-up, a significant VA improvement in the amblyopic eye (AE) was observed in both groups, with no significant differences between them. Additionally, CS was measured in PL Group and exhibited a significant improvement in the AE one month after the beginning of treatment for 3, 6, 12, and 18 cycles/º (p = 0.003). Both groups showed long-lasting retention of visual improvements. A combined therapy of PL-based visual training and patching seems to be effective for improving VA in children with amblyopia who did not recover vision with patching alone or had a poor patching compliance. This preliminary outcome should be confirmed in future clinical trials.
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Yuan Y, Zhu C, Wang P, Hu X, Yao W, Huang X, Ke B. Alternative Flicker Glass: a New Anti-suppression Approach to the Treatment of Anisometropic Amblyopia. Ophthalmic Res 2021; 64:967-973. [PMID: 33652438 DOI: 10.1159/000515599] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/20/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Amlyopia always presents with monocular and binocular dysfunction. In this study, we aim to investage the efficacy of alternative occlusion using liquid crystal glasses versus continuous occlusion therapy using traditional patches for treating amblyopia. METHODS Eligible subjects with anisometropic amblyopia were randomized into two groups: alternative flicker glass (AFG) or patching group. In the AFG group, subjects were instructed to wear the flicker glasses for 1 hour a day. The AFG is a lightweight spectacle frame with liquid crystal lenses that provide direct square-wave alternating occlusion, which were pre-programmed at temporal frequency of 7Hz. In the patching group, the patients were prescribed to wear traditional patches for 2 hours a day. The best corrected visual acuity (BCVA), contrast sensitivity function (CSF) and stereoacuity were measured at the baseline, 3 and 12 weeks. RESULTS In this pilot study, a total of forty children were recruited, with twenty in the AFG group. Mean BCVA improved by 0.17±0.14logMAR (95% CI=0.10 to 0.23) in the AFG group, while 0.18±0.18logMAR (95% CI=0.09 to 0.26) in the patching group from baseline to 12 weeks. The improvement of BCVA in both groups were significant (both P<0.01), while no significant difference between the groups (P=0.82). The CSF of both low and high spatial frequencies exhibited significant improvement at 12 weeks in the AFG group (P<0.01, respectively), while just have a significant improvement at low spatial frequency in the patching group (P<0.01). The stereoacuity significantly improved by 504.00±848.00 (95% CI= -900.88 to -107.12) arc seconds in the AFG group (P<0.05), while 263.50± 639.55 (95% CI=-562.82 to 35.82) arc seconds in the patching group (P>0.05). CONCLUSION Alternative flicker glass was effective in improving both monocular and binocular function, which was most likely achieved by reducing the suppression and promoting binocular fusion. This therapy exhibited promise as an alternative method for amblyopia treatment.
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Affiliation(s)
- Ying Yuan
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Chengcheng Zhu
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Peng Wang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Xiaojun Hu
- National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Wenbo Yao
- Shanghai Eye Disease Prevention and Treatment Center, Shanghai, China
| | - Xinhui Huang
- Shanghai Eye Disease Prevention and Treatment Center, Shanghai, China
| | - Bilian Ke
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,
- National Clinical Research Center for Eye Diseases, Shanghai, China,
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Liu Z, Chen Z, Gao L, Liu M, Huang Y, Feng L, Yuan J, Deng D, Huang CB, Yu M. A New Dichoptic Training Strategy Leads to Better Cooperation Between the Two Eyes in Amblyopia. Front Neurosci 2020; 14:593119. [PMID: 33324154 PMCID: PMC7725751 DOI: 10.3389/fnins.2020.593119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/15/2020] [Indexed: 11/13/2022] Open
Abstract
Recent clinical trials failed to endorse dichoptic training for amblyopia treatment. Here, we proposed an alternative training strategy that focused on reducing signal threshold contrast in the amblyopic eye under a constant and high noise contrast in the fellow eye (HNC), and compared it to a typical dichoptic strategy that aimed at increasing the tolerable noise contrast in the fellow eye (i.e., TNC strategy). We recruited 16 patients with amblyopia and divided them into two groups. Eight patients in Group 1 received the HNC training, while the other eight patients in Group 2 performed the TNC training first (Phase 1) and then crossed over to the HNC training (Phase 2). We measured contrast sensitivity functions (CSFs) separately in the amblyopic and fellow eyes when the untested eye viewed mean luminance (monocularly unmasked) or noise stimuli (dichoptically masked) before and after training at a particular frequency. The area under the log contrast sensitivity function (AULCSF) of masked and unmasked conditions, and dichoptic gain (the ratio of AULCSF of masked to unmasked condition) were calculated for each eye. We found that both dichoptic training paradigms substantially improved masked CSF, dichoptic gain, and visual acuity in the amblyopic eye. As opposed to the TNC paradigm, the HNC training produced stronger effects on masked CSFs, stereoacuity, dichoptic gain, and visual acuity in the amblyopic eye. Interestingly, the second-phase HNC training in Group 2 also induced further improvement in the masked contrast sensitivity and AULCSF in the amblyopic eye. We concluded that the HNC training strategy was more effective than the TNC training paradigm. Future design for dichoptic training should not only focus on increasing the tolerable noise contrast in the fellow eye but should also "nurture" the amblyopic eye under normal binocular viewing conditions and sustained interocular suppression.
