Comparison of different surgery procedures for convergence insufficiency-type intermittent exotropia in children

Medial Rectus Inferior Half Plication for the Treatment of Near Exotropia

PURPOSE

To report a relatively new surgical treatment for near exotropia called medial rectus inferior half plication.

METHODS

This was a retrospective analysis of the outcomes from a single surgeon performing a plication of the inferior half of the medial rectus muscle in 17 consecutive patients with near exotropia unresponsive to medial rectus bupivacaine injection.

RESULTS

Thirteen of 17 (76%) patients were asymptomatic after surgery with no diplopia for near fixation and with either a normal or slightly reduced prism fusion range enabling them to have comfortable binocular single vision. There was one minor surgical overcorrection with distance diplopia that disappeared within 2 weeks of surgery. Of the 4 of 17 (24%) patients who required further intervention, 3 required one further surgical procedure and 1 required an injection of bupivacaine into the contralateral medial rectus muscle to obtain a satisfactory alignment and control of symptoms. No patient needed more than two total operations.

CONCLUSIONS

The data show medial rectus inferior plication can produce excellent outcomes with minimal risk of overcorrection. [J Pediatr Ophthalmol Strabismus. 2024;61(3):219-222.].

Revisiting the surgical table: An analysis of surgical dose-response in Asian exotropia

BACKGROUND

Previous research on the factors associated with surgical dose-response in strabismus surgery for exotropia has yielded inconsistent results. This study determined the factors influencing surgical dose-response in exotropia patients who underwent recession and resection (R&R).

METHODS

Exotropia patients who underwent unilateral R&R at the National Taiwan University Hospital between 2006 and 2021 were evaluated. Deviation-angle differences in prism diopters (PD) were measured preoperatively and at 1 month postoperatively. Surgical dose-response (PD/mm) was defined as the difference in deviation angle (in PD) divided by the surgical dose in millimeters. Linear and non-linear regression models were used to evaluate the influence of variables including age, sex, axial length, and preoperative deviation on surgical dose-response.

RESULTS

Overall, 295 patients (162 children; 133 adults) were included. Average surgical dose-response in the pediatric and adult groups was 2.82 ± 0.60 PD/mm and 3.02 ± 0.62 PD/mm, respectively. Male sex was negatively correlated with surgical dose-response in children. The surgical dose-response was larger in adults with longer axial length (>25.64 mm) and patients with larger preoperative deviation (>42.6 PD and >38.7 PD in pediatric and adult groups, respectively). Surgical dose-responses peaked at 35.1 years.

CONCLUSION

Age, axial length, and preoperative deviation have a nonlinear effect on surgical dose-responses in exotropia patients undergoing R&R. Surgical dose-responses were larger in patients in young adulthood, with longer axial length and larger preoperative deviation angle. A table with fitted values for surgical dose-response based on age, axial length, and preoperative deviation was established for clinical reference.

Intermittent exotropia with convergence insufficiency — diagnostics, methods of invasive treatment

The review analyzes most common injection and surgical methods of treatment of intermittent exotropia of convergence insufficiency: injections of botulinum toxin type A, injections of bupivacaine, bilateral recession of lateral rectus muscles with imposition of fixation sutures or without it (including hemi-hang-back, no-noose technique), recession of lateral rectus muscles according to Stellard, unilateral or bilateral resection of medial rectus muscle, a combination of resection with recession in one eye, the formation of a duplication of medial rectus muscle. The results before and after treatment are presented. The results of evaluating the effectiveness of invasive therapy in patients with exotropia with convergence insufficiency are summed up.

How to Better Treat Patients with Intermittent Exotropia: A Review of Surgical Treatment of Intermittent Exotropia

Intermittent exotropia (X(T)) is the most common form of strabismus, especially in Asians. Treatment of X(T) includes occlusion, overminus lens, and surgery, of which, surgery is the mainstay of treatment. Commonly performed surgical procedures for X(T) are bilateral lateral rectus muscle recession or unilateral lateral rectus recession with medial rectus resection; however, it is unclear which of the two surgeries is more effective. The purpose of this review is to provide an insight on the surgical treatment of X(T). Randomized controlled trials, comparative observational studies, and case series with a large number of patients as well as a long follow-up period of over a year were included.

