Outcome of unilateral lateral rectus recession and medial rectus resection in primary exotropia

Indications and results of exotropia surgical management

AIM

To study the clinical particularities and the surgical management of the different forms of exotropia, and to analyze the prognostic factors influencing the surgical result.

METHODS

Medical records of 132 patients who underwent exotropia surgery from 1995 to 2015, were retrospectively reviewed. Ophthalmological examination and a complete sensorimotor assessment were performed for each patient. All surgeries were performed by the same surgeon.

RESULTS

We had 57 cases of intermittent exotropia (IE), 22 cases of infantile exotropia (IfE), 43 cases of sensory exotropia (SE) and 10 cases of concecutive exotropia (CE). The average age of onset of exotropia was 6.8 years +/- 8 SD. Amblyopia was noted in 36.4% of cases  of  IfE.  The mean deviation angle was  36.5  DP in (IE),  39.6  DP in (IfE)  and  44.5  DP  in  (SE). A vertical syndrome was frequently found in (IfE) patients. Bilateral recession of  lateral  rectus  was  the  most  performed  surgery  type.  The overall success rate after a  single  surgery  was  72%.  A multivariate logistic regression analysis  showed  that good prognosis  factors  were  the absence  of  amblyopia, the intermittent form of the strabismus,  a low  preoperative deviation angle and the ocular alignment on day one postoperatively.

CONCLUSIONS

IE is the most common divergent strabismus.  Surgery resulted in successful alignment in most of the cases.  Early management and rigorous analysis of  patients sensorimotor status are the best guarantors of long-term success.

Extraocular muscle resection, recession length and surgery outcome modelling in strabismus treatment: a pilot study

Background

Many surgical formulas have been developed and proposed based on the experience of surgeons to improve the predictability of strabismus surgery. However, the consent among strabismus surgeons regarding the dose effect of the extraocular muscle (EOM) recession or resection was not achieved yet and the disagreement about the appropriate amount of strabismus surgery still exists.

Objective

Our study aimed to propose an instrument for EOM resection (RsL) and recession length (RcL) estimation before the surgery and second to elaborate an postoperative angle of deviation (PAD) predictive model using simple potential predictors.

Methods and Analysis

The analytical prospective clinical study was conducted from April 2016 to July 2019, on a sample of 216 patients (aged between 2–58) with concomitant strabismus who underwent strabismus surgery in Clinical Republican Hospital ‘Timofei Mosneaga’and Children Hospital ‘Em Cotaga’ from Republic of Moldova. The correlations of patients’ age, strabismus type, amblyopia degree, RsL, RcL, preoperative angle of deviation (PreAD) with PAD were estimated using Pearson’s correlation analysis. Multiple linear regression analysis, multicollinearity analysis and residual analysis were performed.

Results

The EOM RsL was predicted using strabismus type, patient’s age, PreAD and EOM RcL. EOM RcL, in turn, was estimated by the similar covariates set, instead of RcL being RsL. PAD modelling showed the PreAD, EOM RsL and EOM RcL predictive ability for strabismus surgery outcome prediction.

Conclusion

In our study, we propose four mathematical models as potential instruments for EOM RsL, EOM RcL and PAD modelling in esotropia and exotropia surgery.

Supramaximal Recession and Resection Surgery in Large-Angle Strabismus: Outcomes of Large Interventional Case Series Exotropia and Esotropia

Purpose:

To assess the postoperative surgical outcomes and the changes in deviation in patients treated by supramaximal recession and resection (R&R) of rectus muscles to correct the large-angle exotropia and esotropia.

Methods:

This study was a prospective interventional case series, and patients with esotropia of ≥65 prism diopter (PD) or exotropia of ≥60 PD who had undergone supermaximal R&R in non-fixating eye with lower vision in unilateral strabismus or bilateral medial rectus (BMR) recession up to 8.5 mm for esotropia and bilateral lateral rectus (BLR) recession up to 12.5 mm for exotropia in bilateral strabismus were enrolled. Successful results were achieved if postoperation deviation was <10 PD for esotropia and <15 PD for exotropia during their final examinations.

