Surgical treatment of unilateral acquired superior oblique muscle palsy in adults by inferior oblique belly transposition: a retrospective analysis.

PURPOSE: Evaluate and analyze the efficacy of inferior oblique belly transposition (IOBT) in treating adult patients with diplopia and small-angle hypertropia caused by mild to moderate inferior oblique overaction (IOOA) secondary to acquired superior oblique palsy (SOP). METHODS: Nine adult patients with diplopia and small-angle hypertropia associated with mild to moderate IOOA secondary to unilateral acquired SOP were included in the current retrospective study. All patients received the IOBT procedure between February 2019 and May 2023 at The Second People's Hospital of Jinan and were followed up for more than 6 months after the surgery. During the procedure, the belly of the inferior oblique muscle was fixed to the sclera at 5 mm posterior to the temporal insertion of the inferior rectus muscle. The following indicators were reviewed pre- and post-surgery: the vertical deviation (VD) in the primary position and in the Bielschowsky test, the fovea disc angle (FDA) of the affected eye, changes in IOOA, and diplopia. RESULTS: After IOBT, the VD in the primary position decreased from 7.22△ ± 1.72△ (range 4△-10△) to 1.22△ ± 1.30△ (range 0△-3△). The VD in the Bielschowsky test decreased from 13.00△ ± 1.80△ to 3.22△ ± 1.09△. The FDA decreased from 10.02° ± 3.34° to 6.26° ± 1.91°. The grade of IOOA was reduced from 2.00 (1.00, 2.00) to 0.00 (0.00, 1.00). All changes were statistically significant (P < 0.001 or P = 0.006). Diplopia was resolved completely for all patients. CONCLUSIONS: IOBT can effectively treat adults with diplopia and small-angle hypertropia caused by mild to moderate IOOA secondary to acquired SOP.

Levator palpebralis superioris histopathologic findings in congenital ptosis and surgical outcome after its resection: Is there any association?

PURPOSE: To evaluate the histopathologic findings of Levator palpebralis superioris (LPS) muscle biopsy after LPS resection for treatment of congenital ptosis and its possible relation with surgical outcomes.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 4 Given name: [Seyed Mohsen] Last name [Rafizadeh]. Author 6 Given name: [Seyed Ali] Last name [Sonbolestan].Also, kindly confirm the details in the metadata are correct.The author names and the sequence are correct. METHODS: Congenital ptosis patients were enrolled in this retrospective study. All of them underwent full ophthalmologic examination included of Margin-reflex distance 1 (MRD-1) and LPS function measurement preoperatively. The patients were followed for 3 months for the postoperative period and after that the measurements were repeated. Histologic parameters including percentages of fat, striated and smooth muscle, and fibrous tissue. The histopathologic findings and their possible correlation with the measurements are analyzed. RESULTS: Sixty-seven patients with unilateral congenital ptosis were enrolled. 45 patients (67.2%) were males. The mean age of patients was 16.10 ± 11.18 years. The patients' MRD-1 was improved significantly from 0.82 ± 1.26 mm to 3.85 ± 1.25 mm after LPS resection (P = 0.000). The success rate was 80.3%. There were no correlations between MRD change and histopathologic tissue percentages but significant correlation was found between success of surgery and fibrous tissue percentage of resected sample (P = 0.033). CONCLUSIONS: The histopathology of the LPS may be useful in prediction of surgical outcome after LPS resection in congenital ptosis patients. The percentage of fibrous tissue play an important role.

Medial Rectus Disinsertion for the Management of Large-Angle Sensory Esotropia.

Background and Objectives: The aim of the report is to report the outcomes of the medial rectus (MR) disinsertion procedure for the management of large-angle esotropia (ET) patients. Materials and Methods: This is a retrospective case series of patients with large-angle ET who underwent an MR disinsertion procedure between March 2012 to April 2022. The procedure happened accidentally during muscle surgery. The demographic and clinical data, including sex, age, visual acuity, pre- and postoperative angle of strabismus, duction limitations, results of intraoperative forced duction tests, and follow-up duration were collected from medical records. Results: Five patients were enrolled in this study. The mean age was 62.2 ± 9.8 years, and the mean follow-up was 24.8 ± 8.7 months. The ET at the primary position of gaze was 92.0 ± 17.9 prism diopters (PD) before MR disinsertion and 38.0 ± 29.5 PD after MR disinsertion only. Abduction deficiency was -4 before after MR disinsertion, which improved to -1 at the last follow-up. Conclusions: The results of MR disinsertion were not as frustrating as anticipated. MR disinsertion may be considered in patients with large-angle sensory ET who refuse surgery on the opposite eye.

