Unilateral Lateral Rectus Recession Research Articles

Outcomes for Intermittent Exotropia Using Three Common Surgical Approaches.

To compare a single surgeon's surgical outcomes for treating intermittent exotropia using bilateral lateral rectus recession (BLR), unilateral lateral rectus recession and medial rectus resection (RR), and unilateral lateral rectus recession and medial rectus plication (RP). A retrospective review of all surgeries for basic intermittent exotropia between 2015 and 2023 was performed. Only patients with initial correction using BLR, RR, or RP were included. Exclusion criteria included age older than 18 years, vertical deviation, any nonrefractive ocular diagnoses, prior ocular surgery, and inadequate follow-up. There were 460 patients identified; 123 met inclusion criteria with 54 in the BLR group, 41 in the RR group, and 28 in the RP group. The average preoperative distance alignment (and standard error) values for the BLR, RR, and RP groups were 25.07 (7.35), 22.44 (5.95), and 23.84 (6.42) prism diopters (PD), respectively. At 1 year, the postoperative distance alignment values for the BLR, RR, and RP groups were 8.72 (7.89), 7.46 (6.31), and 12.83 (6.82) PD, respectively (P = .03). A subanalysis found a significant difference between the BLR and RP (P = .02) and RR and RP (P = .02) groups. There was no difference between the BLR and RR groups (P = .57). This study of three surgical approaches for intermittent exotropia found RP had a significantly larger angle of exodeviation compared to BLR and RR at 1 year of follow-up. Both BLR and RR were equally effective approaches for treating intermittent exotropia. [J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XX-XX.].

Analysis of postoperative exodrift according to surgical methods for intermittent exotropia.

This study aimed to compare the periods for exodrift stabilization and the long-term surgical outcomes among different surgical methods in intermittent exotropia. The medical records of 350 patients who had undergone intermittent exotropia correcting surgery [unilateral lateral rectus recession-medial rectus resection (R&R, n = 221), bilateral lateral rectus recession (BLR, n = 51) and unilateral lateral rectus recession (ULR, n = 78)] with a postoperative follow-up period of 1.5 years or more were retrospectively reviewed. The deviation angles every 6 months after surgery, periods of exodrift stabilization and surgical outcomes were analysed. The period of postoperative exodrift stabilization was defined as when exodrift was no longer significantly different from that at the next visit (p > 0.05). An alignment of 5 PD (prism diopters) esotropia to 10 PD exotropia at a distance and near fixation was considered surgical success. The mean angle of exodeviation was significantly different among surgical procedures at postoperative 1 month (BLR > ULR > R&R, p < 0.001); however, there were no differences among the procedures at 6 months (p = 0.088). The periods of exodrift stabilization were 6 months after ULR, 1 year after BLR and 4.5 years after R&R. The surgical success and reoperation rates did not show significant differences among procedures at the final follow-up. Patients undergoing R&R showed smaller exodeviation shortly after surgery but required a longer period to stabilize the exodrift. Following ULR, exodeviation was larger in the early postoperative period, but the exodrift was stabilized earlier. Therefore, the long-term surgical outcomes were similar among ULR, BLR and R&R.

Cirugía monocular de 4 músculos extraoculares para la exotropía monocular de gran ángulo

IntroductionRecurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). MethodsRetrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. ResultsTwelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9±15.1 (range 35–80; median 60PD) to 3.3±5.5 (range 0–16; median 0PD) postoperatively (p<0.005). Two (66%) patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10PD or less (range 0–16PD median 0PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured −0.6±1 (0 to −3) and adduction −0.4±0.7 (0 to −2). ConclusionWeakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

Unilateral four muscle surgery for extra-large monocular exotropia

IntroductionRecurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). MethodsRetrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. ResultsTwelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9 ± 15.1 (range 35–80; median 60 PD) to 3.3 ± 5.5 (range 0–16; median 0 PD) postoperatively (p < 0.005). Two of 3 patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10 PD or less (range 0–16 PD median 0 PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured −0.6 ± 1 (0 to −3) and adduction −0.4 ± 0.7 (0 to −2). ConclusionWeakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

Results of Unilateral Lateral Rectus Recession Surgery in 15 - 30 PD Intermittent Exotropia.

