Treatment Of Convergence Insufficiency Research Articles

One-year follow-up of clinical convergence measures in children enrolled in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial.

To assess the long-term stability of clinical measures of convergence (near point of convergence [NPC] and positive fusional vergence [PFV]) in participants enrolled in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial (CITT-ART) who received 16 weeks of office-based vergence/accommodative therapy. A total of 310 children, 9-14 years old, with symptomatic convergence insufficiency were enrolled in CITT-ART. Some 270 completed both their 16-week primary outcome visit followed by a 1-year follow-up visit. Of those 270, 181 (67%) were randomised to the vergence/accommodative therapy. Of the 181 in the vergence/accommodative group, 121 (67%) reported not receiving any additional treatment after the 16-week primary outcome visit. The mean change in NPC, PFV and percentages of children classified by the predetermined success criteria of convergence (normal NPC [<6 cm] and/or improved by ≥4 cm; normal PFV [passing Sheard's criterion and base-out break >15Δ] and/or improved by ≥10Δ) were compared at the 16-week primary outcome visit and 1 year later. Of the 121 who returned for their 1-year follow-up visit, there was no significant change in mean adjusted NPC (reduction of -0.2 cm; 95% CI: -1.0 to 0.5 cm) at 1 year. There was a statistically significant decrease in mean-adjusted PFV (-4.7∆; 95% CI: -6.5 to -2.8Δ) at 1 year. There were similar percentages of participants classified as 'normal' (p = 0.30), 'normal and/or improved' (p > 0.50) and 'normal and improved' (p > 0.14) based on NPC and PFV at the 1-year visit compared with the 16-week primary outcome visit. The improvements in NPC and PFV following 16 weeks of vergence/accommodative therapy (with no reported additional treatment thereafter) in children with symptomatic convergence insufficiency persisted 1-year post-treatment.

Vergence/accommodative therapy for symptomatic convergence insufficiency in children: Time course of improvements in convergence function.

To evaluate the time course of improvements in clinical convergence measures for children with symptomatic convergence insufficiency treated with office-based vergence/accommodative therapy. We evaluated convergence measures from 205, 9- to 14-year-old children with symptomatic convergence insufficiency randomised to office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial - Attention and Reading Trial (CITT-ART). Near-point of convergence (NPC) and near-positive fusional vergence (PFV) were measured at baseline and after 4, 8, 12 and 16 weeks of therapy; mean change in NPC and PFV between these time points were compared using repeated measures analysis of variance. Rates of change in NPC and PFV from: (1) baseline to 4 weeks and (2) 4-16 weeks were calculated. For each time point, the proportion of participants to first meet the normal criterion for NPC (<6cm), PFV blur (break if no blur; >15Δ and >2 times the exodeviation) and convergence composite (NPC and PFV both normal) were calculated. The greatest change in NPC and PFV (7.6cm and 12.7 Δ) and the fastest rate of improvement in NPC and PFV (1.9cm/week and 3.2 Δ/week, respectively) were both found during the first 4 weeks of therapy, with both slowing over the subsequent 12 weeks. After 12 weeks of therapy, the NPC, PFV and convergence composite were normal in 93.2%, 91.7% and 87.8% of participants, respectively, and normalised with another 4 weeks of therapy in 4.4%, 2.0% and 4.4% of participants, respectively. Although the greatest improvements in NPC and PFV occurred in the first 4 weeks of therapy, most participants had weekly improvements over the subsequent 12 weeks of treatment. While most children with convergence insufficiency obtained normal convergence following 12 weeks of therapy, an additional 4 weeks of vergence/accommodative therapy may be beneficial for some participants.

Treatment of convergence insufficiency type intermittent exotropia with bupivacaine injection to the medial rectus combined with lateral rectus recession

