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Ma MML, Scheiman M. Divergence excess and basic exotropia types of intermittent exotropia: a major review. Part 1: prevalence, classification, risk factors, natural history and clinical characteristics. Strabismus 2023; 31:97-128. [PMID: 37489263 DOI: 10.1080/09273972.2023.2227681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
INTRODUCTION Intermittent exotropia (IXT) is a common form of strabismus. It is an outward deviation of one eye typically when viewing at distance. Symptoms include, but are not limited to double vision, eyes feeling tired, excessive blinking, and reduced quality of life. Its clinical characteristics are distinctive from other types of strabismus. This paper provides a comprehensive review of prevalence, classification, risk factors, natural history and clinical characteristics of the divergence excess and basic exotropia types of IXT. METHODS Search strategies involving combination of keywords including intermittent exotropia, exotropia, divergences excess, basic exotropia, prevalence, incidence, classification, terminology, risk factor, natural history, observation, angle of deviation, control, control score, symptom, quality of life, suppression, anomalous retinal correspondence, AC/A, accommodative convergence/accommodation, accommodative convergence, convergence, accommodation, vergence, incomitance and vertical were used in Medline. All English articles from 1900/01/01 to 2020/09/01 were reviewed. The reference list of the identified article was also checked for additional relevant article. Studies focused on animal model or strabismus associated with neurologic disorder or injury were excluded. RESULTS The estimated prevalence of IXT in children ranges from 0.1% to 3.7%. Hypoxia at birth and being female are potential risk factors of IXT. Using validated measures of control, multicenter prospective studies showed that the rate of conversion from IXT to constant exotropia is low. The angle of deviation is the most reported outcome measure in studies of IXT. It is often used to represent the severity of the condition and has been suggested as one of the four core outcomes for studies of the surgical management of IXT. Control of exodeviation is one of the four suggested core outcomes for study of surgery of IXT and is considered the main parameter of disease severity. Several validated tools for quality of life score are available to evaluate the subjective severity of IXT. DISCUSSION We reviewed the prevalence, classification, risk factors, natural history and clinical characteristics of the divergence excess and basic exotropia types of IXT. Further research into these areas, especially its clinical characteristics (e.g. suppression, dual retinal correspondence), will increase our understanding of this condition and potentially lead to better management of this common form of strabismus.
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Affiliation(s)
- Martin Ming-Leung Ma
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou
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Shen T, Chen J, Kang Y, Deng D, Lin X, Wu H, Li J, Wang Z, Qiu X, Jin L, Yan J. Surgical treatment versus observation in moderate intermittent exotropia (SOMIX): study protocol for a randomized controlled trial. Trials 2023; 24:153. [PMID: 36855155 PMCID: PMC9976535 DOI: 10.1186/s13063-023-07189-0] [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: 04/13/2022] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Intermittent exotropia (IXT) is the most common type of strabismus in China, but the best treatment and optimal timing of intervention for IXT remain controversial, particularly for children with moderate IXT who manifest obvious exodeviation frequently but with only partial impairment of binocular single vision. The lack of randomized controlled trial (RCT) evidence means that the true effectiveness of the surgical treatment in curing moderate IXT is still unknown. The SOMIX (surgical treatment versus observation in moderate intermittent exotropia) study has been designed to determine the long-term effectiveness of surgery for the treatment and the natural history of IXT among patients aged 5 to 18 years old. METHODS/DESIGN A total of 280 patients between 5 and 18 years of age with moderate IXT will be enrolled at Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. After initial clinical assessment, all participants will be randomized to receive surgical treatment or observation, and then be followed up for 5 years. The primary objective is to compare the cure rate of IXT between the surgical treatment and observation group. The secondary objectives are to identify the predictive factors affecting long-term outcomes in each group and to observe the natural course of IXT. DISCUSSION The SOMIX trial will provide important guidance regarding the moderate IXT and its managements and modify the treatment strategies of IXT. TRIAL REGISTRATION ClinicalTrials.gov: NCT02736526 . Registered April 13, 2016.
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Affiliation(s)
- Tao Shen
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Jingchang Chen
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Ying Kang
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Daming Deng
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Xiaoming Lin
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Heping Wu
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Jinrong Li
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Zhonghao Wang
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Xuan Qiu
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Ling Jin
- grid.12981.330000 0001 2360 039XState Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060 China
| | - Jianhua Yan
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China.
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Kim DH, Jung JH, Choi MY, Hwang JM, Kim SJ, Lee YH, Han SH, Choi DG, Choi HY, Choi DG, Kim DH, Lee DC, Lee SY, Lim HW, Lim HT, Lim KH, Ryu WY, Yang HK, Choi HY, Lim HT, Jung JH, Baek SH, Choi MY, Hwang JM, Kim SJ, Lee YH, Han SH, Park SH, Lee HJ, Kim SY, Lee SY, Gye HJ, Kim SY, Shin SY, Park J, Ryu WY, Park HS, Kim DH, Paik HJ, Choi DG, Lee JY, Yang HK, Oh SY, Lee SJ, Chung SA, Choi J, Oh SY, Kim M, Suh YW, Kang NY, Yum HR, Kim SA, Kim H, Han J, Cho YA, Kim H, Lew H, Lee DC, Rah SH, Yoo YJ, Lim KH, Ahn H, Kim US, Lee JH, Choung H, Kim SJ, Jeon H, Shin HJ, Han SY, Heo H, Park S, Park S, Kyung SE, Kim C, Park KA, Jung EH, Hong EH, Lim HW, Choi D, Choi YJ, Moon NJ, Lyu IJ, Cho SY. A cross-sectional study of ophthalmologic examination findings in 5385 Koreans presenting with intermittent exotropia. Sci Rep 2023; 13:1329. [PMID: 36693891 PMCID: PMC9873724 DOI: 10.1038/s41598-023-28015-2] [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: 06/21/2022] [Accepted: 01/11/2023] [Indexed: 01/25/2023] Open
Abstract
The Korean Intermittent Exotropia Multicenter Study (KIEMS) was a retrospective, cross-sectional and multicenter study for the investigation of intermittent exotropia involved 65 strabismus specialists from 53 institutions in Korea. Purpose of this study was to present ophthalmologic findings of intermittent exotropia from the KIEMS. Consecutive patients with intermittent exotropia of ≥ 8 prism diopters (PD) at distance or near fixation were included. Best-corrected visual acuity, cycloplegic refraction data, angles of deviation at several cardinal positions, ocular dominance, fusion control, oblique muscle function, and binocular sensory outcomes were collected. A total of 5385 participants (2793 females; age 8.2 years) were included. Non-dominant eye was more myopic than the dominant eye (- 0.60 vs. - 0.47 diopters, P < 0.001). Mean exodeviation angles were 23.5 PD at distance and 25.0 PD at near fixation. Basic type (86.2%) was the most, followed by convergence insufficiency (9.4%) and divergence excess (4.4%) types. Alternating ocular dominance and good fusion control were more common at near than at distance fixation. Good stereopsis at 40 cm was observed in 49.3% in Titmus stereo test (≤ 60 arcsec) and in 71.0% in Randot stereo test (≤ 63 arcsec). Intermittent exotropia was mostly diagnosed in childhood and patients with the condition showed relatively good binocular functions. This study may provide objective findings of intermittent exotropia in a most reliable way, given that the study included a large study population and investigated comprehensive ophthalmology examinations.
