Frequency of convergence insufficiency among fifth and sixth graders. The Convergence Insufficiency and Reading Study (CIRS) group

Diagnostic validity of clinical signs associated with a large exophoria at near

Purpose. To analyze the diagnostic validity of accommodative and binocular tests in a sample of patients with a large near exophoria with moderate to severe symptoms. Methods. Two groups of patients between 19 and 35 years were recruited from a university clinic: 33 subjects with large exophoria at near vision and moderate or high visual discomfort and 33 patients with normal heterophoria and low visual discomfort. Visual discomfort was defined using the Conlon survey. A refractive exam and an exhaustive evaluation of accommodation and vergence were assessed. Diagnostic validity by means of receiver operator characteristic (ROC) curves, sensitivity (S), specificity (Sp), and positive and negative likelihood ratios (LR+, LR-) were assessed. This analysis was also carried out considering multiple tests as serial testing strategy. Results. ROC analysis showed the best diagnostic accuracy for receded near point of convergence (NPC) recovery (area = 0.929) and binocular accommodative facility (BAF) (area = 0.886). Using the cut-offs obtained with ROC analysis, the best diagnostic validity was obtained for the combination of NPC recovery and BAF (S  =  0.77, Sp = 1, LR+ = value tending to infinity, LR- = 0.23) and the combination of NPC break and recovery with BAF (S  =  0.73, Sp = 1, LR+ = tending to infinity, LR- = 0.27). Conclusions. NPC and BAF tests were the tests with the best diagnostic accuracy for subjects with large near exophoria and moderate to severe symptoms.

Concurrent vision dysfunctions in convergence insufficiency with traumatic brain injury

PURPOSE

This study assessed the prevalence of convergence insufficiency (CI) with and without simultaneous vision dysfunctions within the traumatic brain injury (TBI) sample population because although CI is commonly reported with TBI, the prevalence of concurrent visual dysfunctions with CI in TBI is unknown.

METHODS

A retrospective analysis of 557 medical records from TBI civilian patients was conducted. Patients were all evaluated by a single optometrist. Visual acuity, oculomotor function, binocular vision function, accommodation, visual fields, ocular health, and vestibular function were assessed. Statistical comparisons between the CI and non-CI, as well as inpatient and outpatient subgroups, were conducted using χ and Z tests.

RESULTS

Approximately 9% of the TBI sample had CI without the following simultaneous diagnoses: saccade or pursuit dysfunction; third, fourth, or sixth cranial nerve palsy; visual field deficit; visual spatial inattention/neglect; vestibular dysfunction; or nystagmus. Photophobia with CI was observed in 16.3% (21 of 130), and vestibular dysfunction with CI was observed in 18.5% (24 of 130) of the CI subgroup. Convergence insufficiency and cranial nerve palsies were common and yielded prevalence rates of 23.3% (130 of 557) and 26.9% (150 of 557), respectively, within the TBI sample. Accommodative dysfunction was common within the nonpresbyopic TBI sample, with a prevalence of 24.4% (76 of 314). Visual field deficits or unilateral visual spatial inattention/neglect was observed within 29.6% (80 of 270) of the TBI inpatient subgroup and was significantly more prevalent compared with that of the outpatient subgroup (p < 0.001). Most TBI patients had visual acuities of 20/60 or better in the TBI sample (85%; 473 of 557).

CONCLUSIONS

Convergence insufficiency without simultaneous visual or vestibular dysfunctions was observed in about 9% of the visually symptomatic TBI civilian population studied. A thorough visual and vestibular examination is recommended for all TBI patients.

Binocular vision in glaucoma

OBJECTIVE

To describe the possible impairment of binocular vision in primary open angle glaucoma (POAG) patients.

METHOD

A cross-sectional study was conducted on 58 glaucoma patients, 76 ocular hypertensives and 82 normal subjects. They were examined with a battery of binocular tests consisting of the measurement of phoria angles, amplitudes of fusion (AF), near point of convergence (NPC) assessment, an evaluation of suppression (Worth test), stereoacuity according to Titmus, and TNO tests.

RESULTS

The patients with glaucoma showed significantly increased phoria angles, especially in near vision, compared with the ocular hypertensives and controls (P=.000). AF were reduced mainly in near distances compared to hypertensives and controls (P=.000). The NPC of glaucoma was higher than the other two groups (P=.000). No differences were found in the near-distance suppression test between the three groups (P=.682), but there were differences in the distance vision of patients with glaucoma compared to hypertensives (OR=3.867, 95% CI; 1.260-11.862; P=.008) and controls (OR= 5.831, 95% CI; 2.229-15.252; P=.000). The stereoacuity of patients with glaucoma was reduced in both tests (P=.001).

CONCLUSIONS

POAG is mostly associated with, an increased exophoria in near vision, a decreased AF in near vision, a far-distance NPC, central suppression in far-vision, and a loss of stereoacuity. These changes do not seem to appear early as they were not observed in hypertensive patients versus controls.

Symptoms in children with convergence insufficiency: before and after treatment

PURPOSE

To investigate symptom patterns and evaluate the relationship between patient characteristics and symptom severity before and after treatment for symptomatic children with convergence insufficiency (CI).

METHODS

In a randomized clinical trial, the convergence insufficiency symptom survey was administered pre- and posttreatment to 221 children aged 9 to <18 years with symptomatic CI. Frequency of symptom type was determined at baseline, mean change in performance-related vs. eye-related symptoms for treatment responders was compared, and the relationship between patient characteristics and symptom severity at baseline for the entire cohort and after treatment for those who responded to treatment was determined.

RESULTS

At baseline, the score for performance-related symptoms was greater than that for eye-related symptoms (mean response of 2.3 vs. 1.8, p < 0.001) regardless of age, sex, race/ethnicity, or presence of parent-reported Attention Deficit Hyperactivity Disorder (ADHD). Symptom severity increased with age for both the overall and eye-related subscale scores (p = 0.048, p = 0.022, respectively). Children with parent-reported ADHD were more symptomatic (p = 0.005) than those without parent-reported ADHD because of a higher performance-related score (p < 0.001). A significant and equal improvement (p < 0.01) for the performance- and eye-related symptoms was found in treatment responders. Girls had significantly lower performance-related symptoms than boys (p = 0.014), and black children reported less eye-related symptoms than white children (p = 0.022). Children without parent-reported ADHD had significantly less symptoms overall and less eye-related symptoms than children with parent-reported ADHD (p = 0.019, p = 0.011, respectively).

CONCLUSIONS

Because of a high frequency of both performance- and eye-related symptoms, clinicians should perform a targeted history that addresses both types of symptoms to help identify children with symptomatic CI. Future study regarding the relationship of CI and symptoms and their potential influence on ADHD, reading performance, and attention is warranted.

