Near work symptoms and measures of accommodation in children.

CLINICAL RELEVANCE: Some children experience significant symptoms while doing near work, and accommodative deficits can be a contributory factor. However, studies investigating near work symptoms in children are sparse. BACKGROUND: To investigate the association between clinical and objective measures of accommodation and near point symptoms. METHODS: Twelve asymptomatic and 14 symptomatic children (mean age = 11.1 and 11.8 years, respectively) based on their Convergence Insufficiency Symptom Survey scores participated in the study. The clinical measures of accommodation were monocular amplitude of accommodation, monocular accommodative facility, and monocular estimation method. Objective measurements of the accommodative stimulus response function were recorded with a WAM-5500 autorefractor for two consecutive minutes at five viewing distances (0.33, 2, 3, 4, and 5 Dioptres [D]). Accommodative findings were compared between the groups using the Mann-Whitney U-tests. Spearman's rank correlation coefficient was used to assess the association between symptoms and clinical and objective measures of accommodation. RESULTS: The mean CISS scores were 32.8 and 7.3 for the symptomatic and asymptomatic groups, respectively (p = <0.001). The symptomatic group showed a reduced accommodative functions compared to the asymptomatic group (p = 0.002 for accommodative facility, p = 0.04 for accommodative amplitude, p = 0.029 and 0.01 for objective measures of accommodation at 4D and 5D viewing distance, respectively). Clinical tests of accommodative amplitude and facility (correlation coefficient = -0.407 and -0.54, respectively) showed the highest correlation with the CISS scores, compared to the objective measures of accommodation. CONCLUSION: Clinical tests of accommodation showed a greater association with symptoms than objective measures of accommodation in children aged 8-16 years. In children presenting with visual discomfort symptoms, measurement of accommodative amplitude and facility should be considered.

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

PURPOSE: To determine whether coexisting accommodative dysfunction in children with symptomatic convergence insufficiency (CI) impacts presenting clinical convergence measures, symptoms and treatment success for CI. METHODS: Secondary data analyses of monocular accommodative amplitude (AA; push-up method), monocular accommodative facility (AF; ±2.00 D 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 - » age); those with AA < 5 D 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)]. RESULTS: 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 = 6.1 cm; 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. CONCLUSIONS: 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.

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.

Effect of treatment of symptomatic convergence insufficiency on reading in children: a pilot study.

BACKGROUND: To evaluate the impact of treatment of symptomatic convergence insufficiency using office-based vergence/accommodative therapy on reading skills in children. METHODS: Children (n = 44) ages nine to 17 years with symptomatic convergence insufficiency were administered the following four reading tests: Wechsler Individual Achievement Test II; Test of Word Reading Efficiency; Test of Silent Word Reading Fluency; and the Gray Oral Reading Test, at baseline and eight weeks after completion of a 16-week program of office-based vergence/accommodative therapy. To determine whether significant change occurred with therapy, change in performance was compared to zero. Treatment response was determined using a composite score of symptoms and signs at the conclusion of treatment and at the 24-week outcome visit. Participants were classified as early responders, late responders, or non-responders based upon whether criteria for successful treatment were met at the completion of 16 weeks of treatment, at the 24-week outcome visit, or not met at either visit, respectively. RESULTS: After treatment for convergence insufficiency, statistically significant improvements were found for reading comprehension (mean = 4.2, p = 0.009) and the reading composite score (mean = 2.4, p = 0.016) as measured by the Wechsler Individual Achievement Test at the 24-week visit. These improvements were related to the clinical treatment outcome measures (p = 0.011) with the largest improvements occurring in those who were early responders to treatment. Reading speed (words per minute) increased significantly on the Gray Oral Reading Test (p < 0.0001). No significant improvements were observed for single word reading or reading fluency as measured by the Test of Word Reading Efficiency, the Test of Silent Word Reading Fluency or the Gray Oral Reading Test. CONCLUSION: Improvements in reading comprehension and reading composite were found after office-based vergence/accommodative therapy, with the greatest improvements in those who responded early to treatment.

Tonic accommodation predicts closed-loop accommodation responses.

