Bilateral lateral rectus recession for exotropia: a survival analysis

Long-Term Outcome of Patients with Large Overcorrection following Surgery for Exotropia

To provide long-term surgical results for patients with large initial overcorrection following surgery for exodeviation, 68 consecutive patients with initial overcorrection of 20 prism diopters (PD) or more at distance or near following surgery for exodeviation performed between 1994 and 2002 were included in this study. The patients were managed with an alternate full-time occlusion, echothiophate iodide, or prism glasses for the period of overcorrection. One day postoperatively, the amount of overcorrection was 8--40 PD at distance and 0--35 PD at near, and decreased to 10 PD or less both at distance and near vision within 4 weeks postoperatively in 49 patients (72%). Seven patients needed prism glasses for esotropia of less than 10 PD. Four patients (5.9%) needed a reoperation for consecutive esotropia and 1 patient for postoperative hypotropia following recession of the superior and lateral rectus. The final outcome showed orthophoria to exo/esodeviation of <or=10 PD in 48 patients (71%) and exodeviations of >10 PD in 11 patients (16%) at near or distance. In conclusion, overcorrection was reduced to 10 PD or less at distance and near within 4 weeks after surgery in most patients. Even with initial overcorrection of 20 PD or more after surgery for exodeviation, reoperation for consecutive esotropia was necessary only in 5.9% of the patients.

The Comparison of outcomes between lateral rectus muscles re-recession and medial rectus muscles resection in recurrent exotropia

PURPOSE

To compare the surgical outcomes between bilateral lateral rectus muscles (BLR) re-recession and bilateral medial rectus muscles (BMR) resection in recurrent exotropia.

METHODS

The medical records of patients with recurrent exotropia who underwent surgery for intermittent exotropia during the 6 years from January 2001 to December 2006 and followed up for more than 6 months were reviewed retrospectively.

RESULTS

In group A, BLR recessions was performed at the first surgery and BLR re-recession was performed at the second surgery. In group B, BLR recession was performed at the first surgery and BMR resection at the second surgery. Success rates at the last follow-up after the second operation were 81.9% in Group A and 83.3% in Group B, showing no statistical difference between the two groups. In group A, no significant underaction of the BLR was noted. Success rates were not statistically different between the 2 mm re-recessed subgroup and 3 mm re-recessed subgroup.

CONCLUSIONS

The results support the notion that BLR re-recession successfully corrects recurrent exotropia without producing significant limitation of abduction.

Timing of surgery for primary exotropia in children

OBJECTIVE

To compare the postoperative alignment and sensory functions in patients with primary exotropia who had been operated at an early age (< 7 years) with those in patients who had been operated at an older age (> 7 years).

METHODS

In a consecutive retrospective cohort study, 112 patients who had had a surgical intervention for primary exotropia between 1997 and 2003 were evaluated for postoperative results. After applying criteria for eligibility, the group of patients was divided into two groups: those who had had surgery before the age of seven years (n = 24) and those who had had surgery after the age of seven years (n = 36). Age at surgery, preoperative alignment and sensory functions were correlated with the postoperative status. The follow-up was at least one year (1.0 year to 7 years; median: 2.3 and 3.5 years, respectively).

RESULTS

Patients who had had surgery before the age of seven had significantly better alignment and sensory functions. The univariate logistic regression model confirmed a statistically significant association between motor outcome (exodeviation less than 10 diopters) and age at the time of surgery (before or after the age of seven; p = 0.002). In the multivariate model, the association between age at time of surgery and motor outcome was even stronger. The number of re-operations in the group operated before the age of 7 years was significantly less than in the group operated after the age of seven (2 versus 12, p = 0.023).

CONCLUSION

The postoperative alignment and sensory functions for patients with primary exotropia who had had a surgical intervention before the age of seven years were, in this study, better than those in patients who had had surgery after the age of seven years.

[Surgical results in childhood primary comitant large-angle exotropia]

INTRODUCTION

The purpose of this study was to evaluate the surgical results in childhood primary comitant large-angle exotropia (>30Delta) after a single operation and to analyze the factors that could influence these results.

