Bilateral Lateral Rectus Recession Research Articles

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.

Large consecutive esotropia after uneventful surgical correction of infantile exotropia: A post-operative surprise

Abstract The incidence of consecutive esotropia developing after exotropia surgery has been reported to be 6%–20%. Consecutive esotropia with limited abduction requires reoperation on the muscles that were operated during the first surgery. It is difficult to predict the result of the second surgery because it may convert to exodeviation after the advancement of lateral rectus (LR) muscle, the contracture of the previously recessed muscle, or hypertrophy of resected medial rectus (MR). We present a case of 20-year-old woman with infantile exotropia who underwent bilateral lateral rectus recession and left MR resection in view of a large primary position deviation of 55 prism diopter (PD) at a 6-meter distance. But the patient developed large consecutive esotropia of 50 PD within 3 weeks of surgery with abduction limitation in the left eye, which was highly suspicious of slippage of the left LR. But when the LR was explored, it was found at 16 mm from the limbus without any evidence of slippage. In view of the abnormal response after the first surgery, the LR was advanced by 9 mm, and was inserted at 7 mm from limbus. The patient was orthophoric on the first postoperative day, and the alignment was maintained till 6 months of follow-up. This case is unique in terms of unexpected large consecutive esotropia of 50 PD after uncomplicated routine strabismus surgery, which was corrected by advancement of one LR only. This event could be possibly due to lack of binocularity and fusion in these patients with an associated component of dissociated horizontal deviation. This report emphasizes the possibility of some unusual postoperative outcomes in spite of careful and meticulous preoperative workup, and uneventful squint surgery in patients with infantile deviation.

The long-term surgical outcomes of lateral rectus advancement in consecutive esotropia.

To evaluate the long-term surgical efficacy of lateral rectus advancement (LRadv) in patients with consecutive esotropia (CET). The medical records of 30 patients who developed CET after bilateral lateral rectus (BLR) recession for exotropia (XT) between 2012 and 2020 were reviewed. The characteristics of patients during their XT surgery were summarized. Among them, 15 patients who underwent LRadv as CET treatment with at least a 1-year follow-up were included to evaluate the long-term efficacy of this surgical approach. The main outcomes were the pre- and post-operative angle of deviation after LRadv. Surgical success was defined as the postoperative deviation within 10 prism diopters (PD), and reoperation was not needed. All data were expressed as median and interquartile ranges. The median follow-up was 34months after LRadv surgery. The median postoperative deviation ranged from 28 to 1 PD at 1year (P < 0.05) and to 5 PD at the final follow-up (P < 0.05). The deviation at each follow-up time showed no statistically significant difference (P > 0.05). The final surgical success was reduced compared to 1day and 1year postoperatively (60% VS 100% and 66.7%, respectively). Undercorrection and overcorrection both occurred at the final follow-up. Although the immediate surgical outcome of LRadv was satisfactory, the success rate reduced with time, which suggests long-term observation is necessary to detect and timely provide appropriate interventions for overcorrection or undercorrection.

Botulinum toxin augmented bilateral lateral rectus recession versus three muscles surgery in large-angle intermittent exotropia.

To report the surgical outcomes of correcting large angle intermittent exotropia in adult patients by bilateral lateral rectus muscle recession with intraoperative use of botulinum toxin and to compare the results with those of bilateral lateral rectus muscle recession and unilateral medial rectus resection. The medical records of patients who underwent surgical correction of large angle intermittent exotropia [exotropia >50 prism dioptre (PD)] were retrospectively reviewed. Two groups of patients were identified; Group I (21 patients) had bilateral lateral recti recession augmented with intraoperative botulinum toxin A (BTA) injection into the recessed muscles and group II (30 patients) were treated by bilateral lateral recti recession with unilateral medial rectus muscle resection. Preoperative data were extracted for age, gender, refraction, type of exotropia, angle of stereopsis and angle of deviation. The main outcome measures were the postoperative angle of deviation and stereoacuity angle by Titmus test measured at the end of one year of postoperative follow up. By the end of the first postoperative year, 10 patients in group I (47.6%) and 20 patients in group II (66.7%) achieved esotropia/esophoria <5 PD or exotropia/exophoria <10 PD. The difference in surgical success rate was not statistically significant (P=0.1) but there was a statistically significant higher rate of undercorrection in group I (P=0.03). On the other hand, 3 patients in group I (14.3%) and 5 patients in group II (16.7%) had improved stereopsis; this difference in the sensory outcome was not statistically significant (P=0.8). In the BTA augmented surgery group, good stereoacuity and smaller preoperative angle of deviation were associated with significantly higher surgical success rate (P=0.004, 0.01 respectively). BTA augmented bilateral lateral recti recession is associated with higher rate of undercorrection as compared to bilateral lateral recti recession with unilateral medial rectus resection in the correction of large angle intermittent exotropia. The surgical success rate in BTA augmented surgery group is observed to be higher in patients with preoperative smaller angle of deviation and in patients with good stereoacuity.