The purpose of this study is to examine the potential relationship between tonic accommodation (TA), near work induced TA-adaptation and the steady state closed-loop accommodation response (AR). Forty-two graduate students participated in the study. Various aspects of their accommodation system were objectively measured using an open-field infrared auto-refractor (Grand Seiko WAM-5500). Tonic accommodation was assessed in a completely dark environment. The association between TA and closed-loop AR was assessed using linear regression correlations and t-test comparisons. Initial mean baseline TA was 1.84diopter (D) (SD±1.29D) with a wide distribution range (-0.43D to 5.14D). For monocular visual tasks, baseline TA was significantly correlated with the closed-loop AR. The slope of the best fit line indicated that closed-loop AR varied by approximately 0.3D for every 1D change in TA. This ratio was consistent across a variety of viewing distances and different near work tasks, including both static targets and continuous reading. Binocular reading conditions weakened the correlation between baseline TA and AR, although results remained statistically significant. The 10min near reading task with a 3D demand did not reveal significant near work induced TA-adaptation for either monocular or binocular conditions. Consistently, the TA-adaptation did not show any correlation with AR during reading. This study found a strong association between open-loop TA and closed-loop AR across a variety of viewing distances and different near work tasks. Difference between the correlations under monocular and binocular reading condition suggests a potential role for vergence compensation during binocular closed-loop AR.

Behavioral and Emotional Problems Associated With Convergence Insufficiency in Children: An Open Trial.

OBJECTIVE: This study investigated behavioral and emotional characteristics of children with convergence insufficiency (CI), before and after treatment with office-based vergence accommodative therapy (OBVAT). METHOD: Parents of 44 children ages 9 to 17 years with symptomatic CI completed the Conners 3 ADHD Index and the Child Behavior Checklist (CBCL) before and after OBVAT. Pre-treatment scores were compared with normative data and post-treatment scores were compared with baseline using the Wilcoxon sign rank test. RESULTS: Following OBVAT, CI children showed a significant mean improvement (p < .0001, effect size of 0.58) on the Conners 3 ADHD Index with the largest changes occurring in the 23 children who scored the highest at baseline. On the CBCL, anxious/depressed, somatic, and internalizing problems improved significantly (p < .001, effect sizes of -0.36, -1.15, and -0.67, respectively). CONCLUSION: In an open trial, attention and internalizing problems improved significantly following treatment for CI.

Validity of the decoding-encoding screener for dyslexia.

PURPOSE: The Decoding-Encoding Screener for Dyslexia (DESD) was developed to identify children who may have reading difficulties. The purpose of this study was to evaluate the validity of the DESD using two standardized tests of reading ability in school-aged children. METHODS: Thirty-one children aged 9 to 15 years enrolled in the study. Each child completed the DESD and two standardized reading assessments, the Wide Range Achievement Test-Third Edition (WRAT-3) and the Gray Oral Reading Test-Fourth Edition (GORT-4). Pearson correlations were used to compare the DESD Reading Test with the WRAT-3 and GORT-4, and Spearman correlation coefficients were used to measure the associations between the DESD Spelling Scale and the WRAT-3 and GORT-4. RESULTS: Pearson correlation coefficients between the DESD Reading Test standard score and WRAT-3 Spelling subtest and GORT-4 were large, with the exception of the WRAT-3 Word Reading subtest, which had a small correlation. Spearman rank correlations between the DESD Spelling score and the GORT-4 and WRAT-3 Spelling subtest were large to very large, but only a moderate correlation was found with the WRAT-3 Word Reading subtest. CONCLUSIONS: The DESD Reading Test and Spelling Scale had significant correlations with the WRAT-3 Spelling subtest and GORT-4. However, the small correlation between the DESD Reading Test and the WRAT-3 Word Reading subtest indicates that some caution should be used when interpreting the results of the DESD Reading Test. Therefore, practitioners may find the DESD Spelling Scale to be a more useful tool in identifying children who may have reading difficulties.

Convergence Insufficiency Treatment Trial - Attention and Reading Trial (CITT-ART): Design and Methods.

