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Yu X, Wei L, Chen Y, Zhang H, Yu H, Zhou J, Xu M. Binocular Visual Deficits at Low to High Spatial Frequency in Intermittent Exotropia After Surgery. Invest Ophthalmol Vis Sci 2024; 65:41. [PMID: 39189992 PMCID: PMC11361387 DOI: 10.1167/iovs.65.10.41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 08/03/2024] [Indexed: 08/28/2024] Open
Abstract
Purpose To investigate binocular visual deficits at low to high spatial frequencies in patients with intermittent exotropia (IXT) after surgical correction, using the binocular orientation combination task. Methods Thirteen patients whose IXT has been aligned surgically (17 ± 4.8 years old; 7 females) and 13 normal individuals (21.8 ± 2.5 years old; 6 females) were recruited. All participants had normal or corrected-to-normal visual acuity. The IXT patients had undergone surgery at least one month prior to the study and achieved successful eye alignment post-surgery. We measured participants' balance points (BPs), defined as the interocular contrast ratio (nondominant eye/dominant eye) when both eyes contributed equally to binocular combination, using the binocular orientation combination task at three spatial frequencies (0.5, 4.0, and 8.0 cycles/degree). The absolute values of log10(BP) (i.e., |logBP|) and the area under of the |logBP| versus spatial frequency curve were used to quantify the extent of binocular imbalance. Results Surgery aligned the eye position of patients with IXT, with a postoperative exodeviation of -4.92 ± 4.29 prism diopters at distance. Participants' |logBP| values showed significant differences between groups, F(1,24) = 9.175, P = 0.006, and across spatial frequencies, F(2,48) = 7.127, P = 0.002. However, the interaction between group and spatial frequency was not significant, F(2,48) = 0.379, P = 0.687. Conclusions Patients whose IXT has been alighted surgically experience binocular imbalance across a wide range of spatial frequencies, with greater binocular imbalance occurring at high spatial frequencies than low spatial frequencies.
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Affiliation(s)
- Xi Yu
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Lili Wei
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yiya Chen
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Hanyi Zhang
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Huanyun Yu
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jiawei Zhou
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Meiping Xu
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
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Chen H, Jiang X, Liu W, Zhou J, Chen J, Sun Q, Liang L, Lou J, Yu X, Qu J. Quantitative interocular suppression in children with intermittent exotropia. Front Neurosci 2023; 17:1204061. [PMID: 37600014 PMCID: PMC10434520 DOI: 10.3389/fnins.2023.1204061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/20/2023] [Indexed: 08/22/2023] Open
Abstract
Purpose We have demonstrated that the depth of unbalanced interocular suppression can be quantified by balancing the interocular luminance differences required when both eyes are viewing simultaneously. In this study, we aimed to investigate the applicability of this method in children with intermittent exotropia (IXT), offering a quantitative assessment of interocular suppression in individuals with binocular imbalance. Additionally, we evaluated its association with the clinical characteristics of IXT. Methods Interocular suppression in IXT was quantitatively measured using a polarizer and neutral-density (ND) filters. The density of the ND filter was adjusted incrementally from 0.3ND to 3ND, with a step size of 0.3ND (a total of 10 levels). Our prospective study involved 46 patients with IXT (mean age: 10.12 ± 4.89 years; mean ± SD) and 24 normal observers (mean age: 7.88 ± 1.83 years). Results The suppression test exhibited good test-retest reliability, supported by statistical analysis. We observed more pronounced interocular suppression in individuals with IXT compared to controls. Notably, the magnitude of suppression during distant and near viewing significantly differed in IXT (1.55 ± 0.93 vs. 0.57 ± 0.64; Z = 4.764, p < 0.001). Furthermore, we identified a positive correlation between interocular suppression and data obtained from the Worth-4-Dot test. Additionally, interocular suppression showed a significant association with distance control scores. Conclusion Our novel test offers a convenient and reliable means to quantify interocular suppression in patients with IXT. The quantitative assessment of interocular suppression provides a sensitive tool to evaluate the clinical characteristics of IXT.