PATIENTS AND METHODS

We carried out a retrospective study in all children presenting with comitant primitive exotropia at an angle greater than 30Delta, who were operated on in our department from January 1996 to December 2000 by various surgeons. One hundred thirty-eight (138) cases were reviewed. The children with a substantial A or V phenomenon, retraction syndromes, nystagmus, those presenting with a neurological disease and those who had had previous eye surgery were excluded. The postoperative results were classified in three categories: residual exotropia over 10Delta, good postoperative result (esotropia<10Delta, orthotropia or exotropia<10Delta), and consecutive esotropia over 10Delta.

RESULTS

Ninety-seven children fulfilled the study criteria. Forty (41.2%) were boys and 57 (58.8%) girls. The average age at the time of surgery was 6.5 years (SD 3.1). Sixty-eight of 97 (70.1%) had intermittent exotropia. Twenty-six children (26.8%) underwent a bilateral recession of the lateral rectus, 67 (69.1%) a unilateral operation, recession of a lateral rectus/resection of a medial rectus, and four (4.1%) an operation on three horizontal muscles. Sixty-nine percent of the children operated on had a good postoperative result, according to criteria defined in our study, 1 year after surgery.

DISCUSSION/CONCLUSION

Childhood primary comitant large-angle exotropia can be corrected with a single surgical procedure, unilateral or bilateral, with a success rate which, in our study, reached 69%.

Binocular status after surgery for constant and intermittent exotropia

PURPOSE

To investigate whether constant exotropia patients with a previous history of intermittent exotropia X(T), like X(T) patients, can achieve postoperative bifixation, and whether they have a better postoperative sensory outcome than those without previous history of X(T).

DESIGN

Prospective comparative clinical study.

METHODS

Sixty-three consecutive patients with intermittent or constant exotropia were divided into three groups: X(T) (group 1), constant exotropia with a previous history of X(T) (group 2), and constant exotropia without previous history of X(T) (group 3). The surgical outcomes were assessed and compared in motor and sensory terms separately between the three groups. Successful motor alignment was defined as within 8 prism diopters (PD) (exo or eso). A stereoacuity < or =60 seconds of arc was considered as bifixation, and a stereoacuity < or =800 seconds of arc was considered as gross stereopsis.

RESULTS

The successful motor alignment rates of group 1, group 2, and group 3 were 79%, 71%, and 67%, respectively (group 1 vs group 2, P = .826; group 1 vs group 3, P = .551; group 2 vs group 3, P = 1.000). Twenty-five (74%) patients in group 1 achieved bifixation and none achieved in group 2 or group 3 (group 1 vs group 2, P = .001; group 1 vs group 3, P = .001). Meanwhile, 34 patients (100%) in group 1, 11 (79%) in group 2, and 5 (33%) in group 3 achieved gross stereopsis (group 1 vs group 2, P = .021; group 2 vs group 3, P = .025; group 1 vs group 3, P = .001). Compared with patients in the two constant exotropia groups, patients in X(T) group had a significantly better sensory outcome in both bifixation and gross stereopsis. Patients in group 2 had a better sensory outcome than those in group 3 in gross stereopsis.

CONCLUSIONS

Constant exotropia patients with a previous history of X(T) have a better postoperative sensory outcome in gross stereopsis than those without previous history of X(T), but a worse surgical sensory outcome when compared with X(T) patients in both bifixation and gross stereopsis. Constant exotropia patients decompensated from X(T) may have missed the best time for treatment.

Interventions for intermittent exotropia

BACKGROUND

The clinical management of intermittent exotropia has been discussed frequently in the literature, but there is a lack of clarity regarding the indications for intervention, the most effective type and if there is a time point at which it should be carried out.

OBJECTIVES

The objective of this review was to analyse the effects of various surgical and non-surgical treatments in randomised trials of people with intermittent exotropia, to report intervention criteria and determine the significance of factors such as age with respect to outcome.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (2006, Issue 1), MEDLINE (1966 to March 2006), EMBASE (1980 to March 2006) National Research Register (2006, Issue 1), PubMed (searched on 13 March 2006; last 90 days) and LILACS (Latin American and Caribbean Literature on Health Sciences) (1966 to 2002). We manually searched the British Orthoptic Journal, proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA) and American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS). We contacted researchers who are active in the field for information about further published or unpublished studies. There were no language restrictions in the manual or electronic searches.