OBJECTIVE: To describe the design and methodology of the Convergence Insufficiency Treatment Trial: Attention and Reading Trial (CITT-ART), the first randomized clinical trial evaluating the effect of vision therapy on reading and attention in school-age children with symptomatic convergence insufficiency (CI). METHODS: CITT-ART is a multicenter, placebo-controlled, randomized clinical trial of 324 children ages 9 to 14 years in grades 3 to 8 with symptomatic CI. Participants are randomized to 16 weeks of office-based vergence/accommodative therapy (OBVAT) or placebo therapy (OBPT), both supplemented with home therapy. The primary outcome measure is the change in the Wechsler Individual Achievement Test-Version 3 (WIAT-III) reading comprehension subtest score. Secondary outcome measures are changes in attention as measured by the Strengths and Weaknesses of Attention (SWAN) as reported by parents and teachers, tests of binocular visual function, and other measures of reading and attention. The long-term effects of treatment are assessed 1 year after treatment completion. All analyses will test the null hypothesis of no difference in outcomes between the two treatment groups. The study is entering its second year of recruitment. The final results will contribute to a better understanding of the relationship between the treatment of symptomatic CI and its effect on reading and attention. CONCLUSION: The study will provide an evidence base to help parents, eye professionals, educators, and other health care providers make informed decisions as they care for children with CI and reading and attention problems. Results may also generate additional hypothesis and guide the development of other scientific investigations of the relationships between visual disorders and other developmental disorders in children.

Can chronic visual discomfort measures accurately predict acute symptoms?

PURPOSE: Several surveys exist to determine the severity and frequency of chronic symptoms related to visual discomfort. To our knowledge, there are no studies that investigate the potential of chronic visual discomfort ratings to predict acute discomfort symptoms that are experienced after tests of accommodation and vergence. We examined the ability of two measures of chronic visual discomfort symptoms to predict acute symptoms experienced. METHODS: The Conlon et al. and the convergence insufficiency symptom surveys were administered to 40 participants to assess chronic visual discomfort symptoms. Two measures were used to assess acute symptoms. The first consisted of four Likert-scaled questions relating to comfort level during last test, visual distortions or movement, discomfort caused by overhead lights, and presence of headache symptoms. These questions were asked before and after binocular examination, and the scores were used to generate a postexamination symptom score. The second measure of acute symptoms consisted of participants rating their general discomfort on a four-point Likert scale after each binocular test, and the ratings were summed to produce a General Symptom Score. Participants were then categorized into a high or low Post-exam symptom group and General symptom group. Data were analyzed with a binary logistic regression to determine whether the chronic surveys could predict acute symptom group classification. RESULTS: Approximately 75% of predictions were accurate for either chronic symptom survey. Headache, soreness, and eye-related questions were more reliable predictors of symptom acute outcome. CONCLUSIONS: These data suggest that the Conlon and Convergence Insufficiency Symptom Survey (CISS) surveys are good predictors of acute symptoms induced during a binocular examination and validate the use of chronic symptom surveys as screening tools for symptomatic binocular dysfunction. Further investigation is required to determine predictability of accommodative or vergence performance.

Chromatic aberration, accommodation, and color preference in asthenopia.

PURPOSE: Asthenopia is a common problem associated with near work and reports suggest that colored lenses or overlays may be applied to reduce symptoms. In this study, we examine the relationship between eyestrain, color preferences, and function of the accommodation and vergence system. Specifically, we examine whether symptomatic observers select colors that reduce accommodative demand based on longitudinal chromatic aberration (LCA). METHODS: Forty-seven undergraduate students participated in this study. Visual discomfort symptoms were assessed using the Conlon survey. A Mark 2 Intuitive Colorimeter was used to obtain optimal colored light preferences. LCA was modeled using the Chromatic Eye and spectral power density data. A comprehensive evaluation of accommodation and vergence was performed following standard procedures. RESULTS: A significant negative correlation (r = -0.51) was found between eyestrain symptoms and the International Commission on Illumination (CIE) v' axis of colors preferences. Additionally, a significant negative correlation (r = -0.31) was found between eyestrain symptoms and LCA accommodation. Two thirds of the participants in the high discomfort group chose colors that decreased accommodative demand. Accommodative amplitude and vergence facility also correlated with LCA, accounting for 25% of the variance. CONCLUSIONS: The color preferences of individuals are systematically influenced by the functioning of their accommodation and vergence systems with increased symptomatology resulting in color selections that reduce LCA accommodative stimulus demand.

