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Post-Dilatino 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 17 Years
Gender All
Contact Vicki Chen, MD


The aim of our investigation is to determine whether strabismus measurements change significantly after dilation whit cyclopentolate ophthalmic drops in children. The impetus for this study is a recent 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 cyclopentolate.

In a hospital or clinical learning institution, there may be multiple clinicians who evaluate a 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 in their treatment of eye turn.

Study Details

Inclusion Criteria

  • Between 5 and 17 years of age
  • Best-corrected visual acuity of 20/40 or better in each eye at distance and near in primary gaze
  • Correction of farsightedness greater than 4.00 D, nearsightedness greater than 1.00 D, and astigmatism greater than 2.00 D

Exclusion Criteria

  • Neurological or developmental limitations that would preclude the patient from attending to a letter or figure during cover test measurement
  • Use of eccentric viewing in either eye
  • Presence of dissociated vertical deviation

Study Requirements

Only one research visit will be required, and this visit will be embedded into a previously scheduled eye exam. During the visit, two additional cover tests will be performed during their exam: one set of measurements taken before dilating drops, and another taken after dilation drops. The patient will need only to attend to a letter of figure during cover testing.