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

PURPOSE

To 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).

METHODS

The 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 ≤10^Δ of exophoria/tropia and ≤5^Δ of esophoria/tropia.

RESULTS

A 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 8.30^Δ ± 5.88^Δ in the BPX group and 14.67^Δ ± 9.83^Δ in the control group (P = 0.80). Distance-near differences were significantly reduced in the CI-IXT group receiving BPX, by a mean of 6.60^Δ, from a preoperative mean of 10.50^Δ ± 3.65^Δ to 3.90^Δ ± 3.26^Δ (P < 0.01).

CONCLUSIONS

BPX 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.

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.

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

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

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

Purpose

To 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.

Methods

Retrospective 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.

Results

The 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.

Conclusions

Slanted 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.

Interventions for intermittent exotropia

BACKGROUND

The clinical management of intermittent exotropia (X(T)) has been discussed extensively in the literature, yet there remains a lack of clarity regarding indications for intervention, the most effective form of treatment, and whether there is an optimal time in the evolution of the disease at which any given treatment should be carried out.

OBJECTIVES

The objective of this review was to analyze the effects of various surgical and non-surgical treatments in randomized controlled trials (RCTs) of participants with intermittent exotropia, and to report intervention criteria and determine whether the treatment effect varies by age and subtype of X(T).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 1), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Ovid Embase; Latin American and Caribbean Health Science Information database (LILACS); the ISRCTN registry; ClinicalTrials.gov, and the WHO ICTRP. The date of the search was 20 January 2021. We performed manual searches of the British Orthoptic Journal up to 2002, and the proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA), and American Association for Pediatric Ophthalmology and Strabismus meeting (AAPOS) up to 2001.

SELECTION CRITERIA

We included RCTs of any surgical or non-surgical treatment for intermittent exotropia.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We included six RCTs, four of which took place in the United States, and the remaining two in Asia (Turkey, India). A total of 890 participants with basic or distance X(T) were included, most of whom were children aged 12 months to 10 years. Three of these six studies were from the 2013 version of this review. Overall, the included studies had a high risk of performance bias as masking of participants and personnel administering treatment was not possible. Two RCTs compared bilateral lateral rectus recession versus unilateral lateral rectus recession with medial rectus resection, but only one RCT (n = 197) reported on the primary outcomes of this review. Bilateral lateral rectus recession likely results in little difference in motor alignment at near (MD 1.00, 95% CI -2.69 to 4.69) and distance (MD 2.00, 95% CI -1.22 to 5.22) fixation as measured in pupillary distance using PACT (moderate-certainty evidence). Bilateral lateral rectus recession may result in little to no difference in stereoacuity at near fixation (risk ratio (RR) 0.77, 95% CI 0.35 to 1.71), adverse events (RR 7.36, 95% CI 0.39 to 140.65), or quality of life measures (low-certainty evidence). We conducted a meta-analysis of two RCTs comparing patching (n = 249) with active observation (n = 252), but were unable to conduct further meta-analyses due to the clinical and methodological heterogeneity in the remaining trials. We found evidence that patching was clinically more effective than active observation in improving motor alignment at near (mean difference (MD) -2.23, 95% confidence interval (CI) -4.02 to -0.44) and distance (MD -2.00, 95% CI -3.40 to -0.61) fixation as measured by prism and alternate cover test (PACT) at six months (high-certainty evidence). The evidence suggests that patching results in little to no difference in stereoacuity at near fixation (MD 0.00, 95% CI -0.07 to 0.07) (low-certainty evidence). Stereoacuity at distance, motor fusion test, and quality of life measures were not reported. Adverse events were also not reported, but study authors explained that they were not anticipated due to the non-surgical nature of patching. One RCT (n = 38) compared prism adaptation test with eye muscle surgery versus eye muscle surgery alone. No review outcomes were reported. One RCT (n = 60) compared lateral rectus recession and medial rectus plication versus lateral rectus recession and medial rectus resection. Lateral rectus recession and medial rectus plication may not improve motor alignment at distance (MD 0.66, 95% CI -1.06 to 2.38) (low-certainty evidence). The evidence for the effect of lateral rectus recession and medial rectus plication on motor fusion test performance is very uncertain (RR 0.92, 95% CI 0.48 to 1.74) (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Patching confers a clinical benefit in children aged 12 months to 10 years of age with basic- or distance-type X(T) compared with active observation. There is insufficient evidence to determine whether interventions such as bilateral lateral rectus recession versus unilateral lateral rectus recession with medial rectus resection; lateral rectus recession and medial rectus plication versus lateral rectus recession and medial rectus resection; and prism adaptation test prior to eye muscle surgery versus eye muscle surgery alone may confer any benefit.