SELECTION CRITERIA

We included randomised controlled trials of any surgical or non-surgical treatment for intermittent exotropia.

DATA COLLECTION AND ANALYSIS

Each review author independently assessed study abstracts identified from the database and manual searches. Author analysis was then compared and full papers for appropriate studies were obtained.

MAIN RESULTS

We found one randomised trial that was eligible for inclusion. This trial showed that unilateral surgery was more effective than bilateral surgery for correcting basic intermittent exotropia.

AUTHORS' CONCLUSIONS

The available literature consists mainly of retrospective case reviews which are difficult to reliably interpret and analyse. The one randomised trial included found unilateral surgery more effective than bilateral for basic intermittent exotropia but there remains a need for more carefully planned clinical trials to be undertaken to improve the evidence base for the management of this condition.

Surgical experiences with two-muscle surgery for the treatment of intermittent exotropia

BACKGROUND

The surgical management of intermittent exotropia, or X(T), remains a challenge. Not only are some quoted success rates relatively low (40-83%), but the outcome is notoriously unpredictable with a tendency to exotropic drift over time.

METHODS

In this retrospective study, 118 patients who underwent either bilateral lateral rectus muscle recession (BLR) or unilateral medial rectus muscle resection and lateral rectus muscle recession (R&R) surgery during a 4-year period were reviewed. Surgical outcome between the 2 groups in addition to factors that influence outcome within groups were analyzed. Success was defined as an X(T) < or = 10PD.

RESULTS

Sixty-four subjects underwent BLR, and 54 subjects underwent R&R surgery. Mean preoperative distant X(T) size was 38.7 +/- 6.7 PD. Subjects who underwent R&R did significantly better at 1-year follow-up (success 74.2% vs. 42.2%) but showed significantly more exotropic drift over time (P = 0.01). Within both BLR and R&R groups, subjects with basic-type X(T) did worse than those with divergence-excess X(T) at 1-year follow-up. Consecutive esotropias, however, were more likely with R&R surgery and in those with divergence excess X(T). Preoperative strabismus control, distant X(T) size, and patient age at surgery did not significantly influence outcome.

CONCLUSION

In many cases, selection of surgery type continues to depend on the surgeon's preference, which is in turn influenced by his/her past experiences. The debate about which surgical type is best for different X(T) types continues.

Bilateral lateral rectus recession versus unilateral recess-resect procedure for exotropia with a dominant eye

PURPOSE

To compare the surgical outcomes of bilateral lateral rectus recession and unilateral recess-resect (RR) procedure on the nondominant eye for the patients of exotropia with a dominant fixating eye.

DESIGN

Prospective randomized comparative clinical trial.

METHODS

One hundred twenty-four patients of exotropia with an invariably fixating eye were enrolled to this study. Patients were assigned randomly to two groups, those who underwent bilateral lateral rectus (BLR) recessions (BLR group) or unilateral RR procedures on the nondominant eye (RR group); surgical outcomes were compared. An outcome was considered satisfactory if there was between 10 prism diopters of exophoria/tropia and 10 prism diopters of esophoria/tropia at 6 months after surgery.

RESULTS

In the BLR group, 28 of the 58 patients (48.3%) had a satisfactory outcome, and 30 patients (51.7%) had recurrence. There was no case of overcorrection in the BLR group. In the RR group, 55 of the 66 patients (83.3%) had a satisfactory outcome; 6 patients (9.1%) had recurrence, and 5 patients (7.6%) were overcorrected (P < .001, Fisher's exact test). All overcorrected patients in the RR group had poor stereoacuity and constant exotropia before the operation. The cumulative probability of surgical success was significantly higher in the RR group than in the BLR group (P = .012, log rank test).