Vision therapy and computer orthoptics: evidence-based approach to use in your practice

Convergence insufficiency is a commonly seen disorder of the vergence system. Its clinical characteristics and symptoms have been well described by Duane and von Graefe. Laboratory studies have clarified the vergence pathway, which includes a bi-phasic response. Several recent randomized controlled trials show the effectiveness of common treatment modalities, including pencil pushups, computer orthoptics, and office-based therapy. More studies are needed to investigate the possibility that other treatments may treat convergence insufficiency in a more profound way by acting on other parts of the vergence system.

A comparison of self-reported and measured autostereogram skills with clinical indicators of vergence and accommodative function

Failure to perceive the disparity-defined form in autostereograms by those with clinically normal stereoacuity can occur when achieving or maintaining the precise vergence angle required to place the intended left and right images on corresponding areas of the two retinas is difficult. Since vergence and accommodation must be maintained at different depth planes to permit sensory fusion of an autostereogram, poor autostereogram skill has been suggested by different investigators to be related either to the presence of a binocular vision anomaly (ie a poorly tuned binocular system) or to a binocular system that is well-coordinated. The purpose of this study was to clarify the relationship between binocular visual performance and autostereogram skill.

Effects of wearing yellow spectacles on visual skills, reading speed, and visual symptoms in children with reading difficulties

BACKGROUND

Possible beneficial effects of yellow-tinted spectacle lenses on binocular vision, accommodation, oculomotor scanning, reading speed and visual symptoms were assessed in children with reading difficulties.

METHODS

A longitudinal prospective study was performed in 82 non-dyslexic children with reading difficulties in grades 3-6 (aged 9-11 years) from 11 elementary schools in Madrid (Spain). The children were randomly assigned to two groups: a treatment (n = 46) and a without-treatment group (n = 36). Children in the treatment group wore yellow spectacle lenses with best correction if necessary over 3 months (in school and at home). The tests were first undertaken without the yellow filter. With best spectacle correction in each subject, measurements were made of: distance and near horizontal heterophoria, distance and near horizontal fusional vergence ranges, the accommodative convergence/accommodation (AC/A) ratio, near point of convergence (NPC), stereoacuity, negative relative accommodation (NRA) and positive relative accommodation (PRA), monocular accommodative amplitude (MAA), binocular accommodative facility (BAF), oculomotor scanning, and reading speed (words per minute). The Convergence Insufficiency Symptom Survey (CISS) questionnaire was completed by all children. After the 3-month period, measurements were repeated with the yellow lenses (treatment group) or without the yellow lenses (without-treatment group) but with refractive correction if needed.

RESULTS

Over the 3 months, the two groups showed similar mean changes in the variables used to assess binocular vision, accommodation, oculomotor scanning, and reading speed. However, mean relative changes in convergence insufficiency symptoms differed significantly between the groups (p = 0.01).

CONCLUSION

No effects of wearing yellow spectacles emerged on binocular vision, accommodation, oculomotor scanning, and reading speed in children with reading difficulties. The yellow filter had no effect even in children with low MAA and BAF. The reduction in visual symptoms observed in children with reading difficulties using the yellow filters was clinically insignificant.

Improvement in academic behaviors after successful treatment of convergence insufficiency

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.

Saccades and vergence performance in a population of children with vertigo and clinically assessed abnormal vergence capabilities

Purpose

Early studies reported some abnormalities in saccade and vergence eye movements in children with vertigo and vergence deficiencies. The purpose of this study was to further examine saccade and vergence performance in a population of 44 children (mean age: 12.3±1.6 years) with vertigo symptoms and with different levels of vergence abnormalities, as assessed by static orthoptic examination (near point of convergence, prism bar and cover-uncover test).

Methods

Three groups were identified on the basis of the orthoptic tests: group 1 (n = 13) with vergence spasms and mildly perturbed orthoptic scores, group 2 (n = 14) with moderately perturbed orthoptic scores, and group 3 (n = 17) with severely perturbed orthoptic scores. Data were compared to those recorded from 28 healthy children of similar ages. Latency, accuracy and peak velocity of saccades and vergence movements were measured in two different conditions: gap (fixation offset 200 ms prior to target onset) and simultaneous paradigms. Binocular horizontal movements were recorded by a photoelectric device.

Results

Group 2 of children with vergence abnormalities showed significantly longer latency than normal children in several types of eye movements recorded. For all three groups of children with vergence abnormalities, the gain was poor, particularly for vergence movement. The peak velocity values did not differ between the different groups of children examined.

Interpretation

Eye movement measures together with static orthoptic evaluation allowed us to better identify children with vergence abnormalities based on their slow initiation of eye movements. Overall, these findings support the hypothesis of a central deficit in the programming and triggering of saccades and vergence in these children.

Effectiveness of vision therapy for convergence dysfunctions and long-term stability after vision therapy

BACKGROUND

Symptomatic convergence insufficiency (CI) is a common binocular dysfunction. It is often associated with accommodative insufficiency (AI). Optimum therapy for this condition was recently shown to be in-clinic vision therapy (VT). More scientific studies are needed to assess the effectiveness of VT and verify these evidence-based results.

METHODS

Fifty-seven children aged 9-13 years were diagnosed with symptomatic CI (n = 27) or combined symptomatic CI and AI (n = 30). They were independently divided into a treatment and a control group, matched by age and gender. The treatment group received 12 weeks of VT while the control group received no therapy. A quality of life instrument documented the symptomatic patients and charted improvement in symptoms after therapy. Clinical aspects were also assessed to determine the treatment effects on clinical findings. Twenty children in the treatment group completed a 1 year follow-up examination.

RESULTS

Symptom scores and clinical measures of the treatment and control groups were not significantly different at baseline (p > 0.05), but showed significant differences after completion of 12 weeks of treatment (p < 0.001). No significant changes of either symptoms or signs were evident for the control group. One year follow-up examination revealed that most children maintained the improved symptom and clinical measures after VT.

CONCLUSION

This study supports the notion that VT is a successful method of treating CI and CI combined with AI.

Treatment of symptomatic convergence insufficiency with a home-based computer orthoptic exercise program

PURPOSE

To determine the efficacy of a home-based computer orthoptic program to treat symptomatic convergence insufficiency.

METHODS

A retrospective review of consecutive patients with symptomatic convergence insufficiency treated with a home-based computer orthoptic program was performed. Symptomatic convergence insufficiency was defined as: near point of convergence (NPC) >6 cm, decreased positive fusional vergence, exophoria at near at least 4(Δ) greater than at far, and documented complaints of asthenopia, diplopia, or headaches with reading or near work. The Computer Orthoptics CVS program was used for this study. Before beginning the computer orthoptic program, patients with an NPC >50 cm were given 4 base-in prisms and push-up exercises (NPC exercises with an accommodative target) for 2 weeks.

