A case-comparison of intermittent exotropia and quality of life measurements

Patient reported outcomes for phosphomannomutase 2 congenital disorder of glycosylation (PMM2-CDG): listening to what matters for the patients and health professionals

Background

Congenital disorders of glycosylation (CDG) are a growing group of rare genetic disorders. The most common CDG is phosphomannomutase 2 (PMM2)-CDG which often has a severe clinical presentation and life-limiting consequences. There are no approved therapies for this condition. Also, there are no validated disease-specific quality of life (QoL) scales to assess the heterogeneous clinical burden of PMM2-CDG which presents a challenge for the assessment of the disease severity and the impact of a certain treatment on the course of the disease.

Aim and methods

This study aimed to identify the most impactful clinical signs and symptoms of PMM2-CDG, and specific patient and observer reported outcome measures (PROMs and ObsROMs, respectively) that can adequately measure such impact on patients’ QoL. The most burdensome signs and symptoms were identified through input from the CDG community using a survey targeting PMM2-CDG families and experts, followed by family interviews to understand the real burden of these symptoms in daily life. The list of signs and symptoms was then verified and refined by patient representatives and medical experts in the field. Finally, a literature search for PROMs and ObsROMs used in other rare or common diseases with similar signs and symptoms to those of PMM2-CDG was performed.

Results

Twenty-four signs/symptoms were identified as the most impactful throughout PMM2-CDG patients’ lifetime. We found 239 articles that included tools to measure those community-selected PMM2-CDG symptoms. Among them, we identified 80 QoL scales that address those signs and symptoms and, subsequently, their psychometric quality was analysed. These scales could be applied directly to the PMM2-CDG population or adapted to create the first PMM2-CDG-specific QoL questionnaire.

Conclusion

Identifying the impactful clinical manifestations of PMM2-CDG, along with the collection of PROMs/ObsROMs assessing QoL using a creative and community-centric methodology are the first step towards the development of a new, tailored, and specific PMM2-CDG QoL questionnaire. These findings can be used to fill a gap in PMM2-CDG clinical development. Importantly, this methodology is transferable to other CDG and rare diseases with multiple signs and symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02551-y.

Impact of strabismus on the quality of life of Chinese Han teenagers

BACKGROUND

Although much research has been conducted on the impact of strabismus on the quality of life (QoL) of adults, the effect of this condition on teenagers has not been extensively studied. This study therefore aimed to assess the effect of strabismus on the vision-related QoL of Chinese teenagers.

METHODS

The Chinese version of the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) was self-administered by 1,040 teenagers with strabismus and 1,002 individuals with normal vision. All the participants were from the Chinese Han population. The independent samples t-test was used to compare QoL between teenagers with and without strabismus.

RESULTS

The majority of scores on the NEI-VFQ-25 domains were significantly different between the two groups. QoL was significantly lower in individuals with strabismus compared with teenagers with normal vision on all domains, with the exception of social functioning.

CONCLUSION

Statistically significantly lower vision-related QoL scores were found in Chinese Han teenagers with strabismus compared with those without strabismus.

Comparison of quality-of-life instruments in childhood intermittent exotropia

PURPOSE

To compare 2 health-related quality-of-life (HRQOL) instruments: the condition-specific Intermittent Exotropia Questionnaire (IXTQ) and the generic Pediatric Quality of Life Inventory (PedsQL) in children with intermittent exotropia.

METHODS

Fifty-one children with intermittent exotropia (median, 7 years; range, 5-16 years) were recruited from outpatient clinics with one of their parents. All children completed age-appropriate Child IXTQ (12 items) and Child PedsQL (23 items). Parents completed parallel Proxy IXTQ and Proxy PedsQL (parent assessment of child's HRQOL). Possible scores ranged from 0 to 100 (worst to best HRQOL). Normal thresholds were defined using the 5th percentile in a control group of 47 normal nonstrabismic children. Proportions scoring below normal on each questionnaire were compared. Median scores in intermittent exotropia and control groups also were compared.

RESULTS

More scores were subnormal using Proxy IXTQ than Proxy PedsQL (55% vs 18%, p = 0.0004). When Child questionnaires were used, we found that similar proportions scored below normal (IXTQ 8% vs PedsQL 14%, p = 0.3). Median scores were lower for intermittent exotropia children compared with control patients for Child IXTQ (83 vs 92; p = 0.04), Proxy IXTQ (81 vs 98; p < 0.0001), and Proxy PedsQL (p = 0.04) but not for Child PedsQL (p = 0.3).

CONCLUSIONS

The Proxy IXTQ detects reduced HRQOL related to intermittent exotropia more often than the Proxy PedsQL. There were few subnormal scores on Child IXTQ and Child PedsQL. Children with intermittent exotropia scored, on average, lower than control patients on the IXTQ, but most individual scores fell within the normal range. The IXTQ may prove useful for clinical assessment of intermittent exotropia.

