The influence of accommodative insufficiency on reading

Comparison of Short-Term Effects of Treatment of Accommodative Infacility with Low Plus Addition in Single Vision Rx or Vision Therapy: A Pilot Study

PURPOSE

To compare the short-term treatment effect of low plus reading addition (ADD) and home-based vision therapy (VT) in a small group of symptomatic children with accommodative infacility (AIF) being the most significant dysfunction.

METHODS

Nineteen children, 8 to 12 years of age, with a first-time diagnosis of AIF were consecutively and alternately allocated to treatment with ADD (+0.50 D addition in single vision Rx) or VT (accommodation exercises using Hart Charts) for a period of 6 weeks. Accommodation facility (AF) was measured monocularly (MAF-R, MAF-L) and binocularly (BAF) with +2 D/-2 D flipper and registered in cycles per minute (cpm). Symptoms were graded using the convergence insufficiency symptom survey (CISS). Measurements were compared before and after treatment and between groups using nonparametric statistics (p < 0.05).

RESULTS

Ten children were allocated to ADD (median age 9.0 F:5) and 9 to VT (median age 11.0 F:7). Baseline median measurements of MAF-R, MAF-L, BAF and CISS were 3.0, 3.0, 2.2 cpm, and 27.5 points, respectively, for ADD, and 2.0, 2.0, 2.0 cpm, and 27.0 points, respectively, for VT. There were no significant differences between groups at baseline. After 6 weeks of treatment, the median change of MAF-R, MAF-L, BAF and CISS was +5.0, +4.5, +4.7 cpm, and -7.5 points, respectively, for ADD and +8.0, +8.0, +10.0 cpm, and -20.0 points, respectively for VT. All changes within groups were significant. Comparison of groups showed a significantly greater effect of treatment with VT compared to ADD for BAF (p = 0.008) and CISS (p = 0.017).

CONCLUSION

In children with newly diagnosed AIF, treatment with accommodation exercises for 6 weeks gives greater short-term relief of symptoms and improvement of binocular accommodative facility compared to treatment with spectacle single vision correction with a weak plus addition.

Feasibility of optical quality analysis system for the objective assessment of accommodation insufficiency: a phase 1 study

PURPOSE

To assess differences in a new objective metric obtained with a double-pass technique between a group with accommodation insufficiency (AI) and a control group and to explore the diagnostic capabilities of this new tool in comparison to conventional procedures.

METHODS

Retrospective cross-sectional case-control phase 1 study. Two groups with ages ranging from 8 to 18 years were recruited: AI and control group. The diagnostic criterion of AI was based on monocular accommodative amplitude (AA), 2 D below Hofstetter's calculation for minimum AA, and monocular accommodative facility (MAF), failing with minus lens and cut-off at ≤ 6 cycles per minute. Accommodative response with a double pass device (HD Analyzer, Visiometrics) was measured, performing an evaluation from +1.00 D to -3.50D (-0.5D steps), offering the width of the profile at 50% (WP) in minutes of arc.

RESULTS

Differences were found between groups for the AA, MAF and MEM retinoscopy (p < 0.0001, p < 0.001, p = 0.037). The discriminative capacity of MEM retinoscopy for AI diagnosis was significant and the cut-off that maximized the sensitivity and specificity was > 0.5 D. Considering WP 50% in different points, the discriminative AI diagnosis capacities for the points of 2.0 D and 2.50 D were significant (ROC-AUC 0.78; p = 0.03 and p = 0.02).

CONCLUSIONS

Double-pass system metric differed between patients with AI and control group, therefore the aim of a Phase I study was achieved. Further steps with higher sample sizes are required to evidence if the system really provides any advantage versus conventional methods in the diagnosis of AI.

Accommodative Insufficiency: Prevalence, Impact and Treatment Options

PURPOSE

Accommodative insufficiency (AI), defined as the inability to stimulate accommodation in pre-presbyopic individuals, has gained much attention over recent years. Despite the enormity of the available information, there is a significant lack of clarity regarding the criteria for definition, methodology adopted for testing and diagnosis, and the varied prevalence across the globe. This review aims to gather evidence that is pertinent to the prevalence, impact and efficacy of available treatment options for AI.

METHODS

PubMed, Google Scholar and Cochrane Collaboration search engines were used with the keywords prevalence, accommodative insufficiency, symptoms, plus lens, vision therapy and treatment. Peer-reviewed articles published between 1992 and 2019 were included in the review. After reviewing the studies for study methodology and robustness, 83 articles were chosen for this literature review.

RESULTS

The prevalence of AI ranges between <1.00% and 61.6% across studies. The prevalence shows considerable variation across ethnicities and age groups. There is significant variation in the study methodology, diagnostic criteria and number of tests performed to arrive at the diagnosis. Not many studies have explored the prevalence beyond 20 years of age. The prevalence of AI is high among children with special needs. There is no high-quality evidence regarding the standard treatment protocol for AI. Both vision therapy and low plus lenses have shown efficacy in independent studies, and no studies have compared these two treatment options.