PurposeTo evaluate the outcomes of combined bupivacaine HCL (BPX) injection in the medial rectus (MR) muscle with recession of the lateral rectus muscle in the treatment of convergence insufficiency–type intermittent exotropia (CI-IXT). MethodsThe medical records of patients who underwent combined injection-recession treatment from January 2019 to January 2020 for CI-IXT were reviewed retrospectively along with a group of age-matched controls with IXT without CI who underwent only unilateral LR recession during the same period. The following data were extracted from the record: age at surgery, average follow-up period, angle of deviation at distance and near and the difference between them before and after surgical procedure, correction of near and distance deviations, and recession dosage. Successful outcome was defined as a distance deviation in primary gaze between ≤10Δ of exophoria/tropia and ≤5Δ of esophoria/tropia. ResultsA total of 10 patients and 20 controls were included. Average follow-up was 13.9 ± 3.67 months in the BPX group and 15.9 ± 3.61 months in the control group (P = 0.17). Postoperative distance deviation measured 8.30Δ ± 5.88Δ in the BPX group and 14.67Δ ± 9.83Δ in the control group (P = 0.80). Distance-near differences were significantly reduced in the CI-IXT group receiving BPX, by a mean of 6.60Δ, from a preoperative mean of 10.50Δ ± 3.65Δ to 3.90Δ ± 3.26Δ (P < 0.01). ConclusionsBPX injection combined with unilateral lateral rectus recession yields outcomes comparable to bilateral lateral rectus recession for distance deviations, and results in reduction of the distance-near difference in the angle of exotropia.

Relationships among Clinical Factors and Patient-reported Outcome Measures in Adults with Convergence Insufficiency.

When exploring relationships among clinical measures and patient-reported outcome measures in adults with convergence insufficiency, worse symptoms (Convergence Insufficiency Symptom Survey [CISS] score) seemed to be correlated with worse reading function domain score (Adult Strabismus-20 quality-of-life questionnaire). After treatment, improved symptoms were associated with improved reading function quality of life. This study aimed to explore relationships between clinical measures and patient-reported outcome measures in adults undergoing treatment for symptomatic convergence insufficiency. In a prospective multicenter observational study, we evaluated adults with symptomatic convergence insufficiency (i.e., clinical measures of near exodeviation, receded near point of convergence, reduced near positive fusional vergence; CISS score ≥21). Fifty-seven participants treated with vision therapy/exercises (n = 35) or base-in prism (n = 22) were analyzed. Spearman correlation coefficients ( R ) were used to assess associations among the three clinical measures and patient-reported outcome measures (CISS, Diplopia Questionnaire, four Adult Strabismus-20 quality-of-life domains) before treatment (baseline) and after 10 weeks and 1 year. Associations were interpreted to be present when the lower limit of the 95% confidence interval (CI) was moderate to strong ( R ≥ 0.4). Among multiple exploratory analyses, the only moderate to strong baseline correlation was between worse CISS and worse Adult Strabismus-20 reading function scores ( R = 0.62; 95% CI, 0.43 to 0.76). Regarding change in measures with treatment, the only moderate to strong correlations were between improved CISS and improved Adult Strabismus-20 reading function scores for prism at 10 weeks ( R = 0.78; 95% CI, 0.52 to 0.91) and 1 year ( R = 0.85; 95% CI, 0.65 to 0.94) and for vision therapy/exercises at 1 year ( R = 0.78; 95% CI, 0.57 to 0.89). In exploratory analyses, we found positive correlations between CISS symptom scores and reading function quality-of-life scores. The absence of correlations between symptoms and individual clinical measures is consistent with clinical experience that, in convergence insufficiency, symptoms and clinical findings can be discordant.

The effect of convergence insufficiency treatment on reading performance in school age children – A meta-analysis

Introduction/purpose: Convergence insufficiency (CI) is a binocular vision disorder characterised by difficulty maintaining convergence and fixation at near. Depending on the severity of the CI, patients can present with a variety of symptoms during near vision tasks. Some studies indicate an increased incidence of CI in children with reading difficulties. Although a lot of research has been done on the effects of CI-treatments on eye-related symptoms, not much is known about its effect on performance related symptoms such as reading difficulties. The purpose of this meta-analysis is to determine if CI-treatments have a positive effect on reading performance. Methods: A search string was created to gather all relevant clinical trials on the National Centre for Biotechnology Information (NCBI) and Cochrane libraries. Only clinical trials were included that provided pre- and post treatment data on the effect of CI-treatment on reading performance in school aged children (5-18y). A total of three relevant clinical trials were found that provided pre-and post-treatment data. Results: A total of 352 subjects in CI-treatment groups across three clinical trials and 104 subjects in a placebo group provided pre-and post CI-treatment data on the improvements of reading performance in school aged children. The cumulative within-group treatment effect size (0.21(SD 0.03) [95%CI: 0.15, 0.27]) and the cumulative within-group placebo effect size (0.22(SD 0.05) [95%CI: 0.13, 0.32]) for the improvement of reading performance after CI-treatment in school aged children with CI was calculated. Conclusion: CI-treatment has little to no true effect size on reading performance. Though CI-treatments will cause an increase in reading performance, this is likely caused by improvements in attention, motivation, or other psychological factors (placebo effect).