The Outcome of Inferior Oblique Myectomy for Apparent Inferior Oblique Overaction Associated with Craniosynostosis.

PURPOSE: Strabismus in patients with craniosynostosis is common, but surgical correction of strabismus in these patients remains challenging. We report our findings in six patients (four of whom were Korean) with craniosynostosis who underwent strabismus surgery to specifically address V-pattern horizontal strabismus with moderate-to-severe inferior oblique (IO) overaction, using IO myectomy at a single tertiary hospital between 2005 and 2016. METHODS: We recorded preoperative characteristics including sex, age, type of strabismus, versions grading, refractive error, and visual acuity. The grading of cyclorotation of horizontal rectus muscles by V-pattern categorized using coronal computed tomography imaging. RESULTS: Of the six patients, exodeviation was found in four patients and vertical deviation in two patients in primary position. One patient had both horizontal and vertical strabismus. Available computed tomography imaging showed that V-patterns were category 1 (mild) in two patients, category 2 (moderate) in one patient, and category 3 (severe) in two patients. Complete success was defined as absence of IO overaction any more. Overall complete success rate of IO myectomy was 83.3%. CONCLUSIONS: IO myectomy appeared to have some benefits in V-pattern horizontal strabismus with moderate-to-severe IO overaction in patients with craniosynostosis.

Nasal loop myopexy for management of exotropia-hypotropia complex associated with high myopia.

INTRODUCTION: Exotropia-hypotropia complex is an uncommon phenomenon associated with high myopia. However, some literature reports cases of the exotropia-hypotropia complex where residual hypotropia is managed through a secondary surgery following the conventional recession-resection of the lateral rectus (LR) and medial rectus (MR). Nasal Loop myopexy as a primary surgical procedure for the management of exotropia-hypotropia complex has been rarely reported in the literature. METHODS: A 24-year-old male with unilateral high myopia presented with a large angle exotropia-hypotropia complex with limitation of elevation in abduction in his left eye. His ocular deviation was successfully managed through a nasal loop myopexy of the superior rectus (SR) and MR using a non-absorbable suture, combined with large LR recession and MR resection. RESULTS: Postoperatively, the patient had satisfactory ocular alignment with improved hypotropia and normal elevation in abduction, contributing to enhanced binocular vision and better cosmesis. DISCUSSION: Managing the exotropia-hypotropia complex in the context of high myopia demands a comprehensive approach that addresses both vertical and horizontal deviations. The surgical strategy employed in this case, which included loop myopexy of SR and MR along with LR recession and MR resection, achieved positive outcomes regarding alignment, elevation, and binocular vision. The case supports variations in muscle path and the potential benefits of tailored surgical strategies for complex strabismus cases associated with high myopia.

Challenges in management of congenital enophthalmos due to anomalous accessory orbital extraocular muscle bands.

INTRODUCTION: Congenital enophthalmos is a rare condition characterized by posterior displacement of the globe, often associated with bony orbital anomalies or whole globe development defects. The purpose of this report is to present two unrelated cases of congenital enophthalmos secondary to anomalous accessory orbital bands and to describe characteristics of orbital imaging that differentiate this condition from the other causes. METHODS: The case records of two patients who presented with congenital enophthalmos and were discovered to have anomalous accessory orbital extraocular muscle bands were reviewed. The clinical features, initial diagnosis, high resolution magnetic resonance imaging (MRI) findings, and surgical outcomes were noted. A 3-dimensional reconstruction model was used to understand the approach and surgical management in one of the cases. RESULTS: Both patients presented with unilateral severe enophthalmos, globe retraction, and restricted ocular motility in all directions since birth. High-resolution MRI of the orbits revealed a short anomalous band, isointense to the muscle, arising from a rectus muscle belly and attaching to the posteroinferior part of the globe adjacent to the optic nerve. The caliber of the extraocular muscles and ocular motor nerves was normal. In one patient, surgery was not pursued due to the extreme posterior location of the band with proximity to the optic nerve. In the other patient, the deviation did not improve, despite successfully severing the accessory band, due to extensive scarring. CONCLUSION: Anomalous accessory orbital extraocular muscle bands are a rare and often overlooked cause of congenital enophthalmos when associated with limited ocular motility. Imaging the orbit can aid in diagnosis and help differentiate it from other causes. Safe surgical approaches to address the problem are limited, and available approaches may not be effective. These two cases highlight that the management of accessory extraocular muscle bands causing enophthalmos can be extremely challenging and difficult to improve even with intensive surgical intervention.