Results:

A total of 131 cases (48 patients with esotropia and 83 patients with exotropia) were included. The mean ages of the patients with esotropia and exotropia were 16.83 ± 15.06 and 23.19 ± 11.29 years, respectively. The mean preoperative esodeviations for bilateral and unilateral surgeries were 69.5 ± 6.5 and 80.7 ± 10.3, respectively, and these values for bilateral and unilateral exodeviations surgeries were 67.3 ± 7.6 and 74.2 ± 12.1, respectively. The overall successful outcomes were achieved in 50% of the esotropic patients and 79.5% of the exotropic patients. At final follow-up examination, no patient had diplopia on lateral gazes.

Conclusion:

Based on our surgical results, it is possible to consider monocular recession-resection surgery in non-fixating eye (with poor vision) or BLR and BMR recession in both eyes as a viable option for surgical treatment of large angles deviations.

Do the primary surgical options for basic-type exotropia cause differences in distance-near discrepancy of recurrent exotropia after surgery?

Purpose

Most ophthalmologists appear to have no distinct preference between unilateral recess-resect (R&R) and bilateral lateral rectus (BLR) recessions to treat basic-type exotropia. This study aimed to determine whether differences in distance-near discrepancy and resultant exotropia types of recurrent exotropia following surgery for primary basic-type exotropia exist between the two surgical options.

Methods

Ninety-three patients with recurrent exotropia following BLR recessions for basic-type exotropia (BLR group) and 95 following R&R for basic-type exotropia (R&R group) were included in this retrospective study. The exotropia types in recurrent exotropia were classified into three types according to distance-near discrepancy: basic, divergence-excess, and convergence-insufficiency. The BLR and R&R groups were compared.

Results

After surgery for basic-type exotropia, the type composition changed differently in each group (p < 0.001). The basic-type of primary exotropia was more often maintained in recurrent exotropia in the R&R group than in the BLR group. The incidence of postoperative convergence-insufficiency type exotropia in the BLR group was 28.0% and 8.4% in the R&R group (p = 0.001). Postoperative near stereopsis and fusion control grade of distance deviation did not differ between the two groups (p > 0.05).

Conclusions

Convergence-insufficiency type recurrent exotropia occurred more frequently after BLR recessions than after R&R for basic-type exotropia. The high rate of secondary convergence-insufficiency type exotropia after BLR recessions should be considered when clinicians select a surgical option to treat exotropia.

Comparison of surgical outcomes between bilateral recession and unilateral recession-resection in moderate-angle intermittent exotropia

PURPOSE

To compare postoperative drift after bilateral lateral rectus recession (BLR) and after unilateral recession combined with medial rectus resection (R&R) in children with primary moderate-angle intermittent exotropia.

METHODS

The medical records of children with intermittent exotropia in the range of 25^Δ-50^Δ who underwent BLR or R&R from July 2015 to September 2016 were reviewed retrospectively. Outcomes were classified according to postoperative angle of deviation at distance as overcorrection (esophoria or -tropia of >5^Δ), success (esophoria or -tropia of ≤5^Δ to exophoria/tropia of ≤10^Δ), or recurrence (exophoria or -tropia of >10^Δ). Patients were examined on postoperative day 1 and at 6 weeks, 6 months, and 12 months. Sensory status was evaluated using the Titmus stereoacuity test.

RESULTS

A total of 330 children were included (BLR, 175; R&R, 155). Exotropic drift was greater in the R&R group in the period between day 1 and 6 weeks and from 6 to 12 months (P <0.05). Surgical successful rates in each group were comparable: 57.7% in the BLR group and 60.6% in the R&R group (P > 0.05). However, higher overcorrection rates were noted in the BLR group at 6 and 12 months (16.6% vs 6.5 % at 12 months [P = 0.003]). There were more patients with deteriorated stereopsis after surgery in the BLR group (P = 0.025).

CONCLUSIONS

In our study cohort, BLR was associated with more stable long-term ocular alignment and a higher rate of overcorrection than R&R. Postoperative day 1 overcorrection of <16^Δ following R&R and of <10^Δ following BLR were associated with relatively good results.

Relation between early postoperative deviation and long-term outcome after unilateral lateral rectus recession and medial rectus resection for adult exotropia

AIM

To evaluate the relationship between early postoperative deviation and long-term outcome after unilateral recession and resection surgery for adult exotropia, and to evaluate exotropic shift after surgery.

METHODS

This was a retroprospective study involving adult patients with exotropia who underwent unilateral recession and resection surgery and were followed up for at least 2y. The results were evaluated at 2y and the final visit. Factors influencing a successful outcome were analyzed. Early postoperative deviation at 1wk was used to evaluate relationship with long-term outcome. The long-term outcome was classified into 3 groups: successful, acceptable, and poor. Successful outcome was defined as a distance deviation between esodeviation 8 prism diopters (PD) and exodeviation 10 PD.

