Clinical characteristics of acute acquired concomitant esotropia before and after the COVID-19 pandemic: a retrospective analysis

Purpose This study aimed to observe the clinical characteristics of acute acquired concomitant esotropia (AACE) patients in recent five years and to examine the changes in the proportion of AACE cases before and after the COVID-19 pandemic. Methods A retrospective study included 148 patients who underwent strabismus correction surgery for AACE between January 1, 2017, and December 31, 2021. The study analyzed the changing proportion of AACE cases before and after the COVID-19 pandemic and analyzed its clinical characteristics. Results Abnormalities in the worth 4 dot examination (both distance and near) were present in 134 cases (90.54%) before surgery, while 140 cases (94.59%) showed normal results after surgery. Near stereoacuity was present in 135 cases (91.22%). The near and distance deviations were (55.01 +/- 18.77) PD and (57.30 +/- 17.64) PD, respectively, and there was no significant difference between the two (p = 0.279). There were significant differences in the ratio of refractive status among different age groups (p < 0.001), while no statistically significant difference was observed in the ratio of refractive status for near deviation (p = 0.085) or distance deviation (p = 0.116). The proportion of AACE cases after the COVID-19 pandemic was significantly higher than that before the COVID-19 pandemic (p = 0.042). There was no statistically significant difference in the clinical characteristics between the two groups (p > 0.05). Conclusions Myopia is the most common refractive status in AACE. More than half of patients had occupations that involved long hours of close work. The proportion of AACE cases increased significantly after the COVID-19 pandemic.