CONCLUSIONS

In the patients with exotropia with a dominant eye, the unilateral RR procedure resulted in a better outcome than BLR recession surgery. But, the overcorrection rate was significantly higher in the unilateral RR procedure group, especially in those patients with a poor preoperative stereopsis status and constant exotropia.

Unilateral recession-resection in children with exotropia of the convergence insufficiency type

PURPOSE

The surgical success rates for intermittent exotropia of the convergence insufficiency type have been reported to be variable, and most were studied retrospectively in adults. The purpose of this study was to evaluate prospectively the long-term surgical results of unilateral lateral rectus (LR) muscle recession and medial rectus (MR) muscle resection in children with intermittent exotropia of the convergence insufficiency type.

METHODS

A total of 14 children with intermittent exotropia greater at near than at distance by 10 prism diopters (PD) or more were included in this prospective study. The amounts of resection and recession were based on near and distance deviation, respectively. Minimum follow-up was 1 year (mean 26.6 months; range, 12-68 months) after surgery. The paired t-test was used to compare preoperative and postoperative measurements of the angle of deviation at distance and near, near-distance difference.

RESULTS

Significant postoperative reduction was achieved in terms of mean distance exodeviation, from 22.5 PD to 9.1 PD (P=0.000), and mean near exodeviation from 33.8 PD to 13.6 PD (P=0.000). Mean near-distance difference reduced from 11.3 PD preoperatively to 4.6 PD postoperatively (P=0.000). Fresnel prism was used temporarily to treat postoperative esotropia in only one patient for postoperative 6 months.

CONCLUSIONS

Unilateral surgery biased to MR strengthening more than LR weakening in children with intermittent exotropia of the convergence insufficiency type, was found to successfully reduce both distance and near deviation and to collapse near-distance differences with a low risk of long-term postoperative esotropia.

Survival analysis of 365 patients with exotropia after surgery

PURPOSE

Few reports have included large numbers of exotropia patients. Thus, we undertook this study to perform a survival analysis of over 350 patients with exotropia and to determine which factors might affect the outcome of exotropia surgery.

METHODS

The clinical records of 365 patients who underwent exotropia surgery by one surgeon were retrospectively reviewed. Preoperative patient characteristics, surgical procedures performed, and early postoperative ocular alignment were evaluated as potential risk factors of surgical outcome using survival analysis.

RESULTS

The estimated median time from surgery to recurrence was 48.3 months. None of the characteristics or procedures were found to be significantly associated with surgical outcome. The likelihood of a good postoperative surgical outcome was highest with an initial postoperative alignment of more than 10 prism diopters of esotropia (P<0.001).

CONCLUSIONS

Early postoperative overcorrection was the only predictor of a successful long-term outcome after exotropia surgery.

The long-term result of slanted medial rectus resection in exotropia of the convergence insufficiency type

PURPOSE

To evaluate the long-term results of slanted medial rectus (MR) resection for intermittent exotropia (X(T)) of the convergence insufficiency type.

METHODS

In all, 10 patients with an X(T) greater at near than at distance by 10 prism diopters (PD) or more were included in this prospective study. Patients received slanted bilateral MR resection. The upper edge of the MR was resected according to the distance exodeviation and the lower edge of the MR was resected according to near exodeviation. The postoperative follow-up period was between 6 and 62 months with a mean of 38.9 months. The paired t-test was used to compare: mean distance angle of deviation preoperatively and postoperatively; mean near angle of deviation preoperatively and postoperatively; and mean near-distance exodeviation difference preoperatively and postoperatively.

RESULTS

Bilateral slanted MR resections reduced mean exodeviation at distance from 23.0+/-7.2 to 16.3+/-5.4 PD (P=0.03); mean exodeviation at near from 34.3+/-7.7 to 24.6+/-6.9 PD (P=0.01); and mean near-distance difference from 11.4+/-2.6 to 8.3+/-3.5 PD (P=0.04). At the final follow-up examination, all patients demonstrated an exodeviation of 10 PD or more at distance and near, and the exodeviation difference between distance and near deviation was within 10 PD in five of the 10 patients. Three patients had an esodeviation at distance after surgery, but all resolved within 4 weeks.