RESULTS

Forty-two patients were enrolled. The mean age at surgery was 26y (range, 15-49y). The median follow-up period was 30mo (range, 24-108mo). Successful outcome was found in 81% of patients at 2y and in 71% at the final visit. Overcorrection at 1wk postoperatively was associated with a successful outcome at 2y. Initial postoperative alignment between orthotropia and esodeviation of 8 PD had the highest chance of a successful outcome (RR=2.2). The mean postoperative exotropic drift was 4.7 PD at the first month and 9.3 PD at 2y.

CONCLUSION

Initial postoperative deviation can predict long-term outcome after unilateral recession and resection surgery for adult exotropia. The most desirable outcome at 1wk post-operatively was orthotropia to small esodeviation. Most patients have exotropic drift at a subsequent follow-up, especially in the first month after surgery.

Comparison of Long-term Surgical Outcomes of Two-muscle Surgery in Basic-type Intermittent Exotropia: Bilateral versus Unilateral

Purpose

To compare long-term surgical outcomes after bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession-medial rectus resection (RR) for the treatment of basic-type intermittent exotropia.

Methods

Consecutive patients who underwent BLR or RR for treatment of intermittent exotropia between 1999 and 2010 and underwent ≥5 years of follow-up were recruited for this study. Surgical outcomes were grouped according to postoperative angle of deviation: overcorrection (esophoria/tropia >8 prism diopters [Δ]), success (esophoria/tropia ≤8Δ to exophoria/tropia ≤8Δ), and undercorrection/recurrence (exophoria/tropia >8Δ). Outcomes were compared between the BLR group and the RR group at postoperative week 1, months 1 and 6, and years 1, 2, 3, 4, and 5.

Results

Of 99 patients, 37 underwent BLR and 62 underwent RR. At postoperative month 6 (97.3% vs. 82.3%, p = 0.045) and year 1 (91.9% vs. 74.2%, p = 0.040), the surgical success rates in the BLR group were significantly higher than in the RR group. Recurrence of exophoria/tropia most commonly occurred between 2 and 3 years after surgery in the BLR group, but continuous recurrences were found in the RR group. At postoperative year 5, the surgical success rate was 54.1% in the BLR group and 41.9% in the RR group (p = 0.403). The reoperation rate was 24.3% in the BLR group and 33.9% in the RR group (p = 0.317).

Conclusions

Surgical outcomes 5 years after surgery for intermittent exotropia were comparable between the BLR and RR groups. The surgical success rate and the reoperation rate were not significantly different between the BLR and RR groups.

Bilateral medial rectus resection for primary large-angle exotropia

BACKGROUND

Surgical treatments for large-angle exotropia include bilateral lateral rectus recession, recession-resection procedures, and three- and four-muscle surgery. Undercorrection and limitation of abduction are common complications of these procedures. This study reports the results of bilateral medial rectus resection as a first procedure for primary large-angle exotropia.

METHODS

The medical records of patients who underwent bilateral medial rectus resection for angles ≥60^Δ in the period from 2006 till 2016 with a minimum follow-up period of 6 months were reviewed retrospectively. The amount of resection ranged from 8 mm to 12 mm according to the preoperative angle. Success was defined as a final outcome within the range of 8^Δ of esotropia to 10^Δ of exotropia.

RESULTS

A total of 64 patients were included, in whom angles ranged from 60^Δ to 140^Δ. The overall success rate was 77%, and there was no significant difference in success rate between classes of smaller and larger angles. Limitation of abduction was seen in first postoperative week. At 6 months' follow-up 64% of eyes had no limitation of abduction.

CONCLUSIONS

In our patient cohort bilateral medial rectus resection successfully corrected large-angle exotropia of up to 140^Δ, with results comparable to three- and four-muscle procedures. It has the advantage of not causing significant abduction deficits, even with resections up to 12 mm.

Intermittent exotropia: Surgical treatment strategies

Surgical management of intermittent exotropias (IXTs) is ambiguous, with techniques of management varying widely between institutions. This review aims to examine available literature on the surgical management of IXT. A literature search was performed using PubMed, Web of Knowledge, LILACS, and the University of Liverpool Orthoptic Journals and Conference Transactions Database. All English-language papers published between 1958 and the present day were considered.