To evaluate the surgical outcomes of unilateral lateral rectus muscle recession (ULR) with low surgical dosage in patients with intermittent exotropia (IXT) of 15 - 30 prism dioptres (PD). We retrospectively analysed 92 eyes of 92 patients who underwent ULR surgery with the diagnosis of IXT of 15 - 30 PD at distance fixation between January 2017 and June 2019. ULR surgery of 6.5 mm was performed for exotropia of 15 - 20 PD, 7.5 mm for that of 20 - 25 PD, and 8.5 mm for that of 25 - 30 PD and postoperative results were evaluated at the 1st week, 1st month, 6th month, and the 2nd year. Orthophoria or IXT less than 10 PD was accepted as successful. The mean preoperative deviation angle at distance was 22.3 ± 4.4 PD. Mean postoperative deviation angles at distance were 2.5 ± 1.7, 3.9 ± 2.4, 6.5 ± 3.0, and 8.7 ± 3.1 at 1 week, 1 month, 6 months, and 2 years, respectively. The surgical success rate of ULR was 100, 96.7, 84.7, and 77.1% at the 1st week, 1st month, 6th month, and the 2nd year, respectively. In the long-term results, there were no complications such as lateral gaze incomitance, overcorrection, or deterioration in stereopsis. Using the ULR technique, we were able to obtain effective surgical results in IXT with less surgical dosage and without any serious complications. ULR surgery can be used as an effective method in patients with IXT of 15 - 30 PD.

Early post-operative angle as a predictor of surgical success in adult patients with intermittent exotropia

ABSTRACT Purpose: Intermittent exotropia is a condition where divergent strabismus is present at certain times or fixation distances and is surgically treated with bilateral lateral rectus recession or unilateral lateral rectus recession with medial rectus resection. The main purpose of our study is to assess the relationship between the initial post-operative deviation and surgical outcomes in adult exotropes undergoing recess-resect surgery. Methods: A retrospective chart review was performed on adult patients who underwent unilateral recess-resect surgery for intermittent exotropia between March 2010 and February 2022 at a single institution with at least 3 months of follow-up. Based on their motor alignment at 2 weeks following surgery, they were categorized as having exodeviation, esodeviation within 10 PD and esodeviation exceeding 10 PD. Surgical success was defined as motor alignment within 10 PD of exotropia and 5 PD of esotropia at distance and near at final follow-up. Results: 93 patients were included, 55% female and average age was 37 years. At postoperative week 2, 26 patients demonstrated residual exodeviation (Group A), 53 patients demonstrated an esodeviation of within 10 PD (Group B) and 14 patients demonstrated an esodeviation greater than 10 PD (Group C). There were no significant differences in pre-operative and demographic factors between the group. At the final follow-up, surgical success was observed in 57 patients: 12 in Group A, 41 in Group B and 4 in Group C (P < .01). Conclusion: Overcorrection of within 10 PD at 2 weeks following surgery showed a more favorable surgical outcome compared to exodeviation or esodeviation exceeding 10 PD.

Evaluation of unilateral lateral rectus muscle recession for correction of small-angle intermittent exotropia

Evaluation of unilateral lateral rectus muscle recession for correction of small-angle intermittent exotropia

Comparison of Surgical Outcomes of Two-muscle Surgery in Children with Large-angle Intermittent Exotropia