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Affiliation(s)
- Dae Hee Kim
- Department of Ophthalmology, Kim's Eye Hospital, Seoul, Korea
| | - Jae Ho Jung
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Mi Young Choi
- Department of Ophthalmology, Chungbuk National University College of Medicine, Chungbuk National University Hospital, Cheongju, Korea
| | - Jeong-Min Hwang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Su Jin Kim
- Department of Ophthalmology, Pusan National University School of Medicine, Yangsan Pusan National University Hospital, Yangsan, Korea
| | - Yeon-Hee Lee
- Department of Ophthalmology, Chungnam National University College of Medicine, Chungnam National University Hospital, Daejeon, Korea
| | - Sueng-Han Han
- Department of Ophthalmology, Yonsei University College of Medicine, Severance Eye Hospital, Seoul, Korea
| | - Dong Gyu Choi
- Department of Ophthalmology, Hallym University College of Medicine, Kangnam Sacred Heart Hospital, 1, Singil-Ro, Yeongdeungpo-Gu, Seoul, 07441, Republic of Korea.
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Thuma TBT, Zhang QE, Sharpe J, Gunton KB. Understanding the Use of the Newcastle, PEDIG, and LACTOSE Control Scores Among Pediatric Ophthalmologists for Intermittent Exotropia. J Pediatr Ophthalmol Strabismus 2022; 60:131-138. [PMID: 35611821 DOI: 10.3928/01913913-20220425-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To determine the clinical use patterns of control scores for intermittent exotropia. The Newcastle Control Score Pediatric Eye Disease Investigator Group (PEDIG) score, and Look And Cover, then Ten seconds of Observation Scale for Exotropia (LACTOSE) Control Score were developed to quantify control of exodeviations. METHODS A short survey was posted on the American Association for Pediatric Ophthalmology and Strabismus forum in August and September 2021. Respondents were asked about their assessment of control in intermittent exotropia, including knowledge and use of the various control scales. RESULTS One hundred fourteen pediatric ophthalmologists responded; 54.4% (n = 62) reported not using any specific control score for intermittent exotropia, although 61.4% (n = 70) were familiar with the PEDIG score, 37.7% (n = 43) with the Newcastle Control Score, and 7.9% (n = 9) with the LACTOSE Control Score. The PEDIG score was the most widely used (26.3%, n = 30), but 36.7% (n = 11) of respondents reported that the scale is too time-intensive, limiting its use. To improve the use of the control scores, participants recommended promoting wider understanding of the scales (45.6%, n = 52). CONCLUSIONS Most responding pediatric ophthalmologists do not use a specific control score in managing intermittent exotropia. The PEDIG score is the most frequently used but is reported as time-intensive. Although the LACTOSE Control Score was designed to provide a quicker alternative, it is not widely known. Promoting wider awareness and understanding of intermittent exotropia control scores may be helpful to allow for more objective quantification of control in intermittent exotropia. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XX-XX.].
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Littlewood RA, Rhodes M, Burke J. A Post-Surgical Stereovision Surprise in an Adult With an Exotropia Since Infancy Previously Managed, at Two Years With Surgery. Br Ir Orthopt J 2021; 17:97-103. [PMID: 34278225 PMCID: PMC8269783 DOI: 10.22599/bioj.174] [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: 01/29/2021] [Accepted: 05/25/2021] [Indexed: 11/30/2022] Open
Abstract
Aim To describe an unexpected sensory outcome in an adult male who is seeking ocular re-alignment for a psychosocially symptomatic large non-specific exotropia with suppression. The primary diagnosis was infant onset exodeviation of unclear diagnosis, was managed with bilateral strabismus surgery at two years of age, little memory of follow-up. Result Measurable binocular single vision (BSV) was demonstrable following surgery at 17 years of age, albeit slowly between two weeks and six months postoperatively and subsequently enhanced. His newly acquired sub-optimal BSV led to symptomatic occupation-associated asthenopia. Following two subsequent operations over a 15-year period, he has stable, symptom-free ocular realignment within three prism diopters of orthophoria and performing tasks that require extended periods of near-vision activity. Conclusion Delayed high levels of stereovision were unexpectedly achieved in an adult with infant onset exotropia with pre-operative sensory suppression that was surgically aligned to near orthophoria. The re-establishment of BSV in such a clinical scenario has to attain a level that is robust enough to meet an individual's social and occupational needs.
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Economides JR, Adams DL, Horton JC. Bilateral Occlusion Reduces the Ocular Deviation in Intermittent Exotropia. Invest Ophthalmol Vis Sci 2021; 62:6. [PMID: 33393972 PMCID: PMC7794258 DOI: 10.1167/iovs.62.1.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The most common form of strabismus, intermittent exotropia, is thought to become manifest when the drive to fuse is overcome by excessive divergent muscle tone. This principle is tested by examining the alignment of the eyes in the absence of vision. We compare the ocular deviation in patients with intermittent exotropia under conditions of monocular versus binocular occlusion. Methods This prospective study of a patient cohort referred to our laboratory enrolled 18 patients with typical findings of well-controlled intermittent exotropia. Eye positions were recorded with video eye trackers while patients looked at a fixation spot at a distance of 57 cm. One eye was occluded, and the resulting ocular deviation was measured. Both eyes were then occluded, and the ocular deviation was re-measured. Results The majority of patients (11/18) had a smaller deviation when both eyes were covered. Occlusion of one eye resulted in a mean exotropia of 13.5° ± 4.7°. Occlusion of both eyes reduced the mean exotropia to 6.0° ± 6.5° (paired t-test, P < 0.001), corresponding to a 56% reduction in the ocular deviation. This reduction persisted during prolonged bilateral occlusion but reversed as soon as vision was restored. Conclusions Bilateral occlusion reveals a fixation-free state of alignment that is different from orthotropia and usually less than the exotropia that occurs spontaneously during binocular viewing. This finding demonstrates that the deviation angle in patients with intermittent exotropia is actively mediated by visual feedback, which the fixating eye is capable of providing alone.
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Affiliation(s)
- John R Economides
- Department of Ophthalmology, Program in Neuroscience, University of California, San Francisco, San Francisco, California, United States
| | - Daniel L Adams
- Department of Ophthalmology, Program in Neuroscience, University of California, San Francisco, San Francisco, California, United States
| | - Jonathan C Horton
- Department of Ophthalmology, Program in Neuroscience, University of California, San Francisco, San Francisco, California, United States
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Heydarian S, Hashemi H, Jafarzadehpour E, Ostadi A, Yekta A, Aghamirsalim M, Dadbin N, Ostadimoghaddam H, Khoshhal F, Khabazkhoob M. Non-surgical Management Options of Intermittent Exotropia: A Literature Review. J Curr Ophthalmol 2020; 32:217-225. [PMID: 32775794 PMCID: PMC7382517 DOI: 10.4103/joco.joco_81_20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 03/24/2020] [Accepted: 04/01/2020] [Indexed: 11/04/2022] Open
Abstract
Purpose To review current non-surgical management methods of intermittent exotropia (IXT) which is one of the most common types of childhood-onset exotropia. Methods A search strategy was developed using a combination of the words IXT, divergence excess, non-surgical management, observation, overcorrecting minus lens therapy, patch/occlusion therapy, orthoptics/binocular vision therapy, and prism therapy to identify all articles in four electronic databases (PubMed, Web of Science, Google Scholar, and Scopus). To find more articles and to ensure that the databases were thoroughly searched, the reference lists of the selected articles were also reviewed from inception to June 2018 with no restrictions and filters. Results IXT is treated when binocular vision is impaired, or the patient is symptomatic. There are different surgical and non-surgical management strategies. Non-surgical treatment of IXT includes patch therapy, prism therapy, orthoptic sessions, and overcorrecting minus lens therapy. The objective of these treatments is to reduce the symptoms and the frequency of manifest deviation by decreasing the angle of deviation or enhancing the ability to control it. Conclusions Evidence of the efficacy of non-surgical management options for IXT is not compelling. More comprehensive randomized controlled trial studies are required to evaluate the effectiveness of these procedures and detect the most effective strategy.
