Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt.
BMC Ophthalmol. 2023 Nov 16;23(1):462. doi: 10.1186/s12886-023-03210-x.
V pattern identification is essential for proper strabismus management. Graded recession is a tailored approach to treat inferior oblique overaction (IOOA). The aim is to evaluate the efficacy of graded recession of inferior oblique muscle for correction of different grades of V pattern.
Forty patients from 3 to 18 years old with V pattern strabismus and primary IOOA were evaluated by prism cover test to assess the grade of IOOA and amplitude of V-pattern. Graded recession of IO muscle depends on the amplitude of the V-pattern and degree of IOOA. Eight mm recession for amplitude 15 PD to 20 PD and mild IOOA (10 PD-15 PD or + 1) ,10 mm recession for amplitude 20-30 PD and moderate IOOA (15-25 PD or + 2) and maximum recession for amplitude more than 30 PD and marked IOOA (≥ 25 PD or + 3). Simultaneous correction of the horizontal deviation was performed. Follow up after I week,1 month ,3 month and 6-month. Trial Registration Number (TRN) (NCT05786053) on 23/3/2023.
The mean age of the study patients was 9 ± 4.261. Twenty patients (50%) had V-pattern esotropia, 12 (30%) exotropia, 4 (10%) orthotropic and four (10%) had Dissociated vertical deviation (DVD). Four cases 10% were of grade 1, 20 cases (50%) grade 2 and 16 cases (40%) were of grade 3. Of eighty eyes, 66 eyes (82.5%) were fully corrected with no residual IOOA, and 14 eyes (17.5%) were under corrected. V-pattern was corrected in 28 cases 70% and only 12cases (30%) had residual V-pattern grade 1.
Graded recession is an effective procedure for correction of V pattern strabismus with various grades of primary inferior oblique overaction. It can be tailored according to the the degree of IO overaction which is significantly related to the grade of V pattern. The 8 mm recession for IO was significantly related to recurrence or inadequate break of the V pattern in our studied cases. The grade of IOOA correlates with the amplitude of V-pattern. The amount of recession was planned according to preoperative IOOA and grade of V-pattern with frequent undercorrections obtained by the standard 8 mm recession. A + 2 overaction merits a 10-mm recession of the inferior oblique. A + 3 or + 4 overaction merits a 14-mm maximal recession.
V 型斜视的识别对于斜视的正确管理至关重要。分级后退是治疗下斜肌亢进（IOOA）的一种针对性方法。目的是评估下斜肌分级后退术矫正不同程度 V 型斜视的疗效。
对 3 至 18 岁的 40 例 V 型斜视合并原发性 IOOA 患者进行棱镜遮盖试验，以评估 IOOA 的程度和 V 型斜视的幅度。下斜肌的分级后退取决于 V 型斜视的幅度和 IOOA 的程度。对于 15PD 至 20PD 的幅度和轻度 IOOA（10PD-15PD 或+1），进行 8mm 后退；对于 20-30PD 的幅度和中度 IOOA（15-25PD 或+2），进行 10mm 后退；对于大于 30PD 的幅度和明显 IOOA（≥25PD 或+3），进行最大后退。同时矫正水平偏斜。术后 1 周、1 个月、3 个月和 6 个月进行随访。注册号（TRN）（NCT05786053）于 2023 年 3 月 23 日注册。
研究患者的平均年龄为 9±4.261。20 例（50%）为 V 型内斜视，12 例（30%）为外斜视，4 例（10%）为正位，4 例（10%）为分离性垂直偏斜（DVD）。4 例（10%）为 1 级，20 例（50%）为 2 级，16 例（40%）为 3 级。80 只眼中，66 只眼（82.5%）完全矫正，无残余 IOOA，14 只眼（17.5%）矫正不足。28 例（70%）V 型斜视得到矫正，仅 12 例（30%）有 1 级残余 V 型斜视。
分级后退术是治疗各种程度原发性下斜肌亢进的 V 型斜视的有效方法。它可以根据 IO 过度活动的程度进行调整，而 IO 过度活动与 V 型斜视的程度有显著的相关性。我们研究中的 8mm 下斜肌后退术与 V 型斜视的复发或不充分缓解显著相关。IOOA 的程度与 V 型斜视的幅度相关。根据术前 IOOA 和 V 型斜视的程度计划后退量，标准的 8mm 后退术常导致矫正不足。+2 度过度活动需要下斜肌 10mm 后退。+3 度或+4 度过度活动需要最大 14mm 后退。
