Examining the Validity of a New Method for the Objective Assessment of Binocular Accommodative Facility (2Q-AF Test): A Comparison with ± 2.00 DS Lens Flippers

Vera, Jesús; Redondo, Beatríz; Koulieris, George Alex; Molina, Rubén; Jiménez, Raimundo

doi:10.1080/02713683.2021.1962359

Cited by 3 publications

(10 citation statements)

References 25 publications

(34 reference statements)

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“…The blur, break, and recovery points were also noted [27]. The accommodation facility (AF) [28] was determined using the AF flippers of a +2.00 dioptric sphere (DS) and -2.00 DS lens. Both monocular and binocular AFs were assessed at 40 cm.…”

Section: Methodsmentioning

confidence: 99%

Binocular vision parameters and body mass index

Elangovan¹,

Shanmugham²

2023

Med Hypothesis Discov Innov Optom

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Background: Abnormal body mass Index (BMI) can adversely affect binocular vision. We aimed to assess the presence of possible differences in binocular vision parameters among the four BMI categories. Methods: In this comparative cross-sectional study, we enrolled young adults and categorized them into underweight, normal weight, overweight, and obese groups based on their BMI. A complete orthoptic evaluation was performed to assess the mean values of binocular vision skills. Results: We recruited 120 participants with a mean (standard deviation) age of 21.30 (1.80) years with best-corrected distance and near visual acuities of 6/6 and N6, respectively. The frequency of exophoria > 4 PD was high in the obese group. The frequency of binocular vision dysfunction was higher in the obese and underweight groups, with vergence dysfunction being the most common. The mean values for near negative fusional vergence (NFV), distance positive fusional vergence (PFV), negative relative accommodation, positive relative accommodation, monocular accommodation facility (AF), and monocular estimation method were comparable among the groups (all P > 0.05). The obese group had significantly receded near point of convergence, and reduced accommodative convergence to accommodation ratio and binocular AF than the normal, overweight, and underweight groups (all P < 0.05). The distance and near vergence facilities were significantly lower in the obese group than in the overweight and normal groups, and the distance vergence facility was significantly lower than in the underweight group (all P < 0.05). The mean values of distance NFV and near PFV in the obese group were significantly lower compared to the normal and overweight groups, and the mean values of distance NFV were significantly lower compared to the underweight group (all P < 0.05). The mean values of near PFV were significantly lower in the underweight group than in the overweight group (both P < 0.05). Both the underweight and obese groups had a significantly lower amplitude of accommodation compared to the normal group (both P < 0.05). Conclusions: The frequency of binocular vision dysfunction was higher in the obese and underweight groups. Most convergence and some accommodation parameters were adversely affected in individuals with obesity. Being underweight adversely affects certain binocular vision skills. Further studies are required to determine the relevance of BMI as a predictor of binocular vision abnormalities.

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Section: Methodsmentioning

confidence: 99%

Binocular vision parameters and body mass index

Elangovan¹,

Shanmugham²

2023

Med Hypothesis Discov Innov Optom

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“…As an example, for the 4D free‐space viewing test, accommodative data taken for targets at 2 m and 22 cm were used to assess the accuracy of the response at far and near, respectively. As previously stated, a new equation (2Q‐AF score), considering the number of cycles per minute (cpm) – quantitative data, and the percentage of cycles under‐accommodated and under‐relaxed (qualitative data) (Equation ), has been proposed for the assessment of accommodative facility 11 . Here, we considered both the total number of cycles and 2Q‐AF score for statistical analyses.…”

Section: Methodsmentioning

confidence: 99%

“…As previously stated, a new equation (2Q-AF score), considering the number of cycles per minute (cpm)quantitative data, and the percentage of cycles underaccommodated and under-relaxed (qualitative data) (Equation 1), has been proposed for the assessment of accommodative facility. 11 Here, we considered both the total number of cycles and 2Q-AF score for statistical analyses. Figure 2 shows an example of the procedure for accommodative facility analysis.…”

Section: Accommodative Facility Analysismentioning

confidence: 99%

“…Additionally, as explained by Elliot, 8 this test does not provide objective information (i.e., the change in the accommodative response during the test), and there is no justification for the use of ±2.00 D lenses other than they are the traditional powers. In an attempt to solve these limitations, some researchers have developed an automated accommodative facility test to eliminate operator delays in flipping the lenses 9 or have suggested incorporating an open‐field autorefractor to assess the accommodative response objectively during the test 10,11 …”