RESULTS

A total of 42 patients were included. Mean treatment duration was 12.6 weeks; mean follow-up, 8.5 months. Of the 42 patients, 35 were treated with the home-based computer orthoptic program and push-up exercises; the remaining 7 only used the computer orthoptic program. Because of a remote NPC, 5 patients were given base-in Fresnel prism before starting treatment. Baseline mean NPC was 24.2 cm; posttreatment mean NPC improved to 5.6 cm: 39 patients (92.8%) achieved an NPC of ≤6 cm (p < 0.001). Positive fusional vergence improved in 39 patients (92.8%). Fourteen patients reduced their near exophoria by ≥5(Δ). A total of 27 patients (64.2%) reported resolution of symptoms after treatment.

CONCLUSIONS

In our study, home-based computer orthoptic exercises reduced symptoms and improved NPC and fusional amplitudes. The computer orthoptic program is an effective option for treating symptomatic convergence insufficiency.

Vision therapy in adults with convergence insufficiency: clinical and functional magnetic resonance imaging measures

PURPOSE

This research quantified clinical measurements and functional neural changes associated with vision therapy in subjects with convergence insufficiency (CI).

METHODS

Convergence and divergence 4° step responses were compared between 13 control adult subjects with normal binocular vision and four CI adult subjects. All CI subjects participated in 18 h of vision therapy. Clinical parameters quantified throughout the therapy included: nearpoint of convergence, recovery point of convergence, positive fusional vergence at near, near dissociated phoria, and eye movements that were quantified using peak velocity. Neural correlates of the CI subjects were quantified with functional magnetic resonance imaging scans comparing random vs. predictable vergence movements using a block design before and after vision therapy. Images were quantified by measuring the spatial extent of activation and the average correlation within five regions of interests (ROI). The ROIs were the dorsolateral prefrontal cortex, a portion of the frontal lobe, part of the parietal lobe, the cerebellum, and the brain stem. All measurements were repeated 4 months to 1 year post-therapy in three of the CI subjects.

RESULTS

Convergence average peak velocities to step stimuli were significantly slower (p = 0.016) in CI subjects compared with controls; however, significant differences in average peak velocities were not observed for divergence step responses (p = 0.30). The investigation of CI subjects participating in vision therapy showed that the nearpoint of convergence, recovery point of convergence, and near dissociated phoria significantly decreased. Furthermore, the positive fusional vergence, average peak velocity from 4° convergence steps, and the amount of functional activity within the frontal areas, cerebellum, and brain stem significantly increased. Several clinical and cortical parameters were significantly correlated.

CONCLUSIONS

Convergence peak velocity was significantly slower in CI subjects compared with controls, which may result in asthenopic complaints reported by the CI subjects. Vision therapy was associated with and may have evoked clinical and cortical activity changes.

Non-surgical interventions for convergence insufficiency

BACKGROUND

Convergence insufficiency is a common eye muscle co-ordination problem in which the eyes have a strong tendency to drift outward (exophoria) when reading or doing close work. Symptoms may include eye strain, headaches, double vision, print moving on the page, frequent loss of place when reading, inability to concentrate, and short attention span.

OBJECTIVES

To systematically assess and synthesize evidence from randomized controlled trials (RCTs) on the effectiveness of non-surgical interventions for convergence insufficiency.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov ) on 7 October 2010. We manually searched reference lists and optometric journals.

SELECTION CRITERIA

We included RCTs examining any form of non-surgical intervention against placebo, no treatment, sham treatment, or each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility, risk of bias, and extracted data. We performed meta-analyses when appropriate.

MAIN RESULTS

We included six trials (three in children, three in adults) with a total of 475 participants. We graded four trials at low risk of bias.Evidence from one trial (graded at low risk of bias) suggests that base-in prism reading glasses was no more effective than placebo reading glasses in improving clinical signs or symptoms in children.Evidence from one trial (graded at high risk of bias) suggests that base-in prism glasses using a progressive addition lens design was more effective than progressive addition lens alone in decreasing symptoms in adults. At three weeks of therapy, the mean difference in Convergence Insufficiency Symptoms Survey (CISS) score was -10.24 points (95% confidence interval (CI) -15.45 to -5.03).Evidence from two trials (graded at low risk of bias) suggests that outpatient (or office-based as used in the US) vision therapy/orthoptics was more effective than home-based convergence exercises (or pencil push-ups as used in the US) in children. At 12 weeks of therapy, the mean difference in change in near point of convergence, positive fusional vergence, and CISS score from baseline was 3.99 cm (95% CI 2.11 to 5.86), 13.13 diopters (95% CI 9.91 to 16.35), and 9.86 points (95% CI 6.70 to 13.02), respectively.In a young adult population, evidence from one trial (graded at low risk of bias) suggests outpatient vision therapy/orthoptics was more effective than home-based convergence exercises in improving positive fusional vergence at near (7.7 diopters, 95% CI 0.82 to 14.58), but not the other outcomes.Evidence from one trial (graded at low risk of bias) comparing four interventions, also suggests that outpatient vision therapy/orthoptics was more effective than home-based computer vision therapy/orthoptics in children. At 12 weeks, the mean difference in change in near point of convergence, positive fusional vergence, and CISS score from baseline was 2.90 cm (95% CI 0.96 to 4.84), 7.70 diopters (95% CI 3.94 to 11.46), and 8.80 points (95% CI 5.26 to 12.34), respectively. Evidence was less consistent for other pair-wise comparisons.

AUTHORS' CONCLUSIONS

Current research suggests that outpatient vision therapy/orthoptics is more effective than home-based convergence exercises or home-based computer vision therapy/orthoptics for children. In adult population, evidence of the effectiveness of various non-surgical interventions is less consistent.

Do we really know the prevalence of accomodative and nonstrabismic binocular dysfunctions?

Purpose

To determine the scientific evidence about the prevalence of accommodative and nonstrabismic binocular anomalies.

Methods

We carried out a systematic review of studies published between 1986 and 2009, analysing the MEDLINE, CINAHL, FRANCIS and PsycINFO databases. We considered admitting those papers related to prevalence in paediatric and adult populations. We identified 660 articles and 10 papers met the inclusion criteria.

Results

There is a wide range of prevalence, particularly for accommodative insufficiency (2–61,7 %) and convergence insufficiency (2.25–33 %). More studies are available for children (7) compared with adults (3). Most of studies examine clinical population (5 studies) with 3 assessed at schools and 1 at University with samples that vary from 65 to 2048 patients. There is great variability regarding the number of diagnostic signs ranging from 1 to 5 clinical signs. We found a relation between the number of clinical signs used and prevalence values for convergence insufficiency although this relationship cannot be confirmed for other conditions.