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Affiliation(s)
- Zitian Liu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zidong Chen
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Le Gao
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Manli Liu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yiru Huang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Lei Feng
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Junpeng Yuan
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Daming Deng
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Chang-Bing Huang
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences (CAS), Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
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Stimuli Characteristics and Psychophysical Requirements for Visual Training in Amblyopia: A Narrative Review. J Clin Med 2020; 9:jcm9123985. [PMID: 33316960 PMCID: PMC7764820 DOI: 10.3390/jcm9123985] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/16/2020] [Accepted: 12/07/2020] [Indexed: 12/03/2022] Open
Abstract
Active vision therapy using perceptual learning and/or dichoptic or binocular environments has shown its potential effectiveness in amblyopia, but some doubts remain about the type of stimuli and the mode and sequence of presentation that should be used. A search was performed in PubMed, obtaining 143 articles with information related to the stimuli used in amblyopia rehabilitation, as well as to the neural mechanisms implied in such therapeutic process. Visual deficits in amblyopia and their neural mechanisms associated are revised, including visual acuity loss, contrast sensitivity reduction and stereopsis impairment. Likewise, the most appropriate stimuli according to the literature that should be used for an efficient rehabilitation of the amblyopic eye are described in detail, including optotypes, Gabor’s patches, random-dot stimuli and Vernier’s stimuli. Finally, the properties of these stimuli that can be modified during the visual training are discussed, as well as the psychophysical method of their presentation and the type of environment used (perceptual learning, dichoptic stimulation or virtual reality). Vision therapy using all these revised concepts can be an effective option for treating amblyopia or accelerating the treatment period when combining with patching. It is essential to adapt the stimuli to the patient’s individual features in both monocular and binocular training.
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Milla M, Piñero DP. Characterization, passive and active treatment in strabismic amblyopia: a narrative review. Int J Ophthalmol 2020; 13:1132-1147. [PMID: 32685403 PMCID: PMC7321947 DOI: 10.18240/ijo.2020.07.18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 03/15/2020] [Indexed: 12/22/2022] Open
Abstract
Strabismic amblyopia is characterized by a distorted spatial perception. In this condition, the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding, deficits in the accommodative response, contrast sensitivity, and ocular motility abilities. The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity. Passive treatments such as occlusion, optical and/or pharmacological penalization, and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia. Recent researches have proved new pharmacological options to improve and maintain visual acuity after occlusion treatment in strabismic amblyopia. Likewise, the active vision therapy, in the last years, is becoming a very relevant therapeutic option in combination with passive treatments, especially during and after monocular therapy, in the attempt of recovering the imbalanced binocular vision.
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Affiliation(s)
- Myriam Milla
- Department of Optometry, OFTALVIST Alicante, Alicante 03016, Spain
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, San Vicente del Raspeig, Alicante 03690, Spain
| | - David P. Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, San Vicente del Raspeig, Alicante 03690, Spain
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Lapajne L, Roškar S, Tekavčič Pompe M, Svetina M, Jarc-Vidmar M, Hawlina M. Vision training with VEP biofeedback in amblyopia after the critical period. Doc Ophthalmol 2020; 141:269-278. [PMID: 32468275 DOI: 10.1007/s10633-020-09774-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/20/2020] [Indexed: 01/23/2023]
Abstract
PURPOSE The purpose of this study was to investigate the benefits of vision training with visual evoked potentials (VEP) biofeedback in amblyopia after the critical period in 8 to 17-year (11.5 ± 3.1) old children. METHODS Ten participants with monocular amblyopia after the critical period underwent a 10-week, 20-session vision training program with the Retimax Vision Trainer device. During each session, the participants were instructed to be as focused as possible onto the fixation point in the middle of the screen. The size of the fixation point and the pitch of the background sound were changing according to VEP parameters and thus provided the participants real-time feedback of their visual performance. RESULTS The mean BCVA improvement across our group was 0.12 LogMAR (p < 0.01). There was also a significant increase in contrast sensitivity to the FACT chart across all spatial frequencies (all p < 0.05). Electrophysiologic data revealed higher steady-state visual evoked potentials (SS-VEP) amplitudes and correspondingly lower fixation point values in the last 2 weeks of training compared to the first 2 weeks (both p < 0.01). Due to unexplainably low VEP amplitude levels in later trainings compared to those in the beginning in two participants, we have not found a significant correlation between the increase in BCVA and the increase in SS-VEP amplitude (p = 0.88). At the follow-up at 2 and 12 months following the end of training, both BCVA and contrast sensitivity remained within the levels achieved at the end of training. In some participants, however, no improvement of BCVA was observed. CONCLUSIONS The tested vision training approach demonstrates modest but stable improvement of psychophysical parameters as well as objective characteristics in amblyopia after the critical period. Real-time SS-VEP can be used as an objective parameter to monitor participants' attention during vision training stimulation.
