Unilateral lateral rectus recession is an effective surgery for intermittent exotropia in young children.

BACKGROUND: Different surgical methods have been suggested for the correction of intermittent exotropia. Unilateral lateral rectus recession has been described as a surgical alternative for small and moderate-angle exotropia. In general, previous studies did not focus on the outcomes of unilateral lateral rectus recession in young children with intermittent exotropia. The purpose of this study is to evaluate the surgical outcomes of unilateral lateral rectus recession in the treatment of moderate-angle exotropia (≤ 25 PD (prism diopters)) in children. METHODS: The charts of all patients younger than 12 years of age with moderate-angle exotropia (up to 25 PD) who were operated during the years 2006-2018 were retrospectively reviewed. Fifty-eight patients underwent unilateral lateral rectus recession and had a minimum follow up of 6 months. The angle of exotropia (PD) before and after surgery and the success rate were documented. RESULTS: Mean age at surgery was 6.4 ± 1.9 (range 3.5-11.0) years. Exotropia improved from a preoperative angle of 21.4 ± 4.0 PD to 3.5 ± 5.9 PD postoperatively (p < 0.001). Success rate, defined as deviation of ≤ 10 PD, was achieved in 86.2%. There were 2 (3.4%) cases of overcorrection (consecutive esotropia). There were no intra- or postoperative complications. The mean follow-up duration after surgery was 2.3 ± 1.7 years. CONCLUSIONS: In children with moderate angle exotropia, good postoperative success rate was achieved by performing unilateral lateral rectus recession.

How to Better Treat Patients with Intermittent Exotropia: A Review of Surgical Treatment of Intermittent Exotropia.

Intermittent exotropia (X(T)) is the most common form of strabismus, especially in Asians. Treatment of X(T) includes occlusion, overminus lens, and surgery, of which, surgery is the mainstay of treatment. Commonly performed surgical procedures for X(T) are bilateral lateral rectus muscle recession or unilateral lateral rectus recession with medial rectus resection; however, it is unclear which of the two surgeries is more effective. The purpose of this review is to provide an insight on the surgical treatment of X(T). Randomized controlled trials, comparative observational studies, and case series with a large number of patients as well as a long follow-up period of over a year were included.

A Prospective Study of One-Muscle Surgery in 15-25 Prism Diopters Horizontal Comitant Strabismus in Adults.

PURPOSE: To prospectively evaluate the results of one-muscle surgery in 15-25 prism diopters (PD) horizontal comitant strabismus in adults. PATIENTS AND METHODS: 15-25 PD horizontal strabismus patients, comprising 25 exotropic (XT) patients and 11 esotropic (ET) patients, who underwent one-muscle recession by a single surgeon with a fixed surgical dosage were included in the study with a minimum follow-up of 3 months. The main outcome was a surgical success, which is defined as a residual deviation of <8 PD at the last examination. Other parameters include postoperative lateral incomitance and patient satisfaction. Postoperative lateral incomitance indicated a difference in deviation of >5 PD between the primary position and lateral gaze, or duction limitation at any visit. Patient satisfaction regarding cosmetic and functional outcomes was assessed by using a 5-point Likert scale. RESULTS: Successful alignment was obtained in 19 (76%) and 9 (81.81%) XT and ET patients (p = 1.00), with a median and interquartile range (IQR) of follow-up time of 3, 3-3 months and 3, 3-7 months, respectively. Postoperative lateral incomitance was observed in 8 (32%) XT patients and in 1 (9.09%) ET patient (p = 0.22). One XT patient and one ET patient who developed incomitance reported diplopia, which disappeared 3 months after surgery. One XT patient reported diplopia while gazing towards the operated eye whilst one ET patient reported diplopia occasionally which was unrelated to gaze direction. Patient satisfaction was based on Likert scale scores with 4.12 ± 0.97 in XT patients and 4.73 ± 0.65 in ET patients (p = 0.07). CONCLUSION: One-muscle recession with a fixed surgical dosage was effective for treating small angle horizontal strabismus with a high rate of surgical success and patient satisfaction. Although postoperative lateral incomitance occurred, only a few patients developed symptomatic diplopia, which completely resolved 3 months after surgery.

Interocular difference associated with myopic progression following unilateral lateral rectus recession in early school-aged children.

PURPOSE: To compare refractive changes in operated eyes and fellow unoperated eyes following unilateral lateral rectus recession in early school-aged children. STUDY DESIGN: A retrospective case control study. METHODS: The medical records of children under ten years of age with intermittent exotropia who underwent unilateral lateral recession surgery were reviewed. The operated eyes were reviewed and the fellow unoperated eyes were used as control. The rate of myopic progression was calculated by spherical equivalent (SE) changes per year, and by the rate of refractive growth (RRG) equation. RESULTS: SE showed a myopic shift one week after surgery and in the following months, from -1.43 ± 1.84 diopters (D) at 1 week post operation to -1.57 ± 2.22 D at one year and, finally -2.95 ± 2.97 D at the average 4.62 years following surgery. However, the SE shift was not significantly different from the unoperated eye. The low myopia group (under -3.0 D) showed a significantly higher myopic change in the operated eye until one year post operation (p = 0.022). The average myopic shift ratio was -0.53 ± 0.46 D yearly in the operated eye. CONCLUSIONS: This study presents data of a large series of refractive changes secondary to lateral rectus recession, and of long-term myopia progression in Korean population.

