what causes convergence insufficiency in adultswhat causes convergence insufficiency in adults

Scheiman, M. et al. Learn about causes, symptoms, and treatments. Optom. Participants were properly refracted during all eye movement experiments. J. Validity of the convergence insufficiency symptom survey: A confirmatory study. Wolf, R. C. et al. The vergence eye movement task block was 19s in duration. & He, Y. BrainNet viewer: A network visualization tool for human brain connectomics. Google Scholar. Optom. One or both eyes may turn outward while reading. The first derivative was computed as the velocity response, where the maximum value within the transient portion of the response was measured as peak velocity. Phoria adaptation in CI participants improves post vision therapy40. Exercises are not recommended for all patients with this condition. A mirror on the headcoil, angled in front of the eyes, and situated 87.5cm away from participants nasion, allowed the participant to view a screen that had 1920 by 1080 pixel resolution. 76, 588592 (2005). Cochrane Database Syst. CAS Wajuihian, S. O. They will: Some people are diagnosed but are asymptomatic (have no symptoms). Opt. 12, 1218 (2018). The last correlation method performed a voxel-wise correlation of the entire brain activation with vergence peak velocity and final amplitude for the fast fusional imaging dataset and with magnitude and rate of phoria adaptation for the slow fusional imaging dataset using SPM. Google Scholar. CAS The incidence and clinical characteristics of adult-onset convergence insufficiency. WebWhat are the symptoms of convergence insufficiency? Strabismus 13, 163168 (2005). Sci. It lets your brain merge images from both eyes to process what you see. Sign up for the Nature Briefing newsletter what matters in science, free to your inbox daily. Sci. History. 50, 194197 (1988). Hearing problems or deafness. The MNI coordinate of the most significant T value was extracted and a 5mm radius sphere consisting of 81 voxels was created around this peak voxel coordinate using the MarsBaR MATLAB toolbox as part of SPM77. Google Scholar. Research identifies characteristics of convergence insufficiency in adults, Symptoms of double vision while reading with an exophoria or exotropia at near fixation test and an absence of double vision at distance, An exophoria or exotropia of 10 prism diopters or more at near on prism alternate cover test with orthophoria or small (less than 10 prism diopters) phoria at distance, 13 (11 percent) of 118 patients' records did not supply management data, 92 (88 percent) of the 105 patients were treated with prism spectacles, 9 (9 percent) were treated with convergence exercises, 4 (4 percent) underwent eye muscle surgery. Fast fusional vergence is the process by which the eyes quickly track a target moving in depth, analogous to a baseball batter tracking a fastball25. Testretest reliability of functional magnetic resonance imaging activation for a vergence eye movement task. Hussaindeen, J. R. et al. Squinting, closing or rubbing an Patients were followed up for a mean of 9.3 years. Physiol. 24, 384390 (2004). 97, 10611069 (2020). and S.G. designed the experiment. Infection, traumatic brain injury, certain drugs, neurodegenerative illnesses, myasthenia gravis, or Graves ophthalmopathy can all cause convergence insufficiency. The authors declare no competing interests. The fast fusional disparity system was studied using symmetrical 4 (7) binocular step stimuli. & Alvarez, T. L. Segregation of frontoparietal and cerebellar components within saccade and vergence networks using hierarchical independent component analysis of fMRI. The fast and slow fusional vergence systems were studied using functional imaging employing established methods published by our group using these exact protocols67,68. Assoc. Am. WebPremature sclerosis of lens or ciliary muscle weaknesses due to systemic or local cases may cause accommodative insufficiency. All rights reserved. A 3T Siemens TRIO with a 12-channel head coil (Siemens Medical Solutions, USA) from the Rutgers University Brain Imaging Center was utilized for all functional MRI experiments. But its important to note that learning disabilities are not caused by convergence insufficiency or other eye problems. Learning disabilities are caused by problems with how the brain processes information. What Are the Symptoms of Convergence Insufficiency? In total, 17 patients required strabismus surgery (mean 1.3 operations, range 1-3). (B) Two-sample unpaired t-test of functional activity differences between BNC and CI groups during the vergence jump step fast fusional experiment showing V2, OMV, and right cuneus are significantly different between groups. 132. In American Academy of Optometry Annual Meeting (2019). Exp. Parkinsons disease Alzheimers disease Graves disease myasthenia gravis Convergence insufficiency appears to run in families. Surgical treatment it typically effective. 5, 640649 (2005). PLoS Med. Biomed. 36, 405414 (2019). Yan, C.