Development and initial validation of quality-of-life questionnaires for intermittent exotropia

PURPOSE

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 (age, 2-17 years) with IXT and 1 of their parents. In an initial validation phase, 33 children with IXT and 49 control children (age, 5-17 years), along with 1 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- to 17-year-old children with IXT (n = 15) and parents of 2- to 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 (100, best HRQOL) to almost always (0, worst HRQOL) were used.

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 (quartiles, 79-96; P = 0.04). Median proxy IXTQ scores were significantly lower for IXT children than controls: 83 (quartiles, 75-94) versus 98 (quartiles, 92-100; P<0.0001). Median parent IXTQ scores also were significantly lower in the IXT group compared with the control group: 68 (quartiles, 56-79) versus 93 (quartiles, 87-99; P<0.0001).

CONCLUSIONS

A new 3-part patient-derived HRQOL questionnaire for children with IXT and their parents has been developed and validated, comprising child, proxy, and parent questionnaires. These questionnaires detect reduced HRQOL in children with IXT as reported by the children themselves and perceived by their parents (proxy report). Childhood IXT also seems to affect parent HRQOL. The IXTQ HRQOL questionnaires may prove useful in the clinical assessment of IXT and for clinical trials.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Quality of life in intermittent exotropia: child and parent concerns

OBJECTIVE

To identify specific health-related quality-of-life (HRQOL) concerns for children with intermittent exotropia (IXT) and their parents.

METHODS

Twenty-four children aged 5 to 17 years with IXT and 1 parent for each child were recruited. Individual interviews with the child and then the parent were audiotaped and transcribed. Transcripts were reviewed, phrases regarding effects of IXT on HRQOL recorded, and specific topic areas identified. Topic frequency was analyzed to determine children's perceptions of their own HRQOL, parents' perceptions of their child's HRQOL, and parents' own HRQOL.

RESULTS

Child interviews generated 18 topics. Worry (10 of 24 patients [42%]) was most frequently mentioned. Parent interviews generated 22 topics regarding their children's HRQOL. The most frequently mentioned topic was comments from others (15 of 24 patients [63%]). Regarding the parents' own HRQOL, 14 topics were identified; the most frequently mentioned was worry regarding possible surgery (15 of 24 patients [63%]).

CONCLUSIONS

Multiple individual interviews revealed specific HRQOL concerns, such as worry, in children with IXT and their parents. We will use the concerns identified to develop condition-specific HRQOL instruments for IXT.

The effects of strabismus on quality of life in adults

PURPOSE

As a first step in the development of a health-related quality of life (HRQOL) instrument, we conducted in-depth interviews to identify the specific concerns of adults with strabismus.

DESIGN

Prospective cross-sectional study.

METHODS

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 three 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.

RESULTS

A total of 1,508 phrases were extracted: 207 (14%) of 1,508 were excluded because they did not pertain to HRQOL. From the remaining 1,301 phrases, 48 topic areas were apparent. For patients with diplopia, the most frequently occurring topics were: nonspecific negative feeling (15/17; 88%) ("really hard"); general disability (15/17; 88%) ("affects everything"); and driving (14/17; 82%). In those without diplopia, the most frequently mentioned topics were appearance to others (12/13; 92%) ("people notice my eyes") followed by problems with eye contact (10/13; 77%) and interpersonal relationships (10/13; 77%). Of the topics that were common to both groups (n = 42), two of the most frequent were driving and nonspecific negative feeling.

CONCLUSIONS

Multiple individual interviews revealed many topics that negatively affect quality of life in patients with strabismus. The frequency and type of concerns confirm the importance of HRQOL assessment as an important aspect of strabismus management.

Developmental Eye Movement Test: reliability and symptomatology

BACKGROUND

The Developmental Eye Movement Test (DEM) is a widely used visual skill test, especially in the context of a vision therapy evaluation. It is intended to diagnose oculomotor dysfunction (OMD) and can also identify deficient rapid automatized naming. As such, its reliability and associated symptomatology are important.

METHODS

The DEM test-retest reliability was investigated within two populations: a group of 53 office patients who were participating in vision therapy evaluation in a private optometry practice, and a smaller group of 13 subjects at their school. One to four weeks separated the test and retest for both groups. We also studied the relationship between results on a questionnaire of symptoms associated with OMD and DEM test performance in these two populations.

RESULTS

The first administration of the DEM significantly correlated with the second for all four of its scores for both groups. The office group had higher intra-class correlation coefficients than the school group. There was good agreement between test and re-test in terms of pass-fail classification for the office group. Symptomatic subjects performed poorer than asymptomatic subjects on the DEM. Failing the DEM Ratio, the score used to diagnose OMD, identified 90% of the subjects who were symptomatic.

CONCLUSIONS

The DEM has good intra-subject test-retest reliability for all four of its scores when it is administered in an office setting to patients participating in a vision therapy evaluation. It also has good consistency in classifying patients as pass or fail. Performance on the DEM relates to certain symptoms that are associated with OMD.