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Affiliation(s)
- Samira Heydarian
- Department of Rehabilitation Sciences, School of Allied Medical Sciences, Mazandaran University of Medical Sciences, Sari, Iran
| | - Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | | | - Amin Ostadi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Abbasali Yekta
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Nooshin Dadbin
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Hadi Ostadimoghaddam
- Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Mehdi Khabazkhoob
- Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Cotter SA, Mohney BG, Chandler DL, Holmes JM, Wallace DK, Melia BM, Wu R, Kraker RT, Superstein R, Crouch ER, Paysse EA. Three-year observation of children 12 to 35 months old with untreated intermittent exotropia. Ophthalmic Physiol Opt 2020; 40:202-215. [PMID: 32202318 DOI: 10.1111/opo.12668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/22/2019] [Indexed: 11/27/2022]
Abstract
PURPOSE To describe the clinical course of untreated intermittent exotropia (IXT) in children 12-35 months of age followed for 3 years. METHODS We enrolled 97 children 12-35 months of age with previously untreated IXT who had been randomly assigned to the observation arm of a randomised trial of short-term occlusion versus observation. Participants were observed unless deterioration criteria were met at a follow-up visit occurring at 3 months, 6 months, and 6-month intervals thereafter for 3 years. The primary outcome was deterioration of the IXT by 3 years, defined as (1) a constant exotropia ≥10 prism dioptres (∆) at distance and near (i.e., motor deterioration) or (2) treatment prescribed despite not having met motor deterioration. The primary analysis used the Kaplan-Meier method to determine the cumulative proportion of participants meeting deterioration by three years and 95% confidence interval (CI). RESULTS The cumulative probability of deterioration by 3 years was 28% (95% CI = 20%-39%). Of the 24 participants meeting the primary outcome of deterioration, seven met motor deterioration and 17 were prescribed treatment without meeting motor deterioration. The cumulative probability of motor deterioration by 3 years was 10% (95% CI = 5%-19%). CONCLUSIONS Given the modest rate of motor deterioration over three years, watchful waiting may be a reasonable management approach in 12- to 35-month-old children with IXT. To confirm this recommendation would require a long-term randomised trial of immediate treatment versus observation followed by deferred treatment if needed.
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Affiliation(s)
- Susan A Cotter
- Southern California College of Optometry at Marshall B Ketchum University, Fullerton, California, USA
| | | | | | | | | | | | - Rui Wu
- Jaeb Center for Health Research, Tampa, Florida, USA
| | | | - Rosanne Superstein
- Centre Hospitalier Universitaire Sainte-Justine, Montreal, Quebec, Canada
| | - Eric R Crouch
- Virginia Pediatric Eye Center, Virginia Beach, Virginia, USA
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Wu H, Li X, Tang Y, Xu Q, Zhang X, Zhou L, Lan W, Zhang B, Yang Z. Optimal Stereoacuity Reveals More Than Critical Time in Patients With Intermittent Exotropia. Front Neurosci 2020; 14:133. [PMID: 32132901 PMCID: PMC7040177 DOI: 10.3389/fnins.2020.00133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 02/03/2020] [Indexed: 01/06/2023] Open
Abstract
Synopsis Both optimal stereoacuity and integration time to achieve that are impaired in patients with intermittent exotropia. The deterioration of stereoacuity is more revealing since it correlates well with exotropia control score. Background Despite the periodic misalignment of two eyes, some intermittent exotropia (IXT) patients exhibit normal stereoacuity, particularly when evaluated with static tests. It is not clear if the temporal integration process of stereopsis is altered in IXT patients, thus warranting further research. Methods IXT patients (n = 29) and age-matched normal controls (n = 36) were recruited. Static stereopsis was measured with the Titmus stereoacuity test. In computer-generated random dots tests, stereoacuity was measured with a stimuli presentation duration varying from 100 to 1,200 ms. And the relationship between stereoacuity and stimuli duration was fitted into a quadratic model. Optimal stereoacuity was achieved when fitted curve flattened and the critical integration time was the duration needed to achieve optimal stereoacuity. Results IXT patients were not found to differ significantly from control subjects under the Titmus test, while the Random Dots stereotest showed significantly worse optimal stereoacuity and significantly longer critical integration time. Multiple regression analysis showed that age (R = −4.83; P = 0.04) had statistically significant negative correlation on the critical integration time, age (R = −6.45; P = 0.047) and exotropia control scores (R = 60.71; P = 0.007) had statistically significant effects on optimal stereoacuity. Conclusion The temporal integration for stereopsis is impaired in IXT patients, requiring longer critical integration time to achieve elevated optimal stereoacuity.
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Affiliation(s)
- Haoran Wu
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Institute of Optometry and Vision Science, Changsha, China
| | - Xiaoning Li
- Aier Institute of Optometry and Vision Science, Changsha, China.,Aier School of Optometry and Vision Science, Hubei University of Science and Technology, Xianning, China
| | - Yao Tang
- Aier Institute of Optometry and Vision Science, Changsha, China
| | - Qinglin Xu
- Aier Institute of Optometry and Vision Science, Changsha, China
| | - Xuhong Zhang
- College of Medicine, Zhejiang University, Hangzhou, China
| | - Lu Zhou
- Department of Ophthalmology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Weizhong Lan
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier School of Optometry and Vision Science, Hubei University of Science and Technology, Xianning, China
| | - Bin Zhang
- College of Optometry, Nova Southeastern University, Davie, FL, United States
| | - Zhikuan Yang
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier School of Optometry and Vision Science, Hubei University of Science and Technology, Xianning, China
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Kushner BJ. Conservative management of intermittent exotropia to defer or avoid surgery. J AAPOS 2019; 23:256.e1-256.e6. [PMID: 31526859 DOI: 10.1016/j.jaapos.2019.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/30/2019] [Accepted: 06/09/2019] [Indexed: 11/25/2022]
Abstract
BACKGROUND Surgery for intermittent exotropia performed at a very young age has poorer sensory outcomes than surgery performed later; moreover, postoperative recurrence is common, regardless of age. Alternate occlusion decreases the size of the exotropia and improves control. The purpose of this study was to report the long-term effects of part-time alternate occlusion and overminus spectacles combined with prism on delaying or avoiding surgery in intermittent exotropia. METHODS The study included consecutive patients from 1979 to 2010 who had poorly controlled intermittent exotropia and were treated with alternate occlusion, followed in some cases by overminus spectacles with base-in prism. Outcome measures were initial improvement and subsequent time to surgery, if required. RESULTS A total of 279 patients had initial control poor enough to otherwise be considered candidates for surgery. After occlusion therapy, 219 (78%) improved their angle and control, and 62 (22%) converted to an exophoria. After 1 year, 9 cases deteriorated, and surgery was recommended. In 207 (74%), conservative treatment delayed surgery for at least 1 year. At 20 years, 42 of 279 patients were still being followed. Of these, 22 of 219 (7%) were known to have not undergone surgery, and 127 (45%) had undergone surgery; 130 (47%) were lost to follow-up. CONCLUSIONS Part-time alternate occlusion and overminus spectacles with prism can defer the need for surgery in a large percentage of patients with intermittent exotropia; for a small number it may be curative.