Section: Introductionmentioning

confidence: 99%

“…In an attempt to solve these limitations, some researchers have developed an automated accommodative facility test to eliminate operator delays in flipping the lenses 9 or have suggested incorporating an open-field autorefractor to assess the accommodative response objectively during the test. 10,11 The use of free-space viewing conditions (i.e., using changes in target distance rather than lenses to alter the accommodative stimulus) and comparing accommodative facility measurements under monocular and binocular viewing conditions will allow investigation of the impact of apparent image size, motor reaction time and vergence/ accommodative mismatch on the subjective accommodative facility findings. In addition, integration of a binocular open-field autorefractor and evaluation of the accuracy of the accommodative response at both stimulus levels will enable the qualitative assessment of accommodative facility, thus clarifying the impact of the participants' criteria for determining whether the image is clear or blurry.…”

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Effect of manipulating the vergence/accommodation and image size mismatches of the ±2D flipper test on the frequency and precision of accommodative facility

Vera

Redondo

Martínez-Tovar

et al. 2023

Ophthalmic Physiologic Optic

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Purpose The ±2.00 D accommodative facility test presents several limitations, including the lack of objective information and inherent characteristics such as vergence/accommodative conflict, change in apparent size of the image, subjective criteria for judging blur and motor reaction time. By using free‐space viewing conditions and an open‐field autorefractor to monitor the refractive state, we examined the impact of manipulating these factors on the qualitative and quantitative assessment of accommodative facility. Methods Twenty‐five healthy young adults (24.5 ± 4.5 years) took part in this study. Participants performed three accommodative facility tests (adapted flipper, 4D free‐space viewing and 2.5D free‐space viewing) under both monocular and binocular conditions in random order. A binocular open‐field autorefractor was used to assess the accommodative response continuously, and these data were used to characterise accommodative facility quantitatively and qualitatively. Results There were statistically significant differences between the three testing methods both quantitatively (p < 0.001) and qualitatively (p = 0.02). For the same accommodative demand, a lower number of cycles was obtained for the adapted flipper condition in comparison with the 4D free‐space viewing test (corrected p‐value < 0.001, Cohen's d = 0.78). However, this comparison did not reach statistical significance for qualitative measures of accommodative facility (corrected p‐value = 0.82, Cohen's d 0.05). Conclusions These data provide evidence that the qualitative assessment of accommodative facility is not influenced by the inherent limitations of the ±2.00 D flipper test. The use of qualitative outcomes by incorporating an open‐field autorefractor allows examiners to increase the validity of the accommodative facility test in both clinical and research settings.

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Accommodative response and visual fatigue following a non‐congruent visual task in non‐asthenopic and asthenopic individuals

Coq,

Neveu,

Plantier

et al. 2024

Ophthalmic Physiologic Optic

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PurposeAsthenopia is related to near vision activities or visual tasks that dissociate accommodation from vergence. Since the results of previous studies using objective measures to diagnose asthenopia are inconsistent, this study compared optometric tests and objective metrics of accommodation in non‐asthenopic and asthenopic young adults before and after a visual fatigue task.MethodsThe accommodative response was recorded objectively for 6 min at a 3.33 D accommodative demand using an autorefractor, before and after a 5‐min non‐congruent visual task. Accommodation was disassociated from vergence with a ±2.00 D accommodative flipper while reading at the same distance. Optometric tests and subjective evaluations of asthenopia were performed before and after the task. Twenty‐six non‐presbyopic adults (23.15 ± 2.56 years) were included and identified as asthenopic (n = 14) or non‐asthenopic (n = 12) based on their score on the Computer Vision Syndrome Questionnaire.ResultsA mixed ANOVA found no significant difference between the groups for objective (accommodative response) or subjective metrics (feeling of fatigue, optometric tests), although all participants reported greater visual fatigue after the task. A significant effect of time (before and after the non‐congruent task) was identified for the overall sample for mean accommodative lag (+0.10 D, p = 0.01), subjective visual fatigue (+1.18, p < 0.01), negative relative accommodation (−0.20 D, p = 0.02) and near negative fusional reserve (blur: +2.46Δ, p < 0.01; break: +1.89Δ, p < 0.01; recovery: +3.34Δ, p = 0.02).ConclusionsThe task‐induced asthenopia, measured both objectively and subjectively, was accompanied by a change in accommodative lag, greater visual fatigue and a decrease in negative relative accommodation. Conversely, near negative fusional reserves seem to adapt to the task. No significant differences were found between the two groups with respect to accommodative metrics (objective) or subjective and optometric tests.

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Examining the Validity of a New Method for the Objective Assessment of Binocular Accommodative Facility (2Q-AF Test): A Comparison with ± 2.00 DS Lens Flippers

Cited by 3 publications

References 25 publications

Binocular vision parameters and body mass index

Binocular vision parameters and body mass index

Effect of manipulating the vergence/accommodation and image size mismatches of the ±2D flipper test on the frequency and precision of accommodative facility

Accommodative response and visual fatigue following a non‐congruent visual task in non‐asthenopic and asthenopic individuals

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