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.

Measuring near-induced transient myopia in college students with visual discomfort.

PURPOSE: Visual discomfort is a common problem, and our previous research indicated that 17% of college students experience moderate to high levels of discomfort when reading or studying. There have been several visual factors associated with visual discomfort, and in this study, we focused on measuring the near-induced transient myopia response in a group of college students with significant visual discomfort. METHODS: Visual discomfort was evaluated with a survey developed by Conlon et al. (Conlon et al., Visual Cogn 1999;6:637-663). Twelve college students with high visual discomfort (scoring 1 SD higher than the mean value) and 12 college students with low visual discomfort (scoring within 0.5 SD of the mean value) participated in the study. All students had 20/25 or better visual acuity, no strabismus, and no significant uncorrected refractive error. All refractive error and accommodative measurements were made with the WAM-5500 autorefractor. A pretask distance refraction at 6 m was taken for 60 s, and then the students read a story for 10 min at 20 cm. After reading the passage, the posttask distance refraction was measured for 2 min at 6 m. Values for the pre- and posttask measures were averaged in 10-s blocks of time. RESULTS: A mixed analysis of variance comparing discomfort group by pre- and postnear work distance refraction showed a significant interaction (p = 0.05). Comparing the means of the pre- and posttask distance refraction indicated that the high discomfort group showed no change in refractive error, but the low discomfort group showed a myopic shift of 0.13 diopter. CONCLUSIONS: A near-induced transient myopia response is not associated with high visual discomfort experienced by college students when reading or doing near work.

Accommodation response and visual discomfort.

Although visual discomfort symptoms associated with near work have been correlated with clinical measures of accommodation, studies using objective recordings have not found corresponding deficits in accommodative function. One problem with previous studies is that accommodation measures have been too brief to assess accommodative fatigue. This study examined steady state accommodative responses among a college population with visual discomfort, over a 90-s time period. Thirty-one participants were grouped into high (n = 15) or low visual discomfort groups (n = 16) based on their scores on the Conlon Visual Discomfort Survey. Using the WAM-5500 autorefractor, accommodation responses were recorded at 5 Hz for two consecutive minutes at five viewing distances. The results showed a significant interaction between the high and low discomfort groups over time in accommodation response. The high discomfort group showed an increase in accommodative lag, whereas the low discomfort group had a stable response. Our study suggests that the high visual discomfort group is characterized by accommodative fatigue, with a higher lag of accommodation developing at a near viewing distance over time.

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.

Visual discomfort and objective measures of static accommodation.

PURPOSE: Accommodation insufficiency and fatigue have been associated with near work visual discomfort symptoms, but clinical measures of accommodation amplitude suggest insufficiency is uncommon and often not weak enough to cause symptoms. However, recent studies show that the clinical push-up test used to measure amplitude overestimates accommodative function. This study uses an open-field autorefractor to measure accommodative stimulus-response functions objectively in college students with and without near work induced discomfort symptoms. METHODS: Using a Grand-Seiko WAM 5500 autorefractor, 2 min recordings were made each at five viewing distances (0 to 5 D) to measure an accommodative response function. Visual discomfort symptoms were assessed using the Conlon survey. RESULTS: A strong and positive correlation between accommodative lag and visual discomfort symptoms was found under near work conditions. The prevalence of accommodative insufficiency was much higher than estimated by clinical measures. CONCLUSIONS: Accommodative insufficiency and fatigue should be defined and described by objective methods using extended viewing times to assess function.

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).

Longitudinal study of visual discomfort symptoms in college students.