Outcomes of intermittent exotropia surgery

PURPOSE

To study the epidemiological and clinical characteristics of intermittent exotropia and to describe our therapeutic choices as well as their results and prognostic factors.

MATERIALS AND METHODS

This was a retrospective study including 57 cases of intermittent exotropia. All patients underwent a complete ophthalmological examination with a sensory-motor assessment. Surgery was performed by the same surgeon, and the vertical component was addressed surgically at the same time as the exotropia. Statistical analysis was performed using SPSS software version 21.0.

RESULTS

Our patients were classified as basic exotropia in 46 cases (80.7%), divergence excess in eight cases (14.1%), and convergence insufficiency in three cases (5.2%). Amblyopia was found in 26% of cases. The preoperative maximum angle of deviation was 36.5DP±9.1DS and a vertical component was found in 16 patients (28%). The most common was V pattern (8 patients). The mean age at the time of surgery was 14.8 years old. After a single surgery, we obtained motor success in 78.9% of the patients. Three patients were re-operated, with an overall motor success of 84.2%.

CONCLUSIONS

Motor and sensory success may be achieved in intermittent exotropia. Rigorous, early management is necessary, even if tropic episodes are still rare. The rate of early consultation among children is still low in our country; thus, a national strabismus screening program must be established to obtain the best results.

Interventions for convergence insufficiency: a network meta-analysis

BACKGROUND

Convergence insufficiency is a common binocular vision disorder in which the eyes have a strong tendency to drift outward (exophoria) with difficulty turning the eyes inward when reading or doing close work.

OBJECTIVES

To assess the comparative effectiveness and relative ranking of non-surgical interventions for convergence insufficiency through a systematic review and network meta-analysis (NMA).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed and three trials registers up to 20 September 2019.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) examining any form of non-surgical intervention versus placebo, no treatment, sham treatment, or other non-surgical interventions. Participants were children and adults with symptomatic convergence insufficiency.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. We performed NMAs separately for children and adults.