Comparison of bilateral/unilateral lateral rectus recession and unilateral recession-resection for intermittent exotropia: a Meta-analysis.

AIM: To compare the effectiveness of unilateral recession-resection (R&R) and bilateral/unilateral recession (BLR/ULR) for treatment of basic type of intermittent exotropia [IX(T)]. METHODS: A comprehensive literature search was performed using PubMed, EMBASE, and the Cochrane Library, to identify randomized controlled trials and comparative studies regarding the effectiveness of R&R and BLR/ULR for IX(T). Based on which, a Meta-analysis was then performed in terms of long-term success rate, overcorrection rate, and recurrence rate. RESULTS: Nine studies in total satisfy the specified eligibility criteria. BLR is at disadvantage to R&R at a short-term follow-up [<2y, OR 0.56 (0.33-0.94) for success rate; OR 2.11 (1.17, 3.81) for undercorrection rate]. However, BLR achieved a higher success rate [OR 2.49 (1.61, 3.86)] and a lower undercorrection rate [OR 0.40 (0.23, 0.71)], compared to that of R&R at a long-term follow-up (>2y). There is no significant difference was found in overcorrection rate, regardless of the length of follow-up time [OR 0.85 (0.41, 1.75)]. In the treatment for small-angle IX(T), the final outcome was significantly different between the groups, demonstrating a more successful alignment [OR 0.37 (0.18, 0.74)] and a lower undercorrection [OR 3.50 (1.28, 7.26)] in the R&R group than in the ULR group. While for moderate-angle IX(T) (20 PD-25 PD), the effectiveness of R&R and ULR is quite equivalent with similar success rate [OR 1.08 (0.65, 1.79)] and undercorrection rate [OR 0.89 (0.54, 1.48)]. CONCLUSION: As regard to the effect of BLR and R&R, R&R shows an advantage over BLR at short term. But, BLR is more effective in the long term for the basic type IX(T) in children. R&R surgery should be a better choice for the treatment of small-angle IX(T) of ≤20 PD than ULR. However, both of ULR and R&R are recommended for moderate-angle IX(T) from 20 PD to 25 PD.

Surgical outcomes according to distance between preplaced suture and muscle insertion in lateral rectus recession.

PURPOSE: To compare surgical outcomes according to the distance between the preplaced suture and the muscle insertion in lateral rectus (LR) recession for exotropia. METHODS: We retrospectively reviewed 64 patients who had undergone unilateral LR recession by one right-handed surgeon and divided the patients into 2 groups: right LR recession (R group, 26 patients) and left LR recession (L group, 38 patients). In the R group, the preplaced suture was behind the hook, far from the insertion; in the L group, the suture was in front of the hook, near the insertion. The main outcome measures were postoperative alignment and surgical success rate and the secondary outcome measure was effect/dose ratio. Surgical success was defined as an alignment between 10 prism diopters (PD) of exodeviation and 5 PD of esodeviation both at distance and at near. The effect/dose ratio was defined as the corrected angle of deviation at postoperative 6 months divided by the amount of LR recession. RESULTS: The mean angle of deviation at distance showed a significant difference between the groups at postoperative 3 months (p = 0.022), but not at final follow-up (p = 0.163). There was no difference between the groups in the mean angle of deviation at near postoperatively. Surgical success was achieved in 73.1% of the R group and 71.1% of the L group at final follow-up, which was not significant (p = 0.860). CONCLUSIONS: The distance between the preplaced suture and the muscle insertion in LR recession did not affect the surgical success rate or the postoperative alignment at final follow-up.

Comparison of the stability of postoperative alignment in sensory exotropia: adjustable versus non-adjustable surgery.

PURPOSE: To compare the success rates and stabilities of postoperative alignment between adjustable and the non-adjustable surgeries in the treatment of sensory exotropia. METHODS: A retrospective analysis was performed on all patients with sensory exotropia who had undergone unilateral lateral rectus recession and medial rectus resection (R&R) between January 1998 and August 2005. Thirty-four patients underwent conventional R&R, and 20 patients underwent R&R with adjustable suture of the lateral rectus. The surgical results between the two groups were analyzed with regard to the preoperative and post-operative deviation angles and the postoperative drift. The postoperative deviation angle was measured on postoperative day 1 as well as at two weeks, three months, six months and the final visit after surgery. RESULTS: There were no statistically significant differences in the mean preoperative and postoperative deviation angles between the two groups. In 30 (88%) patients in the non-adjustable group and 15 (75%) patients in the adjustable group, postoperative deviation was less than 15 prism diopters (PD) at the three month follow-up. There was no significant difference in the mean postoperative drift between the two groups. CONCLUSIONS: Strabismus surgery with adjustable sutures did not show a significantly better result than surgery without adjustable sutures in the treatment of sensory exotropia. Considering the amount of postoperative exodrift in both groups, we postulate that the immediate ocular alignment after surgery for sensory exotropia should be orthophoric or 5-6 PD of esodeviation.