Purpose: To evaluate the long-term results of 2-muscle surgery in children with large-angle intermittent exotropia (IXT), comparing bilateral lateral rectus recession (BLR) with unilateral lateral rectus recession &amp; medial rectus resection (RR).Methods: Ninety-two children with IXT of 40 prism diopter or more, who underwent BLR or RR were included in this retrospective study. Final successful alignment rates, and cumulative probabilities of surgical success at 3 years postoperatively were analyzed and compared using Kaplan-Meier survival analysis between the two groups.Results: At 3 years after surgery, 37 (67.3%) of 55 patients in the BLR group achieved successful alignment; 18 (32.7%) had undercorrection, and none of them had overcorrection. In the RR group, 34 (92%) of 37 patients were successfully aligned, two (5%) had undercorrection, and one (3%) had an overcorrection at 3 years after surgery. There was a statistically significant difference in postoperative results between the two groups (p = 0.0012). The cumulative probabilities of surgical success at 3 years postoperatively analyzed using the Kaplan-Meier survival curve were 63% in the BLR group and 92% in the RR group. Postoperative mean recurrence time was 45 months in the BLR group and 50 months in the RR group, showing a significant difference between the two groups (p = 0.0006).Conclusions: The unilateral RR procedure demonstrated more favorable long-term postoperative outcomes than BLR procedure in patients with large-angle IXT.

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.

Treatment of convergence insufficiency type intermittent exotropia with bupivacaine injection to the medial rectus combined with lateral rectus recession

PurposeTo evaluate the outcomes of combined bupivacaine HCL (BPX) injection in the medial rectus (MR) muscle with recession of the lateral rectus muscle in the treatment of convergence insufficiency–type intermittent exotropia (CI-IXT). MethodsThe medical records of patients who underwent combined injection-recession treatment from January 2019 to January 2020 for CI-IXT were reviewed retrospectively along with a group of age-matched controls with IXT without CI who underwent only unilateral LR recession during the same period. The following data were extracted from the record: age at surgery, average follow-up period, angle of deviation at distance and near and the difference between them before and after surgical procedure, correction of near and distance deviations, and recession dosage. Successful outcome was defined as a distance deviation in primary gaze between ≤10Δ of exophoria/tropia and ≤5Δ of esophoria/tropia. ResultsA total of 10 patients and 20 controls were included. Average follow-up was 13.9 ± 3.67 months in the BPX group and 15.9 ± 3.61 months in the control group (P = 0.17). Postoperative distance deviation measured 8.30Δ ± 5.88Δ in the BPX group and 14.67Δ ± 9.83Δ in the control group (P = 0.80). Distance-near differences were significantly reduced in the CI-IXT group receiving BPX, by a mean of 6.60Δ, from a preoperative mean of 10.50Δ ± 3.65Δ to 3.90Δ ± 3.26Δ (P < 0.01). ConclusionsBPX injection combined with unilateral lateral rectus recession yields outcomes comparable to bilateral lateral rectus recession for distance deviations, and results in reduction of the distance-near difference in the angle of exotropia.

Comparative Study of Bilateral Versus Unilateral Strabismus Surgery in the Management of Lateral Incomitance in Intermittent Exotropia.

To evaluate and compare bilateral asymmetric lateral rectus recession versus unilateral resection-recession surgery in the management of lateral incomitance in intermittent exotropia. A prospective randomized interventional comparative study was conducted consisting of 80 patients with intermittent exotropia (older than 7 years) having significant lateral incomitance. They were equally divided into two groups by a sealed envelope system. The bilateral group underwent bilateral asymmetric lateral rectus recession and the unilateral group underwent unilateral lateral rectus recession and medial rectus resection based on post-patch deviation. Parameters assessed were change in horizontal deviation, change in lateral incomitance, binocularity, motility limitation, and complications, if any. Surgical outcome was considered successful if the primary deviation was within ±8 prism diopters (PD) and lateral incomitance was less than 5 PD. The mean lateral incomitance preoperatively and postoperatively was 8.3 ± 1.6 and 2.8 ± 2.4 PD in the bilateral group and 8.9 ± 1.4 and 3.7 ± 2.5 PD in the unilateral group, respectively. There was no statistically significant difference in the postoperative lateral incomitance between the two groups (P = .25), but a statistically significant difference was observed between preoperative and postoperative lateral incomitance in each group (P < .0001). Both procedures are equally efficacious in achieving acceptable ocular alignment and improving significant lateral incomitance in patients with intermittent exotropia with deviations between 15 and 35 PD without causing significant motility limitation. [J Pediatr Ophthalmol Strabismus. 2023;60(4):277-281.].