Validity and reliability of the revised convergence insufficiency symptom survey in adults

PURPOSE

To assess the validity and reliability of the revised Convergence Insufficiency Symptom Survey (CISS) in adults aged 19-30 years. The CISS was developed to be the primary outcome measure for studies evaluating various treatments for convergence insufficiency (CI).

METHODS

CISS mean scores from adults with symptomatic CI and adults with normal binocular vision (NBV) were compared to assess the survey's validity. Adults with symptomatic CI were given the CISS twice to evaluate reliability, which was assessed using intraclass correlation coefficient (ICC) and 95% limits of agreement.

RESULTS

Forty-six adults with CI and 46 adults with NBV participated in the study. The mean CISS score for the CI group was 37.3 (S.D. = 9.3) and 11.0 (S.D. = 8.2) for the NBV group. These mean values were significantly different (p < 0.0001). Good discrimination (sensitivity = 97.8%, specificity = 87%) was obtained using a score of 21 or higher. For the CI group the ICC was 0.885 (95% CI of 0.798, 0.936) and the 95% limits of agreement were -9.0 to 7.6.

CONCLUSIONS

Adults with symptomatic CI had a significantly higher CISS score than adults with NBV. The results of the study demonstrate that the CISS is a valid and reliable instrument that can be used clinically or as an outcome measure for research studies of adults with CI.

Productivity associated with visual status of computer users

BACKGROUND

The aim of this project is to examine the potential connection between the astigmatic refractive corrections of subjects using computers and their productivity and comfort. We hypothesize that improving the visual status of subjects using computers results in greater productivity, as well as improved visual comfort.

METHODS

Inclusion criteria required subjects 19 to 30 years of age with complete vision examinations before being enrolled. Using a double-masked, placebo-controlled, randomized design, subjects completed three experimental tasks calculated to assess the effects of refractive error on productivity (time to completion and the number of errors) at a computer. The tasks resembled those commonly undertaken by computer users and involved visual search tasks of: (1) counties and populations; (2) nonsense word search; and (3) a modified text-editing task.

RESULTS

Estimates of productivity for time to completion varied from a minimum of 2.5% upwards to 28.7% with 2 D cylinder miscorrection. Assuming a conservative estimate of an overall 2.5% increase in productivity with appropriate astigmatic refractive correction, our data suggest a favorable cost-benefit ratio of at least 2.3 for the visual correction of an employee (total cost 268 dollars) with a salary of 25,000 dollars per year.

CONCLUSIONS

We conclude that astigmatic refractive error affected both productivity and visual comfort under the conditions of this experiment. These data also suggest a favorable cost-benefit ratio for employers who provide computer-specific eyewear to their employees.

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.

Quality of life in newly diagnosed glaucoma patients : The Collaborative Initial Glaucoma Treatment Study

OBJECTIVE

The Collaborative Initial Glaucoma Treatment Study (CIGTS) was designed to determine whether patients with newly diagnosed open-angle glaucoma are better treated initially by medicine or immediate filtering surgery. This paper describes the quality-of-life (QOL) measurement approach, instruments included, and the CIGTS participants' QOL findings at the time of diagnosis.

DESIGN

Baseline results from a randomized, controlled clinical trial.

PARTICIPANTS

Six hundred seven patients from 14 clinical centers were enrolled.

INTERVENTION

Patients randomized to initial medication received a stepped medical regimen (n = 307). Those randomized to initial surgery underwent a trabeculectomy (n = 300). The baseline interview was conducted before treatment initiation. All baseline and posttreatment QOL assessments were conducted by telephone from a centralized interviewing center.

MAIN OUTCOME MEASURES

The primary outcome measure described in this paper was QOL. The QOL instrument is multidimensional and incorporates both disease-specific and generic measures, including the Visual Activities Questionnaire, Sickness Impact Profile, and a Symptom and Health Problem CHECKLIST:

RESULTS

The correlations between QOL measures and clinical outcomes were in the expected direction, but relatively weak. At initial diagnosis, difficulty with bright lights and with light and dark adaptation were the most frequently reported symptoms related to visual function, whereas visual distortion was the most bothersome. Approximately half of the patients reported at least some worry or concern about the possibility of blindness. Within the Visual Activities Questionnaire, higher scores on the Peripheral Vision subscale were associated with more field loss (P < 0.01). In regression analyses controlling for sociodemographics and nonocular comorbidities, increased visual field loss was significantly associated with higher dysfunction among five disease-specific QOL measures (P < 0.05).

CONCLUSIONS

Newly diagnosed glaucoma patients reported experiencing some visual function symptoms at the time of diagnosis that would not be intuitively expected based on clinical testing. Some discussion about the association between clinical presentation and worry about blindness may reduce unnecessary concern. These results provide the basis for long-term comparisons of the QOL effects of initial medical and surgical treatment for open-angle glaucoma.