CONCLUSIONS

Bilateral slanted MR resections in patients with X(T) of the convergence insufficiency type resulted in undercorrection in all patients.

The clinical course of recurrent exotropia after reoperation for exodeviation

PURPOSE

To determine the clinical course of recurrent exotropia after a secondary operation for exotropia.

METHODS

The surgical results in 58 patients who had undergone reoperation for recurrent exotropia (reoperation group) were retrospectively investigated and compared with those of 100 patients who had undergone primary strabismus surgery only (primary operation group) using survival analysis.

RESULTS

In the reoperation group, recurrence occurred in 19 of the 58 patients (33%). Survival analysis revealed that the recurrence rates in the reoperation group were significantly lower than those in the primary operation group at the same follow-up period after the corresponding strabismus surgery (p=0.018). The distant esodeviation at the postoperative 1st week after reoperation was the only significant factor associated with the recurrence after reoperation (p=0.01).

CONCLUSIONS

Exotropia did recur after a secondary operation, although the recurrence rate was lower than that after a primary operation only.

Surgical results of patients with A-pattern horizontal strabismus

PURPOSE

To investigate the surgical results of patients having horizontal strabismus with A-pattern associated with superior oblique overaction (SOOA).

METHODS

Twenty patients with horizontal strabismus (12 exotropia [XT] and 8 esotropia [ET] with no previous strabismus surgery) with SOOA-associated A-pattern were analyzed retrospectively. Motor success was defined as a horizontal deviation of 8 prism diopters (PD) or less, 6 PD or less of vertical deviation in all gazes, and no greater than 8 PD of A-pattern. Stereoacuity was measured using the Titmus test (Stereo Optical, Chicago, IL).

RESULTS

Sixty percent of patients had successful results at the final examination. No significant difference was found between the XT and ET patients in preoperative and postoperative horizontal deviations in the primary position, A-pattern collapse, or success rate (P >.05). Four patients had an induced postoperative vertical deviation. Among eight patients without stereoacuity preoperatively, four showed an average of 910 seconds of arc (40 to 3000 seconds of arc) after surgery.

CONCLUSION

Simultaneous surgery on the horizontal and SO muscles in patients with horizontal strabismus with SOOA-associated A-pattern can achieve a relatively high surgical success rate and restore binocular function.

Surgical correction of large-angle exotropia in adults

AIM

A retrospective and longitudinal review of the outcome of strabismus surgery for adults with large- and very-large-angle manifest exodeviations, using two-, three- and four muscle horizontal recti surgery with adjustable sutures.

METHODS

A total of 26 consecutive adult patients undergoing surgery for socially noticeable strabismus comprising five primary, 16 consecutive, and five secondary constant exotropias with a mean near deviation of 58 prism dioptres and a mean distance deviation of 55Delta were evaluated preoperatively and at various time intervals postoperatively. Surgery involved two muscles in seven cases, three muscles in 13 cases, and four muscles in six cases; and 25 of 26 had adjustable sutures. There was a horizontal preoperative ocular movement deficit in 17 that was asymmetrical in four cases.

RESULTS

Binocularity was restored in eight patients (31%), 20 (77%) were within 10Delta of orthotropia, and 24 (92%) were happy with their cosmesis. Two had symptomatic asymmetrical ocular motility deficits postoperatively following a two-muscle procedure and one required reoperation. A total of 19 patients undergoing three- or four-muscle surgery were asymptomatic postoperatively. A total of 22 patients had follow-up of 8 months or more.

CONCLUSION

In adults with large-angle manifest exodeviations, adjustable suture surgery involving three or more horizontal recti successfully restores primary position alignment, a high degree of patient satisfaction, and can be expected to be associated with a low incidence of symptomatic postoperative asymmetrical ocular movement deficits.

Large bilateral lateral rectus recession in large angle divergence excess exotropia

PURPOSE

Classic teaching suggests that surgery for intermittent exotropia should be based on distance/near differences. True divergence excess exotropia should be treated with symmetric lateral rectus recession. The aim of this study was to investigate the effect of large bilateral lateral rectus (LR) recession in large-angle intermittent exotropia.