Analysis of the Changes and Possible Reasons in Aberrations before and after Surgery in Patients with Concomitant Exotropia.

Objective The objective is to observe the changes in aberrations before and after surgery in patients with common horizontal strabismus and to analyze the possible reasons for the changes. Methods Forty eyes of 40 cases with concomitant exotropia who underwent strabismus correction at the Ophthalmology Department of Nantong University Hospital from October 2020 to July 2021 were included in this study, all of whom underwent unilateral lateral rectus recession combined with a medial rectus resection in the same eye. Aberration parameters were measured 1 day before surgery and 1 week, 1 month, 3 months, and 6 months after surgery. Differences in the indicators at each time period were compared by analysis of variance (ANOVA) of repeated measures data for a single factor, and data were analyzed using SPSS 25.0 statistical application software. Results 5 mm pupil diameter: the preoperative and postoperative RMS of total aberration showed statistically significant difference (P < 0.01). Postoperation test (Bonferroni method) and preoperative comparison at each period after surgery showed statistically significant differences between 6 months after surgery (P=0.002) and preoperative comparison. The preoperative and postoperative comparison of RMS in LOAs was statistically significant (P < 0.01); postoperative test (Bonferroni method) and preoperative comparison showed that there were statistically significant differences between 1 week (P=0.033) and 6 months (P=0.002) after operation. The difference of RMS of defocus before and after operation was statistically significant (P < 0.01); postoperation test (Bonferroni method) and preoperative comparison showed that there was statistically significant difference between 6 months after operation (P=0.007) and preoperative comparison. There was statistically significant difference in preoperative and postoperative RMS of HOAs (P=0.013). Postoperative test (Bonferroni method) and preoperative comparison showed that there was statistically significant difference 6 months after surgery (P=0.03). The RMS of secondary astigmatism showed a statistically significant difference before and after operation (P=0.001), and the postoperation test (Bonferroni method) showed a statistically significant difference 6 months after operation (P=0.002). In 5 mm pupil diameter, the preoperative and postoperative RMS of total aberration showed statistically significant difference (P < 0.01), postoperative test (Bonferroni method) was used to compare each period after surgery with that before surgery, and there were statistically significant differences between 1 week after surgery (P=0.034), 3 months after surgery (P=0.033), and 6 months after surgery (P=0.003). The preoperative and postoperative comparison of RMS in LOAs was statistically significant (P < 0.01), postoperative test (Bonferroni method) was used to compare each period after surgery with that before surgery, and there were statistically significant differences between 1 week after surgery (P=0.04), 3 months after surgery (P=0.034), and 6 months after surgery (P=0.004). The difference of RMS of defocus before and after surgery was statistically significant (P=0.002), and the comparison between postoperation test (Bonferroni method) and preoperation showed that the difference was statistically significant 6 months after surgery (P=0.027). The RMS of astigmatism showed statistically significant difference before and after operation (P=0.002), and the postoperation test (Bonferroni method) showed statistically significant difference between 6 months after operation (P=0.009) and before operation. Conclusion We found that horizontal rectus surgery had a transient effect on LOAs and almost no effect on HOAs. Long-term follow-up is recommended after strabismus surgery to observe eye position and binocular visual function. Because of the high prevalence of strabismus in adolescents, long-term observation of the eye axis and aberration is recommended.