MAIN RESULTS

We included 12 trials (six in children and six in adults) with a total of 1289 participants. Trials evaluated seven interventions: 1) office-based vergence/accommodative therapy with home reinforcement; 2) home-based pencil/target push-ups; 3) home-based computer vergence/accommodative therapy; 4) office-based vergence/accommodative therapy alone; 5) placebo vergence/accommodative therapy or other placebo intervention; 6) prism reading glasses; and 7) placebo reading glasses. Six RCTs in the pediatric population randomized 968 participants. Of these, the Convergence Insufficiency Treatment Trial (CITT) Investigator Group completed four RCTs with 737 participants. All four CITT RCTs were rated at low risk of bias. Diagnostic criteria and outcome measures were identical or similar among these trials. The four CITT RCTs contributed data to the pediatric NMA, incorporating interventions 1, 2, 3 and 5. When treatment success was defined by a composite outcome requiring both clinical measures of convergence to be normal, and also show a pre-specified magnitude of improvement, we found high-certainty evidence that office-based vergence/accommodative therapy with home reinforcement increases the chance of a successful outcome, compared with home-based computer vergence/accommodative therapy (risk ratio (RR) 1.96, 95% confidence interval (CI) 1.32 to 2.94), home-based pencil/target push-ups (RR 2.86, 95% CI 1.82 to 4.35); and placebo (RR 3.04, 95% CI 2.32 to 3.98). However, there may be no evidence of any treatment difference between home-based computer vergence/accommodative therapy and home-based pencil/target push-ups (RR 1.44, 95% CI 0.93 to 2.24; low-certainty evidence), or between either of the two home-based therapies and placebo therapy, for the outcome of treatment success. When treatment success was defined as the composite convergence and symptom success outcome, we found moderate-certainty evidence that participants who received office-based vergence/accommodative therapy with home reinforcement were 5.12 (95% CI 2.01 to 13.07) times more likely to achieve treatment success than those who received placebo therapy. We found low-certainty evidence that participants who received office-based vergence/accommodative therapy with home reinforcement might be 4.41 (95% CI 1.26 to 15.38) times more likely to achieve treatment success than those who received home-based pencil push-ups, and 4.65 (95% CI 1.23 to 17.54) times more likely than those who received home-based computer vergence/accommodative therapy. There was no evidence of any treatment difference between home-based pencil push-ups and home-based computer vergence/accommodative therapy, or between either of the two home-based therapies and placebo therapy. One RCT evaluated the effectiveness of base-in prism reading glasses in children. When base-in prism reading glasses were compared with placebo reading glasses, investigators found no evidence of a difference in the three outcome measures of near point convergence (NPC), positive fusional vergence (PFV), or symptom scores measured by the Convergence Insufficiency Symptom Survey (CISS). Six RCTs in the adult population randomized 321 participants. We rated only one RCT at low risk of bias. Because not all studies of adults included composite success data, we could not conduct NMAs for treatment success. We thus were limited to comparing the mean difference (MD) between interventions for improving NPC, PFV, and CISS scores individually using data from three RCTs (107 participants; interventions 1, 2, 4 and 5). Compared with placebo treatment, office-based vergence accommodative therapy was relatively more effective in improving PFV (MD 16.73, 95% CI 6.96 to 26.60), but there was no evidence of a difference for NPC or the CISS score. There was no evidence of difference for any other comparisons for any outcomes. One trial evaluated base-in prism glasses prescribed for near-work activities and found that the prism glasses group had fewer symptoms compared with the placebo glasses group at three months (MD -8.9, 95% CI -11.6 to -6.3). The trial found no evidence of a difference with this intervention in NPC or PFV. No adverse effects related to study treatments were reported for any of the included studies. Excellent adherence was reported for office-based vergence/accommodative therapy (96.6% or higher) in two trials. Reported adherence with home-based therapy was less consistent, with one study reporting decreasing adherence over time (weeks 7 to 12) and lower completion rates with home-based pencil/target push-ups.

AUTHORS' CONCLUSIONS

Current research suggests that office-based vergence/accommodative therapy with home reinforcement is more effective than home-based pencil/target push-ups or home-based computer vergence/accommodative therapy for children. In adults, evidence of the effectiveness of various non-surgical interventions is less clear.

Slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia: a retrospective study

Background

The present study sought to investigate the efficiency and safety of slanted bilateral lateral rectus recession for the treatment of convergence insufficiency-type intermittent exotropia.

Methods

This retrospective study included 34 patients who underwent slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia in Shandong Provincial Hospital affiliated to Shandong First Medical University between September 2013 and October 2015 with a minimum follow-up of 6 months. A successful surgical alignment was defined as + 5 (positive for esotropia) to − 10 (negative for exotropia) prism diopters (PD) of orthotropia in the primary position while viewing distant or near targets and a near-distance deviation difference ≤ 8PD.

