Purpose We report the development of a patient-derived, health related quality of life (HRQOL) questionnaire for adults with strabismus. Design Cross-sectional study. Participants 29 patients with strabismus in a first phase, and 32 patients with strabismus, 18 patients with other eye diseases, and 13 visually normal adults in a second phase. Methods Individual patient interviews generated 181 questionnaire items. For item reduction, we asked 29 patients with strabismus to complete the 181-item questionnaire, analyzed responses, and performed factor analysis. Two prominent factors were identified, and the 10 items with the highest correlation with each factor were selected. The final 20-item questionnaire (10 ‘psychosocial’ items, 10 ‘function’ items) was administered to an additional 32 patients with strabismus (22 with diplopia, 10 without diplopia), 13 visually normal adults, and 18 patients with other eye diseases. A 5-point Likert-type scale was used for responses (‘never’=100, ‘rarely’=75, ‘sometimes’=50, ‘often’=25, and ‘always’=0). Median overall questionnaire scores and psychosocial and function sub-scale scores, ranging from 0 (worst HRQOL) to 100 (best HRQOL), were compared across groups. Main Outcome Measures HRQOL questionnaire response scores. Results Median overall scores were statistically significantly lower (worse quality of life) for patients with strabismus (56) compared to visually normal adults (95; P<0.001) and patients with other eye diseases (86; P<0.001). Median scores on the psychosocial sub-scale were significantly lower for strabismus patients (69) compared to visually normal adults (99; P<0.001) and patients with other eye diseases (94; P<0.001). For the function sub-scale, median scores were again significantly lower for strabismus patients (43) compared to visually normal adults (91; P<0.001) and patients with other eye diseases (78; P<0.001). Conclusions We have developed a 20-item, patient-derived HRQOL questionnaire specific for adults with strabismus, with sub-scales to assess psychosocial and function concerns. This 20-item, condition specific questionnaire will be useful for assessing HRQOL in individual strabismus patients and also as an outcome measure for clinical trials.

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Purpose: As a first step in the development of a health related quality of life instrument, we conducted in-depth interviews to identify the specific concerns of adults with strabismus. Design: Prospective cross-sectional studyMethods: Thirty adults with strabismus, 17 with diplopia and 13 without were recruited. Individual interviews, using 11 open-ended questions, were audiotaped, transcribed and transcripts reviewed independently by 3 investigators. Phrases regarding how strabismus affected everyday life were grouped into topic areas and the frequency of each topic analyzed for subjects with and without diplopia.

Purpose To report changes in health-related quality of life (HRQOL) 1 year following strabismus surgery. Design Retrospective cohort study Methods 73 adults undergoing strabismus surgery in a single clinical practice completed the Adult Strabismus-20 (AS-20) HRQOL questionnaire pre-operatively and at 6 weeks and 1 year post-operatively. All included adults were successfully aligned at 6 weeks post-operatively. Success was defined based on clinical criteria. Change in AS-20 psychosocial and function scores was evaluated as: 1) difference in scores between 6 weeks and 1 year post-operatively and 2) proportions exceeding previously published limits of agreement at 6 weeks and 1 year. Results For patients successfully aligned at both 6 weeks and 1 year (n=51), further improvement in median scores was seen from 6 weeks to 1 year for both the psychosocial scale (83.8 vs 93.8; P<0.0001) and the function scale (72.5 vs 77.5; P=0.007). Also, a greater proportion exceeded limits of agreement at 1 year than at 6 weeks (psychosocial: 48% vs 30%; P=0.007, function: 67% vs 51%; P=0.01). For patients who became partial success (n=18) or failure (n=4) at 1 year there was a numerical decrease in scores at 1 year. Conclusions Adult strabismus patients who remain successfully aligned, show continued improvement in both psychosocial and function scores from 6 weeks to 1 year post-operatively, indicating that improvement in HRQOL is long-lasting. Evaluation of HRQOL should be considered when reporting strabismus surgery outcomes in clinical trials, and may prove helpful in assessing outcomes in clinical practice.

