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 cut-off 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 - <18 years with NBV. Examiners masked to the child’s binocular vision status administered the CISS. The mean CISS score was compared to that from the children with NBV in the original, unmasked CISS study and also to that of the 221 symptomatic CI children enrolled in the CITT. Results The mean (±SD) CISS score for 46 subjects with NBV was 10.4 (±8.1). This was comparable to that from 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 less than 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 and these results confirm the validity of a cut-point of ≥ 16 in distinguishing children with symptomatic CI from those with NBV.

Purpose We report the development and initial validation of patient–derived, health related quality of life (HRQOL) questionnaires for intermittent exotropia (IXT). Design Cross-sectional study Participants In a development phase, 27 children (aged 2–17 years) with IXT and one of their parents. In an initial validation phase, 33 children with IXT and 49 control children (aged 5–17 years) along with one parent for each child. Children in the control group had no strabismus or amblyopia. Methods Individual patient interviews generated 35 items for Child and Proxy (parental assessment of child’s HRQOL) questionnaires and 46 items for a Parent questionnaire. To reduce to a feasible number of items, questionnaires were administered to 5–17 year old children with IXT (n=15) and parents of 2–17 year old children with IXT (n=27). Responses were analyzed using standard item reduction methodology. Three final derived IXT questionnaires (IXTQ): Child, Proxy, and Parent (12, 12, and 17 items respectively) were administered to children with IXT and control children, and to parents of IXT and control children. Likert-type scales ranging from ‘never’ (score 100, best HRQOL) to ‘almost always’ (score 0, worst HRQOL) were used for responses. Main outcome measures Median scores for IXT and control groups, compared using Wilcoxon tests. Results Median Child scores were significantly lower (worse HRQOL) in the IXT group compared with the control group: 85 (quartiles 73–92) versus 92 (79–96); P=0.04. Median Proxy IXTQ scores were significantly lower for IXT children than controls: 83 (75–94) versus 98 (92–100); P<0.0001. Median Parent IXTQ scores were also significantly lower in the IXT group compared with the control group: 68 (quartiles 56–79) versus 93 (87–99); P<0.0001. Conclusions We have developed and validated a new 3-part patient-derived HRQOL questionnaire for children with IXT and their parents, comprising Child, Proxy and Parent questionnaires. These questionnaires detect reduced HRQOL in children with IXT as reported by the child themselves and as perceived by their parents (proxy report). Childhood IXT also appears to affect the HRQOL of the parents. The IXTQ HRQOL questionnaires may prove useful in the clinical assessment of IXT and for clinical trials.

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Purpose To determine whether treatment of symptomatic convergence insufficiency (CI) has an effect on Academic Behavior Survey (ABS) scores. Methods The ABS is a 6-item survey developed by the Convergence Insufficiency Treatment Trial (CITT) 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 ages 9-17 years with symptomatic CI, who were enrolled in the CITT and randomized into: 1) home-based pencil push-ups (HBPP); 2) home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+); 3) office-based vergence/accommodative therapy with home reinforcement (OBVAT); and 4) office-based placebo therapy with home reinforcement (OBPT). 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, near point 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.

Purpose To report fusional divergence in children with intermittent exotropia (XT). Methods We retrospectively studied 32 children with intermittent XT (aged 4 to 13 years) and 38 visually normal non-strabismic children. Fusional divergence break points were measured using a prism bar, starting from a naturally fused state. Distribution of divergence break points was evaluated. Subnormal fusional divergence was defined as below the 5th percentile in visually normal children. In children with intermittent XT, correlations were calculated between divergence break point and control score, angle of deviation, and convergence break point. Results The distribution of fusional divergence break points in intermittent XT was normal at near but bimodal at distance. 9% had subnormal divergence (<10 prism diopters [pd]) at near, and 48% (<6 pd) at distance. There was a moderate correlation between divergence and convergence break points at near (r=0.44; P=0.01) but only weak inverse correlations between divergence break point and control score (r=−0.29; P=0.11) and divergence break point and angle of deviation (r=0.08; P=0.68) at near. Conclusions Most children with intermittent XT have normal near fusional divergence but nearly half have reduced distance fusional divergence. We found the magnitude of near divergence break point correlates with the magnitude of near convergence break point. Measuring divergence may provide useful information about fragility of fusion in patients with intermittent XT. Future studies of fusional divergence are needed to establish whether common measurement methods represent true divergence amplitudes and whether such measures have prognostic significance.