Evaluation of accommodative Insufficiency with the Visual Analogue Scale (VAS)

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.

The role of clinical diagnosis criteria on the frequency of accommodative insufficiency

AIM

To estimate and compare the frequency of accommodative insufficiency (AI) within the same clinical population sample depending on the type of clinical criteria used for diagnosis. Comparing the frequency within the same population would help to minimize bias due to sampling or methodological variability.

METHODS

Retrospective study of 205 medical records of symptomatic subjects free of any organic cause and symptoms persisting despite optical compensation evaluated. Based on the most commonly clinical diagnostics criteria found in the literature, four diagnostics criteria were established for AI (I, II, III and IV) based on subjective accommodative tests: monocular accommodative amplitude two or more diopters below Hofstetter's minimum value [15-(0.25×age)] (I, II, III, IV); failing monocular accommodative facility with minus lens, establishing the cut-off in 0 cycles per minute (cpm) (I) and in 6 cpm (II, III); failing binocular accommodative facility with minus lens, establishing the cut-off in 0 cpm (I) and in 3 cpm (II).

RESULTS

The proportion of AI (95%CI) for criteria I, II, III and IV were 1.95% (0.04%-3.86%), 2.93% (0.31%-4.57%), 6.34% (1.90%-7.85%) and 41.95% (35.14%-48.76%) respectively, with a statistically significant difference shown between these values (χ2 =226.7, P<0.001). A pairwise multiple comparison revealed that the proportion of AI detected for criterion IV was significantly greater than the proportion for the rest of the criteria (P-adjusted<0.05 in all cases).

CONCLUSION

The prevalence of cases of AI within the same clinical population varies with the clinical diagnostic criteria selected. The variation is statistically significant when considering the monocular accommodative amplitude as the only clinical diagnostic sign.