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Affiliation(s)
- Burton J Kushner
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin.
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Wang Y, Xu M, Yu H, Xu J, Hou F, Zhou J, Yu X. Health-related quality of life correlated with the clinical severity of intermittent exotropia in children. Eye (Lond) 2019; 34:400-407. [PMID: 31406354 DOI: 10.1038/s41433-019-0557-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/16/2019] [Accepted: 07/01/2019] [Indexed: 11/09/2022] Open
Abstract
OBJECT To evaluate whether the results of the health-related quality of life (HRQOL) is associated with the various clinical aspects of intermittent exotropia in children. METHODS The HRQOL of children and their parents was evaluated prospectively using the Intermittent Exotropia Questionnaire (IXTQ). The deviation angle, stereo function, sensory fusion, and strabismus control were measured. RESULTS Two hundred and sixty six children with intermittent exotropia (aged 5-17 years) were included in the study. Child HRQOL was significantly correlated with clinical severity; lower IXTQ scores were associated with a larger deviation (p < 0.001 both for distance and near) and poorer Newcastle control scores (p < 0.001). Proxy child HRQOL was significantly correlated with the deviation (p < 0.001), Newcastle control scores (p < 0.001) and stereo function (p < 0.05). Parent HRQOL was associated with their child's deviation (p < 0.01) and stereo function (p < 0.005). Multiple linear regression analysis suggested that the deviation angle at distance and the Newcastle control score at home were associated with the child's HRQOL. CONCLUSION Both the child and their parents' HRQOL showed a trend toward correlating with clinical severity. Large deviation, poor control, and poor stereo function were significantly associated with lower IXTQ scores. The deviation angle at distance and exotropia control at home were associated with the child's HRQOL.
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Affiliation(s)
- Yuanyuan Wang
- Department of Ophthalmology, Huzhou Central Hospital, Huzhou, Zhejiang, China
| | - Meiping Xu
- The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Huanyun Yu
- The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jinling Xu
- The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fang Hou
- The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiawei Zhou
- The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xinping Yu
- The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
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12
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Abstract
Intermittent exotropia (IXT) is the most common type of divergent strabismus. It is the consequence of passive mechanisms due to the anatomy of the globes and orbits or due to active innervational mechanisms, resulting in divergence of the visual axes, which is compensated by fusional convergence. Intermittent insufficiency in this compensation gives this form of exotropia its intermittent nature. The most common symptoms of IXT are closure of one eye, asthenopia and diplopia, but they are often absent. The clinical classification of IXT (according to Burian) is based on the difference between the distant and the near angles of deviation. It defines 4 types: true divergence excess (at distance), pseudo-divergence excess, the basic form (distance and near angles are equal) and convergence insufficiency (near angle greater than distance angle). One of the main difficulties in examination of IXT is neutralizing the fusional convergence in order to classify the strabismus. For this purpose, the monocular occlusion test, a near addition, or a prism adaptation test can be used. IXT is also characterised by the quality of control of the deviation by the patient, which is taken in account for therapeutic decision. Tools for measurement of this control have recently been developed and are not commonly used. The natural history of IXT is not well understood. Treatment relies mainly on optical correction, binocular visual training therapy and surgery, but their indications are not well defined, nor are outcomes analysis criteria. In the case of surgery, it aims to treat the maximum measured distance angle; the medium- and long-term angular results of surgery are often disappointing, although it probably improves control of the strabismus in most cases.
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Affiliation(s)
- F Audren
- Fondation ophtalmologique Adolphe-de-Rothschild, 25, rue Manin, 75019 Paris, France.
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13
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Akbari MR, Mirzajani A, Moeinitabar MR, Mirmohammadsadeghi A, Khorrami-Nejad M, Sharbatoghli L. The effect of alternate occlusion on control of intermittent exotropia in children. Eur J Ophthalmol 2019; 30:275-279. [DOI: 10.1177/1120672119827764] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Purpose: The aim is to investigate the effect of alternate occlusion on control of intermittent exotropia in children 3 to 8 years old. Methods: The ability of 28 children to control of the deviation at far and near was evaluated based on 3-point and 6-point control scales. Stereopsis and fusion were assessed using the Titmus and Worth 4-dot tests, respectively. Two-hour alternate daily occlusion was prescribed for children with no dominancy. For children with a dominant eye, 2-h occlusion of the dominant eye for 5 days and the non-dominant eye for 2 days. All measurements were repeated at 3, 6, and 9 months after the treatment. Results: For all children with a mean age of 4.7 ± 1.56 years, deviation control at far improved significantly after 3, 6, and 9 months of treatment using both control scales when compared with baseline ( p = 0.005 after 3 months and p = 0.008 after 6 and 9 months for the 3-point scale, and p < 0.001 after 3 and 6 months and p = 0.010 after 9 months for the 6-point scale). Control at near showed a significant improvement after 3, 6, and 9 months of treatment based on the 6-point scale ( p = 0.007 for 3 months, p = 0.004 for 6 months, and p = 0.014 for 9 months). Near stereopsis improved significantly after 9 months of treatment ( p = 0.043). Conclusion: Alternate occlusion is significantly effective on control of intermittent exotropia. As a result, it can be used as a useful method to postpone or even eliminate the need for surgery in intermittent exotropia.
