None listed
Conditions
Brief summary
Low dose atropine eye drops of various concentrations are used to slow the rate of myopic refractive error (short-sightedness) progression in children and adolescents. Atropine is an anticholinergic agent (inhibits the parasympathetic nervous system) which when used as an eye drop, leads to pupil dilation and cycloplegia (reduction or temporary elimination of focusing ability). While these side effects are desirable when treating certain ocular conditions like uveitis or amblyopia, when atropine is used in treating myopia progression, only very low concentrations are used to minimise these side effects. While the effect of low dose atropine on pupil dilation and cycloplegia are widely documented, the implications for single and clear binocular vision when taking this medication have not specifically been studied. The objective of this research project is to examine the effect of nightly dosing of 0.05% atropine sulfate eye drops for 10 days with respect to the binocular vision characteristics of young adult myopes. Outcome measures will include: distance and near heterophoria (measures the coordination of the aiming between the two eyes at distance and near), positive and negative relative accommodation (measures the range of the focusing system over which clear focus is maintained when performing near tasks), accommodative posture (accuracy of focusing when reading), positive and negative fusional vergence (measures the range of the focusing system over which single vision is maintained when performing near tasks), binocular accommodative facility (a measure of the flexibility of the focusing system), and near point of convergence (a measure of the degree to which the two eyes can focus inwards while still maintaining single vision). The outcomes of this research would be expected to inform the development of clinical protocols for assessing patient suitability for low dose atropine treatment, through determination of effects on binocular vision, and identification of patients who would be most impacted by these side effects. This will help to identify potentially unsuitable candidates for treatment and any contraindications to treatment.
Interventions
0.05% atropine sulfate (0.1% BAK) eye drops, 1 drop in each eye at night before bed, for 9 nights
To monitor adherence to the intervention, eye drop bottles will be weighed before dispensing, and after conclusion of the clinical trial. Participants will also receive nightly text message reminders at 9pm to encourage compliance.
Sponsors
Queensland University of Technology
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 25 Years
Healthy volunteers
No
Inclusion criteria
Healthy, young adult myopes with a myopic refractive error between -0.75 and -6.00 DS, with no more than 1.50 DC of astigmatism or 2 D of anisometropia, whose refractive error is currently corrected with single vision distance spectacles or contact lenses, and who have stereoacuity of 200 seconds of arc or greater.
Exclusion criteria
• No current or previous myopia control (atropine, OrthoK, peripheral defocus soft CLs) • No amblyopia or strabismus • Best corrected visual acuity (BCVA) greater than or equal to 0.1 logMAR, with no more than 1 line difference in VA between eyes • Habitual correction (either single vision distance spectacles or contact lenses) within 0.50D of cycloplegic refraction result • No pregnancy or breastfeeding • No history of ocular surgery • No history of significant ocular infection or injury • No allergy to atropine, tropicamide, or benzalkonium chloride (BAK) • No known angle closure glaucoma, or temporal VH ratio less than 0.3:1 in either eye • Intraocular pressure of less than 21 mmHg in each eye • No current use of: anticholinergics, antiglaucoma medications, antimyasthenics, potassium drugs, carbachol/physostigmine/pilocarpine, no CNS depressants (such as antiemetics, phenothiazines, or barbiturates).
Outcome results
None listed