Results

The mean age of the patients at surgery was 7.09 ± 3.80 years (range, 3 to 18 years). The mean distance deviations were − 26.09 ± 6.5 PD (range, − 15 to − 35 PD) and the mean near deviations, − 37.21 ± 6.3 PD (range, − 25 to − 45 PD) preoperatively. The mean recession amount of upper pole of the lateral rectus was 5.97 mm (range, 4.0 to 7.5 mm) and that of lower pole of the lateral rectus, 7.49 mm (range, 6.0 to 8.5 mm). At a mean follow-up of 15.0 months (range, 6 to 37 months), the surgical success rate was 70.6% (24/34), the under-correction rate was 17.6% (6/34), and the overcorrection rate was 11.8% (4/34). The mean near-distance deviation difference was significantly reduced from 11.12 ± 2.06 PD (range, 10 to 15 PD) preoperatively to 2.47 ± 3.04 PD (range, 0 to 10 PD) postoperatively (P < 0.001). Each millimeter of difference between the upper and lower poles of the lateral rectus recession was associated with an improvement of 5.65 PD in the near-distance deviation difference. At the final follow up, a near-distance deviation difference of ≤8PD was found in 32 (94.1%) patients. None of the patients developed A-V pattern, torsional diplopia, or restricted abduction of the eyes.

Conclusions

Slanted bilateral lateral rectus recession may successfully reduce the distance and near exodeviations and the near-distance deviation difference, thus was proved to be an effective and safe procedure for the treatment of convergence insufficiency-type intermittent exotropia.

Long-term Results of Slanted Recession of Bilateral Lateral Rectus Muscle for Intermittent Exotropia with Convergence Insufficiency

PURPOSE

To evaluate the long-term efficacy of slanted lateral rectus recession in children for reducing distance and near exodeviation and near-distance deviation difference in intermittent exotropia with convergence insufficiency.

METHODS

The medical records of 53 patients with convergence insufficiency intermittent exotropia who underwent slanted bilateral lateral rectus recession performed by a single surgeon and received follow-up for more than 12 months were retrospectively analyzed. Deviation angles at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively and on the last visit were reviewed. Surgical success was defined as postoperative residual distance and near deviation angles ≤8 prism diopters and a difference between the near and distance angles ≤8 prism diopters.

RESULTS

The mean duration of follow-up was 24 months (range, 12 to 61 months). On the last visit, the residual deviation angles were ≤8 prism diopters in 75.5% for distance, 62.3% for near, and 81.1% for the near-distance difference. Surgical success was achieved in 31 (58.5%) patients, and none of them manifested limitations in eye movements or diplopia at the last follow-up visit.

CONCLUSIONS

Slanted lateral rectus recession is an effective surgical method for reducing distance and near exodeviation and near-distance deviation difference in intermittent exotropia with convergence insufficiency.

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.

Long-term outcomes following resection-recession versus plication-recession in children with intermittent exotropia

Background/Aims

To compare the long-term surgical outcomes between unilateral lateral rectus recession-medial rectus resection (RR) and lateral rectus recession-medial rectus plication (RP) in children with intermittent exotropia.

Methods

Children who underwent RR or RP for intermittent exotropia between January 2008 and July 2016, with a minimum follow-up period of 2 years were retrospectively reviewed. Postoperative angle of deviations and clinical factors including sex, age, refractive errors, preoperative angle of deviation, types of exotropia and stereopsis were investigated. Based on the angle of deviation at year 2, surgical outcomes were classified into two groups as follows: success (esodeviation ≤5 prism dioptres (PD) to exodeviation ≤10 PD) and failure (overcorrection (esodeviation >5 PD) and undercorrection or recurrence (exodeviation >10 PD)).

Results

Of the 186 patients, 114 underwent RR and 72 underwent RP. The angle of exodeviation steadily increased over time in both groups after surgery. The durations of exodrift were longer in the RP group than in the RR group. The surgical success at postoperative year 2 was 55.3% in the RR group and 27.8% in the RP group (p<0.001). The amount of overcorrection was associated with successful outcomes in both groups.