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Affiliation(s)
- Mohammad Reza Akbari
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Mirzajani
- Rehabilitation School, Iran University of Medical Sciences, Tehran, Iran
| | | | | | - Masoud Khorrami-Nejad
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
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14
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Piano M, O'Connor AR. Conservative Management of Intermittent Distance Exotropia: A Review. ACTA ACUST UNITED AC 2017; 61:103-16. [DOI: 10.3368/aoj.61.1.103] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Marianne Piano
- Directorate of Orthoptics and Vision Science, University of Liverpool, Liverpool, United Kingdom
| | - Anna R. O'Connor
- Directorate of Orthoptics and Vision Science, University of Liverpool, Liverpool, United Kingdom
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15
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Normal Topography and Binocularity of the Superior Colliculus in Strabismus. J Neurosci 2017; 38:173-182. [PMID: 29133438 DOI: 10.1523/jneurosci.2589-17.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/30/2017] [Accepted: 11/08/2017] [Indexed: 02/03/2023] Open
Abstract
In subjects with alternating strabismus, either eye can be used to saccade to visual targets. The brain must calculate the correct vector for each saccade, which will depend on the eye chosen to make it. The superior colliculus, a major midbrain center for saccade generation, was examined to determine whether the maps serving each eye were shifted to compensate for strabismus. Alternating exotropia was induced in two male macaques at age 1 month by sectioning the tendons of the medial recti. Once the animals grew to maturity, they were trained to fixate targets with either eye. Receptive fields were mapped in the superior colliculus using a sparse noise stimulus while the monkeys alternated fixation. For some neurons, sparse noise was presented dichoptically to probe for anomalous retinal correspondence. After recordings, microstimulation was applied to compare sensory and motor maps. The data showed that receptive fields were offset in position by the ocular deviation, but otherwise remained aligned. In one animal, the left eye's coordinates were rotated ∼20° clockwise with respect to those of the right eye. This was explained by a corresponding cyclorotation of the ocular fundi, which produced an A-pattern deviation. Microstimulation drove the eyes accurately to the site of receptive fields, as in normal animals. Single-cell recordings uncovered no evidence for anomalous retinal correspondence. Despite strabismus, neurons remained responsive to stimulation of either eye. Misalignment of the eyes early in life does not alter the organization of topographic maps or disrupt binocular convergence in the superior colliculus.SIGNIFICANCE STATEMENT Patients with strabismus are able to make rapid eye movements, known as saccades, toward visual targets almost as gracefully as subjects with normal binocular alignment. They can even exercise the option of using the right eye or the left eye. It is unknown how the brain measures the degree of ocular misalignment and uses it to compute the appropriate saccade for either eye. The obvious place to investigate is the superior colliculus, a midbrain oculomotor center responsible for the generation of saccades. Here, we report the first experiments in the superior colliculus of awake primates with strabismus using a combination of single-cell recordings and microstimulation to explore the organization of its topographic maps.
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16
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Adams DL, Economides JR, Horton JC. Incomitance and Eye Dominance in Intermittent Exotropia. Invest Ophthalmol Vis Sci 2017; 58:4049-4055. [PMID: 28813578 PMCID: PMC5559177 DOI: 10.1167/iovs.17-22155] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine if the deviation angle changes in subjects with intermittent exotropia as they alternate fixation between the right and left eye in primary gaze. Methods In this prospective observational cohort study, 37 subjects with intermittent exotropia were tested for evidence of incomitance. The position of each eye was recorded with a video tracker during fixation on a small central target. A cover-uncover test was performed by occluding one eye with a shutter that passed infrared light, allowing continuous tracking of both eyes. The deviation angle was measured during periods of right eye and left eye fixation. Incomitance was assessed as a function of eye preference, fixation stability, and exotropia variability. Results The mean exotropia was 18.2° ± 8.1°. A difference between right exotropia and left exotropia was detectable in 16/37 subjects. Allowing for potential tracking error, the incomitance had a mean amplitude of 1.7°. It was not related to a difference in accommodative effort, eye preference, fixation stability, or variability in deviation. Conclusions Comitance is regarded as a feature that distinguishes strabismus from paralytic or restrictive processes. Unexpectedly, eye tracking during the cover-uncover test showed that incomitance is present in approximately 40% of subjects with intermittent exotropia. It averages 10% of the exotropia, and can equal up to 5°. When substantial, it may be worth considering when planning surgical correction.
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Affiliation(s)
- Daniel L Adams
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States.,Center for Mind/Brain Sciences, The University of Trento, Trento, Italy
| | - John R Economides
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Jonathan C Horton
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
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17
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Economides JR, Adams DL, Horton JC. Capturing the Moment of Fusion Loss in Intermittent Exotropia. Ophthalmology 2017; 124:496-504. [PMID: 28081943 PMCID: PMC5685669 DOI: 10.1016/j.ophtha.2016.11.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/29/2016] [Accepted: 11/29/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize eye movements made by patients with intermittent exotropia when fusion loss occurs spontaneously and to compare them with those induced by covering 1 eye and with strategies used to recover fusion. DESIGN Prospective study of a patient cohort referred to our laboratory. PARTICIPANTS Thirteen patients with typical findings of intermittent exotropia who experienced frequent spontaneous loss of fusion. METHODS The position of each eye was recorded with a video eye tracker under infrared illumination while fixating on a small central near target. MAIN OUTCOME MEASURES Eye position and peak velocity measured during spontaneous loss of fusion, shutter-induced loss of fusion, and recovery of fusion. RESULTS In 10 of 13 subjects, the eye movement made after spontaneous loss of fusion was indistinguishable from that induced by covering 1 eye. It reached 90% of full amplitude in a mean of 1.75 seconds. Peak velocity of the deviating eye's movement was highly correlated for spontaneous and shutter-induced events. Peak velocity was also proportional to exotropia amplitude. Recovery of fusion was more rapid than loss of fusion, and often was accompanied by interjection of a disconjugate saccade. CONCLUSIONS Loss of fusion in intermittent exotropia is not influenced by visual feedback. Excessive divergence tone may be responsible, but breakdown of alignment occurs via a unique, pathological type of eye movement that differs from a normal, physiological divergence eye movement.
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Affiliation(s)
- John R Economides
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California
| | - Daniel L Adams
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California; Center for Mind/Brain Sciences, The University of Trento, Trento, Italy
| | - Jonathan C Horton
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California.
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18
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Clarke M, Hogan V, Buck D, Shen J, Powell C, Speed C, Tiffin P, Sloper J, Taylor R, Nassar M, Joyce K, Beyer F, Thomson R, Vale L, McColl E, Steen N. An external pilot study to test the feasibility of a randomised controlled trial comparing eye muscle surgery against active monitoring for childhood intermittent exotropia [X(T)]. Health Technol Assess 2016; 19:1-144. [PMID: 26005878 DOI: 10.3310/hta19390] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
INTRODUCTION The evidence base for the treatment of strabismus (squint) is poor. Our main aim is to improve this evidence base for the treatment of a common type of childhood squint {intermittent exotropia, [X(T)]}. We conducted an external pilot study in order to inform the design and conduct of a future full randomised controlled trial (RCT). METHODS Children of between 6 months and 16 years with a recent diagnosis of X(T) were eligible for recruitment. Participants were recruited from secondary care at the ophthalmology departments at four UK NHS foundation trusts. Participants were randomised to either active monitoring or surgery. This report describes the findings of the Pilot Rehearsal Trial and Qualitative Study, and assesses the success against the objectives proposed. RECRUITMENT AND RETENTION The experience gained during the Pilot Rehearsal Trial demonstrates the ability to recruit and retain sites that are willing to randomise children to both trial arms, and for parents to agree to randomisation of their children to such a study. One child declined the group allocation. A total of 231 children were screened (expected 240), of whom 138 (60%) were eligible (expected 228: 95%) and 49 (35% of eligible) children were recruited (expected 144: 63% of eligible). Strategies that improved recruitment over the course of the trial are discussed, together with the reasons why fewer children were eligible for recruitment than initially anticipated. Attrition was low. Outcome data were obtained for 47 of 49 randomised children. TRIAL PROCESSES AND DATA COLLECTION The Trial Management processes proved effective. There were high levels of completion on all of the data collection forms. However, the feedback from the treatment orthoptists revealed that some modifications should be made to the length and frequency of the health service assessment and travel assessment questionnaires, thus reducing the burden on participants in the main trial. Modifications to the wording of the questions also need to be made. MONITORING OF BIAS Children who recruited to the trial were older and had more severe strabismus than those children eligible but declining participation. Strategies to account for this in a full trial are proposed. REASONS FOR PARTICIPATION OR DECLINING STUDY These were identified using qualitative interviews. The principal reasons for declining entry into the study were strong preferences for and against surgical treatment. HARMS There were no serious unexpected adverse events. Two children had overcorrection of their X(T) with reduction in binocular vision following surgery, which is in line with previous studies. No children in the active monitoring arm developed a constant strabismus although two showed some reduction in control. CONCLUSIONS The SamExo study has demonstrated that it is possible to recruit and retain participants to a randomised trial of surgery compared with active monitoring for X(T). For longer-term full RCTs, in order to maximise the generalisability of future studies, consideration needs to be given to planning more time and clinic appointments to assess eligibility and to allow consideration of participation; the greater use of research nurses for recruitment; and accommodating the strong preferences of some parents both for and against surgical intervention. TRIAL REGISTRATION Current Controlled Trials ISRCTN44114892. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 39. See the NIHR Journals Library website for further project information.