-G. et al. For example, we could not easily place a prism in front of the eye while a participant was in the bore of the magnet. Shemesh, A. While, several different step stimuli were studied to reduce anticipatory cues29,58,59,60, in the interest of brevity only the 4 step responses stimulated by an initial vergence angular demand of 6, which then abruptly changed to a final vergence angular demand of 10, were analyzed for this study. Bull. 94, 7488 (2017). (C) Linear regression of mean beta weight from right cuneus ROI using a 5mm radius sphere as a function of peak velocity for BNC (blue circle) and CI (red triangle) participants. WebThree patients had horizontal strabismus due to a decompensated heterophoria or convergence insufficiency. The magnitude and rate were the primary metrics used to assess the slow fusional vergence system. What symptoms does Convergence Insufficiency cause? Convergence insufficiency (CI) is a common disorder of ocular alignment among both children and adults. Once the underlying neural substrate difference(s) are understood then therapeutics can be evaluated to understand how the intervention modifies the underlying functional activity of the brain to ultimately reduce vision symptoms. Investig. Rouse, M. W. et al. and S.G. prepared all figures and supplemental figures. The blood oxygen level-dependent (BOLD) fMRI time-series were extracted from the CSF and WM regions for each participant. If your symptoms dont improve with vision therapy, you may need special prism glasses to read or do other up-close activities. (A) Group-level averaged phoria adaptation results of phoria () as a function of time (min) using a 6 base-out (BO) prism for BNC (blue symbols) and CI (red symbols) groups1 standard error of the mean. The Convergence Insufficiency Neuro-Mechanism in Adult Population Study (CINAPS) is a registered randomized clinical trial (NCT03593031 with ClinicalTrials.gov posted July 19, 2018) where all methods were carried out in accordance with the CONSORT agreement51. Optom. Physiol. 40, 20522054 (2019). Divergence insufficiency is a rare ophthalmologic disorder manifesting itself among older adults. and M.S. Vis. 62.171.131.101 Understanding the neural mechanism of CI is a critical first step towards the optimization of therapeutic interventions via improving success rates along with potentially decreasing treatment duration and cost. Before the imaging experiment began, participants practiced free fusion (the ability to voluntarily converge or diverge their eyes to merge the two targets into one image) in the laboratory to ensure that they understood the directions and could perform the task. Exp. Other causes of diplopia in that group include elimination of suppression in the amblyopic eye or change of fixation pattern, for example, in patients with abnormal retinal correspondence and monofixation syndrome. Article 956, 264272 (2002). Its thought to be linked to a weakness in the muscles and nerves that control eye movement. Our results report two distinct regions of the cuneus correlating to the fast and slow fusional vergence systems that are significantly correlated to behavior. The delta block was then convolved with a canonical double gamma response function. Ophthalmol. Randomized clinical trial of treatments for symptomatic convergence insufficiency in children. WebThis form of strabismus is rare and the cause unknown. We enrolled 50 BNC and 50 symptomatic CI participants from 18 to 35years of age and randomized each group to 12h (two 1-h visits per week) of either office-based vergence/accommodative therapy or office-based placebo therapy52. Significant differences are observed between BNC and CI groups for both functional activity and vergence behavior. Home-based therapy for symptomatic convergence insufficiency in children. J. Eyes tire quickly when you read Words run together Blurred or double vision associated with reading Images side by The following ROIs were significantly different between the BNC and CI groups: right cuneus, secondary visual cortex (V2), and left and right dorsal vermal region VI, which has been defined as the oculomotor vermis (OMV)33. 96, 825835 (2019). Can. The magnitude was calculated as the change from the initial to the last phoria measure. Integr. Arch. Vis. Tara L. Alvarez. Each eye movement recording was 4s in duration, and the entire oculomotor experiment lasted 50min. This low rate of exercises in part may be the result of the difficulties elderly adults encountered with exercises and personal preference of treatment by the ophthalmologists.". Google Scholar. 86, 153156 (2009). fMRI of optokinetic eye movements with and without a contribution of smooth pursuit. PubMed Letourneau, J. Optom. Optom. It can be divided into two types: (CI) is a highly treatable binocular vision condition that can affect adults. They may include, but are not limited Alvarez, T. L. et al. Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, USA, Tara L. Alvarez,Cristian Morales,Ayushi Sangoi,Elio M. Santos,Chang Yaramothu,John Vito dAntonio-Bertagnolli,Xiaobo Li&Bharat B. Biswal, Pennsylvania College of Optometry, Salus University, Philadelphia, PA, USA, Department of Health Informatics, Rutgers University School of Health Professions, Newark, NJ, USA, You can also search for this author in Rouse, M. W. et al. Convergence insufficiency affects near vision and eye muscle coordination. Alvarez, T.L., Scheiman, M., Morales, C. et al. Sci. The rate of phoria adaptation between the groups was 3.40.2 /min for the BNC and 2.50.3 /min for the CI groups, which was significantly different [t(83)=2.46, p=0.016]. Sci. Divergence Insufficiency: An Ongoing Challenge - Review of Thiagarajan, P., Ciuffreda, K. J. A randomized clinical trial of treatments for convergence insufficiency in children. This content does not have an English version. Tibber, M. et al. However, until now, there has been limited information, from just three studies with small sample sizes (N=4 to N=7), about how the neurology of vergence differs in BNC versus CI populations17,28,31. The resulting images were thresholded for significance using a voxel-level value of p<0.001 and then corrected for multiple comparisons using the whole-brain, cluster-wise family-wise error (FWE) with a threshold of p<0.0576. Med. Figure1A shows the group-level average position trace (solid blue line in the unit of as a function of time in the unit of seconds) of the BNC group stimulated by a 4 symmetrical disparity jump step with plus and minus one standard deviation (shaded light blue) and the average velocity trace (dashed blue line in the unit of /s as a function of time in the unit of seconds). Ophthalmol. Tired or sore eyes. We followed the protocols established in multiple randomized clinical trials which included a combination of office-based therapy with home therapy reinforement13,15,16,17,23,53,54. Convergence insufficiency (CI) is the most common binocular vision problem, associated with blurred/double vision, headaches, and sore eyes that are Searle, A. Optom. The Pearsons correlation coefficient between the mean beta weight and the rate of BO phoria adaptation was r=0.25 (p<0.02) and r=0.26 (p<0.02) for the 3mm and 7mm radius spheres, respectively. Vis. Scheiman, M., Talasan, H., Mitchell, G. & Alvarez, T. L. Objective assessment of vergence after treatment of concussion-related CI: A pilot study. Instruction Courses and Skills Transfer Labs, Program Participant and Faculty Guidelines, LEO Continuing Education Recognition Award, What Practices Are Saying About the Registry, Provider Enrollment, Chain and Ownership System (PECOS), Subspecialty/Specialized Interest Society Directory, Subspecialty/Specialized Interest Society Meetings, Minority Ophthalmology Mentoring Campaign, Global Programs and Resources for National Societies, International Society of Refractive Surgery, autoimmune disease (when the body attacks its own tissues and organs) that harm the eye muscles, squinting or closing one eye while reading, words appearing to move around or float on the page while reading, use prism lenses to measure the eye misalignment, surgeryin rare casesto strengthen the eye muscles. J. Optom. Future studies investigating the intersection of oculomotor vergence function and visual attention would be prudent to further explore how new therapeutic interventions may be designed. Of 118 patients, 32 percent had hyperopia and 38 percent had myopia. Convergence insufficiencyis usually not found during school vision screenings. Regional brain activation changes and abnormal functional connectivity of the ventrolateral prefrontal cortex during working memory processing in adults with attention-deficit/hyperactivity disorder. (Chicago) 126, 13361349 (2008). Google Scholar. convergence Hum. CITT-ART Investigator Group. PubMed T.L.A., M.S., B.B.B. Using an unpaired t-test, the mean beta weight from the 5mm radius sphere within the right cuneus for the fast fusional experiment were significantly greater in the BNC group (mean with standard deviation=0.070.08) compared to the CI group (0.030.08) [t(85)=2.33; p=0.02]. All rights reserved. Res. A. M. Distance vergence adaptation is abnormal in subjects with convergence insufficiency. Psychol. Youll typically practice focusing on things at various distances. report a large subgroup of patients with convergence insufficiency who were asymptomatic before the surgery . Double vision and blurred vision are the most common side effects of CI, but other symptoms may be present, including: Sore or tired eyes. The knowledge gained from this study is the critical first step toward understanding the neurophysiology of CI. Article Convergence Insufficiency 95, 505514 (2018). Esotropia CAS The change in disparity was 6 base-out, which was analogous to the 6 base-out prism used in the behavioral experiment. Vis. Our prior studies showed that the 5mm radius sphere produced the highest intraclass correlation coefficients within our repeatability studies67,68 and has been used in a prior oculomotor fMRI investigation78. Google Scholar. Double vision (diplopia). Biol. Opt. For the fast fusional system, significant differences are observed between the BNC and CI groups for convergence peak velocity, final position amplitude, and functional imaging activity within the secondary visual cortex, right cuneus, and oculomotor vermis. For positive fusional vergence, the CI group mean was 12.54.0, which was significantly less than the BNC group mean of 27.88.4 [t(98)=13.4, p<0.0001]. CINAPSConvergence insufficiency neuro-mechanism in adult population study: Effect of vision therapy on clinical, objective eye movement, and functional MRI measures. Headache. To test this hypothesis, a lose 6 base-out wedge prism on a rod was placed in front of the participants right eye for the duration of the experiment after two baseline phoria measurements were recorded. Disorders of Vergence Eye Movements WebConvergence insufficiency (CI) is a common disorder of ocular alignment among both children and adults. How close to your face you can focus before an eye starts to move outward. PubMed J. Neurosci. Vis. Monti, M. Statistical analysis of fMRI time-series: A critical review of the GLM approach. The region that was significantly different between the groups was the medial cuneus. How much your eyes drift outward while looking at things up close and far away. Get the most important science stories of the day, free in your inbox. Opt. The ROI-based and voxel-based correlation analyses between the functional activity beta weights and vergence eye movement peak velocity were similar. 