Accommodation
Conditions
Brief summary
The investigators believe that this simple, clear, and objective study may be a great help in understanding the accommodative response during various accommodative stimulation conditions.
Detailed description
The purpose in this study was to investigate physiological changes in accommodative power, pupil diameter, astigmatic value, and axis when visual stimuli were applied under binocular, monocular (dominant eye, non-dominant eye, ipsilateral, and contralateral), and pinhole conditions using the WAM-5500 binocular autorefractor/keratometer (Grand Seiko Co. Ltd., Hiroshima, Japan).
Interventions
DEVICEthe WAM-5500 binocular autorefractor/keratometer (Grand Seiko Co. Ltd., Hiroshima, Japan)
: Subjects underwent a basic ophthalmic examination and the accommodative response to refractive stimuli was measured. Refractive stimuli were given at 0.25 diopters (D) (4 m distance), 2D (50 cm), 3D (33 cm), and 4D (25 cm) and stimulation was applied with the eyes in binocular, monocular (dominant eye, non-dominant eye, ipsilateral, and contralateral), and pinhole conditions. In addition, changes in the astigmatic value and direction of the astigmatism axis under binocular stimulus were evaluated.
Sponsors
Chung-Ang University Hosptial, Chung-Ang University College of Medicine
Study design
Observational model
CASE_CROSSOVER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
20 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
1. age between 20 and 40 years 2. spherical equivalent (SE) within ± 4.0 diopters (D) 3. correctable distant and near visual acuity by glasses to 20/20 4. normal ocular alignment.
Exclusion criteria
1. disturbance of accommodation (e.g., Adie's pupil, Parkinson's disease, accommodative esotropia, accommodative spasm, presbyopia) 2. disorders that can affect accommodation (e.g., history of ocular trauma, previous ocular surgery) 3. disorders that might limit testing accuracy (e.g., corneal pathological features, cataract, glaucoma, vitreous opacity, and retinal abnormalities).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Accommodative power | Subjects performed this examination while being under binocular, monocular, and pinhole conditions with one week apart in random order after baseline study | Accommodative powers in diopters were measured using WAM-5500 binocular autorefractor/keratometer |
| Pupil diameter | Subjects performed this examination while being under binocular, monocular, and pinhole conditions with one week apart in random order after baseline study | Pupil diameters in millimeters were measured using WAM-5500 binocular autorefractor/keratometer |
| Astigmatic value and axis change | Subjects performed this examination while being under binocular, monocular, and pinhole conditions with one week apart in random order after baseline study | Astigamtic value in diopters and axis change in degrees were measured using WAM-5500 binocular autorefractor/keratometer The spherical equivalent (sphere + 1/2 cylinder) was used to assess the response to refractive stimuli. The principal meridian of the cylinder for 0.25D refractive stimulus was set to the baseline axis. For 2D, 3D, and 4D refractive stimuli, vertical movement was determined when the baseline meridian moved to the 90' axis, and it was considered horizontal movement when it moved to the 0' or 180' axis. |
Outcome results
None listed