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Affiliation(s)
- Michael Clarke
- Department of Ophthalmology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK
| | - Vanessa Hogan
- Newcastle Clinical Trials Unit, Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Deborah Buck
- Institute of Neuroscience, Newcastle University, Newcastle, UK
| | - Jing Shen
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Christine Powell
- Department of Ophthalmology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK
| | - Chris Speed
- Newcastle Clinical Trials Unit, Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Peter Tiffin
- Sunderland Eye Infirmary, City Hospitals Sunderland NHS Foundation Trust, Sunderland, UK
| | - John Sloper
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Robert Taylor
- Department of Ophthalmology, York Hospitals NHS Foundation Trust, York, UK
| | - Mahmoud Nassar
- Ophthalmology Department, Faculty of Medicine, Minia University, Al-Mini, Egypt
| | - Kerry Joyce
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Fiona Beyer
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Richard Thomson
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Luke Vale
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Elaine McColl
- Newcastle Clinical Trials Unit, Institute of Health and Society, Newcastle University, Newcastle, UK
| | - Nick Steen
- Institute of Health and Society, Newcastle University, Newcastle, UK
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19
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Yang M, Chen J, Shen T, Kang Y, Deng D, Lin X, Wu H, Chen Q, Ye X, Li J, Yan J. Clinical Characteristics and Surgical Outcomes in Patients With Intermittent Exotropia: A Large Sample Study in South China. Medicine (Baltimore) 2016; 95:e2590. [PMID: 26844467 PMCID: PMC4748884 DOI: 10.1097/md.0000000000002590] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The clinical characteristics and surgical outcomes in a large sample of patients with intermittent exotropia (IXT) as well as an analysis of risk factors associated with surgical failures are presented in this article. Data from IXT patients who received surgical management at the Eye Hospital, in the Zhongshan Ophthalmic Center, of Sun Yat-Sen University, China from January 2009 to December 2013 were reviewed retrospectively. Included within this analysis were data from pre- and postoperative ocular motility, primary alignment, and binocular vision.A total of 1228 patients with IXT were reviewed. Males (50.4%) and females (49.6%) were nearly equally represented in this sample. Thirty-two patients (2.6%) had a family history of strabismus. The mean age at onset was 6.77 ± 6.43 years (range 7 months -48.5 years), mean duration at presentation was 7.35 ± 6.68 years (range 6 months-47 years), and mean age at surgery was 13.7 ± 8.8 years (range 3-49 years). The mean refractive error was -0.84 ± 2.69 diopter in the right eye and -0.72 ± 2.58 diopter in the left eye. Amblyopia (4.2%), oblique muscle dysfunction (7.0%), and dissociated vertical deviation (4.7%) were also present in these patients. The most common subtype of IXT was the basic type (88.1%). Orthophoria was observed in 80.5% of patients and the ratios of surgical undercorrection and overcorrection were 14.7% and 4.8%, respectively, as determined with a mean follow-up time of 7.8 ± 3.7 months. When combining ocular alignment with binocular vision as the success criteria, the success rate decreased to 35.6%. Multivariate risk factor analysis showed that only the loss of stereoacuity (P = 0.002) was associated with a poor outcome. There were no differences in the long-term results between bilateral lateral rectus recession and unilateral lateral rectus recession with medial rectus resection.Most IXT patients displayed normal vision, with few having positive family histories, amblyopia, oblique muscle dysfunction, and dissociated vertical deviation. The most common subtype of IXT was the basic type. Long-term surgical results were less favorable when sensory status was included in the criteria for success. Patients with stereoacuity loss were at an increased risk for poor outcomes.
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Affiliation(s)
- Min Yang
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, The People's Republic of China
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Mohney BG, Cotter SA, Chandler DL, Holmes JM, Chen AM, Melia M, Donahue SP, Wallace DK, Kraker RT, Christian ML, Suh DW. A Randomized Trial Comparing Part-time Patching with Observation for Intermittent Exotropia in Children 12 to 35 Months of Age. Ophthalmology 2015; 122:1718-25. [PMID: 26072346 DOI: 10.1016/j.ophtha.2015.04.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To determine the effectiveness of part-time patching for treating intermittent exotropia (IXT) in young children. DESIGN Multicenter, randomized clinical trial. PARTICIPANTS Two hundred one children 12 to 35 months of age with untreated IXT meeting the following criteria: (1) IXT at distance OR constant exotropia at distance and either IXT or exophoria at near, and (2) 15-prism diopter (Δ) or more exodeviation at distance or near by prism and alternate cover test (PACT) but at least 10 Δ exodeviation at distance by PACT. METHODS Participants were assigned randomly to either observation (no treatment for 6 months) or patching prescribed for 3 hours daily for 5 months, followed by 1 month of no patching. MAIN OUTCOME MEASURES The primary outcome was deterioration, defined as constant exotropia measuring at least 10 Δ at distance and near or receipt of nonprotocol treatment for IXT. RESULTS Of the 177 participants (88%) completing the 6-month primary outcome examination, deterioration occurred in 4.6% (4 of 87) of the participants in the observation group and in 2.2% (2 of 90) of the participants in the patching group (difference, 2.4%; P = 0.27; 95% confidence interval, -3.8% to +9.4%). Motor deterioration occurred in 2.3% (2 of 87) of the observation group and in 2.2% (2 of 90) of the patching group (difference, 0.08%; P = 0.55; 95% confidence interval, -5.8% to +6.1%). For the observation and patching groups, respectively, 6-month mean PACT measurements were 27.9 Δ versus 24.9 Δ at distance (P = 0.02) and 19.3 Δ versus 17.0 Δ at near (P = 0.10); 6-month mean exotropia control scores were 2.8 versus 2.3 points at distance (P = 0.02) and 1.4 versus 1.1 points at near (P = 0.26). CONCLUSIONS Among children 12 to 35 months of age with previously untreated IXT, deterioration over 6 months was uncommon, with or without patching treatment. There was insufficient evidence to recommend part-time patching for the treatment of IXT in children in this age group.