Correlation between the Limbus-Insertion Distance of the Lateral Rectus Muscle and Lateral Rectus Recession Surgery in Intermittent Exotropia

The aim of this study was to investigate whether the limbus-insertion distance (LID) of the lateral rectus (LR) muscle can be a useful indicator for predicting the surgical effect of recession surgery in intermittent exotropia (IXT). Patients who underwent unilateral or bilateral LR recession for the basic type of IXT were included. The distance between the corneal limbus and the posterior edge of the insertion of LR muscle (limbus-insertion distance) was measured intraoperatively using surgical calipers (graded with 0.25 mm precision). We calculated the actual dose-response effect as the difference between the angle of preoperative deviation and the angle of postoperative deviation, and then divided the figure by the total amount of recession at postoperative months 1, 3, and 6. The correlation between the limbus-insertion distance (LID) of LR muscle and each dose-response effect was statistically analyzed. A total of 60 subjects were enrolled in this study. The mean LID of LR muscle was 5.8±0.7 mm. The dose-response effect was 3.2±1.0 prism diopters (PD)/mm at postoperative month 1, 3.4±1.0 PD/mm at postoperative month 3, and 3.4±1.1 PD/mm at postoperative month 6. The LID of the LR muscle was significantly correlated with dose-response effects in cases of unilateral and bilateral LR recession at postoperative months 3 and 6 (P = 0.01, <0.01, 0.04 and <0.01 respectively). As the LID of the LR muscle increased by 1 mm, the dose-response effect increased by 0.2PD/mm in unilateral LR recession, and by 0.4 PD/mm in bilateral LR recession at postoperative month 6. In conclusion, the LID of the LR muscle can be used as one predictor of the recession effect to assist in surgical planning for IXT. Moreover, undercorrection at the time of LR recession might be considered in patients with long LID of the LR muscle.

Single Stage Surgical Outcomes for Large Angle Intermittent Exotropia

Although there were many prior studies about exotropia, few focused on large-angle intermittent exotropia. The goal of this study was to evaluate single-stage surgical outcomes for large-angle intermittent exotropia and analyze risk factors that may affect the success of surgery. Records from intermittent exotropia patients with exodeviations >60 prism diopters(PD) who were surgically treated at the Zhongshan Ophthalmic Center, of Sun Yat-Sen University were reviewed. Included within this review were data on, pre- and post-operative ocular motility, primary alignment, binocular vision and complications. Patients with exodeviations ≤70PD received two-muscle surgery, while those with exodeviations >70PD were subjected to a three-muscle procedure. A total of 40 records were reviewed. The mean exodeviation was 73±9PD at distance and 75±26PD at near. There were 25 patients received two-muscle surgery and 15 the three-muscle procedure. Orthophoria (deviation within 8PD) was obtained in 77.5% of these patients and the ratios of surgical under-correction and over-correction were 15% and 7.5% respectively. However, when combining ocular alignment with binocular vision as the success criteria, success rates decreased to 30%. No statistically significant differences in success rates were obtained between the two- and three-muscle surgery groups. Seven subjects experienced an abduction deficit during the initial postoperative stages, but eventually showed a full recovery. One patient required a second surgery for overcorrection. No statistically significant risk factors for poor outcome were revealed. Our data showed that single-stage two- and three-muscle surgeries for large-angle intermittent exotropia are effective in achieving a favorable outcome.

Clinical Characteristics and Surgical Outcomes in Patients With Intermittent Exotropia: A Large Sample Study in South China