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.

Comparison between Down Transposition and Slanted Surgery for Bilateral Lateral Rectus Recession in Convergence Insufficiency-Type Exotropia

Purpose: We compared bilateral lateral rectus recession with down transposition and slanted bilateral lateral rectus recession as surgical methods for convergence insufficiency-type exotropia.Methods: We included patients who underwent bilateral lateral rectus recession with down transposition or slanted bilateral lateral rectus recession for convergence insufficiency-type exotropia from January 2012 to January 2021 and observed them for more than 1 year. We retrospectively analyzed sex, age, preoperative best-corrected visual acuity, spherical equivalent, axial length, amount of surgery, and deviation angle before surgery and after surgery (immediately, 1 week, 6 months, and 1 year). We also examined surgical success and stereopsis before surgery and after 6 months and 1 year.Results: The down transposition group included 45 patients and the slanted group included 40. The deviation angle of distance, deviation angle of near and the near-distance disparity (NDD) all decreased in the down transposition group and slanted group 1 year after surgery (1.96 ± 8.77 prism diopter [PD] and 4.60 ± 4.99 PD, respectively; 5.53 ± 9.09 PD and 9.03 ± 9.09 PD, respectively; and 3.58 ± 5.26 PD and 4.43 ± 5.32 PD, respectively). Surgical success after 1 year was 55.6% in the down transposition group and 52.5% in the slanted group, and there was no significant difference between the two groups.Conclusions: In convergence insufficiency-type exotropia, both bilateral lateral rectus recession with down transposition and slanted bilateral lateral rectus recession were effective to correct the deviation angle of near, distance, and NDD. Both are suitable primary surgical methods for convergence insufficiency-type exotropia.

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.].

Surgical outcomes and observation in exotropia cerebral palsy children with cortical visual impairment

PurposeCortical visual impairment (CVI) is the common cause of pediatric visual impairment in cerebral palsy (CP) while exotropia is the most common strabismus associated with CP. We aim to observe the strabismic surgery outcomes in pediatric patients with CP and CVI.MethodOur medical records were collected from pediatric patients treated in our hospital from May 1, 2017 to Jan 1, 2022. With normal intelligence assessment and diagnosis of exotropia in children with CP and CVI, microsurgeries were performed under intravenous combined inhalation anesthesia. The strabismus was examined by the prism test under best vision correction and the contrast sensitivity testing (CST) was measured at five levels of spatial frequencies.ResultA total of 38 exotropia patients with CP and CVI were identified and included for analysis during the study period with age ranged from 5 to 12 years (mean 8.45 years) and mean follow up duration was 8.7 months (6–42 months). After bilateral lateral rectus recession (with/without medial rectus resection or inferior oblique transposition), the exotropia amount of participants were obviously revealed from − 30 ~ − 140 (median, IQR: − 50, 40) prism diopters (PD) preoperatively to 0 ~ − 15 (0, 5) PD postoperatively. Statistically significantly improvements were observed at all levels of spatial frequency on CST postoperatively, especially at high spatial frequency areas (p < 0.05).ConclusionOur results demonstrated that the effect of strabismus surgery on exotropia in children with CP and CVI were stable and monocular contrast sensitivity post- operation increased significantly at all spatial frequencies levels.

