Correlations between clinical measures and symptoms: Report 2: Accommodative and vergence measures with symptoms

A Novel Device for Vergence Exercises: Testing Automatic Dual Rotational Risley Prisms on Asymptomatic Adults and Patients with Convergence Insufficiency

INTRODUCTION

This study investigated the effects of automatic dual rotational Risley prisms (ADRRPs), a mobile phone application-operated device, on vergence abilities in young adults.

METHODS

Fifty-six participants aged 20-24 performed vergence exercises. The test group used prisms with power changes from 30Δ base-out to 10Δ base-in, while the control group used plano lenses for 10 min. Ophthalmic examinations included lateral heterophoria, near point of convergence (NPC), vergence facility (VF), negative fusional vergence (NFV), and positive fusional vergence (PFV), all measured before and after the vergence exercises. Pre- and post-test results were analyzed using a paired sample t test. Additionally, three cases with convergence insufficiency (CI) performed similar exercises for 12 weeks.

RESULTS

Participants were divided into the test group (n = 39; age 21.82 ± 1.10 years) and control group (n = 17; age 20.53 ± 0.51 years). In the test group, NPC improved from 6.11 ± 2.52 cm to 5.77 ± 2.30 cm (p = 0.023). VF increased from 13.75 ± 4.10 cpm to 16.50 ± 4.42 cpm (p = 0.007). PFV at 6 m and 0.4 m increased from 19.49 ± 6.77∆ to 22.19 ± 6.64∆ (p < 0.001) and 20.51 ± 7.05∆ to 22.69 ± 6.44∆ (p = 0.012), respectively. After 12 weeks, convergence insufficiency symptom survey scores for cases with CI decreased significantly, with NPC improving from 7.0 to 0 cm, 6.0 to 5.8 cm, and 6.0 to 4.7 cm. PFV increased from 10 to 25∆, 20 to 30∆, and 25 to 50∆.

CONCLUSION

This preliminary study showed the effect of ADRRPs on improving vergence abilities. Further studies are needed to investigate the long-term sustainability and effects in a larger population of individuals with CI of this approach.

Evaluation and application of a Chinese version symptom questionnaire for visual dysfunctions (CSQVD) in school-age children

Objective

To develop and evaluate a Chinese version of the Symptom Questionnaire for Visual Dysfunctions (CSQVD) to quantify visual dysfunction symptoms in school-age children with various eye diseases, and to explore the relationship between ophthalmological disorders and visual dysfunction symptoms.

Methods

Following standard scale adaptation procedures, the Symptom Questionnaire for Visual Dysfunctions (SQVD) was translated into Chinese (CSQVD). We employed random sampling to survey 198 outpatients aged 7-18 to assess the psychometric properties of the CSQVD. Using the reliable and validated questionnaire, we evaluated the determinants of visual dysfunction symptoms among 406 school-age patients at an eye center. The CSQVD scores were correlated with demographic and clinical variables, including gender, age, eye position, refractive power, and best-corrected visual acuity. Univariate analysis identified potential risk factors, followed by binary logistic regression and multiple linear regression analysis on factors with a P-value <0.05.

Results

The CSQVD scale's critical ratio (CR) values ranged from 6.028 to 10.604. The Cronbach's Alpha coefficient was 0.779, and Spearman-Brown split-half reliability was also 0.779. The I-CVI varied from 0.83 to 1.000, the S-CVI/Ave was 0.857, and the KMO value was 0.821. Multifactorial regression analysis indicated that high myopia (OR ​= ​5.744, 95% CI [1.632, 20.218], P ​= ​0.006) and amblyopia (OR ​= ​9.302, 95% CI [1.878, 46.058], P ​= ​0.006) were significant predictors of CSQVD symptoms. Multiple linear regression analysis showed that BCVA of amblyopic eyes (B ​= ​-5.052, 95% CI [-7.779, 2.325], P ​= ​0.000) and SE power (B ​= ​-0.234, 95% CI [-0.375, 0.205], P ​= ​0.001) significantly affected the CSQVD scale scores.

Conclusions

The Chinese version of the SQVD scale (CSQVD) demonstrates good feasibility, discriminatory power, validity, and reliability in assessing Chinese school-aged children. Furthermore, those who have severe myopia and amblyopia reported more visual dysfunction symptoms.

Frequencies and patterns of symptoms in Chinese adults with accommodative and binocular dysfunctions

PURPOSE

Recent studies have found that children with convergence insufficiency experience higher frequencies of performance-related symptoms (e.g., losing concentration), but data on performance-related symptoms among adults with accommodative dysfunctions (ADs) and/or binocular dysfunctions (BDs) are lacking, which might cause misdiagnosis, diagnostic confusion, or exacerbation of attention deficits. We aimed to describe frequencies and symptom patterns in adults with ADs and/or BDs who were treated at optometric clinics and explore any correlations between visual symptoms and clinical findings.