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Affiliation(s)
- Luka Lapajne
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia. .,Medical Faculty, University of Ljubljana, Ljubljana, Slovenia.
| | - Sanja Roškar
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia.,Department of Psychology, Faculty of Arts, University of Ljubljana, Ljubljana, Slovenia
| | - Manca Tekavčič Pompe
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia.,Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Matija Svetina
- Department of Psychology, Faculty of Arts, University of Ljubljana, Ljubljana, Slovenia
| | | | - Marko Hawlina
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia. .,Medical Faculty, University of Ljubljana, Ljubljana, Slovenia.
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13
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Chen Y, He Z, Mao Y, Chen H, Zhou J, Hess RF. Patching and Suppression in Amblyopia: One Mechanism or Two? Front Neurosci 2020; 13:1364. [PMID: 32009874 PMCID: PMC6974542 DOI: 10.3389/fnins.2019.01364] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/03/2019] [Indexed: 01/26/2023] Open
Abstract
Purpose To determine if benefits from occlusion therapy are due to decreased suppression from the fellow eye in children with amblyopia. Methods Ten newly diagnosed amblyopes (7.2 ± 1.4 years old), two with strabismus and eight with anisometropia, participated. Patients were first given a 2-month period of refractive adaptation, followed by occlusion therapy (i.e., patching their fellow eye with an opaque patch for 4 h/day). Visual acuity of the amblyopic eye and interocular suppression were measured before and after 0.5, 1, 2, 4, and 6 months of occlusion therapy. We quantified interocular suppression with a binocular phase combination task. Results Visual acuity (in logMAR) improved from 0.50 ± 0.22 (mean ± SD) to 0.33 ± 0.20 for patients who finished a short-term (2 months) occlusion (A1–A10), from 0.53 ± 0.20 to 0.32 ± 0.22 for patients who finished a medium-term (4 months) occlusion (A1–A9), and from 0.48 ± 0.19 to 0.22 ± 0.10 for patients who finished a long-term (6 months) occlusion (A1–A8). Although their visual acuity significantly improved, their degree of suppression, which was abnormal in all cases, did not change consistently. This was true in all durations of occlusion therapy. Conclusion Reduced suppression from the fixing eye might not be result from occlusion therapy.
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Affiliation(s)
- Yiya Chen
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Zhifen He
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yu Mao
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Hao Chen
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Jiawei Zhou
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Robert F Hess
- McGill Vision Research, Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC, Canada
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García-Pérez MA. Psychophysical Tests Do Not Identify Ocular Dominance Consistently. Iperception 2019; 10:2041669519841397. [PMID: 31069044 PMCID: PMC6492369 DOI: 10.1177/2041669519841397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/04/2019] [Indexed: 12/22/2022] Open
Abstract
Classical sighting or sensory tests are used in clinical practice to identify the dominant eye. Several psychophysical tests were recently proposed to quantify the magnitude of dominance but whether their results agree was never investigated. We addressed this question for the two most common psychophysical tests: The perceived-phase test, which measures the cyclopean appearance of dichoptically presented sinusoids of different phase, and the coherence-threshold test, which measures interocular differences in motion perception when signal and noise stimuli are presented dichoptically. We also checked for agreement with three classical tests (Worth 4-dot, Randot suppression, and Bagolini lenses). Psychophysical tests were administered in their conventional form and also using more dependable psychophysical methods. The results showed weak correlations between psychophysical measures of strength of dominance with inconsistent identification of the dominant eye across tests: Agreement on left-eye dominance, right-eye dominance, or nondominance by both tests occurred only for 11 of 40 observers (27.5%); the remaining 29 observers were classified differently by each test, including 14 cases (35%) of opposite classification (left-eye dominance by one test and right-eye dominance by the other). Classical tests also yielded conflicting results that did not agree well with classification based on psychophysical tests. The results are discussed in the context of determination of ocular dominance for clinical decisions.