Unilateral Horizontal Rectus Muscle Recessions for Pediatric Comitant Strabismus

ABSTRACT Introduction Compared to bilateral horizontal rectus muscle recessions (BHR), a unilateral horizontal rectus muscle recession (UHR) confers shorter operating time and anesthesia exposure, limits complication risks to one eye, and requires less recovery from the patient. Methods Retrospective chart review of pediatric patients who underwent unilateral medial rectus recession (UMR) for esotropia (ET), or unilateral lateral rectus recession (ULR) for exotropia (XT). Primary successes were defined as maximum distance deviation at post-operative month 3: −12 to +5 for ET, −5 to +12 for XT. Rates of postoperative horizontal incomitance (HI) >5 PD and success for small medium, and large (in mm, respectively, ET: <5, 5–6 mm, >6; XT: <8, 8–10, >10) recessions were analyzed. Results Seventeen ETs and 40 XTs were analyzed. Overall primary success was 71.9% (p = .02). Significantly, 80% (95% CI: 67.60,92.40) XTs succeeded. ETs were equally likely to succeed (53.9%) or fail (47.1%) (p = .22). For patients without significant preoperative HI, average postoperative HI was 3.90 PD (95% CI: 0.20, 7.60) for ETs; 5.48 PD (95% CI: 3.65, 7.32) for XTs. Conclusions UHR was 71.9% successful in treating pediatric comitant strabismus. ULR for XT, particularly small to medium deviations, was most likely to succeed. In contrast to prior reports, large UMR and ULR were less likely to succeed and post-operative incomitance was frequent but rarely clinically significant.

Effects of Bilateral Medial Rectus Resection on Motor Outcomes in Infantile Exotropia.

PurposeTo evaluate the effects of bilateral medial rectus resection (BMRres) on motor outcomes in infantile exotropia.MethodsWe evaluated 19 cases of infantile exotropia surgery. The mean age at surgical alignment was 4.8±3.4 years (range, 1.5–11.8 years). The surgical procedures included BMRres (5 cases), BMRres with unilateral lateral rectus recession (ULRR) (3 cases), bilateral lateral rectus recession (BLRR) (8 cases), unilateral lateral rectus recession and medial rectus resection (uniRandR) with contralateral lateral rectus recession (2 cases), and uniRandR (1 case). After dividing the cases into two groups (BMRres group, n=8; other group, n=11), the outcomes at 1 day and at 1, 3, and 6 months after surgery were compared. Surgical outcomes were defined as (1) success: distant esotropia ≤5 prism diopters (Δ) or exotropia ≤10Δ, (2) recurrence: exotropia >10Δ, or (3) overcorrection: esotropia >5Δ.ResultsAlthough postoperative distant deviations at 1 day were not different between the two groups, the BMRres group showed smaller distant deviations at 1, 3, and 6 months than the other group (p=0.015, 0.019, and 0.006, respectively). Success rates of the BMRres and other groups were 88% and 73% at 1 day, 100% and 36% at 1 month, 88% and 27% at 3 months, 88% and 18% at 6 months, respectively. Although there were no significant differences between the two groups within 3 months after surgery, surgical outcomes in the BMRres group 6 months after surgery were significantly better than those in the other group (p=0.003).ConclusionBMRres is a better procedure than others for infantile exotropia to achieve desirable motor outcomes after surgery.

Surgical outcomes of unilateral lateral rectus recession versus recess-resect in children with convergence insufficiency type intermittent exotropia

To determine the efficacy of unilateral lateral rectus recession (ULR) for convergence insufficiency-type intermittent exotropia (CI-type IXT), we compared surgical outcomes following ULR and recess‒resect (RR) procedures for CI-type IXT. In this retrospective study, medical records of 57 children who underwent ULR (n = 30) or RR (n = 27) for CI-type IXT of less than 25 PD at distance with a postoperative follow-up of 6 months or more were reviewed. Surgical success was defined as an alignment between 10 PD exodeviation and 5 PD esodeviation at distance and near fixation. The postoperative exodeviation showed no significant difference between the two groups at the last follow-up. A significant reduction in the mean near-distance difference was achieved postoperatively in both groups: from 5.4 PD preoperatively to 2.5 at last follow-up after ULR, and from 8.2 to 2.4 after RR (both p = 0.001). However, this difference between ULR and RR was not statistically significant (p > 0.05). The success rate at the last follow-up was 63.3% for ULR and 70.4% for RR (p = 0.574). ULR was found to be an effective treatment for CI-type IXT, with similar surgical outcomes to RR.