Conclusion

There is a lack of proper epidemiological studies about the prevalence of accommodative and nonstrabismic binocular anomalies. Studies reviewed examine consecutive or selected patients in clinical settings and schools but in any case they are randomized and representative of their populations with no data for general population. The wide discrepancies in prevalence figures are due to both sample population and the lack of uniformity in diagnostic criteria so that it makes difficult to compile results. Biases and limitations of reports determine that prevalence rates offered are only estimations from selected populations.

Treatment of accommodative and nonstrabismic binocular dysfunctions: a systematic review

BACKGROUND

The aim of this study was to analyze the scientific evidence available on the nonsurgical treatment of accommodative and nonstrabismic binocular dysfunctions, identifying the types of treatment used and their efficacy.

METHODS

A systematic review of reports published from 1986 to 2007 was completed using several health science databases: FRANCIS, Medline, Cinahl, and PsycINFO. Those papers that analyzed the treatment of accommodative and nonstrabismic binocular anomalies were included.

RESULTS

Of the 565 articles identified, 16 met the inclusion criteria. Only 3 were clinical trials. All analyzed treatment of convergence insufficiency. Results of clinical trials support the conclusion that vision therapy improves symptoms and signs for convergence insufficiency. Further, the evidence indicates that pencil push-up treatment is not as effective as vision therapy and that prism glasses are no more effective than placebo glasses. For the other nonstrabismic binocular conditions and accommodative disorders, there is a lack of published randomized, clinical trials that support the evidence for the efficacy of each treatment.

CONCLUSION

Scientific evidence exists for the efficacy of vision therapy for convergence insufficiency. Insufficient scientific evidence exists on the best therapeutic options for treatment of the other nonstrabismic binocular anomalies and accommodative disorders.

Binocular function in school children with reading difficulties

INTRODUCTION

Prior findings suggest that poor readers tend to have poor binocular vision skills, but data on the binocular abilities of children with poor reading skills are lacking. Our aim was to characterize distance and near horizontal heterophoria, distance and near horizontal fusional vergence ranges, accommodative convergence/accommodation (AC/A) ratio, near point of convergence, and stereopsis in poor-reading school-age children without dyslexia selected from a non-clinical population.

METHODS

We conducted a cross-sectional study on 87 poor readers and 32 control children (all 8-13 years of age) in grades three to six recruited from eleven elementary schools in Madrid, Spain. With best spectacle correction in each subject, distance and near horizontal heterophoria measurements were obtained using the von Graefe technique, distance and near horizontal fusional vergence ranges were obtained using Risley rotary prisms, the AC/A ratio was measured using the gradient method, near point of convergence (NPC) was evaluated by the standard push-up technique using a transilluminator, and stereoacuity was tested with the Randot stereotest.

RESULTS

Mean distance base-in break and base-in recovery values were nearly 2 Delta lower (p < 0.01) in the poor readers than those recorded in the control group. However, mean distance base-out vergences (blur, break and recovery), mean distance and near horizontal heterophoria, mean near horizontal fusional vergence ranges, mean AC/A ratio, mean near point of convergence (NPC), and mean stereoacuity did not differ significantly between the poor readers and controls.

CONCLUSIONS

This study provides information on the binocular ability of children with poor reading skills but without dyslexia. Our findings suggest reduced distance base-in break and base-in recovery, such that distance fusional vergence ranges should always be assessed in children who complain of reading difficulties.

Academic behaviors in children with convergence insufficiency with and without parent-reported ADHD

PURPOSE

To determine if children with symptomatic Convergence Insufficiency without the presence of parent-reported Attention Deficit Hyperactivity Disorder (ADHD) have higher scores on the academic behavior survey (ABS).

METHODS

The 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- to 17-year old (mean age 11.8 years.) with symptomatic convergence insufficiency before 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 convergence insufficiency group into the convergence insufficiency with parent report of ADHD or convergence insufficiency with parent report of no ADHD groups.

RESULTS

Sixteen percent of the convergence insufficiency 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 convergence insufficiency with parent report of ADHD group (15.6) was significantly higher than the symptomatic convergence insufficiency with parent report of no ADHD group (11.7, p = 0.001) and the NBV group (8.7, p < 0.0001). Children with convergence insufficiency with parent report of no ADHD scored significantly higher on the ABS than the NBV group (p = 0.036).

CONCLUSIONS

Children with symptomatic convergence insufficiency 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 convergence insufficiency.

Treatment of convergence insufficiency in childhood: a current perspective

PURPOSE

To provide a current perspective on the management of convergence insufficiency (CI) in children by summarizing the findings and discussing the clinical implications from three recent randomized clinical trials in which we evaluated various treatments for children with symptomatic CI. We then present an evidence-based treatment approach for symptomatic CI based on the results of these trials. Finally, we discuss unanswered questions and suggest directions for future research in this area.

METHODS

We reviewed three multi-center randomized clinical trials comparing treatments for symptomatic (CI) in children 9 to 17 years old (one study 9 to 18 years old). Two trials evaluated active therapies for CI. These trials compared the effectiveness of office-based vergence/accommodative therapy, office-based placebo therapy, and home-based therapy [pencil push-ups alone (both trials), home-based computer vergence/accommodative therapy, and pencil push-ups (large-scale study)]. One trial compared the effectiveness of base-in prism reading glasses to placebo reading glasses. All studies included well-defined criteria for the diagnosis of CI, a placebo group, and masked examiners. The primary outcome measure was the Convergence Insufficiency Symptom Survey score. Secondary outcomes were near point of convergence and positive fusional vergence at near.

RESULTS

Office-based vergence/accommodative therapy was significantly more effective than home-based or placebo therapies. Base-in prism reading glasses were no more effective than placebo reading glasses for the treatment of symptomatic CI in children.

CONCLUSIONS

Recent clinical trials showed that office-based vision therapy was successful in about 75% of patients (resulting in normal or significantly improved symptoms and signs) and was the only treatment studied which was more effective than placebo treatments for children with symptomatic CI. Eye care providers who do not currently offer this treatment may consider referring these patients to a doctor who provides this treatment or consider expanding the treatment options available within their practice to manage this condition.

Nearpoint phorias after nearwork predict ADHD symptoms in college students

PURPOSE

Phorometric findings have been observed to change with stress. We test the hypothesis that postnearwork phorias predict symptoms that have been theorized to result from nearwork-induced visual stress.

METHODS

We measured nearpoint and farpoint dissociated phorias in 37 unselected college students with an alternate cover test both before and after a challenging reading comprehension test. We also assessed a broad range of putative attention deficit hyperactivity disorder (ADHD)-related symptoms with the Nadeau College-level ADHD Questionnaire.

