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Post-dilation Strabismus Measurements

Title Do strabismus measurements change after pupil dilation and cycloplegia in children?
Therapeutic Area Strabismus
Principal Investigator Vicki Chen, MD
Min Age 5 Years
Max Age 18 Years
Gender All
Contact Sara Galinko


This study aims to determine whether strabismus measurements change significantly after dilation with cyclopentolate ophthalmic drops in children. The impetus for this study is a 2018 report published in the American Journal of Ophthalmology, which concluded that in adults, strabismus measurements do not significantly change after dilation with tropicamide and phenylephrine. We would like to replicate this study in a pediatric population with the standard of care dilating agent: cyclopentolate.

In a hospital or clinical learning institution, there may be multiple clinicians who evaluate the pediatric patient. Because so much of strabismus management is predicated upon the results of cover testing, it is common to ask the attending to repeat the measurement, based on the belief that strabismus measurements can change after dilation. If the results of the aforementioned report were applied to the pediatric population, it could dramatically affect the current standard of care. We want to ensure providers are using the most accurate measurements of their treatment of eye turn.

Study Details

Inclusion Criteria

  • Patients must wear correction if hyperopia is greater than 4.00 D, myopia greater than 1.00 D, and astigmatism greater than 2.00 D
  • Compliance with spectacle wear: patient must be wearing current spectacles/contact lenses ≥75% of waking hours, as determined by self-report during case history

Exclusion Criteria

  • Neurological or developmental limitations which would preclude a patient from reliably participating in visual acuity testing and/or cover testing
  • Use of eccentric viewing in either eye: this is a condition in which a patient uses a retinal area other than the fovea to fixate an object of interest

Study Requirements

There is one study visit at the time of the patient’s routine clinic visit. The patient will be asked to fixate on a letter or target while a plastic paddle is held over their eye to evaluate the exo or eso deviation. The same set of measurements will be taken after the patient is dilated, which is routinely done at their standard of care visit.