Virtual reality-based vision therapy versus OBVAT in the treatment of convergence insufficiency, accommodative dysfunction: a pilot randomized controlled trial

BackgroundVirtual reality is being increasingly applied in vision therapy. However, the differences in effectiveness, optimal treatment cycle, and prognosis between virtual reality-based vision therapy and traditional therapies remain unknown. The purpose of this study was to compare the effectiveness of virtual reality-based vision therapy and office-based vergence/accommodative therapy in young adults with convergence insufficiency or accommodative dysfunction.MethodsThe patients were randomly assigned to either the virtual reality-based vision therapy group or the office-based vergence/accommodative therapy group. The vision therapy lasted 12 weeks (1 h/week) in both groups. Binocular visual functions (vergence and accommodation) were measured and a subjective questionnaire-based assessment was performed at baseline and after 6 and 12 weeks of therapy.ResultsIn total, 33 patients with convergence insufficiency and 30 with accommodative dysfunction completed the study. After 12 weeks of treatment for convergence insufficiency, the Convergence Insufficiency Symptom Survey score (F2,31 = 13.704, P < 0.001), near point of convergence (F2,31 = 21.774, P < 0.001), positive fusional vergence (F2,31 = 71.766, P < 0.001), and near horizontal phoria (F2,31 = 16.482, P < 0.001) improved significantly in both groups. Moreover, the monocular accommodative amplitude (F2,25 = 22.154, P < 0.001) and monocular accommodative facility (F2,25 = 86.164, P < 0.001) improved significantly in both groups after 12 weeks of treatment. A statistically significant difference was observed in monocular accommodative facility (F1,25 = 8.140, P = 0.009) between the two groups, but not in other vergence and accommodative functions (0.098 < P < 0.687).ConclusionVirtual reality-based vision therapy significantly improved binocular vision functions and symptoms in patients with convergence insufficiency and accommodative dysfunction, thereby suggesting its effectiveness as a new optional or additional treatment for young adults with these conditions.Trial registrationThis study was registered at the Chinese Clinical Trials Registry on 16/04/2019 (identifier: ChiCTR1900022556).

Prevalence of convergence insufficiency among Spanish school children aged 6 to 14 years

Clinical relevanceConvergence insufficiency (CI) at an early age can lead to learning difficulties affecting school performance. The aim of this study was to examine the prevalence of CI in a non-clinical population of Spanish children using well defined clinical criteria and to determine whether sex is a risk factor. MethodsVisual acuity and binocular vision tests were performed in 628 children aged 6–14 years (mean age 9.6 ± 1.3 years) at three schools in the Madrid Community, Spain. To assess CI prevalence we used CITT (Convergence Insufficiency Treatment Trial) criteria. The three signs considered were: i) exophoria at least 4∆ greater at near than at far; ii) near break point of convergence (NPC) ≥ 6 cm; and iii) reduced positive fusional vergence (PFV) at near (≤ 15∆ base-out break or failed Sheard's criterion). ResultsThe CI prevalence detected was 5.30% (33 children). Proportions of children with one or two signs of CI were 23.76% (148 children) and 12.20% (76 children), respectively. No differences in these CI rates by sex were detected. ConclusionThe clinically significant CI prevalence observed here suggests the need for more binocular vision screening programmes in school settings.

Effectiveness of Therapy for the Treatment of Accommodative Insufficiency: An Open Pilot Study