RESULTS

For phorias measured at nearpoint after nearwork, greater deviation from the median phoria (three exophoria) predicted higher symptoms (rho (35) = 0.52, p < 0.001), whether that deviation was in a convergent or a divergent direction (both rho's (18) = >0.48, p's < 0.04). An analogous result was obtained for "distance-near" stimulus accommodative convergence to accommodation (AC/A) ratios calculated from phorias, where greater deviation from median postnearwork AC/A ratio predicted higher symptoms (rho (35) = 0.52, p < 0.0001). Symptoms did not correlate with prenearwork phorias, prenearwork AC/A ratios, or postnearwork farpoint phorias (p's > 0.05).

CONCLUSIONS

Phorias postnearwork, but not prenearwork, predicted self-reported ADHD-related symptoms in college students. These results link binocular imbalance immediately after sustained nearwork to symptoms theorized to result from nearwork-induced visual stress.

Are Orthoptic Exercises an Effective Treatment for Convergence and Fusion Deficiencies?

PURPOSE

To investigate whether orthoptic exercises are an effective way to influence the near point of convergence, fusion range and asthenopic symptoms.

METHODS

Seventy-eight patients met the inclusion criteria of visual acuity 6/9 or better, no history of orthoptic treatment, squint surgery or Meares Irlen syndrome/dyslexia. Information was collected from case records related to diagnosis, near point of convergence, fusion range, prism and cover test measurements and symptoms. Type, duration and frequency of exercises were also recorded. Non-parametric statistics were applied.

RESULTS

Patients ranged in age from 5 to 73 years (mean 11.9). Females outnumbered males (46:32). The diagnoses were: decompensating heterophoria (n = 50) or convergence insufficiency (n = 28: primary 27; secondary 1). Exophoria was more common (n = 65), than esophoria (n = 11) or orthophoria (n = 1). Treatments were aimed at improving near point of convergence and/or reduced fusional reserves. The mean treatment period was 8.2 months. Reduced near point of convergence normalized following treatment in 47/55 cases, and mean near point of convergence improved from 16.6 to 8.4 cm (p = 0.0001). Fusional reserves normalized in 29/50. Fusional convergence improved significantly for those with exodeviation (p > 0.0006). Asthenopic symptoms improved in 65 patients. A reduction in deviation of 5 pd or more occurred in 20 patients.

CONCLUSIONS

Orthoptic exercises are an effective means of reducing symptoms in patients with convergence insufficiency and decompensating exophoria, and appear to target the proximal and fusional components of convergence. Their role in esophoria is unclear and needs further study.

Validity of the convergence insufficiency symptom survey: a confirmatory study

PURPOSE

The objectives of the present study were to evaluate whether investigator bias influenced the Convergence Insufficiency Symptom Survey (CISS) scores of children with normal binocular vision (NBV) in our original validation study, reevaluate the usefulness of the cutoff score of 16, and reexamine the validity of the CISS.

METHODS

Six clinical sites participating in the Convergence Insufficiency Treatment Trial (CITT) enrolled 46 children 9 to <18 years with NBV. Examiners masked to the child's binocular vision status administered the CISS. The mean CISS score was compared with that from the children with NBV in the original, unmasked CISS study and also to that of the 221 symptomatic convergence insufficiency (CI) children enrolled in the CITT.

RESULTS

The mean (+/-standard deviation) CISS score for 46 subjects with NBV was 10.4 (+/-8.1). This was comparable with our prior unmasked NBV study (mean = 8.1 (+/-6.2); p = 0.11) but was significantly different from that of the CITT CI group (mean = 29.8 +/- 9.0; p < 0.001). Eighty-three percent of these NBV subjects scored <16 on the CISS, which is not statistically different from the 87.5% found in the original unmasked study (p = 0.49).

CONCLUSIONS

Examiner bias did not affect the CISS scores for subjects with NBV in our prior study. The CISS continues to be a valid instrument for quantifying symptoms in 9 to <18-year-old children. These results also confirm the validity of a cut-point of > or = 16 in distinguishing children with symptomatic CI from those with NBV.

Effectiveness of placebo therapy for maintaining masking in a clinical trial of vergence/accommodative therapy

PURPOSE

To evaluate the effectiveness of the Convergence Insufficiency Treatment Trial (CITT) placebo therapy program in maintaining masking of patients randomized to the office-based treatment arms, determine whether demographic variables affect masking, and determine whether perception of assigned treatment group was associated with treatment outcome or adherence to treatment.

METHODS

Patients (n = 221, ages, 9-17 years) were randomized to one of four treatment groups, two of which were office-based and masked to treatment (n = 114). The placebo therapy program was designed to appear to be real vergence/accommodative therapy, without stimulating vergence, accommodation, or fine saccades (beyond levels of daily visual activities). After treatment, patients in the office-based groups were asked whether they thought they had received real or placebo therapy and how confident they were in their answers.

RESULTS

Ninety-three percent of patients assigned to real therapy and 85% assigned to placebo therapy thought they were in the real therapy group (P = 0.17). No significant differences were found between the two groups in adherence to the therapy (P >or= 0.22 for all comparisons). The percentage of patients who thought they were assigned to real therapy did not differ by age, sex, race, or ethnicity (P > 0.30 for all comparisons). No association was found between patients' perception of group assignment and symptoms or signs at outcome (P >or= 0.38 for all comparisons).

CONCLUSIONS

The CITT placebo therapy program was effective in maintaining patient masking in this study and therefore may have potential for use in future clinical trials using vergence/accommodative therapy. Masking was not affected by demographic variables. Perception of group assignment was not related to symptoms or signs at outcome (ClinicalTrials.gov number, NCT00338611).

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

Gender differences in early accommodation and vergence development

A remote haploscopic photorefractor was used to assess objective binocular vergence and accommodation responses in 157 full-term healthy infants aged 1-6 months while fixating a brightly coloured target moving between fixation distances at 2, 1, 0.5 and 0.33 m. Vergence and accommodation response gain matured rapidly from 'flat' neonatal responses at an intercept of approximately 2 dioptres (D) for accommodation and 2.5 metre angles(MA) for vergence, reaching adult-like values at 4 months. Vergence gain was marginally higher in females (p = 0.064), but accommodation gain (p = 0.034) was higher and accommodative intercept closer to zero (p = 0.004) in males in the first 3 months as they relaxed accommodation more appropriately for distant targets. More females showed flat accommodation responses (p = 0.029). More males behaved hypermetropically in the first two months of life, but when these hypermetropic infants were excluded from the analysis, the gender difference remained. Gender differences disappeared after three months. Data showed variable responses and infants could behave appropriately and simultaneously on both, neither or only one measure at all ages. If accommodation was appropriate (gain between 0.7 and 1.3; r(2) > 0.7) but vergence was not, males over- and under-converged equally, while the females who accommodated appropriately were more likely to overconverge (p = 0.008). The apparent earlier maturity of the male accommodative responses may be due to refractive error differences but could also reflect gender-specific male preference for blur cues while females show earlier preference for disparity, which may underpin the earlier emerging, disparity dependent, stereopsis and full vergence found in females in other studies.

