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Eye Teaming and Focusing Disorders
Purpose —To determine if children with symptomatic Convergence Insufficiency (CI) without the presence of parent reported Attention Deficit Hyperactivity Disorder (ADHD) have higher scores on the academic behavior survey (ABS).
Methods —The Academic Behavior Survey (ABS) is a 6-item survey that evaluates parent concern about school performance and the parents' perceptions of the frequency of problem behaviors that their child may exhibit when reading or performing schoolwork (such as: difficulty completing work, avoidance, and inattention). Each item is scored on an ordinal scale from 0 (Never) to 4 (Always) with a total score ranging from 0 to 24. The survey was administered to the parents of 212 children 9-17 years old (mean age 11.8 yrs.) with symptomatic CI prior to enrolling into the Convergence Insufficiency Treatment Trial and to 49 children with normal binocular vision (NBV) (mean age 12.5 years). The parents reported whether the child had ADHD and this information was used to divide the symptomatic CI group into the CI with parent-report of ADHD or CI with parent-report of no ADHD groups.
Results —Sixteen percent of the CI group and 6% of the NBV group were classified as ADHD by parental report. An analysis of covariance showed that the total ABS score for the symptomatic CI with parent-report of ADHD group (15.6) was significantly higher than the symptomatic CI with parent-report of no ADHD group (11.7, p=0.001) and the NBV group (8.7, p<0.0001). Children with CI with parent-report of no ADHD scored significantly higher on the ABS than the NBV group (p=0.036).
Conclusions — Children with symptomatic CI with parent-report of no ADHD scored higher on the ABS when compared to children with NBV. Children with parent-report of ADHD or related learning problems may benefit from comprehensive vision evaluation to assess for the presence of CI.
Purpose: To determine whether treatment of symptomatic convergence insufficiency (CI) has an effect on Academic Behavior Survey (ABS) scores.
Methods: The ABS is a six-item survey developed by the Convergence Insufficiency Treatment Trial Group that quantifies the frequency of adverse school behaviors and parental concern about school performance on an ordinal scale from 0 (never) to 4 (always) with total scores ranging from 0 to 24. The ABS was administered at baseline and after 12 weeks of treatment to the parents of 218 children aged 9 to 17 years with symptomatic CI, who were enrolled in the Convergence Insufficiency Treatment Trial and randomized into (1) home-based pencil push-ups; (2) home-based computer vergence/accommodative therapy and pencil push-ups; (3) office-based vergence/accommodative therapy with home reinforcement; and (4) office-based placebo therapy with home reinforcement. Participants were classified as successful (n = 42), improved (n = 60), or non-responder (n = 116) at the completion of 12 weeks of treatment using a composite measure of the symptom score, nearpoint of convergence, and positive fusional vergence. Analysis of covariance methods were used to compare the mean change in ABS between response to treatment groups while controlling for the ABS score at baseline.
Results: The mean ABS score for the entire group at baseline was 12.85 (SD = 6.3). The mean ABS score decreased (improved) in those categorized as successful, improved, and non-responder by 4.0, 2.9, and 1.3 points, respectively. The improvement in the ABS score was significantly related to treatment outcome (p < 0.0001), with the ABS score being significantly lower (better) for children who were successful or improved after treatment as compared to children who were non-responders (p = 0.002 and 0.043, respectively).
Conclusions: A successful or improved outcome after CI treatment was associated with a reduction in the frequency of adverse academic behaviors and parental concern associated with reading and school work as reported by parents.
Convergence insufﬁciency is a common binocular vision disorder affecting approximately 5% of the population in the United States. It is often associated with a host of symptoms that occur when doing near work, such as reading and computer viewing. This article reviews the existing literature on convergence insufﬁciency including etiology, diagnosis, sensorimotor ﬁndings, and management.
Objective - To compare home-based pencil push-ups (HBPP), home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+), office-based vergence/accommodative therapy with home reinforcement (OBVAT), and office-based placebo therapy with home reinforcement (OBPT) as treatments for symptomatic convergence insufficiency.
Methods - In a randomized clinical trial, 221 children aged 9 to 17 years with symptomatic convergence insufficiency were assigned to 1 of 4 treatments.
