Acute Acquired Comitant Esotropia Type 2-A Retrospective Analysis

Background Acute acquired comitant esotropia (AACE) is an uncommon form of strabismus. The main characteristics of AACE Type 2 in childhood are: acute onset of strabismus around 3 years of age, large and comitant angle of strabismus, absence of accommodative component, hyperopia of not more than 3 dpt, and measurable stereopsis. Strabismus surgery is urgently indicated in AACE Type 2 in order to avoid maldevelopment or loss of stereopsis. Therefore, in order to better describe the characteristics of AACE Type 2, we performed a retrospective analysis of patients previously seen in our clinic. Patients and Methods Retrospective analysis of data from patients who underwent strabismus surgery between October 2011 and September 2019 due to suspected AACE Type 2 could be confirmed during postoperative visits by evaluating ocular alignment and stereopsis at our hospital. Analysed data included: age and symptoms at first visit, visual acuity, refractive status, correction by glasses, age at surgery, period of time between first symptoms and surgery, surgical procedure, stereopsis and angle of strabismus (before surgery and 1 day, 3 months, and 12 months after surgery). Ethical approval was obtained from the Cantonal Ethics Committee of Zurich. Results 18 patients (12 male, 6 female) with mean hyperopia of 1.4 +/- 0.6 dpt were identified as meeting the inclusion criteria during the defined time period. Amblyopia was present at first assessment in two patients. Strabismus surgery was performed at 2.0 to 11.1 years of age and between 0.4 and 24.6 months after onset of symptoms. Surgery was performed within 6 months after onset of symptoms in 12/18 children. Before surgery, angle of strabismus at near was measured as 38 +/- 10 prism diopters (PD) and was reduced after surgery to 3 +/- 3 PD at 3 months and 2 +/- 2 PD at 12 months. Stereopsis was confirmed in 5/18 patients one day after surgery and in 18/18 patients 12 months after surgery. Conclusion Our analysis showed that our patients with diagnosis of AACE Type 2 had mild hyperopia and large comitant non-accommodative esotropia; prognosis for recovery of stereopsis is excellent. Preoperative amblyopia does not exclude the diagnosis of AACE Type 2. Therapeutic intervention is advisable within a short period of time after first symptoms and the diagnosis of AACE Type 2.