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Affiliation(s)
- Brian G Mohney
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
| | - Susan A Cotter
- Southern California College of Optometry at Marshall B. Ketchum University, Fullerton, California
| | | | | | - Angela M Chen
- Southern California College of Optometry at Marshall B. Ketchum University, Fullerton, California
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21
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Korah S, Philip S, Jasper S, Antonio-Santos A, Braganza A. Strabismus surgery before versus after completion of amblyopia therapy in children. Cochrane Database Syst Rev 2014; 10:CD009272. [PMID: 25315969 PMCID: PMC4438561 DOI: 10.1002/14651858.cd009272.pub2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Normal visual development occurs when the brain is able to integrate the visual input from each of the two eyes to form a single three-dimensional image. The process of development of complete three-dimensional vision begins at birth and is almost complete by 24 months of age. The development of this binocular vision is hindered by any abnormality that prevents the brain from receiving a clear, similar image from each eye, due to decreased vision (e.g. amblyopia), or due to misalignment of the two eyes (strabismus or squint) in infancy and early childhood. Currently, practice patterns for management of a child with both strabismus and amblyopia are not standardized. OBJECTIVES To study the functional and anatomic (ocular alignment) outcomes of strabismus surgery before completion of amblyopia therapy as compared with surgery after completion of amblyopia therapy in children under seven years of age. SEARCH METHODS We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2014), EMBASE (January 1980 to July 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to July 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 24 July 2014. A manual search for articles from a review of the references of the selected publications and conference abstracts was completed to identify any additional relevant studies. SELECTION CRITERIA We searched for randomized controlled trials (RCTs) that provided data on strabismus surgery in children less than seven years of age, performed after initiation of, but before completion of amblyopia therapy, as compared with strabismus surgery after completion of amblyopia therapy. DATA COLLECTION AND ANALYSIS Two authors independently assessed studies identified from the electronic and manual searches. MAIN RESULTS There were no RCTs that fit our inclusion criteria and so no analysis was possible. AUTHORS' CONCLUSIONS As there are no RCTs currently available and the best existing evidence is only from non-randomized studies, there is a need for prospective RCTs to investigate strabismus surgery in the presence of strabismic amblyopia. The optimal timing of when to perform strabismus surgery in children with amblyopia is unknown.
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Affiliation(s)
- Sanita Korah
- Department of Ophthalmology, Christian Medical College, Vellore, Tamil Nadu, India, 632001
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Cotter SA, Mohney BG, Chandler DL, Holmes JM, Repka MX, Melia M, Wallace DK, Beck RW, Birch EE, Kraker RT, Tamkins SM, Miller AM, Sala NA, Glaser SR. A randomized trial comparing part-time patching with observation for children 3 to 10 years of age with intermittent exotropia. Ophthalmology 2014; 121:2299-310. [PMID: 25234012 DOI: 10.1016/j.ophtha.2014.07.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 05/19/2014] [Accepted: 07/10/2014] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE To determine the effectiveness of prescribed part-time patching for treatment of intermittent exotropia (IXT) in children. DESIGN Multicenter, randomized clinical trial. PARTICIPANTS Three hundred fifty-eight children 3 to <11 years of age with previously untreated (except for refractive correction) IXT and near stereoacuity of 400 seconds of arc or better were enrolled. Intermittent exotropia met the following criteria: (1) IXT at distance OR constant exotropia at distance and either IXT or exophoria at near; (2) exodeviation (tropia or phoria) of at least 15 prism diopters (PD) at distance or near by prism and alternate cover test (PACT); and (3) exodeviation of at least 10 PD at distance by PACT. METHODS Participants were assigned randomly either to observation (no treatment for 6 months) or to patching for 3 hours daily for 5 months, with a 1-month washout period of no patching before the 6-month primary outcome examination. MAIN OUTCOME MEASURES The primary outcome was deterioration at either the 3-month or the 6-month follow-up visit, defined as: (1) constant exotropia measuring at least 10 PD at distance and near by simultaneous prism and cover test, and/or (2) near stereoacuity decreased by at least 2 octaves from baseline, both assessed by a masked examiner and confirmed by a retest. Participants who were prescribed any nonrandomized treatment without first meeting either deterioration criteria also were counted as having deteriorated. RESULTS Of the 324 participants (91%) completing the 6-month primary outcome examination, deterioration occurred in 10 of the 165 participants (6.1%) in the observation group (3 of these 10 started treatment without meeting deterioration criteria) and in 1 of the 159 participants (0.6%) in the part-time patching group (difference, 5.4%; lower limit of 1-sided exact 95% confidence interval, 2.0%; P = 0.004, 1-sided hypothesis test). CONCLUSIONS Deterioration of previously untreated childhood IXT over a 6-month period is uncommon with or without patching treatment. Although there is a slightly lower deterioration rate with patching, both management approaches are reasonable for treating children 3 to 10 years of age with IXT.
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Affiliation(s)
| | - Susan A Cotter
- Southern California College of Optometry, Marshall B. Ketchum University, Fullerton, California.
| | | | | | | | - Michael X Repka
- Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, Maryland
| | | | | | - Roy W Beck
- Jaeb Center for Health Research, Tampa, Florida
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Chiu AKC, Din N, Ali N. Standardising reported outcomes of surgery for intermittent exotropia--a systematic literature review. Strabismus 2014; 22:32-6. [PMID: 24564726 DOI: 10.3109/09273972.2013.877940] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Intermittent exotropia (IXT) is one of the most common strabismus entities worldwide, but it remains poorly understood. Investigators differ regarding which parameters should be used to characterize IXT and to evaluate interventions. Surgery is an established treatment option but problems can arise when comparing surgical effectiveness if there is a wide range of different outcome measures that can be used. This study aimed to assess the extent of standardization of reported outcomes in studies of surgery for IXT. METHODS With institutional R&D committee approval, we conducted, according to a predefined protocol, a systematic literature review of outcomes of surgery for IXT published in the last 10 years. The databases used were Medline and EMBASE. Two analysts independently performed the searches. The separate lists were then compared and collated to maximize our return rate for included papers and allow evaluation of our strategies. RESULTS Fifty-six studies met our inclusion criteria. Thirty-two were retrospective and twenty-four prospective. Outcome measures varied widely between studies and variously included ocular alignment, stereopsis, visual acuity, re-operation rate, and postoperative drift. Even for ocular alignment, there was no agreed definition of postoperative success. Time frames for assessing outcomes ranged from two months to two years after surgery. CONCLUSIONS The lack of harmony in outcome reporting for studies of surgery for IXT is counterproductive. We suggest 4 core outcomes for all future studies, which have already been incorporated into two current randomized trials: alignment, near stereoacuity, control score, and quality of life score.