The clinical characteristics and surgical outcomes in a large sample of patients with intermittent exotropia (IXT) as well as an analysis of risk factors associated with surgical failures are presented in this article. Data from IXT patients who received surgical management at the Eye Hospital, in the Zhongshan Ophthalmic Center, of Sun Yat-Sen University, China from January 2009 to December 2013 were reviewed retrospectively. Included within this analysis were data from pre- and postoperative ocular motility, primary alignment, and binocular vision.A total of 1228 patients with IXT were reviewed. Males (50.4%) and females (49.6%) were nearly equally represented in this sample. Thirty-two patients (2.6%) had a family history of strabismus. The mean age at onset was 6.77  ±  6.43 years (range 7 months -48.5 years), mean duration at presentation was 7.35  ±  6.68 years (range 6 months-47 years), and mean age at surgery was 13.7  ±  8.8 years (range 3-49 years). The mean refractive error was -0.84  ±  2.69 diopter in the right eye and -0.72  ±  2.58 diopter in the left eye. Amblyopia (4.2%), oblique muscle dysfunction (7.0%), and dissociated vertical deviation (4.7%) were also present in these patients. The most common subtype of IXT was the basic type (88.1%). Orthophoria was observed in 80.5% of patients and the ratios of surgical undercorrection and overcorrection were 14.7% and 4.8%, respectively, as determined with a mean follow-up time of 7.8  ±  3.7 months. When combining ocular alignment with binocular vision as the success criteria, the success rate decreased to 35.6%. Multivariate risk factor analysis showed that only the loss of stereoacuity (P = 0.002) was associated with a poor outcome. There were no differences in the long-term results between bilateral lateral rectus recession and unilateral lateral rectus recession with medial rectus resection.Most IXT patients displayed normal vision, with few having positive family histories, amblyopia, oblique muscle dysfunction, and dissociated vertical deviation. The most common subtype of IXT was the basic type. Long-term surgical results were less favorable when sensory status was included in the criteria for success. Patients with stereoacuity loss were at an increased risk for poor outcomes.

Three and Four Horizontal Muscle Surgery for Large Angle Exotropia

PURPOSE

Surgery on two horizontal recti typically is most effective for angles less than 40 prism diopters (PD). The authors evaluate their experience operating on three or four rectus muscles for angles exceeding 40 PD.

METHODS

Retrospective chart review of 47 patients who underwent a first surgical procedure for a large angle comitant exodeviation. Patients were observed for a minimum of 2 months. Success was defined as deviation ±10 PD.

RESULTS

Median age was 48 years (range: 1 to 79 years). Thirty-four patients underwent three muscle surgery and 13 underwent four muscle surgery. Mean preoperative angles were 55 ± 9.8 and 72 ± 8.8 PD, respectively. Following three muscle surgery, rates of success, undercorrection, and overcorrection were 67%, 27%, and 7% at 2 months and 42%, 58%, and 0% at final follow-up (12 ± 8.7 months), respectively. Rates for four muscle surgery were 44%, 33%, and 22% at 2 months and 50%, 38%, and 13% at final follow-up (11 ± 12.2 months), respectively. Patients who were successfully aligned at 2 months had a mean preoperative angle of 55 PD, whereas those who were undercorrected had a mean preoperative angle of 67 PD (P = .009). Between 1 week and 2 months, 77% of patients experienced exotropic drift averaging 10 ± 9.1 PD. By final follow-up, 90% experienced exotropic drift averaging 15 ± 14.1 PD. Success rates for traditional and adjustable suture surgeries did not differ significantly.

CONCLUSIONS

Three and four horizontal muscle surgeries are effective for correcting large angle exotropia. Higher preoperative deviations predisposed to undercorrection. Postoperative exotropic drift should be anticipated.

Long-term postoperative outcomes of bilateral lateral rectus recession vs unilateral recession-resection for intermittent exotropia

AIM

To discuss the long-term postoperative results of bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession-medial rectus resection (RR) in therapy of intermittent exotropia.

METHODS

We retrospectively analyzed 213 cases of intermittent exotropia who underwent surgery between 2008 and 2010. The patients were grouped into BLR group and RR group. Motor outcomes were divided into three groups on the basis of the angle of deviation after surgery: overcorrection (esotropia/phoria >5(Δ)), orthophoria (esotropia/phoria ≤5(Δ) to exotropia/phoria ≤10(Δ)), and undercorrection/recurrence (exotropia/phoria >10(Δ)). Titmus test was used to evaluate stereoacuity, the stereoacuity <800s of arc meaned the patients had stereopsis. Surgical outcome including motor criteria and sensory status were compared at postoperative 6, 12, 24mo and at 36mo examination between groups.

RESULTS

At 12, 24mo after surgery, the motor outcomes had no difference (P>0.05) between groups. However, the motor outcomes at 6, 36mo were signally different in each group, indicating the success rate in RR group at 6mo was higher than that in BLR group (83.02% vs 82.24%, P<0.05) but the result was contrary at the 3y examination (60.75% vs 43.40%, P<0.05). No statistical significance were found in the sensory outcomes between the groups at mean of 3.7y follow-up.

CONCLUSION

The motor outcomes in RR group were better than in BLR group at 6mo after surgery, while the 3y outcomes were better in BLR group. This may be due to the recurrence rate of the BLR was lower than the RR group's.