Conclusions

In children with intermittent exotropia, RR group presented better surgical outcomes than RP group. The amount of initial overcorrection was important to achieve favourable outcomes in children with intermittent exotropia.

Comparison of bilateral medial rectus plication and resection for the treatment of convergence insufficiency-type intermittent exotropia

PURPOSE

To compare the clinical outcomes of bilateral medial rectus plication and resection for the treatment of convergence insufficiency (CI)-type intermittent exotropia (IXT).

METHODS

Fifty-five patients with CI-type IXT were included in this prospective study and were followed for 6 months. The patients were randomized into two groups: the bilateral medial rectus plication (BMRP) group (n = 27) and the bilateral medial rectus resection (BMRR) group (n = 28). The eye examinations of each patient were carried out before the surgery and at 1 day and 1, 3 and 6 months postoperatively. The success rate, angle of deviation, stereoacuity, operative time and postoperative conjunctival swelling and redness score were analysed.

RESULTS

The mean deviation at distance at 1 day postoperatively was +6.6 ± 5.6 prism dioptres (PD) in the BMRP group, which was lower than the value of +10.8 ± 9.3 PD observed in the BMRR group (p = 0.046). There was more overcorrection in the BMRR group at first day after surgery. However, there were no significant differences in deviations or success rates were observed between the two groups at 1, 3 and 6 months after surgery (p > 0.05). The operative time in the BMRP (12.9 ± 1.4 min) group was shorter than that in the BMRR (14.7 ± 1.4 min) group (p < 0.001). Postoperative conjunctival swelling and redness were milder in the BMRP group than in the BMRR group (p < 0.001).

CONCLUSION

The BMRP surgery could be an alternative procedure to BMRR for the treatment of CI-type IXT with less immediate postoperative overcorrection and simpler, safer, less traumatic characteristics.

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.

Development of a core outcome set for amblyopia, strabismus and ocular motility disorders: a review to identify outcome measures

BACKGROUND

Core Outcome Sets (COS) are defined as the minimum sets of outcomes that should be measured and reported in all randomised controlled trials to facilitate combination and comparability of research. The aim of this review is to produce an item bank of previously reported outcome measures from published studies in amblyopia, strabismus and ocular motility disorders to initiate the development of COS.

METHODS

A review was conducted to identify articles reporting outcome measures for amblyopia, strabismus and ocular motility disorders. Using systematic methods according to the COMET handbook we searched key electronic bibliographic databases from 1st January 2011 to 27th September 2016 using MESH terms and alternatives indicating the different subtypes of amblyopia, strabismus and ocular motility disorders in relation to treatment outcomes and all synonyms. We included Cochrane reviews, other systematic reviews, controlled trials, non-systematic reviews and retrospective studies. Data was extracted to tabulate demographics of included studies, primary and secondary outcomes, methods of measurement and their time points.

RESULTS

A total of 142 studies were included; 42 in amblyopia, 33 in strabismus, and 68 in ocular motility disorders (one study overlap between amblyopia and strabismus). We identified ten main outcome measure domains for amblyopia, 14 for strabismus, and ten common "visual or motility" outcome measure domains for ocular motility disorders. Within the domains, we found variable nomenclature being used and diversity in methods and timings of measurements.

CONCLUSION

This review highlights discrepancies in outcome measure reporting within published literature for amblyopia, strabismus and ocular motility and it generated an item bank of the most commonly used and reported outcome measures for each of the three conditions from recent literature to start the process of COS development. Consensus among all stakeholders including patients and professionals is recommended to establish a useful COS.

Postoperative changes of intermittent exotropia type as classified by 1-hour monocular occlusion

PURPOSE

To evaluate postoperative changes of the intermittent exotropia type as classified by 1-hour monocular occlusion test.

DESIGN

Institutional, retrospective study.