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Buck D, McColl E, Powell CJ, Shen J, Sloper J, Steen N, Taylor R, Tiffin P, Vale L, Clarke MP. Surgery versus Active Monitoring in Intermittent Exotropia (SamExo): study protocol for a pilot randomised controlled trial. Trials 2012; 13:192. [PMID: 23072556 PMCID: PMC3521171 DOI: 10.1186/1745-6215-13-192] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 09/26/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Childhood intermittent exotropia [X(T)] is a type of strabismus (squint) in which one eye deviates outward at times, usually when the child is tired. It may progress to a permanent squint, loss of stereovision and/or amblyopia (reduced vision). Treatment options for X(T) include eye patches, glasses, surgery and active monitoring. There is no consensus regarding how this condition should be managed, and even when surgery is the preferred option clinicians disagree as to the optimal timing. Reports on the natural history of X(T) are limited, and there is no randomised controlled trial (RCT) evidence on the effectiveness or efficiency of surgery compared with active monitoring. The SamExo (Surgery versus Active Monitoring in Intermittent Exotropia) pilot study has been designed to test the feasibility of such a trial in the UK. METHODS DESIGN an external pilot patient randomised controlled trial. SETTING four UK secondary ophthalmology care facilities at Newcastle NHS Hospitals Foundation Trust, Sunderland Eye Infirmary, Moorfields Eye Hospital and York NHS Trust. PARTICIPANTS children aged between 6 months and 16 years referred with suspected and subsequently diagnosed X(T). Recruitment target is a total of 144 children over a 9-month period, with 120 retained by 9-month outcome visit.Randomisation: permuted blocks stratified by collaborating centre, age and severity of X(T). INTERVENTIONS initial clinical assessment; randomisation (eye muscle surgery or active monitoring); 3-, 6- and 9-month (primary outcome) clinical assessments; participant/proxy completed questionnaire covering time and travel costs, health services use and quality of life (Intermittent Exotropia Questionnaire); qualitative interviews with parents to establish reasons for agreeing or declining participation in the pilot trial. OUTCOMES recruitment and retention rates; nature and extent of participation bias; nature and extent of biases arising from crossover or loss to follow-up; reasons for agreeing/declining participation; variability of cure rates (to inform power calculations for a definitive RCT); completion rates of outcome measures. DISCUSSION The SamExo pilot trial will provide important pointers regarding the feasibility of a full RCT of immediate surgery versus deferred surgery/active monitoring. The results of this pilot, including differences in cure rates, will inform the design of a definitive RCT. TRIAL REGISTRATION ISRCTN44114892.
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Affiliation(s)
- Deborah Buck
- Institute of Neuroscience, c/o Clinical Trials Unit, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Elaine McColl
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | - Christine J Powell
- Royal Victoria Infirmary Eye Department, Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, UK
| | - Jing Shen
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | | | - Nick Steen
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | | | | | - Luke Vale
- Institute of Health & Society, Baddiley-Clark Building, Newcastle University, Newcastle upon Tyne, UK
| | - Michael P Clarke
- Royal Victoria Infirmary Eye Department, Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, UK
- Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne, UK
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Chung SA, Chang YH, Rhiu S, Lew H, Lee JB. Parent-reported symptoms of attention deficit hyperactivity disorder in children with intermittent exotropia before and after strabismus surgery. Yonsei Med J 2012; 53:806-11. [PMID: 22665350 PMCID: PMC3381481 DOI: 10.3349/ymj.2012.53.4.806] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To investigate the symptoms of attention deficit hyperactivity disorder (ADHD) as reported by parents in children with intermittent exotropia [X(T)] and to determine whether strabismus surgery for X(T) affects ADHD symptoms. MATERIALS AND METHODS Fifty-one consecutive children undergoing muscle surgery for X(T) were prospectively recruited. One parent of each child completed the ADHD rating scale IV (ADHD RS-IV) assessment consecutively before and one year after surgery. Patients whose preoperative scores were above the cut-off point, the 90th percentile based on a Korean sample, were regarded as demonstrating the ADHD trait. The impact of muscle surgery on ADHD symptoms was assessed by comparing the preoperative scores with the post-operative scores. RESULTS Eight (15.7%) of the 51 patients demonstrated the ADHD trait. ADHD RS-IV scores following strabismus surgery significantly decreased in patients with the ADHD trait (p=0.014), while they did not differ in patients without the ADHD trait. Seven (87.5%) of the 8 patients with the ADHD trait showed improvement in their ADHD RS-IV scores after surgery. There was no difference in surgical success rates between X(T) patients with and without the ADHD trait. CONCLUSION The ADHD trait was relatively common in children with X(T), and the parent-reported symptoms of the children with the ADHD trait improved after strabismus surgery. These results suggest that childhood X(T) may be one contributing factor to ADHD- related symptoms.
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Affiliation(s)
- Seung Ah Chung
- Department of Ophthalmology, Ajou University School of Medicine, Suwon, Korea
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Yoon Hee Chang
- Department of Ophthalmology, Ajou University School of Medicine, Suwon, Korea
| | - Soolienah Rhiu
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Helen Lew
- Department of Ophthalmology, CHA University College of Medicine, Bundang CHA Hospital, Seongnam, Korea
| | - Jong Bok Lee
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
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Buck D, Powell CJ, Rahi J, Cumberland P, Tiffin P, Taylor R, Sloper J, Davis H, Dawson E, Clarke MP. The improving outcomes in intermittent exotropia study: outcomes at 2 years after diagnosis in an observational cohort. BMC Ophthalmol 2012; 12:1. [PMID: 22257496 PMCID: PMC3293086 DOI: 10.1186/1471-2415-12-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 01/18/2012] [Indexed: 11/25/2022] Open
Abstract
Background The purpose of this study was to investigate current patterns of management and outcomes of intermittent distance exotropia [X(T)] in the UK. Methods This was an observational cohort study which recruited 460 children aged < 12 years with previously untreated X(T). Eligible subjects were enrolled from 26 UK hospital ophthalmology clinics between May 2005 and December 2006. Over a 2-year period of follow-up, clinical data were prospectively recorded at standard intervals from enrolment. Data collected included angle, near stereoacuity, visual acuity, control of X(T) measured with the Newcastle Control Score (NCS), and treatment. The main outcome measures were change in clinical outcomes (angle, stereoacuity, visual acuity and NCS) in treated and untreated X(T), 2 years from enrolment (or, where applicable, 6 months after surgery). Change over time was tested using the chi-square test for categorical, Wilcoxon test for non-parametric and paired-samples t-test for parametric data. Results At follow-up, data were available for 371 children (81% of the original cohort). Of these: 53% (195) had no treatment; 17% (63) had treatment for reduced visual acuity only (pure refractive error and amblyopia); 13% (50) had non surgical treatment for control (spectacle lenses, occlusion, prisms, exercises) and 17% (63) had surgery. Only 0.5% (2/371) children developed constant exotropia. The surgically treated group was the only group with clinically significant improvements in angle or NCS. However, 8% (5) of those treated surgically required second procedures for overcorrection within 6 months of the initial procedure and at 6-month follow-up 21% (13) were overcorrected. Conclusions Many children in the UK with X(T) receive active monitoring only. Deterioration to constant exotropia, with or without treatment, is rare. Surgery appears effective in improving angle of X(T) and NCS, but rates of overcorrection are high.
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Affiliation(s)
- Deborah Buck
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.
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Buck D, Clarke MP, Powell C, Tiffin P, Drewett RF. Use of the PedsQL in childhood intermittent exotropia: estimates of feasibility, internal consistency reliability and parent–child agreement. Qual Life Res 2011; 21:727-36. [PMID: 21786058 DOI: 10.1007/s11136-011-9975-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2011] [Indexed: 10/18/2022]
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Current World Literature. Curr Opin Ophthalmol 2010. [DOI: 10.1097/icu.0b013e32833e6970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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