Surgical approach for treatment of congenital exotropia in children with neurologic impairment

Bilateral lateral rectus recession (BLR-recess) is a common surgical procedure for exotropia but often is insufficient for treatment of congenital exotropia, particularly among children with neurological impairment. We sought to determine factors predictive of surgical failure of BLR-recess in congenital exotropia and describe an alternative surgical approach.

Intermittent exotropia: a novel surgical algorithm based on a postocclusion distance-near relationship

For the preoperative evaluation of patients with intermittent exotropia, prior studies have revealed that prism alternate cover testing at distance and at near should be performed after a period of monocular occlusion, and that the use of a reading add at near helps to exclude accommodative convergence. Using these evaluation techniques, a performance improvement project was undertaken to evaluate a dosage-modification algorithm created to improve outcomes with bilateral lateral rectus recession surgery.

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.

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.

Slanted recession on bilateral lateral rectus for the treatment of intermittent Exotropia with convergence insufficiency

PurposeTo evaluate the efficacy and safety of slanted bilateral lateral rectus recession (S-BLRc) for the treatment of convergence insufficiency-type intermittent exotropia (CI-IXT) in children and to probe the relationship of the slanted amount and surgical outcomes.MethodsRetrospective study. Fifty-eight patients with CI-IXT, aged 4 to 10 years old, underwent S-BLRc procedures. According to the different slanted amount between the upper and lower poles of lateral rectus, all the patients were grouped: Group A (slanting 1 mm, n = 22), Group B (slanting 1.5 mm, n = 18) and Group C (slanting 2 mm, n = 18). The successful surgical outcome was defined as deviation in the primary position ranging from exotropia< 8△ to esotropia< 5△ both at near and at distant as well as the near-distance difference (NDD) < 5△. We analyzed and compared the preoperative and postoperative data including deviations both at near and at distance, NDD, objective torsion, horizontal deviation at up and down gaze, lateral incomitance, binocular vision and surgical success rate among three groups.ResultsThe average deviations were significantly decreased from − 37.1△ ± 4.2△ (−,exotropia) to − 1.4△ ± 4.6△ at near (P < 0.05) and from − 25.8△ ± 3.7△ to − 0.1 ± 4.1△ at distance (P < 0.05). The postoperative NDD on average was significantly reduced from 10.0△ to 1.8△ in Group A (P < 0.05), from 11.2△ to 0.8△ in Group B (P < 0.05) and from 13.3△ to 0.9△ in Group C (P < 0.05). There was a significant difference in the mean corrections of NDD among the three groups (8.2△ in group A, 10.3△ in group B and 12.4△ in group C respectively, P < 0,05). All the patients attained various improvement of stereopsis after surgery. None had torsional diplopia, A-V pattern and lateral incomitance after strabismic surgery. Totally, the surgical success rate was 89.7% in our series at the 6- to 8-month follow-up.ConclusionsSlanted bilateral lateral rectus recession is an effective and safe procedure for the treatment of CI-IXT in children. S-BLRc can successfully collapse exotropia both at distance and at near, decrease NDD and benefit to gain binocular vision. The correction of NDD was associated with the slanted amount.

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.].

Augmented lateral rectus muscle recession for treatment of infantile exotropia.

The surgical outcome is usually not satisfactory for treatment of primary infantile exotropia (PIE) with large exodeviation angels of more than 50 prism diopters (PD). Here, we evaluate the effectiveness of augmented bilateral lateral rectus muscle recession (ABLRR) in treatment of PIE with large deviation angles. A retrospective analysis was performed for 25 patients with PIE who underwent ABLRR. ABLRR was performed using a hemi-hang-back technique. Ocular alignment, ocular motility and binocular vision were evaluated pre- and postoperatively. Fourteen males and 11 females with PIE were included in this study, with a mean age of (3.92 ± 2.02) years (range, 1-7years). The average exodeviation angle was (-66.32 ± 7.84) PD (range, -60--80 PD) preoperatively. All patients underwent ABLRR using the hemi-hang-back technique. Three of them underwent bilateral inferior oblique muscle anterior transposition in the same operation. The mean surgical dosage was (11.08 ± 1.19) mm for each lateral rectus muscle. The mean of deviation angel was -2.28 ± 5.08 PD postoperatively (P < 0.05). All patients did not have abduction deficiency after a large amount of lateral rectus recession. Twenty-one of 25 patients (84.0%) achieved orthophoria at the primary gaze position at the final visit, and 13 patients obtained binocular vision. ABLRR is an effective and safe surgical procedure for treatment of PIE with a large deviation angle.

