Incidence of Strabismus and Amblyopia Among Children Initially Diagnosed With Pseudostrabismus Using the Optum Data Set

Abstract

To determine the frequency of strabismus among children initially diagnosed with pseudostrabismus using big data. Population-based retrospective cohort study. Setting: Population-based retrospective cohort study using claims data. StudyPopulation: 17,885 children diagnosed with pseudostrabismus at age ≤3 years who were later diagnosed with strabismus using the Optum deidentified Clinformatics Data Mart Database (2003-2016). We excluded patients diagnosed with strabismus before the diagnosis of pseudostrabismus or diagnosed simultaneously with strabismus and pseudostrabismus. We assessed age, refractive error, and presence of amblyopia. Patients with pseudostrabismus were compared to a group of patients from the Optum data set diagnosed with esotropia, exotropia, and unspecified heterotropia who had not been previously diagnosed with pseudostrabismus. MainOutcomeMeasures: Incidence of strabismus, among patients initially diagnosed with pseudostrabismus vs those without an initial diagnosis of pseudostrabismus. Strabismus was diagnosed in 9.6% (n= 1,725) of children initially diagnosed with pseudostrabismus at a median age of 1.65 years (IQR: 1.17-2.46) compared to 1.7% (136,047 of 7,787,743) of children in the control group (P < .001). Strabismus was diagnosed more than a year later in the pseudostrabismus group (3.32 years; IQR: 2.28-4.74) compared with the control group (2.28 years, IQR: 1.43-3.16) (P < .001). Esotropia was the most common type of strabismus in both groups (pseudostrabismus, 69.7%; control, 62.1%). A total of 377 children (21.9%) in the pseudostrabismus group underwent strabismus surgery compared with 12.1% of children in the control group (P < .001). Young children diagnosed with pseudostrabismus are at increased risk of developing strabismus and undergoing strabismus surgery.