Pencil push-up training compared with binocular vision training in the management of slight post-operative under-correction of intermittent exotropia: A prospective study.

PURPOSE: This study aims to compare the effectiveness of pencil push-up training and binocular vision training in treating post-operative mild under-correction in patients with intermittent exotropia. METHODS: A prospective cohort study was conducted, including patients who underwent surgery for intermittent exotropia at Children's Hospital of Nanjing Medical University between June 2022 and January 2023 and experienced post-operative mild under-correction (-8∆ to -15∆). Patients were divided into two groups: pencil push-up training group and binocular vision training group. All patients underwent measurements of exodeviation and stereoacuity at distance and near, sensory fusion, and fusion convergence amplitude. The data were analyzed using independent sample t-tests, repeated measures analysis of variance, and Chi-square tests. RESULTS: There were no statistically significant differences in exodeviation at distance and near between the two training groups before the training. After 6 months of training, the exodeviation at distance and near achieved a significant decrease in both groups (P < 0.05), and the pencil push-up training group showed a similar distance and near exodeviation compared to the binocular vision training group (t = 1.58, P ＞ 0.05; t = 0.43, P ＞ 0.05). After 6 months of training, the binocular vision training group exhibited significantly superior stereoacuity and fusion convergence amplitude compared to the pencil push-up training group (P < 0.001). CONCLUSION: Both pencil push-up training and binocular vision training are effective in reducing exodeviation in patients with post-operative mild under-correction of intermittent exotropia. However, binocular vision training demonstrates superior efficacy in restoring stereopsis and fusion convergence amplitude compared to pencil push-up training.

Assessment of surgical strategies for management of complicated strabismus reoperation in Graves' ophthalmopathy.

PURPOSE: Strabismus reoperation in Graves' ophthalmopathy (GO) is complicated and challenging. The purpose of this study was to evaluate the various surgical strategies of strabismus reoperation and their outcomes in patients with GO. METHODS: A retrospective study was conducted on strabismus reoperations performed at the Zhongshan Ophthalmic Center of Sun Yat-sen University, Guangzhou, China from 2008 to 2018. Data collected included sex, age at surgery, duration of deviation, ocular alignment, ocular motility, various surgical procedures performed and surgical outcomes. Surgical methods included rectus recession for newly developed strabismus, rectus resection for undercorrection and anterior advancement of a previously recessed rectus for overcorrection. Surgical success was defined as an absence of diplopia, a horizontal deviation of ≤ 10 prism diopters (PD) and a vertical deviation of ≤ 5 PD at distance in primary and reading positions. RESULTS: Of the 153 GO patients receiving strabismus surgery, 27 cases (20 males, 7 females) underwent reoperation for strabismus, with a reoperation rate of 17.6%. Success rates of reoperation in patients with a previous undercorrection and overcorrection were 45% and 71.4%, respectively. Success rates of rectus recession, rectus resection and anterior advancement were 47.1%, 66.7% and 50%, respectively. Two patients underwent the third surgery. The overall success rate was 51.9%. CONCLUSIONS: Rectus recession is an effective method for GO patients with newly-developed strabismus. Rectus resection may benefit some patients with undercorrection who underwent a maximal degree of rectus recession. Anterior advancement of a previously recessed rectus is effective for cases with overcorrection.

Characteristics and Trends of Strabismus Surgeries at a Tertiary Hospital Over 2 Decades - What Can Be Learned for Years to Come?

PURPOSE: To analyze characteristics and trends of strabismus surgeries in an Israeli hospital over 2 decades. METHODS: A descriptive, retrospective study including all strabismus surgeries (666) performed during 2000-2019 at an Israeli tertiary hospital. Electronic medical records (EMRs) were directly retrieved to produce an anonymized database. RESULTS: No trends were evident for age, sex, or ethnicity (p = .294, 0.914 and p = .167, respectively). The mean number of horizontal muscles remained stable, while an increase was noted in the mean number of muscles operated on to repair vertical strabismus (p < .0001). Among acquired cases, a 2.67-fold increase was noted in the proportion of spontaneous strabismus and a decrease of traumatic causes to a third (p < .001). An increase was noted in the proportion of exotropia among horizontal strabismus corrections (p = .022), and esotropia correction techniques distribution changed (p = .004). Reoperations comprised a third of all cases during both decades (p = .198). Reoperations were more prevalent among younger and Jewish patients (p < .001 and p = .024, respectively). Techniques to correct esotropia and exotropia differed significantly between primary surgeries and reoperations (p < .00001 each). CONCLUSIONS: The complexity of surgical techniques increased over time. Ethnic minorities were less prone to reoperations.