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.

Medial rectus recession versus lateral rectus advancement in surgical correction of consecutive esotropia

Background Following surgery to address intermittent exodeviation, consecutive esotropia (ET), in which postoperative ET continues for more than 6 months, may arise. Both lateral rectus advancement (LRA) and medial rectus recession (MRR) are effective in correction of consecutive ET. Purpose The aim of this study was to compare the results of LRA and MRR in correction of consecutive ET (within 40 PD) following bilateral lateral rectus recession for treatment of intermittent exotropia. Patients and methods This was a randomized double-blind controlled trial that included 30 patients who were divided into two groups: group 1 (LRA group, 15 patients) and group 2 (MRR group, 15 patients). Unilateral or bilateral LRA or MRR was done according to the preoperative angle of deviation. All patients had preoperative ocular examination, which included history taking, visual acuity testing, slit-lamp examination, fundus examination, preoperative angle of deviation at near and far using the Krimsky method, stereopsis using the Titmus test, and suppression using the Worth 4-dot test. The patients were followed up at 1, 3, and 6 months after surgery. Results There was no statistically significant difference between the two groups in the preoperative angle of deviation (P=0.213). In group 1, the mean preoperative angle of consecutive ET was 29.0±6.14 PD, which improved to 0.87±3.56 PD 6 months after surgery, with a statistically significant difference (P<0.001). In group 2, the mean preoperative angle of consecutive ET was 25.47±8.81 PD and improved to 1.67±4.58 PD 6 months after surgery, with a statistically significant difference (P<0.001). However, there was no statistically significant difference between the two groups in the postoperative angle of deviation (P=0.562). Six months postoperatively, there were two (13.3%) undercorrected cases and one (6.7%) overcorrected case, with a success rate of 80% in group 1, whereas in group 2, there were two (13.3%) undercorrected cases and two (13.3%) overcorrected cases, with a success rate of 73.4%, with no statistically significant difference between the two groups in the success rate (P=0.66). In group 1, the mean preoperative stereoacuity value was 291.7±206.5, which improved significantly postoperatively to 140±35.71 (P=0.005). Similarly, in group 2, the mean preoperative stereoacuity value was 506.7±810.5 and improved significantly postoperatively to 150±46.41, (P=0.003). Conclusion Both LRA and MRR were effective in the correction of consecutive ET.

Outcomes of Early Surgery in Children under Four Years Old with Large Angle Intermittent Exotropia

Purpose: To find out the significance of early surgery in children of 4 years old and under with large angle intermittent exotropia of 35 prism diopters (PD) and more by examining the results of bilateral lateral rectus recession surgery and factors influencing the surgical outcome.Methods: It was a retrospective study of patients who underwent bilateral lateral rectus muscle recession surgery between 2006 to 2016 with intermittent exotropia greater than or equal to 35 PD and who were able to follow-up for at least 2 years after surgery were divided into two groups based on age of 4 years old. The surgical motor success was defined as exodeviation less than 10 PD, esodeviation less than 8 PD. The angle of deviation, binocular function, best corrected visual acuity, and amount of corrected PD per lateral recession (PD/mm) were compared at each observation point after surgery.Results: The motor success of bilateral rectus muscle recession surgery was 85% in children of age 4 years and under, 65.5% in age over 4 years. Success rate of early surgery was 1.3 times higher in younger age group, but there was no statistical meaning. The complication of surgery after 2 years of follow up was less in younger group-the rate of recurrent exotropia was 15% in younger group, 31.3% in older group and the rate of consecutive esotropia was 0% and 3.1%, respectively. Stereoacuity after 2 years of surgery was not fall behind in younger group compared to older group.Conclusions: It is possible to obtain good surgical results by performing early surgery rather than hesitating to operate due to the younger age in patients younger than 4 years old with large angle exotropia of 35 PD and more for long-term follow up and efficient patient management.