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Affiliation(s)
- Hui Chen
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiaohui Jiang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Weijie Liu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jiawei Zhou
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jie Chen
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Qianqian Sun
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Lin Liang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jiangtao Lou
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xinping Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jia Qu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
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Zhu B, Liao M, Liu L. Measuring the impact of suppression on visual acuity in children with amblyopia using a dichoptic visual acuity chart. Front Neurosci 2022; 16:860620. [PMID: 35911993 PMCID: PMC9334724 DOI: 10.3389/fnins.2022.860620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeTo develop a novel dichoptic visual acuity chart that measures the impact of interocular suppression on the visual acuity of each eye when two eyes are open.MethodsFifty-four subjects (19 anisometropic amblyopia, 20 treated amblyopia, and 15 normal children) participated in this study. The visual acuity that was tested under dichoptic-optotypes condition (i.e., presented optotypes to the untested eye) was compared with that under monocular condition (i.e., cover the untested eye with opaque patch). Visual acuity differences between these two conditions were compared among the three groups. The correlations between visual acuity differences and the depth of interocular suppression were then computed. Some participants performed the visual acuity test under dichoptic-luminance condition (i.e., presented mean luminance to the untested eye), and the test-retest reliability was established.ResultsA reduced visual acuity of the non-dominant eye was found in the dichoptic-optotypes condition for the amblyopia group (P < 0.001) and the treated group (P = 0.001); the difference in the treated group was less than that in the amblyopia group (P < 0.001) but more than that in the normal group (P = 0.026). A significant correlation was found between the visual acuity differences and the depth of suppression, which was tested with a binocular phase combination task (P = 0.005). No change was found in the dichoptic-luminance condition.ConclusionThe amblyopic eye and the previous amblyopic eye seem to suffer from a reduced visual acuity when two eyes are open due to suppression. This was successfully captured by our novel and reliable dichoptic-optotypes visual acuity chart.
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Affiliation(s)
- Bixia Zhu
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China
| | - Meng Liao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 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, China
- *Correspondence: Longqian Liu,
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Evaluation of the Efficacy of a New Dichoptic Digital Platform to Treat the Anisometropic and Isometropic Amblyopia. Brain Sci 2022; 12:brainsci12070815. [PMID: 35884623 PMCID: PMC9312954 DOI: 10.3390/brainsci12070815] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 02/05/2023] Open
Abstract
The aim of the current study was to evaluate the results of a novel dichoptic training program using an online platform in a group of subjects with refractive amblyopia, performing a comparative analysis of unilateral and bilateral amblyopic cases. For this purpose, a retrospective study analysis of data of 161 children (4−13 years) who underwent dichoptic treatment with the Bynocs® platform (Kanohi Eye Pvt. Ltd., Mumbai, India) was performed. In all cases, the therapy protocol consisted of sessions of training of 30 min daily 5 times a week for 6 weeks. Best corrected visual acuity (BCVA) in the non-dominant eye improved significantly with the treatment, with a mean change of 0.39 logMAR in the whole sample (p < 0.001). Regarding binocularity, the binocular function (BF) score also experienced a significant improvement (p < 0.001), with a mean change of 1.55 with therapy in the whole sample. The BCVA of the dominant eye only improved significantly (p < 0.001) in the isometropic amblyopic subgroup. In conclusion, the use of the dichoptic therapy with the digital platform evaluated allows an effective restoration of visual acuity and binocular function in children with anisometropic and isometropic amblyopia.
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Panachakel JT, Ramakrishnan AG, Manjunath KP. VR Glasses based Measurement of Responses to Dichoptic Stimuli: A Potential Tool for Quantifying Amblyopia? ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:5106-5110. [PMID: 33019135 DOI: 10.1109/embc44109.2020.9176510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Amblyopia is a medical condition in which the visual inputs from one of the eyes is suppressed by the brain. This leads to reduced visual acuity and poor or complete loss of stereopsis. Conventional clinical tests such as Worth 4-dot test and Bagolini striated lens test can only detect the presence of suppression but cannot quantify the extent of suppression, which is important for identifying the effectiveness of treatments for amblyopia. A novel approach for quantifying the level of suppression in amblyopia is proposed in this paper. We hypothesize that the level of suppression in amblyopia can be measured by measuring the symmetry/asymmetry in the suppression experienced during a dichoptic image recognition task. Preliminary studies done on fifty one normal subjects prove that the differences between the accuracies of the left and right eyes can be used as a measure of asymmetry. Equivalence test performed using 'two-one-sided t-tests' procedure shows that the equivalence of the accuracies of left and right eyes for normal subjects is statistically significant (p = .03, symmetric equivalence margin of 5 percentage points). To validate this method, six amblyopic children underwent this test and the results obtained are promising. To the knowledge of the authors, this is the first work to make use of VR glasses and dichoptic image recognition task for quantifying the level of ocular suppression in amblyopic patients.