Main Outcome Measures- Convergence Insufficiency Symptom Survey score after 12 weeks of treatment. Secondary outcomes were near point of convergence and positive fusional vergence at near.
Results - After 12 weeks of treatment, the OBVAT group's mean Convergence Insufficiency Symptom Survey score (15.1) was statistically significantly lower than those of 21.3, 24.7, and 21.9 in the HBCVAT+, HBPP, and OBPT groups, respectively (P < .001). The OBVAT group also demonstrated a significantly improved near point of convergence and positive fusional vergence at near compared with the other groups (P <or= .005 for all comparisons). A successful or improved outcome was found in 73%, 43%, 33%, and 35% of patients in the OBVAT, HBPP, HBCVAT+, and OBPT groups, respectively.
Conclusions - Twelve weeks of OBVAT results in a significantly greater improvement in symptoms and clinical measures of near point of convergence and positive fusional vergence and a greater percentage of patients reaching the predetermined criteria of success compared with HBPP, HBCVAT+, and OBPT. Application to Clinical Practice Office-based vergence accommodative therapy is an effective treatment for children with symptomatic convergence insufficiency.
Purpose - To determine the effectiveness of vision therapy among Korean elementary school children with convergence insufficiency.
Methods - A total of 235 elementary schoolchildren, 10.13 ± 2.45 years of age, were subjected to thorough eye examination including binocular vision testing. Of them, 32 individuals with symptomatic convergence insufficiency without strabismus, amblyopia, and ocular disease were chosen to receive vision therapy via brock string, barrel card, mirror stereoscope, prism goggles, and aperture rule for a duration of 8 weeks.
Results - The results showed that most of the participants had severe problems in near point of convergence. After the vision therapy, the average near point of convergence improved by approximately 5.48 ± 0.96 cm in all participants. Moreover, vision therapy had an effect on increasing near positive fusional vergence and decreasing exophoria. Negative relative accommodation improved to 2.54 ± 0.51 and positive relative accommodation improved to -3.10 ± 1.08 diopters. After treatment, near phoria was 4.19 ± 1.66 and distance phoria was 1.61 ± 0.71 prism diopters.
Conclusion - Among convergence insufficiency symptoms, the following improved in particular: near point of convergence, exophoria, and near positive fusional vergence. These findings suggest that vision therapy is very effective to recover from symptomatic convergence insufficiency.
Background - Most studies investigating the impact of optometric vision therapy on reading speed and reading eye movements utilize ocular motility and visual processing procedures. Only one study has reported the impact of accommodative and vergence therapy alone on reading speed, but only with three subjects.
Methods - Six patients with symptomatic accommodative/vergence anomalies received vision therapy along with objective eye movement recordings before and after therapy. Therapy consisted of procedures to treat accommodative and vergence skills - no saccadic or ocular motor procedures were utilized.
Results - Each of the patients showed clinically significant improvements in reading speed and eye movement efficiency.
Conclusions - Accommodative and vergence therapy alone has the potential to improve reading speed and reading eye movements. Ocular motor therapy may not be necessary for some patients with accommodative/vergence disorders who also demonstrate reduced reading speed and poor reading eye movements. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Purpose - To report the effectiveness of various forms of vision therapy/orthoptics in improving accommodative amplitude and facility in children with symptomatic convergence insufficiency (CI) and co-existing accommodative dysfunction.
Methods - In a randomized clinical trial, 221 children aged 9 to 17 years with symptomatic CI were assigned to one of four treatments. Of the enrolled children, 164 (74%) had accommodative dysfunction; 63 (29%) had a decreased amplitude of accommodation with respect to age, 43 (19%) had decreased accommodative facility, and 58 (26%) had both. Analysis of variance models were used to compare mean accommodative amplitude and accommodative facility for each treatment group after 4, 8, and 12 weeks of treatment.
