Surgical dose-effect relationship in single muscle advancement in the treatment of consecutive strabismus

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.

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

PURPOSE

To review cases of newly developed AHP and secondary esotropia (ET) after surgical correction for IXT.

METHODS

Medical records of cases with newly developed AHP and secondary ET after surgical correction for IXT were retrospectively reviewed.

RESULTS

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 3-5 mm downward displacement of the new attachment. Surgical management mainly included advancement of LR to the original insertion with a 3-5 mm 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 2-5 months after the first surgery.

CONCLUSION

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.

Longitudinal course of consecutive esotropia in children following surgery for basic-type intermittent exotropia

PURPOSE

To evaluate the longitudinal course of consecutive esotropia following surgery for basic-type intermittent exotropia.

METHODS

Patients who underwent surgery (bilateral lateral rectus muscle recession [BLR] or unilateral lateral rectus muscle recession-medial rectus muscle resection [RR]) for the treatment of intermittent exotropia between 2011 and 2017 with a minimum follow-up period of 2 years were retrospectively reviewed. When esodeviation occurred later in patients with orthotropia or exodeviation at postoperative month 1, it was defined as delayed-onset consecutive esotropia. The number of patients with esodeviation at every follow-up and characteristics of patients were evaluated.

RESULTS

A total of 336 patients (6.2 ± 2.1 years; 236 in the BLR group and 100 in the RR group) were included. After surgery, postoperative esodeviation decreased mostly during the 1st postoperative month in both groups. At postoperative year 2, there were 28 patients (8.3%) with consecutive esotropia: six in the RR group and 22 in the BLR group. Among the 284 patients with orthotropia or exodeviation at postoperative month 1, there were 13 patients with delayed-onset consecutive esotropia; they presented larger preoperative angle of exodeviation, poorer stereopsis, younger at the time of surgery and associated with the types of surgeries for exotropia.

CONCLUSIONS

In patients with consecutive esotropia, the angle of esodeviation decreased and patching/prismatic correction helped achieve the good surgical outcomes. However, delayed-onset consecutive esotropia and persistent esotropia also presented, requiring the reoperation. Therefore, postoperative alignment should be carefully monitored after surgery for intermittent exotropia.

Surgical treatment of consecutive exotropia: Comparison of different surgical methods applied to one eye in one session

PURPOSE

To compare the different surgical methods performed on a single eye in a single session and the factors that affect the success of patients having consecutive exotropia (XT) developed after esotropia surgery.

METHODS

The medical data of the patients who underwent surgery for consecutive XT were reviewed retrospectively. Patients with followed of 6 months or more were divided into four groups; patients with medial rectus (MR) advancement (Group 1 = 10), MR advancement and MR resection (Group 2 = 12), MR advancement and lateral rectus (LR) recession (Group 3 = 13), MR advancement, MR resection, and LR recession (Group 4 = 14). Success results and possible risk factors were investigated.

RESULTS

Forty-nine patients with consecutive XT (21 female, 28 male) were enrolled in the study. The mean age of overall patients was 22.97 years at surgery for consecutive XT. The groups did not display significant differences in terms of surgery ages, gender, refraction values, visual acuity, amblyopia, inferior oblique overaction, limitation of adduction, surgical success rates, and follow-up time (p > 0.05). Patients of Group 4 had larger preoperative and postoperative deviation, while Group 1 had smaller (p < 0.05). The surgical success rates of Groups 1, 2, 3, 4 were 90%, 75%, 76.9%, and 50%, respectively (p = 0.192). Statistically, no factor was found to be effective in surgical success rates (p > 0.05).

CONCLUSION

Surgical treatment of consecutive XT is successful in most of the patients with numerous surgical options performed on a single eye in a single session. Patients, particularly with a high amount of deviation should be warned about the possibility of additional surgery.