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Gong L, Min SH, Chen S, Wei J, Kong D, Tao C, Zhang P, Huang PC, Zhou J. Reduced Monocular Luminance Increases Monocular Temporal Synchrony Threshold in Human Adults. Invest Ophthalmol Vis Sci 2020; 61:1. [PMID: 32609295 PMCID: PMC7425744 DOI: 10.1167/iovs.61.8.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to present our investigation of the influence of reduced monocular luminance on monocular and dichoptic temporal synchrony processing in healthy adults. Methods Ten adults with normal or corrected to normal visual acuity participated in our psychophysical study. The temporal synchrony threshold in dichoptic (experiment 1), monocular (experiment 2), and binocular (experiment 3) viewing configurations was obtained from each observer. Four flickering Gaussian dots (one synchronous and one asynchronous pair of two dots) were displayed, from which the observers were asked to identify the asynchronous pair. The temporal phase lag in the signal pair (asynchronous) but not in the reference pair (synchronous) was varied. In addition, a neutral density (ND) filter of various intensities (1.3 and 2.0 log units) was placed before the dominant eye throughout the behavioral measurement. In the end, dichoptic, monocular, and binocular thresholds were measured for each observer. Results With decreasing monocular luminance, the dichoptic threshold (2 ND vs. 0 ND, P < 0.001; 2 ND vs. 1.3 ND P = 0.001) and monocular threshold (2 ND vs. 0 ND, P < 0.001; 2 ND vs. 1.3 ND, P = 0.003) increased; however, the bincoular threshold remained unaffected (P = 0.576). Conclusions Reduced luminance induces delay and disturbs the discrimination of temporal synchrony. Our findings have clinical implications in visual disorders.
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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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Tao C, Wu Y, Gong L, Chen S, Mao Y, Chen Y, Zhou J, Huang PC. Abnormal Monocular and Dichoptic Temporal Synchrony in Adults with Amblyopia. Invest Ophthalmol Vis Sci 2020; 60:4858-4864. [PMID: 31747686 DOI: 10.1167/iovs.19-27893] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We investigate temporal synchrony within one eye and between both eyes in adults with amblyopia. Methods Eight adult amblyopes (range, 19.88-27.81 years old; median, 22.86 years old) and 12 age-matched adults with normal vision (range, 21.2-50.30 years old; median, 23.78 years old) participated in the experiment. We showed two pairs of Gaussian blobs flickering at 1 Hz as visual stimuli, one pair with the same temporal phase modulation (i.e., the reference) and another pair with a distinct temporal phase (i.e., the signal). We employed the constant stimuli method to measure the minimum degree of temporal phase (temporal synchrony threshold), at which participants were able to discriminate the signal pair under binocular, monocular, and dichoptic viewing configurations. Results The temporal synchrony threshold was different across the six configurations (P = 0.001). There was also an interaction between the configuration and the group (P = 0.004). The synchrony threshold was significantly higher in amblyopes than in controls under the configurations where two pairs of blobs were presented to the amblyopic eye (136.52 ± 50.19 vs. 97.08 ± 22.02 ms, P = 0.027) and where the paired blobs were presented to different eyes (163.15 ± 80.85 vs. 111.61 ± 22.46 ms, P = 0.049). The visual deficits in these two configurations were significantly correlated (r = 0.824, P = 0.012). Conclusions The threshold for detecting temporal asynchrony increased when the stimuli were presented only to the amblyopic eye and when they were dichoptically presented to the amblyopic and fellow eyes.
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Affiliation(s)
- Chunwen Tao
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Yidong Wu
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Ling Gong
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Shijia Chen
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Yu Mao
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Yiya Chen
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Jiawei Zhou
- School of Ophthalmology and Optometry, Affiliated Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Pi-Chun Huang
- Department of Psychology, National Cheng Kung University, Tainan, Taiwan
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