Objective To evaluate the responsiveness of 2 health related quality of life (HRQOL) questionnaires, the Adult Strabismus-20 (AS-20) and National Eye Institute Visual Function Questionnaire-25 (VFQ-25), to changes in HRQOL following strabismus surgery. Design Cohort study Participants 106 adults (aged 18 to 84, median 48.5 years) undergoing strabismus surgery, 80 (75%) with diplopia and 26 (25%) without diplopia. Methods All participants completed AS-20 and VFQ-25 questionnaires pre-operatively and a median of 7 (range 4 to 13) weeks post-operatively. Using pre-defined clinical criteria, post-operative outcomes were graded as either ‘success’ (n=65), ‘partial success’ (n=32) or ‘failure’ (n=9). Main outcome measures For each questionnaire, mean composite and subscale scores (ranging from 0 to 100; worst to best HRQOL) were calculated for each patient. Median change in scores pre- to post-operatively was compared for successes, partial successes, and failures, and the proportion of patients whose scores exceeded 95% limits of agreement was calculated. Results Successfully aligned diplopic patients (n=46) showed greater improvement than failures (n=7) using both the AS-20 questionnaire (21.3 [quartiles 12.5 to 35.0] vs. 8.8 [3.8 to 12.5]; P=0.002) and the VFQ-25 questionnaire (18.3 [8.6 to 26.1] vs. 8.3 [0.8 to 13.5]; P=0.02). Successfully aligned non-diplopic patients (n=19) also showed greater improvement than failures (n=2): (AS-20 23.8 [10.0 to 32.5] vs. −3.1 [−10.0 to 3.8]; P=0.05). In non-diplopic patients, changes on VFQ-25 were small but significantly greater for successes than failures (5.0 [0.0 to 10.1] vs. −15.4 [−19.4 to −11.4]; P=0.03). More successfully aligned patients showed improvement exceeding the 95% limits of agreement for AS-20 scores than VFQ-25 scores (67% vs. 65% [P=0.8] for diplopic patients and 63% vs. 21% [P=0.005] for non-diplopic patients). Conclusions AS-20 and VFQ-25 questionnaires are responsive to improved HRQOL in adults undergoing successful strabismus surgery. Changes on VFQ-25 were smaller, particularly for non-diplopic strabismus. The AS-20 is more responsive than the VFQ-25 across the range of adult strabismus.

Purpose Bangerter filters are designed to cause progressive degradation of distance optotype acuity to predicted levels (density label indicating expected decimal acuity) and are used to treat amblyopia and diplopia. Nevertheless, there are few data reporting induced acuity deficits. We investigated the effect of Bangerter filters on distance and near optotype acuity, vernier acuity, and contrast sensitivity. Methods Fifteen subjects with best corrected optotype acuity of at least 20/25 in each eye were blurred sequentially in one eye with 7 Bangerter filters (densities <0.1, 0.1, 0.2, 0.3, 0.4, 0.8, 1.0). At each filter level distance and near optotype acuity (LogMAR), vernier acuity and contrast sensitivity were assessed. Mean log acuities were compared using generalized estimating equation methods. Results The 1.0, 0.8, and 0.4 filters degraded distance optotype acuity to a similar degree (mean 0.22, 0.23, and 0.28 logMAR). Subsequent filters progressively degraded acuity: 0.44, 0.57, 0.93, 1.69 logMAR. Near optotype acuity was reduced in a similar pattern. Vernier acuity was minimally degraded by 1.0, 0.8, and 0.4 filters (18, 19, and 20 arcsec), followed by progressive degradation with subsequent filters (31, 35, 113, and 387 arcsec). Contrast sensitivity was minimally reduced with filters 1.0 through 0.2, and then precipitously degraded with 0.1 and <0.1 filters. Conclusion The 1.0, 0.8, and 0.4 filters cause similar, minimal degradation of distance and near optotype, and vernier acuity, whereas subsequent filters cause progressive degradation. Contrast sensitivity is not markedly reduced until the 0.1 filter. These results have important implications for using Bangerter filters therapeutically.

