A retrospective survey of strabismus surgery in a tertiary eye center in northern China, 2014–2019

BACKGROUND: To evaluate the distribution pattern and changes of strabismus surgery in northern China. METHODS: The records of strabismus patients at Qingdao Eye Hospital from January 2014 to December 2019 were reviewed retrospectively. The characteristics analyzed included gender, regional distribution, constituent ratio of age and type of strabismus. Changes during the periods 2014–2016 and 2017–2019 were compared and analyzed. RESULTS: A total of 5746 strabismus patients were recruited. The number of strabismus patients was relatively stable each year from 2014 to 2016 but gradually increased each year from 2017 to 2019. Of these, 51.7% (2968/5746) were male, and 48.3% (2778/5746) were female. The majority (89.8%, 5159/5746) of the patients were from Shandong Province. The statistical results of the constituent ratio of age showed that 32.4% (1860/5746) were 7–12 years old (primary school level). Patients under 12 years of age (preschool and primary school level) accounted for 60.0% (3447/5746) of all the patients. In terms of the types of strabismus, exotropia accounted for 63.5% (3650/5746), followed by esotropia and vertical rotational strabismus at 13.2% (758/5746) and 9.7% (555/5746), respectively. Intermittent exotropia was the most common type among the exotropia patients, accounting for 71.3% (2604/3650). Among the patients with intermittent exotropia, 62.5% (1627/2604) were children aged 4–12 years, and the basic type of intermittent exotropia was the main type. Four percent (231/5746) of the patients, of which adult patients comprised the main population, required reoperation. CONCLUSIONS: Patients with strabismus at primary school level comprised the largest group of strabismus patients in north China. Exotropia was the most common type of strabismus, and intermittent exotropia was the most common type of exotropia. The rate of exotropia to esotropia was 5:1.