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Affiliation(s)
- Miguel A. García-Pérez
- Departamento de Metodología, Facultad de Psicología,
Universidad Complutense, Madrid, Spain
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15
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The treatment of amblyopia: current practice and emerging trends. Graefes Arch Clin Exp Ophthalmol 2019; 257:1061-1078. [DOI: 10.1007/s00417-019-04254-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 12/22/2018] [Accepted: 01/17/2019] [Indexed: 02/04/2023] Open
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16
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Zhao W, Jia WL, Chen G, Luo Y, Lin B, He Q, Lu ZL, Li M, Huang CB. A complete investigation of monocular and binocular functions in clinically treated amblyopia. Sci Rep 2017; 7:10682. [PMID: 28878318 PMCID: PMC5587672 DOI: 10.1038/s41598-017-11124-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/18/2017] [Indexed: 11/28/2022] Open
Abstract
The gold standard of a successful amblyopia treatment is full recovery of visual acuity (VA) in the amblyopic eye, but there has been no systematic study on both monocular and binocular visual functions. In this research, we aimed to quantify visual qualities with a variety of perceptual tasks in subjects with treated amblyopia. We found near stereoacuity and pAE dominance in binocular rivalry in "treated" amblyopia were largely comparable to those of normal subjects. CSF of the pAE remained deficient in high spatial frequencies. The binocular contrast summation ratio is significantly lower than normal standard. The interocular balance point is 34%, indicating that contrast in pAE is much less effective as the same contrast in pFE in binocular phase combination. Although VA, stereoacuity and binocular rivalry at low spatial frequency in treated amblyopes were normal or nearly normal, the pAE remained "lazy" in high frequency domain, binocular contrast summation, and interocular phase combination. Our results suggest that structured monocular and binocular training are necessary to fully recover deficient functions in amblyopia.
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Affiliation(s)
- Wuxiao Zhao
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist, Nanning, 530021, P.R. China
| | - Wu-Li Jia
- Department of Psychology, School of Education Science, Huaiyin Normal University, 111 Changjiang West Road, Huaian, 223300, P.R. China
- Key Laboratory of Behavioral Science, Institute of Psychology, CAS, 16 Lincui Road, Chaoyang Dist, Beijing, 100101, P.R. China
| | - Ge Chen
- Key Laboratory of Behavioral Science, Institute of Psychology, CAS, 16 Lincui Road, Chaoyang Dist, Beijing, 100101, P.R. China
- Department of Psychology, University of the Chinese Academy of Sciences, 19A Yuquan Rd, Shijingshan District, Beijing, 100049, P.R. China
| | - Yan Luo
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist, Nanning, 530021, P.R. China
| | - Borong Lin
- Key Laboratory of Behavioral Science, Institute of Psychology, CAS, 16 Lincui Road, Chaoyang Dist, Beijing, 100101, P.R. China
- Department of Psychology, University of the Chinese Academy of Sciences, 19A Yuquan Rd, Shijingshan District, Beijing, 100049, P.R. China
| | - Qing He
- Key Laboratory of Behavioral Science, Institute of Psychology, CAS, 16 Lincui Road, Chaoyang Dist, Beijing, 100101, P.R. China
- Department of Psychology, University of the Chinese Academy of Sciences, 19A Yuquan Rd, Shijingshan District, Beijing, 100049, P.R. China
| | - Zhong-Lin Lu
- Laboratory of Brain Processes (LOBES), Departments of Psychology, Center for Brain and Cognitive Sciences, Center for Cognitive and Behavioral Brain Imaging, The Ohio State University, Columbus, OH, 43210, United States of America
| | - Min Li
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist, Nanning, 530021, P.R. China.
| | - Chang-Bing Huang
- Key Laboratory of Behavioral Science, Institute of Psychology, CAS, 16 Lincui Road, Chaoyang Dist, Beijing, 100101, P.R. China.
- Department of Psychology, University of the Chinese Academy of Sciences, 19A Yuquan Rd, Shijingshan District, Beijing, 100049, P.R. China.