Purpose To compare two health-related quality of life (HRQOL) questionnaires in adults with strabismus: the new AS-20 (developed specifically for adult strabismus) and the NEI VFQ-25 (VFQ-25). Design Cross-sectional study Methods 84 adult patients with strabismus (median age 53, range 18-81 years) completed the AS-20 and VFQ-25 HRQOL questionnaires. Patients were categorized as diplopic (n=65), or non-diplopic (n=19). Subnormal HRQOL was defined as below the 5th percentile for adults with no visual impairment. The proportion of patients below normal was compared overall and by diplopia status. Results Overall, more patients scored below normal with the AS-20 than with the VFQ-25 (90% vs 29%, P <0.0001). Non-diplopic patients were more often below normal on AS-20 psychosocial subscale than function subscale (95% vs 42%, P=0.002), while diplopic patients were more often below normal on the function subscale (85% vs 68% and P=0.01). On the psychosocial subscale, more non-diplopic than diplopic patients scored below normal (95% vs 68%; P=0.01); on the function subscale more diplopic than non-diplopic patients scored below normal (85% vs 42%; P=0.0005). The VFQ-25 appeared insensitive to non-diplopic strabismus: no patients scored below normal on composite score and no more than 11% scored below normal on VFQ-25 subscales. Of diplopic patients, 37% scored below normal on VFQ-25 composite score. No more than 38% scored below normal on VFQ-25 subscales. Conclusion The new AS-20 appears more sensitive than the VFQ-25 for detecting reduced HRQOL in adult strabismus, and therefore may be a more useful tool for clinical assessment and clinical trials.

Purpose-Assessing control is thought to be important in the management of intermittent exotropia (IXT), including the decision to perform surgery. The purpose of this study was to assess the presence and degree of any change in control occurring over the course of 1 day using a previously described 6-point clinic control scale, and to evaluate inter-observer and minute-to-minute variability. Design-Prospective case series. Participants-25 patients with intermittent exotropia.Methods-Inter-observer agreement was determined in 17 patients by comparing control scores assessed simultaneously by 2 observers (kappa test). Minute-to-minute variability was observed in the same 17 patients by assessing control twice within 5 minutes. Variability over one day was assessed in 5 of these patients plus 8 additional patients (n=13) by comparing 3 or 4 assessments at least 2 hours apart.Main outcome measure-Control of IXT measured using a 6-point clinic control scale.Results-Inter-observer agreement was high (k=0.94 for distance and k=0.95 for near fixation). Disagreements were no more than one level on the control scale; therefore, for further analysis, change in control was defined as 2 or more levels. For minute-to-minute variability, 4 (24%) of the 17 patients tested twice within 5 minutes showed a change in control: 1 (6%) changed from tropia to phoria at distance, 3 (18%) from phoria to tropia at near. Of the 13 patients assessed over 1 day, 6 (46%) showed change in control, 2 at distance fixation only, 3 at near only and 1 at near and distance.Conclusions-Control of IXT can vary throughout the day, even within minutes, including from phoric to spontaneously tropic, and vice versa. The worst level of control was not always later in the day. This suggests that an isolated assessment of control may not categorize severity of IXT in an individual patient.Intermittent exotropia (IXT) is a common form of childhood strabismus 1, 2 characterized by intermittent divergent misalignment that is often greater at distance fixation. Severity and progression of IXT are currently assessed by determining angle of deviation, stereoacuity, ability to control the deviation and parental reports of frequency. 'Control' may be defined as an estimate of the proportion of time the deviation is manifest and the ease of re-establishing fusion after dissociation. Although the natural history and indications for surgical intervention are poorly defined, 3 it is commonly held that poor control of the exodeviation is a sign of deterioration. 4 On this basis, surgery has been recommended by some authors when the exotropia occurs more than 50% of waking hours or when there is a gradual loss of fusional control as evidenced by an increasing frequency of the exotropia. [4][5][6] Others have suggested that early surgery results in superior sensory outcomes 7, 8 but the timing of surgery for IXT has not been subjected to a randomized clinical trial and prior to such a trial, outcome measures such as control need to be rigorously studied.Until recen...