Consecutive Esotropia with and without Abduction Limitation - Risk Factors and Surgical Outcomes of Lateral Rectus Advancement

Purpose: To identify risk factors for abduction limitation in consecutive esotropia following surgical correction of exotropia. To study outcomes of lateral rectus advancement for consecutive esotropia correction.Methods: Patients with consecutive esotropia (>10PD) operated between 2007 and 2019 with a minimum follow-up of 2 months were reviewed retrospectively. Preoperative and postoperative alignment and ocular motility were recorded. Patients were classified into those with full abduction (group-A) and with abduction limitation (group-B). Success was defined as deviation ≤10 PD of esotropia or exotropia in the primary position.Results: Forty-cases fulfilled the inclusion criteria (group-A = 28 and group-B = 12). Median age at surgery was five years, median consecutive esotropia was 20PD and follow-up was 29.18 months. Abduction limitation (group-B) was associated with constant exotropia (p = .01) and larger bilateral lateral rectus recession (group-A = 13 mm, group-B = 15 mm; p = .04). Nineteen patients underwent lateral rectus advancement (group-A = 12, group-B = 7), one underwent medial-rectus recession and two were excluded due to lack of postoperative follow-up. Five patients had spontaneous resolution with good alignment (group-A = 3, group-B = 2), two refused surgery, three were observed and eight were lost to follow-up. Success following second surgery was similar in both groups (group-A = 86%, group-B = 77%)(p = 1).Conclusion: Constant exotropia and larger lateral rectus recession were associated with abduction limitation in consecutive esotropia. Lateral rectus advancement produced good outcomes irrespective of abduction limitation.

Pattern strabismus in consecutive esodeviation after bilateral lateral rectus muscle recession for intermittent exotropia

PURPOSE

After bilateral lateral rectus recession for intermittent exotropia, children can develop V- or A-pattern esodeviation and adopt a chin-down or chin-up position to facilitate fusion. The aim of this study was to discuss possible causes and management of this pattern.

METHODS

The medical records of children who developed consecutive esodeviation with V- or A-pattern strabismus after surgery for intermittent exotropia but with no pre- or postoperative oblique muscle dysfunction were reviewed retrospectively. Ductions, versions, angles of deviation, and fundus torsion were evaluated before and after surgery. Patient management and outcomes were analyzed.

RESULTS

A total of 37 patients were identified (mean age, 5.7 ± 1.5 years), with a mean preoperative deviation of 30.6^Δ ± 5.2^Δ; no patient had a preoperative pattern strabismus. Mean bilateral lateral rectus recession was 6.2 ± 0.9 mm. Of the 37, 34 (89%) returned postoperatively with V pattern, 2 with an A pattern, and 1 with an hourglass-like pattern. No patient showed oblique muscle dysfunction or fundus torsion. Reoperation for the consecutive deviation was performed in 19 patients, in all of whom the lateral rectus muscles were not vertically displaced. The pattern disappeared completely after reoperation and reestablishment of adequate alignment in the primary position.

CONCLUSIONS

In our patient cohort, pattern strabismus after bilateral lateral rectus recession was successfully reversed by correction of the consecutive esodeviation.

Comparison of surgical outcomes between lateral rectus recession and medial rectus advancement for postoperative consecutive exotropia

To compare the surgical outcomes of medial rectus advancement and lateral rectus recession in postoperative consecutive exotropia with single-stage adjustable suture surgery.Among 1003 patients who underwent bilateral medial rectus recession between November 1996 and March 2013, the patients who required surgery for consecutive exotopia were retrospectively reviewed. Nineteen patients underwent medial rectus advancement and 15 patients underwent lateral rectus recession. All patients underwent single-stage adjustable surgery under topical anesthesia and were followed up for at least 12 months.The mean follow-up duration was 2.4 years. At final follow-up, a successful surgical outcome was found in 12 patients (63.0%) in the medial rectus advancement group and 14 patients (93.3%) in the lateral rectus recession group (P = .039). The change in ocular deviation was correlated with the amount of recession (P = .008) and preoperative angle (P < .001) in the lateral rectus recession group.Lateral rectus recession showed a higher success rate with predictable and easily performed procedure than medial rectus advancement for the treatment of postoperative consecutive exotropia with adjustable suture.