20, 17 (2020). studying for exams), over work, worry, recent illness or whiplash. Convergence Insufficiency - American Academy of Sci. In the meantime, to ensure continued support, we are displaying the site without styles The most prevalent associated systemic conditions included hypertension in 23 percent and coronary artery disease, hyperlipidemia and cancer in approximately 10 percent each. Optom. PLoS ONE 8, 68910 (2013). 8, 50 (2014). Sheard, C. Zones of ocular comfort. PubMed Correlation analyses demonstrate that the functional activity within the medial cuneus is significantly correlated to the rate of base-out phoria adaptation. For the fast fusional experiment, the design matrix was the sustained fixation resting blocks and the vergence eye movement task blocks convolved with a canonical waveform of a double gamma function. The slow fusional vergence system is assessed via phoria adaptation. J. Optom. Funct. B. Vis. Front. Behzadi, Y., Restom, K., Liau, J. The Modified Thorington technique, using the Bernell Muscle Imbalance Measure (MIM) card, a penlight, and a Maddox Rod (Bernell Corp., South Bend, IN, USA) was used to measure the near phoria63. Supported by the National Eye Institute of the National Institutes of Health NEI R01EY023261 to TLA, Department of Health and Human Services, Bethesda, Maryland, USA. Optometry 83, 137158 (2012). If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. A. 134. Brain Mapp. analyzed the data. The timing protocol began with a rest block of sustained fixation for 21s. Eight vergence step stimuli were then presented between 2 to 5s per eye movement using the following order: 4 convergence (Con), 4 Con, 6 divergence (Div), 4 Con, 4 Con, 6 Div, 4 Con, and 4 Div. A haploscope presented disparity stimuli, utilizing fixed focal lengths to each eye (40cm from the stimulus to the partially reflective mirror to participants globe) which kept accommodative cues constant at 2.5D. The linear regression analysis plotted as a solid black line reports a significant correlation between the mean beta weight activity in the medial cuneus using a 5mm radius sphere and the rate of BO phoria adaptation with a Pearsons correlation coefficient of r=0.25 (p<0.02). & Ducic, S. Prevalence of convergence insufficiency among elementary school children. For the slow-fusional experiment of phoria adaptation, a two-sample unpaired t-test assessed differences between the BNC and CI groups for the magnitude and the rate of phoria adaptation and the mean beta weights from an ROI. Cooper, J. Convergence insufficiency (CI) is the most common binocular vision disorder across the age spectrum, with an estimated prevalence of 4.2% to 17.6% in children1,2,3,4,5, and 3.4% to 7.7% in adults6,7,8,9. Xia, M., Wang, J. WebWhat causes convergence insufficiency? causes Arch. The full description of the study design with inclusion and exclusion criteria, and details of the diagnostic criteria for symptomatic CI, BNC, masking, statistical power analysis, the binocular vision, and accommodative testing, and the office-based vergence accommodative therapy and placebo therapy protocols, are available in our prior publication27. Phoria adaptation disorder has been suggested to be an underlying mechanism in symptomatic CI patients26. Morales, C. et al. What is Convergence Insufficiency The novelty of this current work is that it is the first to demonstrate a correlation between vergence peak velocity and the right cuneus functional activity. Prior functional imaging studies in BNC do report functional activity of the cuneus during vergence jump step experiments29, during stimulation of stereopsis43, and for optokinetic eye movements44. Middle East Afr. The final amplitude for the BNC group was 3.70.36. Neurodegenerative diseases, including Parkinson disease and progressive supranuclear palsy, also cause convergence insufficiency. Sci. Google Scholar. The group-level differences between the BNC and CI groups for the brain activation datasets were compared using a two-sample unpaired t-test for each voxel using an initial threshold of p<0.001. J. Ophthalmol. The mean initial exodeviation at near was 14.1 prism diopters and 1.7 prism diopters at distance. Our results demonstrate that symmetrical vergence jump steps stimulated within a functional MRI experiment evoke functional activity within the visual cortex, cuneus, PEF, FEF, SEF, and cerebellar regions. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. What is Convergence Insufficiency? Symptoms, Treatments