Results - After 12 weeks of treatment, the increases in amplitude of accommodation [office-based vergence/accommodative therapy with home reinforcement group (OBVAT) 9.9 D, home-based computer vergence/accommodative therapy group (HBCVAT+) 6.7 D, and home-based pencil push-up therapy group (HBPP) 5.8 D] were significantly greater than in the office-based placebo therapy (OBPT) group (2.2 D) (p-values ≤0.010). Significant increases in accommodative facility were found in all groups (OBVAT: 9 cpm, HBCVAT+: 7 cpm, HBPP: 5 cpm, OBPT: 5.5 cpm); only the improvement in the OBVAT group was significantly greater than that found in the OBPT group (p = 0.016). One year after completion of therapy, reoccurrence of decreased accommodative amplitude was present in only 12.5% and accommodative facility in only 11%.
Conclusions - Vision therapy/orthoptics is effective in improving accommodative amplitude and accommodative facility in school-aged children with symptomatic CI and accommodative dysfunction.
Evidence Vision Therapy Works
Vision therapy, like any area in a health profession, is practiced differently by various clinicians. I will restrict this discussion to the most commonly practiced and largest portion of the area of vision therapy: treatment of accommodative and vergence anomalies, including strabismus. These categories include the majority of patients treated by optometrists providing vision therapy service. In addition, all schools of optometry include diagnosis and treatment of anomalies of accommodation and vergence in their curricula.
Negative feedback control theory analysis of the accommodative and vergence systems provides the basis of today’s optometric vision therapy. These models have a strong physiological and anatomical basis, and have been described in numerous articles and textbooks. Computer simulations using control theory demonstrates the predictability of both the accommodative and vergence systems. Defects in any component of the system may result in asthenopia, diplopia, and/or strabismus.
The most common cause of asthenopia is related to inadequate slow vergence. Vision therapy differs from orthoptic models in that control theory analysis acknowledges the dynamic interaction of accommodation and vergence, and its respective feedback mechanisms.
‘the power of a lollipop’
Kenneth J. Ciuffreda, OD, PhD, FCOVD-A, FARVO, FAAO
Diana P. Ludlam, BS, COVT
Naveen K. Yadav, BS Optom, MS, PhD, FAAO
When the first author was a third year student at the Massachusetts College of Optometry in 1972, he had a short and simple, but life changing, conversation. While sitting outdoors on the steps after our ocular disease class, the instructor, a very bright ophthalmologist, joined me for a chat. The topic of “vision therapy” came up. I knew very little, and he even less. He asked, “Does vision therapy work?”. I replied a confidant, “Yes.” He was somewhat sympathetic but responded, “Maybe give the child a lollipop instead.” The implication was that the added attention and positive reinforcement given to the student by the optometrist/vision therapist, the classroom teacher, the parents, and others, provided the basis for the ‘improvement’, in reality a placebo effect. That conversation remained in the back of my mind. It had a big impact a few years later---our graduate research laboratory at Berkeley published the first study demonstrating objectively that ‘vision therapy works’ in a small cohort of optometry students with accommodative insufficiency and slowed accommodative dynamics.1 This was confirmed in two subsequent laboratory studies.2,3 That was the beginning for me — I was hooked!. Over the years, we, and others, have used a variety of approaches, including objective techniques,4-12 clinical trials,13,14 retrospective analysis,15,16 meta-analysis,17,18 and well-documented case reports and case series19-22 to demonstrate the efficacy of vision therapy over a range of diagnostic groups, such as traumatic brain injury, convergence insufficiency, amblyopia, and others. Thus, over the past nearly 100 years, our profession, and particularly the area of vision therapy, has evolved from the early days of clinical anecdotes and philosophizing at regional meetings to objective, physiological evidence for direct vision therapy-related brain changes.
Purpose - To report the frequency of binocular vision (BV) anomalies in children with specific learning disorders (SLD) and to assess the efficacy of vision therapy (VT) in children with a non-strabismic binocular vision anomaly (NSBVA).
Methods - The study was carried out at a centre for learning disability (LD). Comprehensive eye examination and binocular vision assessment was carried out for 94 children (mean (SD) age: 15 (2.2) years) diagnosed with specific learning disorder. BV assessment was done for children with best corrected visual acuity of ≥6/9 - N6, cooperative for examination and free from any ocular pathology. For children with a diagnosis of NSBVA (n=46), 24 children were randomized to VT and no intervention was provided to the other 22 children who served as experimental controls. At the end of 10 sessions of vision therapy, BV assessment was performed for both the intervention and non-intervention groups.