Lateral rectus advancement versus medial rectus recession for consecutive esotropia

PURPOSE

To compare lateral rectus advancement with medial rectus recession for patients with consecutive esotropia without abduction limitation.

METHODS

Forty-three patients who developed consecutive esotropia following bilateral lateral rectus recession for intermittent exotropia were reviewed retrospectively. Twenty-two patients underwent lateral rectus advancement (lateral rectus advancement group) and medial rectus recession was performed in 21 patients (medial rectus recession group). Success rate of the surgery was based on the percentage of postoperative esophoria or exophoria of less than 8 PD, which did not require a third surgery. Mean follow-up after second surgery was 23.5 ± 8.7 months.

RESULTS

Mean consecutive esotropia in the lateral rectus advancement group was 24.8 ± 9.0 PD. Eight patients were orthophoric after second surgery; mean postoperative esophoria and exophoria/tropia was 5.4 ± 3.4 PD and 6.5 ± 5 PD, respectively. Postoperative success rate in this group was 90.9%. Mean consecutive esotropia in the medial rectus recession group was 21 ± 98.4 PD. Three patients were orthophoric after second surgery; mean postoperative esotropia/phoria and exophoria was 9.5 ± 5.0 PD and 5.2 ± 1.3 PD, respectively. Postoperative success rate in this group was 71.4%. Postoperative undercorrection rate of 4.5% in lateral rectus advancement group was significantly less than the similar measure of 28.6% in medial rectus recession group (chi-square, P = 0.03).

CONCLUSION

Advancement of the previously recessed lateral rectus has improved consecutive esotropia better than medial rectus recession.

Surgical management of intermittent exotropia: do we have an answer for all?

Intermittent exotropia (X(T)) is one of the most common form of strabismus with surgery being the mainstay of treatment. The main goal of surgery is to preserve binocular vision and stereopsis and to prevent its further loss. The decision to operate is mainly based on four aspects: increasing angle of exodeviation, deteriorating control of X(T), decrease in stereopsis for near or distance and quality of life. Bilateral lateral rectus muscle recession and unilateral lateral rectus recession with medial rectus resection, are the two most common surgical procedures performed and have been studied extensively in basic, divergence excess and convergence insufficiency types of X(T). However, there is no consensus over the relative efficacy of the two procedures in terms of postoperative alignment, residual or recurrent exotropia and consecutive esotropia with widely variable results, which can be attributed to poor understanding of the natural course of the disease. Multiple demographic, clinical and anatomic features that may influence the surgical outcomes have been studied to explain this variability. Moreover, most of the evidence regarding surgical outcomes of X(T) is from retrospective studies and the ongoing randomised prospective trials can shed light on long-term efficacy of these procedures. The goal of this review is to give a comprehensive overview of the outcomes of various surgical techniques in the management of different types of X(T), the preoperative and postoperative factors that may affect the surgical outcomes and to discuss the dilemmas faced by the treating surgeons including the effective management of overcorrection and undercorrection.

Unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia

Background

To evaluate the efficacy of unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia within 25 prism diopters (PD) occurring after bilateral lateral rectus muscle recession for intermittent exotropia.

Methods

Medical records of 11 patients who underwent unilateral lateral rectus muscle advancement for consecutive esotropia from 2011 to 2014 and who were observed for at least 6 months after surgery were retrospectively reviewed. The change in angle of deviation from before to after consecutive esotropia surgery, as well as the success rate and surgical effect, were evaluated.