Strabismus surgery outcomes for internuclear ophthalmoplegia with exotropia

ABSTRACT Exotropia (XT) in internuclear ophthalmoplegia (INO) is a difficult problem to treat. The purpose of this study is to describe surgical approaches in treating INO and glean insight into various pre-operative factors that may affect outcomes for XT in INO. We conducted a retrospective review from 1 January 1995 – 5 January 2021 and identified seven patients with INO who underwent strabismus surgery for XT. Patient age, sex, etiology of INO, pre-operative alignment and sensorimotor exam, presence of diplopia, surgery performed, subsequent surgeries, use of adjustable sutures, post-operative alignment, presence of post-operative diplopia, presence of post-operative diplopia with use of prism correction, and length of follow-up were all collected. Initial surgeries undertaken included unilateral medial rectus (MR) plication and lateral rectus (LR) recession, bilateral medial rectus (MR) plications or resections, or bilateral MR plications combined with either unilateral or bilateral LR recessions. Chart review yielded ten charts, however two were excluded due to manifest esotropia (ET), and one was excluded due to incomplete records. Seven total patients were used in final analysis. The cohort age range was from 29 to 79 years. Pre-operative horizontal distance alignment ranged from 35 to 95 XT with an average exodeviation of 67.8 ± 22.6 prism diopters (PD). Horizontal adduction deficit ranged from −1 to −4 and was present bilaterally in all patients. A variety of initial surgical approaches were undertaken. After two muscle surgeries, distance deviation had an average change of 57.3 PD. After three muscle surgeries, distance deviation had an average change of 75 PD. After four muscle surgeries, distance deviation had an average change of 60 PD. Three patients required additional surgery for XT. Time to follow-up ranged from 1 to 58 months. Horizontal distance alignment in primary gaze at latest follow-up ranged from 30 ET to 30 XT with an average of 0 (orthotropia) ± 16.0 PD. One patient had a consecutive esotropia of 30 PD, one had a persistent exotropia of 30 PD, and five patients were orthotropic at distance. All patients reported relief of diplopia in primary gaze at near and distance either with or without use of prism. Horizontal ductions improved to some degree in all patients. Horizontal rectus surgery can treat many cases of XT in INO. Surgeons should consider INO etiology and concomitant vertical deviations when considering surgery. The degree of pre-operative adduction limitation is another important factor, though did not always dictate final motor and sensory outcomes.

Comparison of Unilateral Versus Bilateral Lateral Rectus Recession for Small Angle Intermittent Exotropia: Outcomes and Surgical Dose-Responses.

To compare the surgical outcomes of unilateral lateral rectus recession to bilateral lateral rectus recession for small angle intermittent exotropia. This was a retrospective cohort study of pediatric patients with an intermittent exotropia between 16 and 20 prism diopters (PD) who underwent unilateral lateral rectus recession or bilateral lateral rectus recession at a single tertiary care pediatric hospital. The primary outcome was success (exotropia < 10 PD of esotropia < 5 PD, no decrease in stereopsis > 0.6 log arcsec, and no reoperation) at 12 months postoperatively. Secondary outcomes included survival analysis of time to surgical failure, surgical dose-response, and improvement in central fusion or stereopsis. At 12 months, successful outcomes were achieved in 13 of 27 patients (46%) in the bilateral lateral rectus recession group and 19 of 28 patients (70%) in the unilateral lateral rectus recession group, which was not a statistically significant difference (P = .10). Survival analysis showed a trend toward a higher rate of failure in the bilateral lateral rectus recession group compared to the unilateral lateral rectus recession group (P = .04). The mean surgical dose-response was 1.7 PD/mm at 1 week and 1.0 PD/mm at 12 months for the bilateral lateral rectus recession group, and 2.0 PD/mm at 1 week postoperatively and 1.4 PD/mm at 12 months postoperatively for the unilateral lateral rectus recession group. There were no cases of long-term postoperative lateral incomitance in either group. Unilateral lateral rectus recession and bilateral lateral rectus recession have similar success rates for small angle intermittent exotropia after at least 12 months of follow-up. Randomized controlled trials in surgical management of intermittent exotropia should consider unilateral lateral rectus recession as a treatment arm. [J Pediatr Ophthalmol Strabismus. 2022;59(5):350-355.].

Efficacy of medial rectus plication versus resection for exotropia: a meta-analysis.