Refractive errors and binocular dysfunctions in a population of university students

PURPOSE

This clinical study was performed to determine the presence of refractive errors and binocular dysfunctions in a population of university students.

METHODS

Refraction and binocular function were evaluated in a young patient population (230 students and 234 nonstudent subjects, aged 18-27 years). Distance visual acuity (DVA) and near visual acuity (NVA), refraction, cover test (CT), ocular motility, near-point of convergence, horizontal phoria measurement by Maddox wing, negative and positive vergence amplitude in prism diopters, fusion amplitude in synoptophore, as well as stereoacuity (Titmus test) were tested.

RESULTS

Emmetropia was the most frequent refractive status in our student and nonstudent groups (78.7%). Myopia was the most frequent refractive disorder in the whole population (13.1%). Myopia and hypermetropia were significantly more frequent in the students than in nonstudents (chi-square emp 47.55). Exophoria is significantly more frequent in myopic subjects. Vergence amplitude (t test 0.000) and fusion amplitude (t test 0.005) show significantly lower values in student population. Results of Titmus test in the student group is significantly worse than in the nonstudent group (t test 0.000). Maddox wing resulted in significantly higher degree of heterophoria in the student population (t test 0.000). Myopic subjects, in the student group (t test 0.002) as well as in the nonstudent group (t test 0.001), show significantly better results in Titmus test.

CONCLUSIONS

High near visual demand could be the most important factor for higher incidence of myopia, worse convergence and fusion amplitude, higher degree of exophoria, and worse results in Titmus test in the student population.

The convergence insufficiency treatment trial: design, methods, and baseline data

OBJECTIVE

This report describes the design and methodology of the Convergence Insufficiency Treatment Trial (CITT), the first large-scale, placebo-controlled, randomized clinical trial evaluating treatments for convergence insufficiency (CI) in children. We also report the clinical and demographic characteristics of patients.

METHODS

We prospectively randomized children 9 to 17 years of age to one of four treatment groups: 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, 4) office-based placebo therapy. Outcome data on the Convergence Insufficiency Symptom Survey (CISS) score (primary outcome), near point of convergence (NPC), and positive fusional vergence were collected after 12 weeks of active treatment and again at 6 and 12 months posttreatment.

RESULTS

The CITT enrolled 221 children with symptomatic CI with a mean age of 12.0 years (SD = +2.3). The clinical profile of the cohort at baseline was 9Delta exophoria at near (+/- 4.4) and 2Delta exophoria (+/-2.8) at distance, CISS score = 30 (+/-9.0), NPC = 14 cm (+/- 7.5), and near positive fusional vergence break = 13 Delta (+/- 4.6). There were no statistically significant nor clinically relevant differences between treatment groups with respect to baseline characteristics (p > 0.05).

CONCLUSION

Hallmark features of the study design include formal definitions of conditions and outcomes, standardized diagnostic and treatment protocols, a placebo treatment arm, masked outcome examinations, and the CISS score outcome measure. The baseline data reported herein define the clinical profile of those enrolled into the CITT.

Measuring Visual Discomfort in College Students

PURPOSE

The purpose of this study was to measure the distribution visual discomfort symptoms in a group of college students using a survey developed by Conlon et al. and to analyze the type and frequency of symptoms in the subjects who display moderate to high amounts of visual discomfort to ascertain if this condition occurs along a single dimension or consists of different subtypes.

METHODS

Members of the research team administered a survey of visual discomfort developed by Conlon et al. (Conlon et al., Vis Cogn 1999;6:637-666) to 571 college students at the Claremont Colleges University over a 2-year period. The survey for measuring visual discomfort developed by Conlon consists of 23 items with a four-point scale (0 to 3) (see below). Scores on the survey can range from 0 to 69.

RESULTS

A Rasch analysis of the survey results showed that a single symptom dimension accounted for 73.5% of the variance. A principle component analysis of the residual variance from the Rasch analysis yielded three factors: factor 1 was associated with text movement and fading; factor 2 was associated with headache and soreness; and factor 3 was associated primarily with blur and diplopia.

CONCLUSIONS

The survey developed by Conlon is an appropriate measure of visual discomfort. In addition to the single dimension reported by Conlon, we found that some subjects with moderate to high amounts of visual discomfort tended to report particular types of symptoms. These results suggest that there may be multiple etiologies of visual discomfort.

Near Point of Convergence Norms Measured in Elementary School Children

PURPOSE

Convergence insufficiency (CI) is the most prevalent of binocular dysfunctions. A prime finding in the diagnosis of CI is the near point of convergence (NPC).

METHODS

The NPC was measured six different times on the same 539 children, once in the fall and once in the spring, over the course of 3 years. At each evaluation, the NPC was performed three consecutive times. An accommodative target was used in the testing and the breaks and recoveries were carefully measured and recorded to the nearest centimeter. Normative data for the break and recovery finding were calculated.

RESULTS

We found that the NPC measures receded significantly over three consecutive tests. The recession was not considered clinically significant for either the break or recovery measures. When various break and recovery findings were compared with reported symptoms, it was discovered that one of the break findings statistically predicted the symptomatic group from the asymptomatic group.

CONCLUSIONS

The NPC break and recovery does not change appreciably with multiple administrations of the test in the same test period. The criteria for a NPC break score to differentiate the more symptomatic and less symptomatic, elementary school children on the average should be 5 cm, or less. The NPC break and recovery criteria described here should be tentatively used as one of the benchmarks in the diagnosis of convergence insufficiency.

Binocular coordination of saccades in children with vertigo: dependency on the vergence state

The present study examines the quality of binocular coordination of saccades at far and near distance in 15 children with symptoms of vertigo headache and equilibrium disorders; these children show normal vestibular function but abnormal convergence eye movements (e.g., long time preparation, slow execution and poor accuracy, see ). The results show normal binocular saccade coordination at far distance, but large abnormal disconjugacy for saccades at near distance. During combined saccade-vergence movements (studied in six of these children), convergence remains abnormally slow. This supports the interpretation according to which poor binocular yoking of the saccades is linked to the reduced ability to produce fast convergence during the saccade; a learning mechanism based on rapid vergence would help to reduce the abducting-adducting asymmetry of the saccades. An alternative interpretation would be reduced learning ability for monocular adjustment of the saccade signals.

Accommodative Insufficiency Is the Primary Source of Symptoms in Children Diagnosed With Convergence Insufficiency

PURPOSE

Accommodative insufficiency (AI) and convergence insufficiency (CI) have been associated with similar symptomology and frequently present at the same time. The severity of symptomology in CI has been linked to the severity of the CI, suggesting a dose-dependent relationship. However, with increasing severity of CI also comes increased comorbidity of AI. AI alone has been shown to cause significant symptomology. We hypothesize that AI drives the symptoms in CI with a comorbid AI condition (CIwAI) and that it is the increased coincidence of AI, rather than increased severity of CI, which causes additional symptomology.