Results - Binocular vision anomalies were found in 59 children (62.8%) among which 22% (n=13) had strabismic binocular vision anomalies (SBVA) and 78% (n=46) had a NSBVA. Accommodative infacility (AIF) was the commonest of the NSBVA and found in 67%, followed by convergence insufficiency (CI) in 25%. Post-vision therapy, the intervention group showed significant improvement in all the BV parameters (Wilcoxon signed rank test, p<0.05) except negative fusional vergence.
Conclusion- Children with specific learning disorders have a high frequency of binocular vision disorders and vision therapy plays a significant role in improving the BV parameters. Children with SLD should be screened for BV anomalies as it could potentially be an added hindrance to the reading difficulty in this special population.
Pediatrician and Parent Advocate for the National Center for Learning Disabilities
Dr. Debra Walhof is a Pediatrician who specializes in Integrative Medicine. During the past 20 years, she has practiced in hospital, academic and community-based clinical settings. Her work has focused primarily on multi-cultural and underserved populations who present as "at risk" across many developmental and behavioral domains. According to Dr. Walhof:
"It is important to remember that normal sight may not necessarily be synonymous with normal vision... That being said, if there is a vision problem, it could be preventing the best tutoring and learning methods from working. Now that certainly doesn't mean every dyslexic child needs vision therapy, however in my opinion, skills such as focusing, tracking and others are essential foundational tools for reading. In general, if your child has trouble with reading or learning to read, getting a vision evaluation to assess these skills from a qualified Developmental Optometrist would be a smart move.”
Strabismus and Amblyopia
Amblyopia is a neuro-developmental disorder of the visual cortex that arises from abnormal visual experience early in life. Amblyopia is clinically important because it is a major cause of vision loss in infants and young children. Amblyopia is also of basic interest because it reflects the neural impairment that occurs when normal visual development is disrupted. Amblyopia provides an ideal model for understanding when and how brain plasticity may be harnessed for recovery of function. Over the past two decades there has been a rekindling of interest in developing more effective methods for treating amblyopia, and for extending the treatment beyond the critical period, as exemplified by new clinical trials and new basic research studies. The focus of this review is on stereopsis and its potential for recovery. Impaired stereoscopic depth perception is the most common deficit associated with amblyopia under ordinary (binocular) viewing conditions (Webber & Wood, 2005). Our review of the extant literature suggests that this impairment may have a substantial impact on visuomotor tasks, difficulties in playing sports in children and locomoting safely in older adults. Furthermore, impaired stereopsis may also limit career options for amblyopes. Finally, stereopsis is more impacted in strabismic than in anisometropic amblyopia. Our review of the various approaches to treating amblyopia (patching, perceptual learning, videogames) suggests that there are several promising new approaches to recovering stereopsis in both anisometropic and strabismic amblyopes. However, recovery of stereoacuity may require more active treatment in strabismic than in anisometropic amblyopia. Individuals with strabismic amblyopia have a very low probability of improvement with monocular training; however they fare better with dichoptic training than with monocular training, and even better with direct stereo training.
Traumatic Brain Injury
The prevalence of vision deficits in the pediatric/young adult concussion population in the private optometric practice setting remains unknown. Thus, a retrospective chart review in this area was conducted in the practice of the first author. Twenty-five consecutive patients with a medical diagnosis of concussion received a comprehensive vision and ocular health examination, which also included an objectively-based Visagraph reading assessment and clinical vergence/accommodative facility testing. Three primary categories of oculomotor-based deficits were found: convergence insufficiency (56%), accommodative insufficiency (76%), and oculomotor-based reading dysfunctions (68-82%). The most common symptom was headaches (84%), with 25% of the symptoms related to reading. 68% (15/22) were categorized as reading at least 2 grade levels below their current school grade level for reading eye movements based on the Visagraph findings. These overall findings are consistent with the general oculomotor-based/reading findings in the concussion/mTBI literature. The present results have important practical ramifications regarding the importance of pre-concussion baseline oculomotor and Visagraph testing, as well as post-concussion follow-up testing, to help assess a student's ability to return-to-learn (RTL).