Results

Preoperative esodeviation was −19.6 ± 4.7 PD [median − 20.0 PD, interquartile range (IQR) 9.0] at distance and −16.5 ± 7.4 PD [median − 18.0 PD, IQR 17.0] at near. The mean surgical amount of unilateral lateral rectus muscle advancement surgeries, based on one-fourth of the angle of consecutive esotropia, was 4.8 ± 1.1 mm [median 5.0 mm, IQR 2.0]. Of the 11 patients, 10 (91%) recovered to orthotropia or exodeviation within 8 PD. The surgical effects of unilateral lateral rectus muscle advancement were 3.3 ± 0.7 PD/mm [median 3.6 PD/mm, IQR 1.0] after 1 day, 3.7 ± 0.6 PD/mm [median 3.8 PD/mm, IQR 1.0] after 1 week, and 3.8 ± 0.7 PD/mm [median 3.8 PD/mm, IQR 1.5] after 6 months.

Conclusions

Unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia within 25 PD was successful in all 11 patients. The surgical effect was significantly greater in unilateral lateral rectus muscle advancement than in primary lateral rectus muscle recession. Reduction in the amount of surgery should be considered carefully in unilateral lateral rectus muscle advancement for consecutive esotropia.

Electronic supplementary material

The online version of this article (10.1186/s12886-017-0658-1) contains supplementary material, which is available to authorized users.

Surgical results for consecutive exotropia

PURPOSE:

To evaluate the surgical results of medial rectus (MR) muscle advancement with or without recession of the antagonist muscle for consecutive exotropia.

METHODS:

Medical records of patients with consecutive exotropia (n = 27) were retrospectively reviewed. All patients received one-eye surgery with MR advancement, lateral rectus (LR) recession, or combined surgery. The pre- and post-operative angle of deviation was recorded. Characteristics were compared between groups. The follow-up period was at least 3 months.

RESULTS:

The overall successful rate was 62.96%, with 50% in MR advancement group, 60% in LR recession group, and 71.4% in combined group. Patients in combined group had larger preoperative deviation. There were comparable surgical results between patients with inferior oblique (IO) muscle overaction receiving correction simultaneously and patients without IO muscle overaction.

CONCLUSIONS:

The overall surgical successful rate for consecutive exotropia in this study was 62.96%. Combined MR advancement and LR recession yielded better results than MR advancement or LR recession alone although it was not statistically significant.

Regression Rates Following the Treatment of Aggressive Posterior Retinopathy of Prematurity with Bevacizumab Versus Laser: 8-Year Retrospective Analysis

Background

Retinopathy is a serious complication related to prematurity and a leading cause of childhood blindness. The aggressive posterior form of retinopathy of prematurity (APROP) has a worse anatomical and functional outcome following laser therapy, as compared with the classic form of the disease. The main outcome measures are the APROP regression rate, structural outcomes, and complications associated with intravitreal bevacizumab (IVB) versus laser photocoagulation in APROP.

Material/Methods

This is a retrospective case series that includes infants with APROP who received either IVB or laser photocoagulation and had a follow-up of at least 60 weeks (for the laser photocoagulation group) and 80 weeks (for the IVB group). In the first group, laser photocoagulation of the retina was carried out and in the second group, 1 bevacizumab injection was administered intravitreally. The following parameters were analyzed in each group: sex, gestational age, birth weight, postnatal age and postmenstrual age at treatment, APROP regression, sequelae, and complications. Statistical analysis was performed using Microsoft Excel and IBM SPSS (version 23.0).

Results

The laser photocoagulation group consisted of 6 premature infants (12 eyes) and the IVB group consisted of 17 premature infants (34 eyes). Within the laser photocoagulation group, the evolution was favorable in 9 eyes (75%) and unfavorable in 3 eyes (25%). Within the IVB group, APROP regressed in 29 eyes (85.29%) and failed to regress in 5 eyes (14.71%). These differences are statistically significant, as proved by the McNemar test (P<0.001).

Conclusions

The IVB group had a statistically significant better outcome compared with the laser photocoagulation group, in APROP in our series.