Background: To evaluate improvements in clinical measures and symptoms in children and young adults with accommodative insufficiency in an open trial of office-based vergence and accommodative therapy. Methods: Major eligibility requirements included ages 9 to 30 years and amplitude of accommodation (AA) ≥2 diopters (D) below Hoffstetter’s minimum. Participants completed 8 weekly, 1-hour sessions of office-based vergence and accommodative therapy. Therapy procedures followed the Convergence Insufficiency Treatment Trial (CITT) therapy protocol with emphasis on accommodative procedures. Clinical measures of accommodation and symptoms (Convergence Insufficiency Symptom Survey [CISS]) were assessed at baseline and after therapy. Results were evaluated using the Student’s t test and Kruskal-Wallis test. Repeatability of CISS scores at baseline was assessed using Bland Altman 95% Limits of Agreement (LoA) and Interclass Correlation Coefficient (ICC). Results: Eighteen participants (mean age 17.4 ± 8.0 years) were enrolled; sixteen completed the study. The mean AA improved significantly from 5.5D OD and OS at baseline to 12.4D OD and 12.8D OS at outcome (p&lt;0.001). Mean monocular accommodative facility (AF) also increased significantly in both eyes from 6.6 cycles per min (cpm) OD and 7.4cpm OS at baseline to 14.2cpm OD and OS at outcome (p≤0.0009). Amplitude-scaled monocular AF also showed significant improvements (p≤0.034 for both). Mean CISS score improved 10.50 points (p=0.0003). Significantly greater improvements in AA were observed in children (9.0D) than in adults (4.3D) in the right eye (p=0.007 for both comparisons). Conversely mean improvement in CISS score was significantly greater in adults than in children (p=0.039). Repeated CISS scores differed by, on average,1.47 points (95% limits of agreement:-5.19, 8.13; p=0.12). The ICC was 0.95 with a 95% confidence interval of 0.87 to 0.98. Conclusion: Eight weekly sessions of office-based accommodative vergence therapy combined with homebased- reinforcement therapy resulted in improvements of symptoms and clinical measures of accommodation in children and young adults with accommodative insufficiency.

Does coexisting accommodative dysfunction impact clinical convergence measures, symptoms and treatment success for symptomatic convergence insufficiency in children?

To determine whether coexisting accommodative dysfunction in children with symptomatic convergence insufficiency (CI) impacts presenting clinical convergence measures, symptoms and treatment success for CI. Secondary data analyses of monocular accommodative amplitude (AA; push-up method), monocular accommodative facility (AF; ±2.00D lens flippers) and symptoms (CI Symptom Survey [CISS]) in children with symptomatic CI from the Convergence Insufficiency Treatment Trial (N=218) and CITT-Attention and Reading Trial (N=302) were conducted. Decreased AA was defined as more than 2D below the minimum expected amplitude for age (15 - ¼ age); those with AA<5D were excluded. Decreased AF was defined as <6 cycles per minute. Mean near point of convergence (NPC), near positive fusional vergence (PFV) and symptoms (CISS) were compared between those with and without accommodative dysfunction using analysis of variance and independent samples t-testing. Logistic regression was used to compare the effect of baseline accommodative function on treatment success [defined using a composite of improvements in: (1) clinical convergence measures and symptoms (NPC, PFV and CISS scores) or (2) solely convergence measures (NPC and PFV)]. Accommodative dysfunction was common in children with symptomatic CI (55% had decreased AA; 34% had decreased AF). NPC was significantly worse in those with decreased AA (mean difference=6.1cm; p<0.001). Mean baseline CISS scores were slightly worse in children with coexisting accommodative dysfunction (decreased AA or AF) (30.2 points) than those with normal accommodation (26.9 points) (mean difference=3.3 points; p<0.001). Neither baseline accommodative function (p≥0.12 for all) nor interaction of baseline accommodative function and treatment (p≥0.50) were related to treatment success based on the two composite outcomes. A coexisting accommodative dysfunction in children with symptomatic CI is associated with worse NPC, but it does not impact the severity of symptoms in a clinically meaningful way. Concurrent accommodative dysfunction does not impact treatment response for CI.

Home- and Office-Based Vergence and Accommodative Therapies for Treatment of Convergence Insufficiency in Children and Young Adults: A Report by the American Academy of Ophthalmology

To review home- and office-based vergence and accommodative therapies for treatment of convergence insufficiency (CI) in children and young adults up to 35 years of age. Literature searches were conducted through October 2020 in the PubMed database for English-language studies. The combined searches yielded 359 abstracts, of which 37 were reviewed in full text. Twelve of these were considered appropriate for inclusion in this assessment and assigned a level of evidence rating by the panel methodologist. Of the 12 studies included in this assessment, 8 were graded as level I evidence, 2 were graded as level II evidence, and 2 were graded as level III evidence. Two of the level I studies included older teenagers and young adults; the remainder of the studies exclusively evaluated children. Two randomized controlled trials found that office-based vergence and accommodative therapies were effective in improving motor outcomes in children with symptomatic CI. However, the studies reported conflicting results on the efficacy of office-based therapy for treating symptoms of CI. Data were inconclusive regarding the effectiveness of home-based therapies (including pencil push-ups and home computer therapy) compared with home placebo. In young adults, office-based vergence and accommodative therapies were not superior to placebo in relieving symptoms of CI. Level I evidence suggests that office-based vergence and accommodative therapies improve motor outcomes in children with symptomatic CI, although data are inconsistent regarding symptomatic relief.Evidence is insufficient to determine whether home-based therapies are effective.