METHODS

Thirty-three consecutive patients with large-angle divergence excess exotropia ranging from 50 to 65 (mean 56.7 +/- 6.3) prism diopters were treated with 8.0 to 9.5 mm (mean 8.8 +/- 0.7 mm) recession of both LR muscles.

RESULTS

Successful alignment was achieved in 25 cases (76%) while residual exotropia was seen in eight patients (24%) within the limit of 15 prism diopters. Mean follow-up time was 28.5 +/- 8.4 (range 13 to 38) months. Abduction deficit due to this procedure was not seen in any case.

CONCLUSIONS

We conclude that large bilateral LR recession is an appropriate surgical method for large-angle divergence excess exotropia.

Botulinum toxin management of childhood intermittent exotropia

OBJECTIVE

Intermittent exotropia is a common form of childhood strabismus that has a late onset and presents a difficult and frustrating management dilemma. Surgical treatments have a high recurrence rate, and multiple surgeries often are required to achieve a desirable motor outcome. This study presents long-term observations on the use of botulinum toxin for the treatment of intermittent exotropia in children.

DESIGN

This study is a nonrandomized, case-controlled study of consecutive pediatric patients who had intermittent exotropia.

PARTICIPANTS

Thirty-two neurologically normal children ranging from 3 to 144 months in age were diagnosed with intermittent exotropia with a minimum distance deviation of 15 prism diopters (PD).

INTERVENTION

Simultaneous bilateral injections of 2.5 units botulinum toxin type A were made into the lateral rectus muscles with the patient receiving nitrous oxide-ethrane inhalation anesthesia. Patients were observed for 12 to 44 months after the initial injection.

MAIN OUTCOME MEASURES

A satisfactory outcome was considered to be stable binocular alignment of the eyes to an orthophoric range of +/-10 PD.

RESULTS

Bilateral lateral rectus muscle injections of botulinum toxin were effective in reducing the mean preinjection deviation of -29 PD to an average exotropic angle of -6 PD. Stable orthophoria (+/-10 PD) was achieved in 22 patients (69%). Overall, male patients required significantly fewer injections than did female patients. All patients between 24 and 56 months of age, irrespective of gender, required only a single bilateral injection to achieve a favorable motor outcome.

CONCLUSIONS

Botulinum toxin is at least as effective as surgical outcomes reported previously for the treatment of intermittent exotropia in children. This treatment method is particularly effective in children between 2 and 4.5 years of age irrespective of the initial strabismic angle and is not associated with any secondary abnormalities.

Initial versus subsequent postoperative motor alignment in intermittent exotropia

BACKGROUND

Although initial overcorrection is believed to be important after bilateral lateral rectus muscle recessions for intermittent exotropia, not all patients with desirable amounts of initial overcorrection have good final outcomes. The purpose of this study is to evaluate the relationship between initial postoperative and subsequent postoperative motor outcomes in a group of patients operated on for intermittent exotropia.

METHODS

All patients on whom I performed bilateral lateral rectus muscle recessions as the initial surgical procedure for intermittent exotropia and who had at least 6 months of postoperative follow-up were included in this study.

RESULTS

Of the 60 patients in this study, 38 (63%) had good outcomes (< or = 10 PD exophoria or < or = 5 PD esophoria), 15 (25%) had undercorrection (> 10 PD exodeviation), and seven (12%) had overcorrection (> 5 PD esodeviation). The chance of a good outcome was highest with initial postoperative alignment between orthotropia and 9 PD of esotropia, but 22% of patients with alignment in this range after the operation ended up overcorrected or undercorrected. Most patients had an exotropic drift after the operation, but seven patients had a drift in an esotropic direction.

CONCLUSIONS

Although an initial alignment within the range of orthotropia to 9 PD of esotropia during the first few days after the operation is desirable for patients with intermittent exotropia, alignment within this range does not guarantee a good final outcome, nor does alignment outside this range guarantee a bad outcome. Little predictability exists with respect to the amount and occasionally even the direction of postoperative drift. This unpredictability may in part reflect the artifactual nature of the initial postoperative measurement.