METHODS

We retrospectively reviewed the medical records of 179 patients who had undergone surgery for intermittent exotropia with a postoperative follow-up of 6 months or more. We evaluated the exodeviation obtained before and after 1-hour monocular occlusion preoperatively and again at postoperative 1, 3 and 6 months. Intermittent exotropia was divided into 4 types according to Burian's classification. The main outcome measure was the distribution of intermittent exotropia type based on 1-hour monocular occlusion in both pre- and postoperative periods.

RESULTS

Of the 179 patients, 152 (84.9%) were assigned preoperatively to the basic type, 14 (7.8%) to the pseudo-divergence excess type, and 13 (7.8%) to the convergence insufficiency type. At postoperative 1, 3, and 6 months, the exotropia-type distribution was shifted predominantly to the basic type (p<0.001, p = 0.004, p = 0.029, respectively). Among the preoperative basic-type patients, 96.9% maintained that type postoperatively. However, only 18.2 and 11.1% of the pseudo-divergence excess and convergence insufficiency types maintained the same type. The proportions of the basic type had increased at postoperative 6 months, from 87.8 to 95.7% for bilateral lateral rectus (BLR) recession, from 73.7 to 92.3% for unilateral recess-resect (R&R), and from 88.0 to 95.0% for unilateral lateral rectus (ULR) recession.

CONCLUSION

The type of intermittent exotropia changed mostly to the basic type postoperatively even as classified after 1-hour monocular occlusion. This finding was consistent regardless of the surgical methods (BLR, ULR recession and R&R).

Surgical outcomes of three different surgical techniques for treatment of convergence insufficiency intermittent exotropia

PurposeTo determine the outcomes of three different techniques of strabismus surgery in patients with convergence insufficiency intermittent exotropia (CI-X(T)).Patients and methodsSixty-seven patients with CI-X(T) with near-distance disparity (NDD) ≥10 prism diopter (PD) were included in this 1-year follow-up prospective study and were randomly divided into three groups: slanted bilateral LR recession (S-BLR) group in which 22 patients underwent bilateral slanting recession of the lateral rectus (LR) muscle, the I-RR group with 23 patients who underwent improved unilateral medial rectus (MR) resection and LR recession with the amounts of resection and recession biased to near and distance deviation, respectively, and the A-BLR group with 22 patients who underwent bilateral augmented LR recession based on the near deviation. A successful outcome at distant and near was defined as exodeviation between 10 PD of exophoria/tropia and 5 PD of esophoria/tropia. Cumulative probabilities of success, preoperative and postoperative distant, near deviations, and NDD among groups were analyzed and compared.ResultsThe success rate of distant exodeviation, near exodeviation, and NDD in the three groups after 1 year was statistically insignificant (P=0.054, 0.233, and 0.142, respectively). At the 1 year follow-up, vertical pattern strabismus (V and A patterns) was a feature of the S-BLR group, whereas the rate of postoperative overcorrection and undercorrection was significant in the A-BLR and I-RR groups, respectively.ConclusionThe success rate of correction of distant exodeviation, near exodeviation, and NDD was statistically indifferent among the three groups. However, each procedure has its specific postoperative concerns, which should be considered before implementing in patients with CI-X(T).

Long-term outcomes of augmented unilateral recess-resect procedure in children with intermittent exotropia

BACKGROUND

Initial overcorrection after exotropia surgery has been considered as a desirable result. Recently, there had been several studies that reported better surgical results of augmented bilateral lateral rectus muscle recession procedure over the conventional procedure.

OBJECTIVES

To compare the long-term results of augmented unilateral lateral rectus recession-medial rectus resection procedure (RR) with the original surgery in exotropic children.

DATA EXTRACTION

A retrospective cohort study was performed on a total of 121 children with exotropia who underwent RR from February 2005 to December 2012 and were followed-up for at least 24 months. In 64 patients, RR was performed based on the original surgical table (original RR group). In 57 patients, the amount of medial rectus muscle resection was increased by 1 mm (augmented RR group).