METHODS

This cross-sectional study divided 235 participants (age: 23.7 ± 2.9 years) into three groups: ADs, BDs, and normal binocular vision (NBV) groups. Convergence Insufficiency Symptom Survey (CISS), refractive examinations, and binocular tests were administered to all participants. After 1-to-1 propensity score matching, outcomes were assessed using Mann‒Whitney U test and Pearson's correlation analysis among three groups.

RESULTS

In this sample, the number (frequency) of individuals with ADs and/or BDs was 117 (49.8%). ADs and BDs groups experienced significantly more performance-related symptoms (feeling sleepy, losing concentration, trouble remembering, reading slowly, losing place, and having to re-read; all P < 0.05) than the NBV group. Significant correlations were observed between performance-related symptoms and clinical findings, including accommodative amplitude (r =  - 0.294), accommodative facility (r =  - 0.452), near phoria (r =  - 0.261), near point of convergence (r = 0.482), and positive fusional vergence (r =  - 0.331) (all P < 0.001).

CONCLUSION

ADs and/or BDs are commonly present in adults treated at optometric clinics, and adults diagnosed with ADs and/or BDs exhibit more performance-related symptoms than participants with NBV.

Short-Term Effect of Spinal Manipulation on the Magnitude of Exophoria in Adults Who Are Asymptomatic: A Randomized Controlled Trial

OBJECTIVE

This study aimed to assess the immediate and short-term effects of cervical spinal manipulation (SM), compared with a placebo, on the magnitude of near and distance exophoria in adults with asymptomatic exophoria.

METHODS

In this single-blind, randomized controlled trial, individuals with a clinical diagnosis of horizontal exophoria confirmed with the prism alternating cover test (PACT) were allocated to a single intervention session using a high-velocity, low-amplitude cervical SM technique or a sham intervention (manual contact under the head). Outcomes were the magnitude of horizontal heterophoria, as a measure of binocular vision efficiency at near (40 cm) or distance (4 m) fixation, using the PACT. Evaluations were made at baseline, immediately after intervention, and at a 1-week follow-up.

RESULTS

From May to September 2021, 44 volunteers (23 women), with a mean age of 35 (SD = 9.5) years, were recruited and equally distributed into the study groups. All participants completed follow-up assessments, and no adverse events were reported. There was a significant time × group interaction for exophoria at near vision, but not at distance fixation. The SM group showed a significant decrease of near exophoria compared with the control group at the 1-week follow-up (mean difference = -1.09 prism diopters; 95% CI = -0.20 to -1.98 prism diopters).

CONCLUSION

The use of cervical SM therapy resulted in a significant reduction of the magnitude of horizontal exophoria at near vision (medium effect size), compared with the placebo, in young adults who are asymptomatic. However, these effects were not observed at distance fixation and should be considered cautiously due to the pre-post design with a single intervention session and the short-term follow-up.

IMPACT

The findings suggest short-term benefits of SM therapy can manage undiagnosed ocular convergence disorders, although changes were not clinically relevant.

Validation of the Symptom Questionnaire for Visual Dysfunctions (SQVD): A Questionnaire to Evaluate Symptoms of any Type of Visual Dysfunctions

Purpose

To assess psychometric properties of the Symptom Questionnaire for Visual Dysfunctions (SQVD) questionnaire, including accuracy, validity, and reliability, in a clinical sample of patients having any type of visual dysfunction.

Methods

A clinical sample of 306 patients self-administered the SQVD. Rasch analysis was performed to analyze the functionality of the response categories, fit statistics, differential item functioning (DIF), person and item reliability, targeting, local dependency, unidimensionality, and transformation table. Accuracy was assessed by means of receiver operating characteristic (ROC) curves, using symptoms reported in each patient's clinical record as the gold standard for classifying patients with and without symptoms. The concurrent validity, known group validity, and test–retest reliability (repeatability, using the intraclass correlation coefficient [ICC]) were also examined.

Results

SQVD showed orderly category responses. The 14 items fit the Rasch model without significant DIF for gender, presbyopia, and dysfunctions. Person and item reliabilities were 0.81 and 0.85, respectively. Targeting was –1.49 logits. Yen's Q3 statistic showed no local dependency. SQVD was unidimensional (first contrast of the residual = 1.852 eigenvalue with a variance explained by measures of 52.23%). The area under the ROC curve was 0.836 (95% confidence interval [CI], 0.792–0.879) with a cutoff of ≥6 showing good accuracy (sensitivity = 0.759; specificity = 0.783). SQVD showed good concurrent and known group validity and high repeatability (ICC, 0.857; 95% CI, 0.710–0.933) when administered twice 1 week apart.

Conclusions

SQVD has shown good psychometric properties. It can be considered an accurate, valid, and reliable questionnaire to detect visual symptoms related to any type of refractive, accommodative, and binocular dysfunction.

Translational Relevance

SQVD may be used for diagnostic purposes, as it can accurately detect symptoms related to any sort of visual dysfunction. It may also be useful to monitor the treatment outcomes of these conditions.