To compare the outcomes of medial rectus plication and medial rectus resection procedures in the treatment of exotropia. Articles from Pubmed, EMBASE, Web of Science, and Cochrane Library databases until July 2021 with a minimum follow-up period of 1month were retrieved. No restriction on language was applied. Eligible studies must comply with the inclusion criteria. Only studies with comparisons between unilateral medial rectus plication versus unilateral medial rectus resection, unilateral lateral rectus recession-medial rectus plication (RP) versus unilateral lateral rectus recession-medial rectus resection (RR), or bilateral medial rectus plication(BMRP) versus bilateral medial rectus resection (BMRR) would be included for subsequent analysis. Two primary outcomes were specified: success rate and mean postoperative deviation. Dichotomous data were calculated as pooled odds ratios (ORs) with 95% confidence intervals (CIs) and continuous data as weighted mean differences (WMD) with 95% CIs. A total of 8 studies with 557 participants were enrolled in the meta-analysis based on the inclusion criteria. Seven studies compared lateral rectus recession + medial rectus plication to unilateral lateral rectus recession + medial rectus resection and one study compared bilateral medial rectus plication to bilateral medial rectus resection. Differences in success rates between plication and resection groups were not statistically significant (OR = 0.66; 95% CI, 0.43-1.02; P = 0.06), and the unsatisfactory effects (the undercorrection and overcorrection rates) between the two groups were comparable. Additionally, there were also no significant differences in postoperative deviation and the amount of exodrift between the two groups. This meta-analysis provides evidence that both the medial rectus plication and medial rectus resection procedures have similar efficacy in the treatment of exotropia.

Newly developed abnormal head position and secondary esotropia after strabismus surgery for children with intermittent exotropia.

To review cases of newly developed AHP and secondary esotropia (ET) after surgical correction for IXT. Medical records of cases with newly developed AHP and secondary ET after surgical correction for IXT were retrospectively reviewed. Fifteen cases were included and the mean pre-operative exodeviation was 31.7 ± 10.6 prism diopters (PD) (range: 16-50) at distance. They received bilateral lateral rectus (LR) recessions (13/15), unilateral LR recession and medial rectus (MR) resection (1/15) or bilateral LR recession plus unilateral MR resection (1/15). Fourteen patients developed chin-down AHP with secondary V-pattern ET and 1 presented chin-up AHP with secondary A-pattern ET. The mean esodeviation in primary gaze was 22.7 ± 10.0 PD (range: 3-40) at distance. Twelve cases underwent a second surgery for correction of AHP and secondary ET, and approximately half (5/11) of the recessed LR muscles explored showed a 3-5mm downward displacement of the new attachment. Surgical management mainly included advancement of LR to the original insertion with a 3-5mm upward transposition. The AHP dissipated and ocular alignment returned to normal in all of these cases. Three cases did not require further surgery, and their AHP and secondary ET were no longer present at 2-5months after the first surgery. A downward shift of the recessed LR in IXT may lead to secondary V-pattern ET and development of a chin-down AHP. Advancement of LR with an upward transposition serves as an effective procedure for the correction of this complication.

Outcome of Strabismus Surgery for Exotropia in a 4-year-old with Silver-Russell Syndrome (SRS): A Case Report

Silver-Russell Syndrome (SRS) is a rare disorder associated with prenatal and postnatal growth retardation with associated characteristic facial and ocular features including strabismus. We report the outcome of strabismus surgery performed for exotropia in a 4-year-old patient with SRS. The patient presented with decreased visual acuity and constant exotropia of the right eye noted since 3 months of age. Systemic SRS characteristics consisted of relative macrocephaly, short stature, forehead prominence and stunted growth pattern. An X-pattern exotropia is consistent with bilateral tight lateral recti muscles with over-elevation in adduction of the left eye was present. Patient underwent unilateral right lateral rectus recession and right medial rectus resection for a 50-prism diopter constant exotropia. Patient had a favorable outcome of within 8 prism diopters from orthotropia at 1st, 3rd-, 6th- and 12th-month post-operatively.