METHODS

Elementary school children (n = 299) participated in a vision screening that included tests for CI and AI and the CISS-V15 symptom survey. They were categorized into four groups:1) normal binocular vision (NBV); 2) AI-only; 3) CI-only; and 4) CIwAI. One hundred seventy elementary school children fell into the categories of interest.

RESULTS

Pairwise comparison of the group means on the symptom survey showed: 1) children with AI-only (mean = 19.7, p = 0.006) and children with CIwAI (mean = 22.8, p = 0.001) had significantly higher symptom scores than children with NBV (mean = 10.3); and 2) children with CI-only (mean = 12.9, p = 0.54) had a similar symptom score to children with NBV. Using a two-factor analysis of variance (AI and CI), the AI effect was significant (AI mean = 21.56; no AI mean = 11.56, p < 0.001), whereas neither the CI effect (p = 0.16) nor the CI by AI interaction effect (p = 0.66) were significant.

CONCLUSION

CI is a separate and unique clinical condition and can occur without a comorbid AI condition, our CI-only group. Past reports of high symptom scores for children with CI are the result of the presence of AI, a common comorbid condition. When AI is factored out, and children with CI only are evaluated, they are not significantly more symptomatic than children with NBV.

The relationship between convergence insufficiency and ADHD

BACKGROUND

Children being evaluated for attention deficit hyperactivity disorder (ADHD) often have an eye exam as part of their evaluation. The symptoms of convergence insufficiency (CI) can make it difficult for a student to concentrate on extended reading and overlap with those of ADHD.

METHODS

A retrospective review of 266 patients with CI presenting to an academic pediatric ophthalmology practice was performed. All patients included were diagnosed with CI by one author (DBG) and evaluated for the diagnosis of ADHD. A computerized review was also performed looking at the converse incidence of CI in patients carrying the diagnosis of ADHD.

RESULTS

We reviewed 266 charts of patients with CI. Twenty-six patients (9.8%) were diagnosed with ADHD at some time in their clinical course. Of the patients with ADHD and CI, 20 (76.9%) were on medication for ADHD at the time of diagnosis for CI while 6 (23.1%) were either not on medication or the medication was discontinued several months before the diagnosis of CI. The review of computer records showed a 15.9% incidence of CI in the ADHD population.

CONCLUSION

We report an apparent three-fold greater incidence of ADHD among patients with CI when compared with the incidence of ADHD in the general US population (1.8-3.3%). We also note a seeming three-fold greater incidence of CI in the ADHD population. This may simply represent an association and not be a causative relationship. Until further studies are performed, however, patients diagnosed with ADHD should be evaluated to identify the small subset that may have CI -- a condition that responds well to treatment at home.

Measuring ADHD behaviors in children with symptomatic accommodative dysfunction or convergence insufficiency: a preliminary study

BACKGROUND

Accommodative dysfunction and convergence insufficiency (CI) are common pediatric vision problems that have been associated with an increase in frequency and severity of vision-specific symptoms that affect children when doing schoolwork. However, the relationship between accommodative dysfunction and CI and other learning problems, such as attention deficit hyperactivity disorder (ADHD), are not well understood. The purpose of this study was to evaluate the frequency of ADHD behaviors in school-aged children with symptomatic accommodative dysfunction or CI.

METHODS

Children 8 to 15 years of age with symptomatic accommodative dysfunction or CI were recruited from the teaching clinic at the Southern California College of Optometry. Children with learning disabilities or ADHD were excluded. One parent of each child completed the Conners Parent Rating Scale-Revised Short Form (CPRS-R:S). The children's scores on the CPRS-R:S were compared with the normative sample.

RESULTS

Twenty-four children (9 boys and 15 girls) participated in the study with a mean age of 10.93 years (SD = 1.75). On the CPRS-R:S, cognitive problem/inattention, hyperactivity, and ADHD index were significantly different from normative values (p < or = .001 for all tests).

CONCLUSIONS

The results from this preliminary study suggest that school-aged children with symptomatic accommodative dysfunction or CI have a higher frequency of behaviors related to school performance and attention as measured by the CPRS-R:S.

Horizontal and vertical prism adaptation are different mechanisms

As part of a study on subjects with convergence insufficiency (CI), their vertical and horizontal vergence adaptation was assessed and compared with age matched controls in order to investigate whether the horizontal adaptation system can be regarded as being independent of the vertical adaptation system. Using a flashed Maddox rod technique horizontal vergence adaptation was found to be reduced in CI subjects whereas no difference could be found in vertical adaptation. These results confirm that the vertical and horizontal adaptation systems can be treated as independent mechanisms.

Distance vergence adaptation is abnormal in subjects with convergence insufficiency

It is well known that in convergence insufficiency (CI) prism adaptation is reduced in response to base-out (BO) prisms at near. There have also been some suggestions in the literature that adaptation is reduced at other distances as well. The present data show that in CI adaptation is not only reduced in response to BO at near, but also in response to base-in (BI) at near and for both BI and BO at distance. This raises the interesting question whether distance adaptation becomes reduced because of reduced near adaptation or whether these subjects have a generally reduced horizontal adaptation mechanism.

Validity and Reliability of the Revised Convergence Insufficiency Symptom Survey in Children Aged 9 to 18 Years

PURPOSE

To assess the validity and reliability of the Convergence Insufficiency Symptom Survey (CISS) in children aged 9 to 18 years. The CISS is the primary outcome measure for a pilot study evaluating two different treatments for convergence insufficiency (CI).

METHODS

Children with CI were given the CISS twice to assess reliability. CISS scores for the first administration were also compared with scores from children with normal binocular vision to assess the validity of the CISS.

RESULTS

Forty-seven children with CI and 56 children with normal binocular vision participated in the study. Reliability was assessed using intraclass correlation and 95% limits of agreement for the children with CI. For children with CI, the intraclass correlation was 0.77 (95% confidence interval, 0.613 to 0.873), and the 95% limits of agreement were -10.2 to +12.1. The mean (+/-SD) CISS score was 30.8 +/- 8.4 for the children with CI and 8.4 +/- 6.4 for the children with normal binocular vision. These means were significantly different (p < 0.0001). Good discrimination (sensitivity, 96%; specificity, 88%) was obtained using a score of >/=16.

CONCLUSIONS

Children with CI showed a significantly higher CISS symptom score than children with normal binocular vision. The results of the study indicate that the CISS is a valid and reliable instrument to use as an outcome measure for children aged 9 to 18 who are enrolled in clinical research concerning CI.

A tolerability study of pirenzepine ophthalmic gel in myopic children

PURPOSE

The objective of this study was to determine the safety and tolerability of pirenzepine ophthalmic gel (PIR) and the magnitude of mydriatic and accommodative effects in myopic children.

