Effects of vision therapy on near exodeviation in children with convergence insufficiency treated during the convergence insufficiency treatment trials

PURPOSE

To report the change in the magnitude of near exodeviation in children with symptomatic convergence insufficiency successfully treated with office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial.

METHODS

A total of 131 children 9-14 years of age with symptomatic convergence insufficiency classified as successfully treated with office-based vergence/accommodative therapy at the 16-week outcome visit were included. Masked examiners measured the near ocular deviation by the prism and alternate cover test at baseline, primary outcome and 1-year post-treatment. The mean change in near deviation was calculated from baseline to primary outcome, from primary outcome to 1-year post-treatment and from baseline to 1-year post-treatment.

RESULTS

Of the 131 participants successfully treated with vergence/accommodative therapy, 120 completed the 1-year post-treatment visit. A significant change in near exodeviation was observed at baseline to primary outcome (2.6Δ less exo, p < 0.001, moderate effect size d = 0.61) and at baseline to 1-year post-treatment (2.0Δ less exo; p < 0.001, small effect size d = 0.45). The change from primary outcome to 1-year post-treatment (0.6Δ more exo; p = 0.06, small effect size d = 0.11) was not significant. Forty per cent (48/120) of participants had a decrease in near exodeviation >3.5∆ (expected test/retest variability) between baseline and the primary outcome examination. Of the 120 participants, one (1.0%) was esophoric at the primary outcome and was subsequently exophoric at 1-year post-treatment. Four participants (3.3%) who were orthophoric or exophoric at the primary outcome were esophoric (all ≤3∆) at the 1-year post-treatment visit.

CONCLUSION

On average, the near exodeviation was smaller in size immediately after the discontinuation of vergence/accommodative therapy (2.6∆, moderate effect size) and 1 year post vergence/accommodative therapy (2.0∆, small effect size) in children with convergence insufficiency who were successfully treated; 40% had a clinically meaningful decrease in exophoria. The development of near esophoria was rare.

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

PURPOSE

To evaluate the time course of improvements in clinical convergence measures for children with symptomatic convergence insufficiency treated with office-based vergence/accommodative therapy.

METHODS

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 (<6 cm), PFV blur (break if no blur; >15Δ and >2 times the exodeviation) and convergence composite (NPC and PFV both normal) were calculated.

RESULTS

The greatest change in NPC and PFV (7.6 cm and 12.7 Δ) and the fastest rate of improvement in NPC and PFV (1.9 cm/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.

CONCLUSION

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.

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

PURPOSE

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.

METHODS

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 16 weeks 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.

RESULTS

From baseline to 16 weeks, the mean improvement in amplitude was 8.6 dioptres (D) and 5.2 D in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 3.5 D, 95% confidence interval (CI): 1.5 to 5.5 D; p = 0.01). The mean improvement in facility was 13.5 cycles per minute (cpm) and 7.6 cpm in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 5.8 cpm, 95% CI: 3.8 to 7.9 cpm; 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 1.5 D per week during the first 4 weeks (p < 0.0001), then slowed to 0.2 D per week (p = 0.002) from weeks 4 to 16. Similarly, facility increased at an average rate of 1.5 cpm per week during the first 4 weeks (p < 0.0001), then slowed to 0.6 cpm per week from weeks 4 to 16 (p < 0.0001).

CONCLUSION

Office-based vergence/accommodative therapy is effective for improving accommodative function in children with symptomatic convergence insufficiency and coexisting accommodative dysfunction.

Relief of asthenopic symptoms with orthoptic exercises in convergence insufficiency is achieved in both adults and children

Background

Asthenopic symptoms associated with convergence insufficiency (CI) may compromise a person's ability to work or study. We investigated the effectiveness of orthoptic exercises in relieving symptoms related to CI and long-time results in adults and children.

Methods

The data were retrospectively gathered from the patient clinical files. A total of 135 patients met the inclusion criteria of suffering asthenopic symptoms and CI but had not received prior strabismus surgery or orthoptic exercises.

Results

The mean age was 26 ± 17 years, 74% of them were female. The patients (N = 135) suffered from CI and had at least one of the following symptoms: eyestrain, blurring of vision, problems in reading and while doing work-up at close distance or headache. In the two-year follow-up time, 4% of the patients needed to be retreated and 3% of the patients required strabismus surgery. There were no significant differences between adults and children in near point of convergence (NPC), number of visits needed or fusional vergence at the end of treatment nor did the outcome depend on the number of visits. 59.5% of children vs. 51.9% of adults were free of symptoms when completing the exercises.

