| Abstract: | Objective: To investigate the clinical characteristics and surgical effects in type Ⅲ acute acquired concomitant esotropia (AACE Ⅲ). Methods: This was a retrospective self-control study. Thirty-one AACE Ⅲ patients, aged 14 to 39 years, who underwent routine strabismus surgery at the Affiliated Eye Hospital of Nanjing Medical University, were enrolled from July 2016 to July 2019. The following data were collected: Onset time, binocular ametropia, time of near work, the attachment point of the internal rectus muscle, pre- and postoperative deviation, fusion range, and distance and near stereopsis. The followup period ranged from 6 months to 12 months (7.4±2.6 months). A Wilcoxon signed rank test was used to compare the difference in esodeviation and binocular fusion range before and after strabismus surgery. Preand postoperative distance stereopsis were analyzed by the traditional paired Chi square test, while pre- and postoperative near stereopsis was analyzed by the enhanced paired Chi square test. Results: Among the 31 patients with AACE Ⅲ, 3 patients (10%) had high myopia, 25 patients (81%) had moderate myopia, 2 patients (6%) had low myopia, and only one patient (3%) had emmetropia. All patients had performed nearwork with an average time of 7.8±1.1 hours per day. The average distance between the attachment point of the internal rectus muscle and the corneal limbus was 4.9±0.1 mm. The median pre-operative esodeviation at near (33 cm) was 35 PD, and at distance (6 m) was 40 PD. The difference between them was statistically significant (Z=-3.136, P=0.002). In this study, all patients underwent a successful strabismus operation and at the time of the final follow-up, whether it was at 33 cm or 6 m, the median degree of postoperative strabismus was 0 PD. Compared with the pre-operative degree of strabismus at the same distance, the postoperative degree was significantly smaller (both Z=-4.865, both P<0.001). The median of pre- and postoperative binocular fusion range was 14° and 19°, respectively, and the difference between them was statistically significant (Z=-3.149, P=0.002). Compared with distance and near stereopsis before strabismus surgery, 16(84%) patients recovered distance stereopsis and 19(95%) patients recovered near stereopsis after the surgery. Both distance and near stereopsis significantly improved when comparing stereopsis before and after surgery. The difference was statistically significant (χ2 =14.063, 24.000, respectively; P<0.001, P=0.001, respectively). Conclusions: Prolonged near work, the forward attachment point of the internal rectus muscle and moderate myopia appear to be important risk factors for AACE Ⅲ. Strabismus surgery to establish the proper angle can significantly diminish the degree of esotropia and improve the binocular fusion range and stereopsis in AACE Ⅲ patients. |
