Demographic and clinical characteristics and risk factors of stereoacuity in convergence insufficiency-type intermittent exotropia.

Purpose: To investigate characteristics and risk factors of poor stereoacuity of Convergence insufficiency-type Intermittent Exotropia (CI-type X(T)). Design: Observational, cross-sectional study. Methods: The medical records of 615 CI-type X(T) and 222 basic-type intermittent exotropia (X(T)) were enrolled from January 2018 to January 2022. The characteristics were compared between the two types, and the associations between clinical factors and poor stereoacuity were examined using logistic regression. Results: Compared with basic-type X(T), earlier surgery age, shorter misalignment duration, and the smaller distance exodeviation were observed in CI-type X(T). The CI-type X(T) demonstrated better sensory status and lower incidence of ocular muscle dysfunction than did the basic-type X(T). The surgery age between 6 and 12 years (odds ratio [OR], 0.595; compared with ≤6 years) was inversely associated with poor near stereoacuity, whereas duration more than 4 years (OR, 2.474), amblyopia (OR, 4.057), large distance exodeviation (>60PD: OR, 2.462) and anisometropia (>2.00D: OR, 3.874) were positively associated with poor near stereoacuity. The onset age older than 6 years (6-9 years: OR, 0.397; >9 years: OR, 0.317) was associated with better distance stereoacuity, whereas large distance exodeviation (>60PD: OR, 23.513), and dominant eye best corrected visual acuity (BCVA) worsen than 0.20 (OR, 2.987) were positively associated with poor distance stereoacuity. Conclusion: CI-type X(T) declined surgery early, with small distance exodeviation, better sensory status, and low incidence of ocular muscle dysfunction. A strong dose-dependent link between early onset age, long misalignment duration, worse dominant eye BCVA, distance exodeviation, amblyopia, anisometropia, and poor stereoacuity was confirmed.

Efficacy of inferior oblique belly transposition combined with inferior oblique recession for asymmetric inferior oblique overaction.

OBJECTIVE: To evaluate the efficacy of inferior oblique belly transposition (IOBT) combined with inferior oblique (IO) recession in treating bilateral asymmetric inferior oblique overaction (IOOA). METHODS: A retrospective review. The data of 14 patients who underwent IOBT on the mild side of IOOA and IO recession on the severe side for bilateral asymmetric IOOA were analyzed retrospectively. The main surgical results including the correction of IOOA, hypertropia, horizontal deviation, V pattern, and fovea-disc angle (FDA) were observed. RESULTS: The IOBT corrected the preoperative grade (+1.86 ± 0.53) of the mild-side IOOA to a postoperative grade (+0.07 ± 0.27; p < 0.001), and the severe-side IOOA was corrected from a grade of +3.14 ± 0.53 to a postoperative grade of +0.14 ± 0.36 by the IO recession (p < 0.001). The vertical deviation at distance in the primary position was decreased from 8.43 ± 4.05 PD preoperatively to 1.21 ± 1.48 PD postoperatively (p < 0.001). The mean V pattern was 25.00 ± 11.62 PD preoperatively and 3.18 ± 2.18 PD postoperatively (p < 0.001). The mean preoperative FDA on the side where IOBT was performed was -10.47 ± 5.85 degrees, and the postoperative FDA was -7.82 ± 6.42 degrees (p = 0.023). The mean FDA on the side with IO recession was -11.05 ± 5.14 degrees before surgery and -6.09 ± 4.52 degrees after surgery (p = 0.001). The overall success rate was 71.4% (10 of 14). CONCLUSIONS: IOBT combined with IO recession is effective and safe in eliminating hypertropia, V pattern, and extorsion with bilateral asymmetric IOOA.