Botulinum toxin type A in treating early-stage patients with small-angle acute acquired comitant esotropia.

AIM: To investigate botulinum toxin A (BTXA) efficacy on small-angle (≤25Δ) acute acquired concomitant esotropia (AACE) in early-stage patients. METHODS: The electronic medical record data of AACE patients during March 2019 and June 2023 were collected in this retrospective and hospital-based cohort study. A total of 72 small-angle AACE patients received BTXA extraocular muscle injection. Patients were grouped by onset-to-treatment time (Group A: ≤6mo, Group B: >6mo). Deviation of esotropia, eye alignment and stereopsis were analyzed at the period of pre/post-injection (1wk, 1, 3, and 6mo). Orthophoria rate at 6mo (horizontal deviation <10Δ and binocular single vision) were considered as outcome index. RESULTS: There were no significant baseline differences (P>0.05) between two groups except onset-to-treatment time (2mo vs 11mo, P<0.001). Higher orthophoria rates were in Group A at last follow-up (94.74% vs 73.53%, P=0.013). Post-BTXA deviations of two groups at 1mo showed no difference (P>0.05); while in 3 and 6mo Group A was significantly smaller than group B (all P<0.001). No statistically significant differences were observed among all post-BTXA deviations of near and distance in Group A. In Group B, deviation at 3mo (near: 2Δ vs 0, P<0.001; distance: 4Δ vs 0, P<0.001) and 6mo (near: 6Δ vs 0, P<0.001; distance: 6Δ vs 0, P<0.001) was significant increased compared to deviation at 1wk after treatment. Group A showed better stereopsis recovery in last follow-up compared to Group B (80″ vs 200″, P=0.002). Both groups obtained improved stereopsis after treatment (Group A: 80″ vs 300″, P<0.001; Group B: 200″ vs 300″, P=0.037). CONCLUSION: BTXA is effective for AACE with small deviation (≤25Δ) in early stage. Delayed treatment (>6mo) may reduce BTXA efficacy. Early BTXA intervention benefits long-term eye alignment and stereopsis recovery.

Effects of slanted bilateral lateral recession vs conventional bilateral lateral recession on convergence insufficiency intermittent exotropia: a prospective study.

AIM: To observe the surgical effects of slanted bilateral lateral recession (S-BLR) versus conventional bilateral lateral recession (C-BLR) in convergence insufficiency intermittent exotropia (CI-IXT). METHODS: Using a randomized, double-blind, prospective design, 22 patients with CI-IXT who were admitted to Renmin Hospital of Wuhan University from July 2019 to December 2020 were included. Patients were randomly divided into either S-BLR or C-BLR group for their subsequent strabismus surgery. All patients were followed up for 12mo. Near deviation, distant deviation, and near-distance difference (NDD) were measured in all patients. RESULTS: Twelve months after surgery, NDD improvement was 10 (8, 13) prismatic degrees (PD) in S-BLR group and 3 (1, 6) PD in C-BLR group (P=0.011). The near deviation of S-BLR group was 0 (-2, 2) PD, while that of C-BLR group was -4 (-6, -3) PD (P=0.005). Before and after surgery, the difference in the distant deviation between the two groups was not statistically significant. There was no statistically significant difference in near stereopsis between the two groups (P=0.380) at 12mo. The success rate at 12mo after operation was 90.91% and 72.73% in the two groups (P=0.280). CONCLUSION: CI-IXT patients treated with S-BLR have better surgical outcomes than those treated with C-BLR, which indicates S-BLR is a safe and effective operation pattern.