The effect of caffeine on the accommodative response/accommodative stimulus function and on the response AC/A ratio

Zhai, Huifang; Goss, David A.; Hammond, Raymond W.

doi:10.3109/02713689309001827

Cited by 8 publications

(6 citation statements)

References 15 publications

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“…The results of this study are in agreement with findings of earlier studies by other researchers suggesting changes of accommodative functions after caffeine consumption. [15][16][17] Kirshner and Schmid 15 investigated the extent to which the eye is able to relax accommodation through a +4.00 D lens after consumption of 150 mg caffeine in 11 subjects. The conclusion was that caffeine increased the tonicity of the ciliary muscles by about half of a diopter, hence resulting in the rejection of reading plus lens.…”

Section: Discussionmentioning

confidence: 99%

“…The conclusion was that caffeine increased the tonicity of the ciliary muscles by about half of a diopter, hence resulting in the rejection of reading plus lens. In addition, Zhai et al 16 studied changes in accommodative response at varied accommodative stimuli levels in 17 subjects before and after consumption of caffeine. They reported that caffeine increased the accommodative response only when the accommodative stimulus (object vergence) was not o5.00 D. We measured amplitude of accommodation of younger subjects with greater accommodation ability, hence all our subjects had a sustained blur at a distance of o20 cm (5.00 D).…”

Section: Discussionmentioning

confidence: 99%

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Caffeine intake is associated with pupil dilation and enhanced accommodation

Abokyi

Owusu-Mensah

Osei

2016

Eye

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PurposeIt is purported that caffeine, an autonomic stimulant, affects visual performance. This study sought to assess whether caffeine intake was associated with changes in pupil size and/or amplitude of accommodation.Patients and methodsA double-masked, crossover study was conducted in 50 healthy subjects of age range 19 to 25 years. Subjects were randomized to treatments such that subjects consumed either 250 mg caffeine drink or vehicle on separate days. Amplitude of accommodation was measured by the push-up technique, and pupil size using a millimeter ruler fixed to a slit lamp biomicroscope in dim illumination (5 lux). Amplitude of accommodation and pupil size were taken at baseline, and at 30, 60 and 90 min time points post treatment. Repeated measures one-way ANOVA and paired t-test were used in analyzing data.ResultsAmplitude of accommodation and pupil size after caffeine intake were significantly greater than vehicle (P<0.001) at each time point. Consumption of the caffeine beverage was associated with significant increases in amplitude of accommodation and pupil size with time (P<0.001). Amplitude of accommodation rose from 12.4 (±2.2 D) at baseline to 15.8(±2.6 D) at 90 min. Similarly, pupil size increased from 3.4 (±0.4 mm) at baseline to 4.5 (±0.72 mm) at 90 min. Consumption of vehicle was not associated with increase in amplitude of accommodation or pupil size with time.ConclusionPupil size and accommodation are affected after ingestion of caffeine. This study suggests caffeine may have some influence on visual functions.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Caffeine intake is associated with pupil dilation and enhanced accommodation

Abokyi

Owusu-Mensah

Osei

2016

Eye

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“…The dissociation of these 2 functions is the basis of orthoptic treatment for certain types of accommodative esotropia. 14,23 Studies have also shown that the AC/A ratio is changed through surgery, 24,25 drugs, 14,26 and orthoptic treatment. 14,27 In Kushner's 8 study, two-thirds of patients with a high AC/A ratio who were treated with minus lenses showed ''normalization'' of their AC/A ratio.…”

Section: Discussionmentioning

confidence: 99%

The fixation target influences the near deviation and AC/A ratio in intermittent exotropia

Koklanis

Georgievski

2010

Journal of American Association for Pediatric Ophthalmology and

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“…Particular attention has been given to the amplitude of accommodation and pupil size following the consumption of caffeine, with many studies reporting resultant increases in both the amplitude of accommodation 14,20 and pupil dilation. 14,21 The increase in the amplitude of accommodation is as a result of caffeine binding to the adenosine receptors.…”

Section: Introductionmentioning

confidence: 99%

The short-term effects of energy drinks on near visual performance

Hansraj

Xulu-Kasaba

Tini

et al. 2022

Afr. vis. eye health

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Caffeine is the main constituent in energy drinks, and therefore, remains the most widely studied energy drink ingredient. 9 Most energy drinks have a caffeine content of 50 mg -550 mg per can and/or bottle depending on the brand. 2 Glade, 10 following a detailed literature review of the beneficial effects of caffeine on human physiological systems, reported that caffeine decreases fatigue, enhances physical and cognitive performance, increases alertness, decreases mental fatigue and enhances short-term memory. These may be some reasons for its popularity particularly with young adults and anecdotally more particularly at stressful times such as during examinations. Research, however, has also shown many potential adverse effects resulting from the consumption of large amounts of caffeine. Excessive caffeine consumption has been linked to acute and chronic headaches caused by hyper excitability of cortical cells, 11 as well as irregular Background: Energy drinks have gained popularity amongst young adults in recent years. Widespread effects of its main ingredient caffeine have been observed on the nervous system; however, little is known about the effects of these drinks on the visual system.Aim: This research study investigated the effects of a chosen energy drink on near vision and near contrast sensitivity.Setting: The data were collected at a university optometry clinic in south eastern South Africa.Methods: A single-blinded, crossover study was conducted on 56 healthy subjects aged 18-30 years. Subjects were randomised, such that they consumed either the energy drink reboost or water (control) on separate days. Near visual acuity was measured using a near Logarithm of the Minimum Angle of Resolution (LogMAR) chart and contrast sensitivity using the MARS contrast sensitivity test. Near visual acuity and contrast sensitivity measurements were taken at baseline and again at 30 min, 60 min and 90 min intervals, following consumption. Data were analysed using repeated measures analysis of variance (ANOVA) and univariate analysis.Results: Both near visual acuity and contrast sensitivity, post-energy drink consumption, showed a marginal increase over the testing period. Near visual acuity increased from -0.13 LogMAR at baseline to -0.17 LogMAR at 90 min. Contrast sensitivity increased from 1.77 log units at 30 min to 1.78 log units at 90 min similar to that observed with the control. In both cases; however, the changes were neither statistically (p > 0.05) nor clinically significant. Conclusion:The energy drink reboost had no short-term effect on near vision performance as measured with near visual acuity and contrast sensitivity.

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The effect of caffeine on the accommodative response/accommodative stimulus function and on the response AC/A ratio

Cited by 8 publications

References 15 publications

Caffeine intake is associated with pupil dilation and enhanced accommodation

Caffeine intake is associated with pupil dilation and enhanced accommodation

The fixation target influences the near deviation and AC/A ratio in intermittent exotropia

The short-term effects of energy drinks on near visual performance

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