A Study Determining the Efficacy of Brock String Therapy in the Treatment of Convergence Insufficiency

A Study Determining the Efficacy of Brock String Therapy in the Treatment of Convergence Insufficiency

Effect of Vergence/Accommodative Therapy on Attention in Children with Convergence Insufficiency: A Randomized Clinical Trial.

The results of this study suggest that clinicians providing vergence/accommodative therapy for convergence insufficiency in children should not suggest that such treatment will lead to improvements in attention when compared with placebo treatment. This study aimed to compare the effects of 16 weeks of vergence/accommodative therapy and placebo therapy on changes in attention for children in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial. Three hundred ten children 9 to 14 years old with convergence insufficiency were assigned to receive treatment with office-based vergence/accommodative therapy or placebo therapy. Attention tests were administered at baseline and after 16 weeks of treatment. The primary measure of attention was the Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behavior (SWAN) scale. Other measures included the Swanson, Nolan, and Pelham checklist; the Homework Problems Checklist; and the d2 Test of Attention. Within and between-group differences are reported using Cohen d effect sizes. For the SWAN, there was no significant difference between the groups for the inattention scale parental report (d = 0.036; 95% confidence interval, -0.21 to 0.28) or for the hyperactivity impulsivity scale parental report (d = -0.003; 95% confidence interval, -0.24 to 0.24). Similar results were found for teacher reports and the secondary measures (d estimates from -0.97 to +0.10). There were, however, large within-group changes with d ≥ 1 in both treatment groups for the SWAN, the Homework Problems Checklist, and the d2 Test of Attention. These results suggest that vergence/accommodative therapy is no better than placebo therapy in improving attention. Large improvements in inattention, completing homework, and selective and sustained attention were found in each group. However, these improvements cannot be attributed to improvements in vergence and accommodation and are likely due to nonspecific effects of an intensive therapy regimen.

New Progress in the Study of Convergence Insufficiency

Convergency insufficiency is typical symptoms such as blurring of distant vision, reexamination of near vision, jumping words and walking while reading, visual fatigue and so on after reading or working closely for a period of time, According to the corresponding symptoms and signs, visual function tests were carried out, such as far and near eye position, accommodative response (BCC), positive relative accommodation (PRA), negative relative accommodation (NRA), near point of convergence (NPC), accommodation amplitude (AMP), etc., The detected visual function data were evaluated according to the normal value of Morgan and Sherad criteria. In daily life, people not only require clear vision, but also pay great attention to the comfort of using eyes, and the convergency insufficiency has become one of the important factors hindering the clarity, persistence and comfort of vision. Making binocular vision system to produce the cognition of regulation, convergence and eye movement through various methods such as optics, psychology and physics, vision therapy improves the application ability of eye vision system, and finally cures visual function problems such as visual fatigue, adjustment and convergence abnormality. We review the incidence, pathogenesis, new progress in the treatment of convergence insufficiency, the mechanism of visual formation and the basic principles of visual training.

Negative Fusional Vergence Is Abnormal in Children with Symptomatic Convergence Insufficiency.