Conclusions

In conclusion orthoptic exercises are effective in relieving asthenopic symptoms in adults and children. The effects of orthoptic exercises on NPC and fusional vergence were equal in adults and in children and not dependent on the number of visits needed for successful outcome. With orthoptic exercises it is possible to achieve longstanding relief on the symptoms of CI.

Convergence Insufficiency Treatment Trial Study Group. Randomized clinical trial of treatments for symptomatic convergence insufficiency in children

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

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.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00338611.

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Key Words

• convergence insufficiency
• asthenopia
• vision therapy
• orthoptics
• vergence/accommodative therapy
• pencil push-ups
• computer vergence/accommodative therapy
• placebo therapy
• exophoria
• eyestrain
• symptom survey

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MESH Headings

• Adolescent
• Child
• Confidence Intervals
• Convergence, Ocular
• Female
• Home Nursing
• Humans
• Male
• Multivariate Analysis
• Ocular Motility Disorders/diagnosis
• Ocular Motility Disorders/therapy
• Office Visits
• Ophthalmology/methods
• Orthoptics/methods
• Patient Compliance
• Probability
• Recovery of Function
• Reference Values
• Sensitivity and Specificity
• Severity of Illness Index
• Strabismus/diagnosis
• Strabismus/therapy
• Treatment Outcome
• Vision, Binocular
• Visual Acuity

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Grants

• U10 EY014712 NEI NIH HHS
• U10 EY014676-02 NEI NIH HHS
• U10 EY014712-04 NEI NIH HHS
• U10 EY014659-03 NEI NIH HHS
• U10 EY014676-01A1 NEI NIH HHS
• U10 EY014713-01A2 NEI NIH HHS
• U10 EY014713-02 NEI NIH HHS
• U10 EY014715-01A1S1 NEI NIH HHS
• U10 EY014716-04 NEI NIH HHS
• U10 EY014710-04 NEI NIH HHS
• U10 EY014676 NEI NIH HHS
• U10 EY014706-01A1S1 NEI NIH HHS
• U10 EY014713 NEI NIH HHS
• U10 EY014709 NEI NIH HHS
• U10 EY014659-01A2 NEI NIH HHS
• U10 EY014715-04 NEI NIH HHS
• U10 EY014712-01A1 NEI NIH HHS
• U10 EY014713-03 NEI NIH HHS
• U10 EY014706-01A1 NEI NIH HHS
• U10 EY014715-02 NEI NIH HHS
• U10 EY014709-03 NEI NIH HHS
• U10 EY014715-03 NEI NIH HHS
• U10 EY014676-04 NEI NIH HHS
• U10 EY014715 NEI NIH HHS
• U10 EY014716-03 NEI NIH HHS
• U10 EY014710-02 NEI NIH HHS
• U10 EY014709-04 NEI NIH HHS
• U10 EY014716-02 NEI NIH HHS
• U10 EY014716-02S1 NEI NIH HHS
• U10 EY014706-02 NEI NIH HHS
• U10 EY014713-04 NEI NIH HHS
• U10 EY014709-02 NEI NIH HHS
• U10 EY014712-03 NEI NIH HHS
• U10 EY014706-04 NEI NIH HHS
• U10 EY014710-01A1S1 NEI NIH HHS
• U10 EY014710-01A1 NEI NIH HHS
• U10 EY014659-04 NEI NIH HHS
• U10 EY014676-03 NEI NIH HHS
• U10 EY014712-01A1S1 NEI NIH HHS
• U10 EY014659-02 NEI NIH HHS
• U10 EY014676-01A1S1 NEI NIH HHS
• U10 EY014716-01A1 NEI NIH HHS
• U10 EY014709-01A1 NEI NIH HHS
• U10 EY014706-03 NEI NIH HHS
• U10 EY014716-01A1S1 NEI NIH HHS
• U10 EY014716 NEI NIH HHS
• U10 EY014715-01A1 NEI NIH HHS
• U10 EY014709-01A1S1 NEI NIH HHS
• U10 EY014712-02 NEI NIH HHS
• U10 EY014710-03 NEI NIH HHS
• U10 EY014659 NEI NIH HHS

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Affiliation(s) Collapse