Vision Therapy and Reading
Purpose - To report the frequency of binocular vision (BV) anomalies in children with specific learning disorders (SLD) and to assess the efficacy of vision therapy (VT) in children with a non-strabismic binocular vision anomaly (NSBVA).
Methods - The study was carried out at a centre for learning disability (LD). Comprehensive eye examination and binocular vision assessment was carried out for 94 children (mean (SD) age: 15 (2.2) years) diagnosed with specific learning disorder. BV assessment was done for children with best corrected visual acuity of ≥6/9 – N6, cooperative for examination and free from any ocular pathology. For children with a diagnosis of NSBVA (n = 46), 24 children were randomized to VT and no intervention was provided to the other 22 children who served as experimental controls. At the end of 10 sessions of vision therapy, BV assessment was performed for both the intervention and non-intervention groups.
Results - Binocular vision anomalies were found in 59 children (62.8%) among which 22% (n = 13) had strabismic binocular vision anomalies (SBVA) and 78% (n = 46) had a NSBVA. Accommodative infacility (AIF) was the commonest of the NSBVA and found in 67%, followed by convergence insufficiency (CI) in 25%. Post-vision therapy, the intervention group showed significant improvement in all the BV parameters (Wilcoxon signed rank test, p < 0.05) except negative fusional vergence.
Conclusion - Children with specific learning disorders have a high frequency of binocular vision disorders and vision therapy plays a significant role in improving the BV parameters. Children with SLD should be screened for BV anomalies as it could potentially be an added hindrance to the reading difficulty in this special population.
Reading requires three-dimensional motor control: saccades bring the eyes from left to right, fixating word after word; and oblique saccades bring the eyes to the next line of the text. The angle of vergence of the two optic axes should be adjusted to the depth of the book or screen and - most importantly - should be maintained in a sustained manner during saccades and fixations. Maintenance of vergence is important as it is a prerequisite for a single clear image of each word to be projected onto the fovea of the eyes. Deficits in the binocular control of saccades and of vergence in dyslexics have been reported previously but only for tasks using single targets. This study examines saccades and vergence control during real text reading. Thirteen dyslexic and seven non-dyslexic children read the French text “L'Allouette” in two viewing distances (40 cm vs. 100 cm), while binocular eye movements were measured with the Chronos Eye-tracking system. We found that the binocular yoking of reading saccades was poor in dyslexic children (relative to non-dyslexics) resulting in vergence errors; their disconjugate drift during fixations was not correlated with the disconjugacy during their saccades, causing considerable variability of vergence angle from fixation to fixation. Due to such poor oculomotor adjustments during reading, the overall fixation disparity was larger for dyslexic children, putting larger demand on their sensory fusion processes. Moreover, for dyslexics the standard deviation of fixation disparity was larger particularly when reading at near distance. We conclude that besides documented phoneme processing disorders, visual/ocular motor imperfections may exist in dyslexics that lead to fixation instability and thus, to instability of the letters or words during reading; such instability may perturb fusional processes and might – in part - complicate letter/word identification.
Purpose - This descriptive study provides a summary of the binocular anomalies seen in elementary school children identified with reading problems.
Methods - A retrospective chart review of all children identified with reading problems and seen by the University of Waterloo, Optometry Clinic, from September 2012 to June 2013.
Results - Files of 121 children (mean age 8.6 years, range 6–14 years) were reviewed. No significant refractive error was found in 81% of children. Five and 8 children were identified as strabismic at distance and near respectively. Phoria test revealed 90% and 65% of patients had normal distance and near phoria. Near point of convergencia (NPC) was <5 cm in 68% of children, and 77% had stereoacuity of ≤40 seconds of arc. More than 50% of the children had normal fusional vergence ranges except for near positive fusional vergencce (base out) break (46%). Tests for accommodation showed 91% of children were normal for binocular facility, and approximately 70% of children had an expected accuracy of accommodation.
Conclusion - Findings indicate that some children with an identified reading problem also present with abnormal binocular test results compared to published normal values. Further investigation should be performed to investigate the relationship between binocular vision function and reading performance.