RESULTS

In the original RR group, 47 of 64 patients (73.4%) had a successful outcome, 13 patients (20.3%) had recurrence, and 4 patients (6.3%) had overcorrection at 2 years after surgery. In the augmented RR group, 45 of 57 patients (79.0%) were successful, 4 patients (7.0%) had recurrence and 8 patients (14.0%) had overcorrection at 2 years after surgery. The recurrence rate was significantly lower in the augmented RR group than the original RR group, whereas the overcorrection rate was not significantly different between two groups at 2 years after surgery (P = 0.036 and P = 0.153, respectively). The cumulative probability of recurrence was lower in the augmented group at 36 months after surgery (P = 0.046, log rank test).

CONCLUSIONS

The long-term success rate of augmented RR in exotropic children was 79.0% and the recurrence rate was significantly lower than original RR with comparable overcorrection rates. Augmented RR can be considered as an alternative procedure in children with basic and convergence insufficiency type exotropia.

A chronicle of surgical thinking and doing for exotropia: innovations and rediscoveries

PURPOSE

To review the evolution of theories and practices concerning surgery for exotropia over the last approximately 200 years.

METHODS

Major ophthalmology texts and relevant references were reviewed to discover experience and thinking concerning the causes of comitant intermittent and constant exotropia and corrective surgical approaches.

RESULTS

The concept that excessive divergence is the cause of comitant exotropia has given way to one recognizing that this disorder is a position of rest modified by convergence. Some operations discarded as unreliable or dangerous remain so today. Others continue to be well accepted, whether or not relating to advances in understanding of this condition. Several procedures practiced at former times have regained popularity.

CONCLUSIONS

Concern for the characteristics of extraocular muscle structure and function has led to surgical thinking that goes beyond consideration only of direction and magnitude of deviation. Sophisticated devices now provide heretofore unavailable information consistent with this new approach. The history of progress in surgery for exotropia is mixed. Although some procedures now employed are new, others currently in favor had been well known and formerly utilized by ophthalmologists for many decades. These should be regarded as rediscoveries or revivals rather than as novel. This review also suggests a need to address how to better report retrospective studies.

Bilateral lateral rectus muscle recession for the convergence insufficiency type of intermittent exotropia

PURPOSE

To evaluate the surgical efficacy of bilateral lateral rectus recession (BLRR) for intermittent exotropia with convergence insufficiency (CI-type X[T]).

METHODS

The medical records of patients with CI-type X(T) who underwent BLRR on adjustable suture from January 2011 to March 2014 were retrospectively reviewed. Ocular alignment and sensory status were evaluated pre- and postoperatively for each patient. The mean distance and mean near deviation, before and after surgery, as well as the mean near-distance difference, were compared. Success was defined as postoperative alignment of esophoria/tropia of ≤5(Δ) and exophoria/tropia of ≤8(Δ) at distance.

RESULTS

A total of 25 patients were included. The mean exodeviation was significantly reduced, from 32.5(Δ) preoperatively to 0.08(Δ) postoperatively (P < 0.001) at distance and from 45(Δ) preoperatively to 2.4(Δ) (P < 0.001) postoperatively at near. The mean near-distance difference was reduced from 16(Δ) preoperatively to 2(Δ) postoperatively (P < 0.01). Of the 25 patients, 21 (84%) obtained successful motor alignment, 2 had recurrent exodeviation of ≥10(Δ) at distance, and 2 had overcorrected esotropia with deviation angles of >8(Δ).

CONCLUSIONS

In this cohort of patients, bilateral lateral rectus recession using an adjustable suture technique successfully treated CI-type X(T).

Advances in surgery procedures for convergence insufficiency-type intermittent exotropia

Intermittent exotropia with convergence insufficiency is defined as a greater exodeviation measured at near than at distance of at least 10 prism diopters and it is harmful to binocular vision at earlier time. This paper mainly introduces three operation patterns including lateral rectus recession(s) with or without a slanting procedure, unilateral lateral rectus recession with medial rectus resection, and medial rectus resection(s) with or without a slanting procedure.