Deficits of disparity divergence found with objective eye movement recordings may not be apparent with standard clinical measures of negative fusional vergence (NFV) in children with symptomatic convergence insufficiency. This study aimed to determine whether NFV is normal in untreated children with symptomatic convergence insufficiency and whether NFV improves after vergence/accommodative therapy. This secondary analysis of NFV measures before and after office-based vergence/accommodative therapy reports changes in (1) objective eye movement recording responses to 4° disparity divergence step stimuli from 12 children with symptomatic convergence insufficiency compared with 10 children with normal binocular vision (NBV) and (2) clinical NFV measures in 580 children successfully treated in three Convergence Insufficiency Treatment Trial studies. At baseline, the Convergence Insufficiency Treatment Trial cohort's mean NFV break (14.6 ± 4.8Δ) and recovery (10.6 ± 4.2Δ) values were significantly greater (P < .001) than normative values. The post-therapy mean improvements for blur, break, and recovery of 5.2, 7.2, and 1.3Δ, respectively, were statistically significant (P < .0001). Mean pre-therapy responses to 4° disparity divergence step stimuli were worse in the convergence insufficiency group compared with the NBV group for peak velocity (P < .001), time to peak velocity (P = .01), and response amplitude (P < .001). After therapy, the convergence insufficiency group showed statistically significant improvements in mean peak velocity (11.63°/s; 95% confidence interval [CI], 6.6 to 16.62°/s), time to peak velocity (-0.12 seconds; 95% CI, -0.19 to -0.05 seconds), and response amplitude (1.47°; 95% CI, 0.83 to 2.11°), with measures no longer statistically different from the NBV cohort (P > .05). Despite clinical NFV measurements that seem greater than normal, children with symptomatic convergence insufficiency may have deficient NFV when measured with objective eye movement recordings. Both objective and clinical measures of NFV can be improved with vergence/accommodative therapy.

Interventions for convergence insufficiency: a network meta-analysis.

Interventions for convergence insufficiency: a network meta-analysis.

Frequency of Convergence Insufficiency in a Refraction Clinic of Karachi

Purpose: To find out the frequency of convergence insufficiency in a refraction clinic of Karachi.&#x0D; Study Design: Cross Sectional Study.&#x0D; Place and Duration of Study: Al-Ibrahim Rye Hospital, Karachi from June to December 2019.&#x0D; Methods: A total of 150 patients were included in the study (52 males and 98 females). Patients with un-corrected visual acuity of ≥6/9 and age between 16 – 35 years were included. Patients who had received treatment for convergence insufficiency (CI), mentally retarded patients, patients with Manifest strabismus or any other ocular pathology were excluded. Near point of convergence (NPC), near phoria and positive fusional vergence (PFV) were measured for the diagnosis of CI.&#x0D; Results: Mean age of the patients was 23.55 years. Gender wise distribution showed that 52 (34.7%) were males and 98 (65.3%) were females. Out of 150 patients, 64 patients had CI and 42 were normal with no reduction in NPC, PFV or exophoria. Rest of the patients had only one of the three criteria of CI but did not qualify our definition of CI. Twenty-five male patients and 39 female patients had CI. CI was more common in teenagers. With increasing age, the frequency of CI was reduced. CI due to remote NPC was seen in 12 (8%) and CI due to decreased PFV was seen in 21 (14%).&#x0D; Conclusion: Females are affected more with CI than males especially in the younger age group.&#x0D; Keywords: Convergence insufficiency, near point of convergence, Positive fusional vergence.

Effectiveness of vergence/accommodative therapy for accommodative dysfunction in children with convergence insufficiency.

To determine the effectiveness of office-based vergence/accommodative therapy for improving accommodative amplitude and accommodative facility in children with symptomatic convergence insufficiency and accommodative dysfunction. We report changes in accommodative function following therapy among participants in the Convergence Insufficiency Treatment Trial - Attention and Reading Trial with decreased accommodative amplitude (115 participants in vergence/accommodative therapy; 65 in placebo therapy) or decreased accommodative facility (71 participants in vergence/accommodative therapy; 37 in placebo therapy) at baseline. The primary analysis compared mean change in amplitude and facility between the vergence/accommodative and placebo therapy groups using analyses of variance models after 4, 8, 12 and 16weeks of treatment. The proportions of participants with normal amplitude and facility at each time point were calculated. The average rate of change in amplitude and facility from baseline to week 4, and from weeks 4 to 16, were determined in the vergence/accommodative therapy group. From baseline to 16weeks, the mean improvement in amplitude was 8.6 dioptres (D) and 5.2D in the vergence/accommodative and placebo therapy groups, respectively (mean difference=3.5D, 95% confidence interval (CI): 1.5 to 5.5D; p=0.01). The mean improvement in facility was 13.5 cycles per minute (cpm) and 7.6cpm in the vergence/accommodative and placebo therapy groups, respectively (mean difference=5.8cpm, 95% CI: 3.8 to 7.9cpm; p<0.0001). Significantly greater proportions of participants treated with vergence/accommodative therapy achieved a normal amplitude (69% vs. 32%, difference=37%, 95% CI: 22 to 51%; p<0.0001) and facility (85% vs. 49%, difference=36%, 95% CI: 18 to 55%; p<0.0001) than those who received placebo therapy. In the vergence/accommodative therapy group, amplitude increased at an average rate of 1.5D per week during the first 4weeks (p<0.0001), then slowed to 0.2D per week (p=0.002) from weeks 4 to 16. Similarly, facility increased at an average rate of 1.5cpm per week during the first 4weeks (p<0.0001), then slowed to 0.6cpm per week from weeks 4 to 16 (p<0.0001). Office-based vergence/accommodative therapy is effective for improving accommodative function in children with symptomatic convergence insufficiency and coexisting accommodative dysfunction.