CONCLUSION

The understanding of AI prevalence is currently limited owing to the lack of a standard set of diagnostic criteria and wide variations in the study methodology. There is a lack of high-quality evidence suggesting the best possible treatment for AI. The current gaps in the literature have been identified and future scope for exploration is elucidated.

Accommodative insufficiency in a student population in Iran

PURPOSE

To determine the prevalence of accommodative insufficiency (AI) and its relation with age, gender, and refractive errors in a college-age student population in Iran.

METHODS

The present study was conducted cross-sectionally in 2017. All students had optometric tests including measurement of visual acuity, objective and subjective refraction, as well as binocular vision and accommodative examinations. Amplitude of accommodation was measured with the Donders' push-up method using the Royal Air Force (RAF) rule. Monocular accommodative facility was measured with ±2.00diopter flipper lenses. The accommodative response was tested using dynamic retinoscopy with the monocular estimation method (MEM).

RESULTS

The prevalence of AI in the studied population was 4.07% (95% CI: 2.61-5.52). The rate was 6.04% (95% CI: 3.58-8.50) in females and 2.01% (95% CI: 0.53-3.48) in males, and logistic regression showed a significantly higher odds of AI in females (OR=3.14, 95% CI: 1.33-7.45, p-value=0.009). The prevalence of AI was 2.59% (95% CI: 0.55-7.56) in the 18-19-year-old age group and 4.08% (95% CI: 0.09-8.07) in the 24-25-year-old group (p-value=0.848). The prevalence of AI among emmetropic, myopic, and hyperopic individuals was 3.74% (95% CI: 1.88-5.61), 4.44% (95% CI: 2.07-6.81), and 5.26% (95% CI: 4.79-16.32), respectively (p-value=0.869). In the multiple regression model, only gender showed significant relationship with AI (Odds ratio=3.14, 95% CI: 1.33-7.45; p-values=0.009).

CONCLUSION

The prevalence of AI in the present study is lower than the most prevalence rates reported in previous studies. In the present study, gender and AI showed a strong association, such that AI prevalence was significantly higher in females than males.

Symptomatology associated with accommodative and binocular vision anomalies

PURPOSE

To determine the symptoms associated with accommodative and non-strabismic binocular dysfunctions and to assess the methods used to obtain the subjects' symptoms.

METHODS

We conducted a scoping review of articles published between 1988 and 2012 that analysed any aspect of the symptomatology associated with accommodative and non-strabismic binocular dysfunctions. The literature search was performed in Medline (PubMed), CINAHL, PsycINFO and FRANCIS. A total of 657 articles were identified, and 56 met the inclusion criteria.

RESULTS

We found 267 different ways of naming the symptoms related to these anomalies, which we grouped into 34 symptom categories. Of the 56 studies, 35 employed questionnaires and 21 obtained the symptoms from clinical histories. We found 11 questionnaires, of which only 3 had been validated: the convergence insufficiency symptom survey (CISS V-15) and CIRS parent version, both specific for convergence insufficiency, and the Conlon survey, developed for visual anomalies in general. The most widely used questionnaire (21 studies) was the CISS V-15. Of the 34 categories of symptoms, the most frequently mentioned were: headache, blurred vision, diplopia, visual fatigue, and movement or flicker of words at near vision, which were fundamentally related to near vision and binocular anomalies.

CONCLUSIONS

There is a wide disparity of symptoms related to accommodative and binocular dysfunctions in the scientific literature, most of which are associated with near vision and binocular dysfunctions. The only psychometrically validated questionnaires that we found (n=3) were related to convergence insufficiency and to visual dysfunctions in general and there no specific questionnaires for other anomalies.

Accommodative function in school children with reading difficulties

BACKGROUND

Prior findings suggest correlation between reading problems and accommodative function, but few studies have assessed accommodation in children with poor reading skills. Our aim was to characterize monocular accommodative amplitude, relative accommodation and binocular accommodative facility in a population of healthy, non-dyslexic primary school children with reading difficulties.

METHODS

We conducted a cross-sectional study on 87 poor readers and 32 control children (all between 8 and 13 years of age) in grades three to six recruited from 11 elementary schools in Madrid, Spain. In each subject with best spectacle correction, negative relative accommodation (NRA) and positive relative accommodation (PRA) were measured using a phoropter, monocular accommodative amplitude (MAA) was determined using the minus lenses method, and binocular accommodative facility (BAF) was measured using the Bernell Acuity Suppression Slide (VO/9) and a +/- 2.00 D accommodative demand for a period of 1 minute.

RESULTS

Monocular accommodative amplitude was significantly lower (p < 0.001) in the group of poor readers (right eye 9.1 D +/- 2.3, left eye 9.0 D +/- 2.3) than in the control group (right eye 10.5 D +/- 1.7, left eye 10.5 D +/- 1.7). Binocular accommodative facility values were significantly lower (p < 0.05) in the poor readers (4.9 cpm +/- 3.1) than controls (6.3 cpm +/- 2.9). Negative and positive relative accommodation values were similar in both groups of children.

CONCLUSIONS

This study provides data on the accommodative capacity of a population of children with reading difficulties. Our findings suggest a reduced monocular accommodative amplitude and binocular accommodative facility, such that this function should be assessed by an optometric clinician in children whose reading level is below average.