PURPOSE: To determine the variation of visual discomfort symptom reporting in a group of college students over a 1 year period. METHODS: Subjects were screened for visual acuity and uncorrected refractive error before participating in the study. A survey of visual discomfort developed by Conlon et al., Vis Cogn 1999;6:637-666, and the Convergence Insufficiency Symptom Survey (CISS) were administered to a group of 23 college students twice with approximately 1 year between administrations. All subjects also completed two clinical assessments of accommodation and vergence. RESULTS: The mean time between administrations of the symptom surveys was 13 months. There was no clinically significant mean difference between the first and second administration of both visual discomfort surveys. The intraclass correlation coefficient was 0.82 for the Conlon et al., Vis Cogn 1999;6:637-666 survey and 0.85 for the CISS. The 95% limits of agreement for the Conlon et al., Vis Cogn 1999;6:637-666 survey was -18.44, 17.92 and for the CISS was -14.36, 13.36. The intraclass correlation coefficient values for the optometric tests ranged from 0.38 to 0.83. CONCLUSIONS: Visual discomfort symptoms were found to be stable in the majority of young college students over a 1 year period. However, a minority of students showed large variability between the two administrations of the surveys.

Feasibility of using placebo vision therapy in a multicenter clinical trial.

PURPOSE: The Convergence Insufficiency Treatment Trial (CITT) Investigator Group conducted a preliminary study assessing the effectiveness of home-based push-up therapy and office-based vision therapy/orthoptics for the treatment of convergence insufficiency (CI). The CITT group developed a placebo therapy program that was designed to simulate real vision therapy/orthoptics. The purpose of this paper is to evaluate the effectiveness of this placebo therapy program in maintaining masking of subjects randomized to the office-based treatment arms (real or placebo). METHODS: Subjects (ages 9 to 30 years) were enrolled, stratified into two groups by age, and then randomly assigned to one of three treatment groups: pencil push-up therapy, office-based vision therapy/orthoptics, or office-based placebo vision therapy/orthoptics. At the end of treatment, subjects in the two office-based therapy groups (placebo and real) were asked: (1) which treatment do you think you received? and (2) how sure are you about your answer? RESULTS: Ninety-five percent of subjects assigned to real therapy and 83% assigned to placebo therapy thought they were in the real therapy group. Of the subjects who thought they received real therapy, 90% assigned to real therapy and 89% assigned to placebo therapy were "somewhat sure," "pretty sure," or "very sure" of their answer. Those assigned to real therapy had more responses in the "very sure" category. CONCLUSION: The CITT placebo therapy program was effective in maintaining subject masking in this multicenter clinical trial.

ERGs and psychophysical thresholds in students with reading discomfort.

PURPOSE: Symptoms of reading discomfort include unpleasant somatic and perceptual effects, such as eye-strain, headache, and blurred text, despite normal visual acuity. Reading discomfort has been proposed to be the result of increased noise in the visual system. Several studies have suggested that the symptoms can be minimized by having the subject wear colored filters. Thus, there may be abnormal neural processing in the cone pathways. This study measured L- and M-cone isolating (1) ERGs and (2) psychophysical thresholds in normal and reading discomfort subjects to determine if cone processing was abnormal in the reading discomfort population. METHODS: Twenty-two normal and nineteen reading discomfort college students took part in this study. The normal subjects had Conlon survey scores within 0.5 SD of the mean and the reading discomfort subjects had scores >1.5 SD above the mean. ERGs were determined for a range (5 to 15%) of L- and M-cone contrasts. Slopes were determined for the L- and M-cone ERG amplitudes for each subject. Psychophysical thresholds were determined with a 2AFC technique combined with a 3-up and 1-down staircase procedure that terminated after 18 reversals occurred. The threshold was calculated as the average of the last 8 reversals. RESULTS: The average ERG slopes were not significantly different between the normal and reading discomfort groups (L-Cone, p = 0.086; M-Cone, p = 0.47). The L/M cone ratios for the slopes were not significantly different (p = 0.55). The log of the color contrast thresholds were not significantly different between the normal and reading discomfort groups (L-Cone, p = 0.97; M-Cone, p = 0.92). CONCLUSIONS: L- and M- cone ERG contrast gains and psychophysical estimates of color contrast thresholds were not significantly different. These results do not support the noisy visual system hypothesis of reading discomfort.