METHODS

This was a placebo-controlled, parallel double-masked study of unequal (4:1) randomization. Children were randomized to receive 0.5% PIR, b.i.d., or vehicle (placebo) for one week, then titrated to 1% PIR for one week, then 2% PIR for two weeks, and then for an additional 11 months. Enrolled were 26 normal healthy children, 9-12 years old, with myopia (-0.75 to -3 D) and minimal astigmatism (< or =1 D, O.U.).

RESULTS

Three of the 26 subjects (all in PIR group) did not complete one year of the study: one child at day 8 who inadvertently received 2.0% PIR as the first concentration, due to accommodative insufficiency, one child for follicular conjunctivitis at 9 months, and one child for administrative reasons at month 1. Other than the child discontinued at day 8, all patients were titrated up to the highest concentration of PIR evaluated. When measured 1 hour after instillation of PIR 0.5%, there was a mean mydriatic effect of less than 1 mm compared to vehicle in either bright or dim light. With increasing concentrations of PIR, this effect became numerically larger, although still remained less than 1 mm in either bright or dim light. Measured approximately 12 hours after instillation, there was little mydriasis within each group (relative to baseline) or between treatments. Similar mild PIR effects were seen on accommodative amplitude. In general, the adverse events reported were mild or moderate in severity, resolved rapidly, and were of the nature and incidence to be expected in a study of a topical anti-muscarinic gel in children of this age.

CONCLUSION

The promising efficacy results and acceptable safety profile justifies proceeding with additional clinical trials to evaluate efficacy and further characterize the safety of pirenzepine in a larger patient population.

Diagnostic signs of accommodative insufficiency

PURPOSE

To determine which are the most sensitive tests, together with accommodative amplitude, to classify accommodative insufficiency (Al), we analyzed the relation between monocular estimated method (MEM) dynamic retinoscopy, monocular and binocular accommodative facility (MAF, BAF), and positive relative accommodation (PRA) with or without the presence of reduced amplitude of accommodation.

METHODS

We studied 328 symptomatic patients who presented consecutively to an optometric clinic. From this sample, we selected the 41 patients who presented amplitude of accommodation at least 2 D below the minimum age-appropriate amplitude according to Hofstetter's formula: 15 - 0.25 x age. We also selected data from 40 consecutive subjects (control group) with no general binocular disorders and normal accommodative amplitudes. We studied the specificity and sensitivity of the four signs related with the accommodative insufficiency: high MEM dynamic retinoscopy, failing MAF and BAF with minus lenses of +/- 2 D flipper lenses, and low PRA.

RESULTS

Using the standard deviation as the cutoff, the specificity values were MEM = 0.88, MAF = 1, BAF = 0.93, and PRA = 1. When using the mean value as the cutoff, the specificity diminished, fundamentally for MEM. The sensitivity for the 41 patients using standard deviation as the cutoff was MEM = 0.44, MAF = 0.34, BAF = 0.27, and PRA = 0.27, and when using the mean value as the cutoff the four, sensitivity values increased.

CONCLUSIONS

According to the sensitivity results, with both cutoffs used, failing the +/- 2 D MAF test seems to be the sign that is most associated with the accommodative insufficiency.

Reliability of binocular vision measurements used in the classification of convergence insufficiency

PURPOSE

To evaluate the reliability of binocular vision measurements used in the classification of convergence insufficiency.

METHODS

Two examiners tested 20 fifth and sixth graders in a school setting who passed a screening of visual acuity, refraction, and binocularity. The tests, conducted using a standard protocol, consisted of von Graefe near heterophoria (NH), phorometric positive fusional vergence (PFV), nearpoint of convergence (NPC), and monocular pushup accommodative amplitude (AA). Each examiner measured each child three consecutive times for each test, on two separate occasions, spaced approximately 1 week apart. Intraexaminer and interexaminer agreement was assessed using intraclass correlation coefficients (ICC), the median absolute difference (MAD), and the coefficient of repeatability (COR).

RESULTS

The within-session reliability of the NH (ICC: 0.95 to 0.99), NPC (ICC: 0.94 to 0.98), and AA (ICC: 0.88 to 0.95) were good, whereas the PFV was less reliable (ICC: 0.71 to 0.94). The intraexaminer reliability between sessions was good for the NPC (ICC: 0.92 and 0.89), less reliable for NH (ICC: 0.81 and 0.81) and AA (ICC: 0.89 and 0.69), and much less reliable for PFV break (ICC: 0.59 and 0.53). Typical between-session PFV differences (MAD) were between 3 and 4 delta, whereas the COR differences were as large as 12 delta.

CONCLUSIONS

Three of the four measures (NH, NPC, and AA) often used in the classification of convergence insufficiency generally have good within-session and between-session reliability. The PFV break was found to have only fair reliability with clinically significant differences between sessions. The large potential test-retest differences found could complicate clinical decision-making in regards to diagnosis and treatment.

The effectiveness of pencil pushups treatment for convergence insufficiency: a pilot study

PURPOSE

To study the effectiveness of pencil pushups treatment (PPT) for the treatment of convergence insufficiency in a clinical situation.

METHODS

PPT was prescribed for use at home for 6 weeks for 25 subjects with convergence insufficiency.

RESULTS

Twelve of the subjects returned for follow-up. Seven of 12 (58%) subjects showed a clinically significant improvement in nearpoint of convergence and positive fusional vergence, and 11 of 12 reported improvement in symptoms. Only one subject became asymptomatic.

CONCLUSIONS

PPT resulted in some improvement in both objective findings and symptoms for some subjects. Compliance with the recommended home therapy protocol was poor.

A survey of treatment modalities for convergence insufficiency

BACKGROUND

Convergence insufficiency (CI) is a common and distinct binocular vision disorder. However, there is a lack of consensus regarding the treatment most appropriate for Cl. Possible treatment modalities include base-in prism, pencil pushup therapy (PPT), reading glasses, home-based vision therapy/orthoptics (HBVT), and office-based vision therapy/orthoptics (OBVT). The purpose of this study was to investigate the care process for Cl by surveying eyecare professionals regarding the most common treatment modalities used by both optometrists and ophthalmologists across the United States.

METHODS

Surveys requesting doctors to indicate which treatment(s) they prescribed and believed to be most effective for symptomatic CI patients were mailed to 863 optometrists and 863 ophthalmologists in the United States.

RESULTS

Fifty-eight percent of the optometrists responded to the survey; the most common treatment prescribed was PPT (36%) followed by HBVT (22%) and OBVT (16%). For the ophthalmologists (who had a 23% response rate), the most common treatment prescribed was PPT (50%) followed by HBVT (21 %) and base-in prism (10%).

CONCLUSIONS

This survey suggests that most eyecare practitioners prescribe PPT as the initial treatment for CI.