Effects Of Home-Based Convergence Insufficiency Vision Therapy On Accommodation Among School Going Children

Effects of home-based convergence insufficiency vision therapy on accommodation among school going children &#x0D; Wekesa Andrew1, Wanzala Maximilla1&#x0D; 1Masinde Muliro University of Science and Technology Kakamega, Kenya.&#x0D; &#x0D; Abstract &#x0D; Background: Convergence and accommodation are always yoked together and any adjustment on the former affects the later. The most effective treatment for convergence insufficiency (CI) is vision therapy.&#x0D; Aim/Purpose: To determine the effects of home-based vision therapy on accommodation in school-going with CI attending the Masinde Muliro University Academic Vision Center in Kenya.&#x0D; Methods: A clinical experimental design involving 23 participants with the mean age of 14±2.4 years, were recruited into the study, however, only 18 were assessed after the therapy. The study took 9 weeks thus majority lost contact while others moved out of the town. Home-based vision therapy which is undertaken at home using a pencil or broke strings. During the therapy, accommodative values were monitored which were; negative relative accommodation, positive relative accommodation, dynamic accommodation, accommodative facility and near point of accommodation. Paired t-test used to compare mean values before and after the therapy.&#x0D; Results: The mean value of negative relative accommodation (NRA) before (mention what the mean values were here) and after (mention what the mean values were here) home-based therapy was statistically significant (p=0.01). However, the mean values before and after home-based therapy for the near point of accommodation (NPA), dynamic (Lag), relativity (PRA) and facility (MAF) showed no difference (p&gt; 0.05). The mean value of the NRA before and after office-based vision therapy was statistically significant (p=0.01).&#x0D; Conclusion: The use of home-based vision therapy for the patients with CI had significant effects on accommodation changing from a lower limit to average after the therapy.&#x0D; &#x0D; Keywords: Convergence insufficiency, Accommodation, Home-based vision therapy.

Vergence Eye Movements: From Basic Science to Clinical Application - Foreword to the Special Issue.

The abstract book of the last European Conference on Eye Movements [1] lists abstracts of 373 presentations, but less than five percent investigate vergence eye movements, i.e. the coordination of the right and left eye. Why then a special issue on this neglected issue? Human vision under natural conditions involves both eyes in coordination controlled by interacting processes subsumed under the concept of vergence.. Further, vergence is important for people in their daily lives since disorders of vergence can have serious consequences: ophthalmologists deal with squinting patients on the basis of heterophoria and heterotropia testing, eye strain or visual complaints can be related to impaired vergence dynamic or less accurate static vergence, remediation by optometrist includes vergence training or prism eye glasses, etc.

Changes in the disparity vergence main sequence after treatment of symptomatic convergence insufficiency in children

This study investigates the underlying physiological mechanisms that may lead to improved outcomes for symptomatic convergence insufficiency (CI) patients after 12 weeks of office-based vergence/accommodation therapy (OBVAT) by evaluating the change in the main sequence of vergence and saccadic eye movements. In this prospective trial, 12 participants with symptomatic CI were recruited and treated with 12 weeks of OBVAT. Outcome measures included the objective assessment of the following: peak velocity, time to peak velocity, latency, response amplitude, and clinical changes in the near point of convergence (NPC), positive fusional vergence (PFV) and symptoms via the Convergence Insufficiency Symptom Survey (CISS). Ten of the twelve participants (83%) were categorized as “successful” and two were “improved” based on pre-determined published criteria (CISS, NPC, PFV). There were statistically significant changes in peak velocity, time to peak velocity, and response amplitude for both 4° and 6° symmetrical convergence and divergence eye movements. There was a significant change in the main sequence ratio for convergence post-OBVAT compared to baseline measurements (P=0.007) but not for divergence or saccadic responses. Phasic/step vergence movements adjust the underlying neural control of convergence and are critical within a vision therapy program for CI patients.