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Jia W, Lan F, Zhao X, Lu ZL, Huang CB, Zhao W, Li M. The effects of monocular training on binocular functions in anisometropic amblyopia. Vision Res 2017. [PMID: 28636883 DOI: 10.1016/j.visres.2017.02.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Intensive monocular perceptual learning can improve visual acuity, contrast sensitivity, and vernier acuity in the amblyopic eye in adults with amblyopia. It is however not clear how much monocular training can enhance binocular visual functions. In the current study, we aimed to evaluate effects of monocular training on a variety of binocular functions. Nineteen anisometropic amblyopes (18.5±1.26yrs, mean±s.e.) were trained in a grating contrast detection task near each individual's cutoff spatial frequency for 6-10days (630 trials/day). Visual acuity, stereoacuity, monocular and binocular contrast sensitivity functions (CSF), binocular phase combination and binocular rivalry were tested before and after training. Although monocular training can improve visual acuity and contrast sensitivity and eye dominance of the amblyopic eye, the magnitudes of improvements did not correlate with each other; the impact of monocular training on binocular phase combination was not significant. The results strongly suggest that structured monocular and binocular training is needed to fully recover deficient visual functions in anisometropic amblyopia.
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Affiliation(s)
- Wuli Jia
- School of Education Science, Huaiyin Normal University, 111 Changjiang West Road, Huaian 223300, China
| | - Fangfang Lan
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist., Nanning 530021, China
| | - Xin Zhao
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist., Nanning 530021, China
| | - Zhong-Lin Lu
- Laboratory of Brain Processes (LOBES), Center for Cognitive and Brain Sciences, Center for Cognitive and Behavioral Brain Imaging, and Department of Psychology, The Ohio State University, Columbus, OH 43210, USA
| | - Chang-Bing Huang
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang Dist., Beijing 100101, China
| | - Wuxiao Zhao
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist., Nanning 530021, China.
| | - Min Li
- Center for Optometry and Visual Science, Department of Optometry and Ophthalmology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Qingxiu Dist., Nanning 530021, China.
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19
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Abstract
PURPOSE OF REVIEW This review article is an update on the current treatments for amblyopia. In particular, the authors focus on the concepts of brain plasticity and their implications for novel treatment strategies for both children and adults affected by amblyopia. RECENT FINDINGS A variety of strategies has been developed to treat amblyopia in children and adults. New evidence on the pathogenesis of amblyopia has been obtained both in animal models and in clinical trials. Mainly, these studies have challenged the classical concept that amblyopia becomes untreatable after the 'end' of the sensitive or critical period of visual development, because of a lack of sufficient plasticity in the adult brain. SUMMARY New treatments for amblyopia in children and adults are desirable and should be encouraged. However, further studies should be completed before such therapies are widely accepted into clinical practice.
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Liao M, Zhao H, Liu L, Li Q, Dai Y, Zhang Y, Zhou Y. Training to improve contrast sensitivity in amblyopia: correction of high-order aberrations. Sci Rep 2016; 6:35702. [PMID: 27752122 PMCID: PMC5067678 DOI: 10.1038/srep35702] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 10/04/2016] [Indexed: 02/05/2023] Open
Abstract
Perceptual learning is considered a potential treatment for amblyopia even in adult patients who have progressed beyond the critical period of visual development because adult amblyopes retain sufficient visual plasticity. When perceptual learning is performed with the correction of high-order aberrations (HOAs), a greater degree of neural plasticity is present in normal adults and those with highly aberrated keratoconic eyes. Because amblyopic eyes show more severe HOAs than normal eyes, it is interesting to study the effects of HOA-corrected visual perceptual learning in amblyopia. In the present study, we trained twenty-six older child and adult anisometropic amblyopes while their HOAs were corrected using a real-time closed-loop adaptive optics perceptual learning system (AOPL). We found that adaptive optics (AO) correction improved the modulation transfer functions (MTFs) and contrast sensitivity functions (CSFs) of older children and adults with anisometropic amblyopia. When perceptual learning was performed with AO correction of the ocular HOAs, the improvements in visual function were not only demonstrated in the condition with AO correction but were also maintained in the condition without AO correction. Additionally, the learning effect with AO correction was transferred to the untrained visual acuity and fellow eyes in the condition without AO correction.
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Affiliation(s)
- Meng Liao
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Haoxing Zhao
- Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, China
- The Key Laboratory on Adaptive Optics, Chinese Academy of Science, Chengdu 610209, China
| | - Longqian Liu
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qian Li
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yun Dai
- Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, China
- The Key Laboratory on Adaptive Optics, Chinese Academy of Science, Chengdu 610209, China
| | - Yudong Zhang
- Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, China
- The Key Laboratory on Adaptive Optics, Chinese Academy of Science, Chengdu 610209, China
| | - Yifeng Zhou
- CAS Key Laboratory of Brain Function and Disease and School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
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