Surgical management of unilateral restrictive strabismus in an 8-month-old dog.

CASE HISTORY: An 8-month-old male, entire, mixed-breed dog was presented with a 1-month history of left exophthalmos and green mucopurulent ocular discharge. Subsequently, exophthalmos resolved but esotropia (medial strabismus) developed in the left eye, prompting referral to an ophthalmologist. CLINICAL FINDINGS: At the initial referral consultation, enophthalmos and esotropia of the left eye were identified. The patient showed mild improvement after a 3-week tapering course of oral prednisolone and doxycycline. MRI was performed and showed left medial rectus muscle atrophy with increased contrast enhancement which was consistent with chronic extraocular muscle myositis (EOM). A forced duction test was performed to confirm the diagnosis of fibrosing esotropia, which is likely a sequela of chronic EOM. DIAGNOSIS: Fibrosing esotropia presumably caused by untreated EOM. TREATMENT AND OUTCOME: One month later, esotropia progressed to a marked ventro-medial strabismus resulting in visual deprivation. Surgical release of the ventral oblique, medial and ventral recti muscles was performed, resulting in immediate resolution of the enophthalmos. Despite a tapering post-operative course of oral prednisolone, mild esotropia was present 4 weeks later. In an effort to stabilise the globe position, the low dose of prednisolone was increased to a higher anti-inflammatory dose before slowly tapering over 2 months. The vision in the left eye was improved after surgery and has been maintained since without further treatment. CLINICAL RELEVANCE: This is the first documented case of fibrosing esotropia in a young dog with prior signs of acute exophthalmos. Fibrosing esotropia has been documented in certain breeds or as a sequela to chronic EOM. In this patient, it was presumably caused by EOM, which was strongly supported by the case history, progression and MRI findings. Most historical reports of EOM described it as a bilateral condition that resolves with systemic corticosteroids at an anti-inflammatory dose. EOM has been shown to also present unilaterally and it can progress to strabismus if not promptly recognised and treated with systemic steroids. Surgical management can restore vision when severe strabismus results in visual deprivation.

The effects of refractive status on the outcomes of strabismus surgery in patients with esotropia.

BACKGROUND: The success of the strabismus surgery can hinge on several factors. One of these factors is refractive condition like hyperopia or myopia. Our study seeks to evaluate the surgical outcomes in patients with esotropia and myopia. METHODS: This case-control study encompassed all surgical cases of esotropia at Torfe and Negah Hospital between 2016 and 2021, which satisfied our specified inclusion criteria. The initial variables from electronic medical records were collected, including demographic, clinical, and surgery-related factors. At the final follow-up appointment, the level of eye deviation, both at distance and near, was recorded. We considered the operation a "success" for patients with a post-surgery distance eye deviation of 10(Pd) or less. Patients with greater deviation were classified as surgery failure. Statistical analyses were executed using SPSS software (version 16.0), and a P-value less than 0.05 was considered significant. RESULTS: Of the 194 patients evaluated, 112 were incorporated into the study. Surgical failure was observed in 14.29% of myopic patients, 29.79% of hyperopic patients, and 31.82% of emmetropic patients. The myopia group displayed a 0.19 odd ratio for surgical failure compared to the combined hyperopia and emmetropia groups, not statistically significant (OR: 0.19, CI 95%: 0.03-1.02). Additionally, patients diagnosed with Lateral Rectus Under-action were found to be 6.85 times more likely to experience surgery failure(OR: 6.85, CI 95%: 1.52-30.94). An elevated risk of surgical failure was also identified in patients who underwent Inferior Oblique Weakening procedure, indicated by a 3.77-fold increase in the odds ratio for failure(OR: 3.77, CI 95%: 1.08-13.17). CONCLUSION: In our study, despite numerical disparities, there was no statistical difference among the success rates of all esotropia patients with different refractive errors. The patients with LRUA or IOOA showed lower success rates. Myopic patients had higher post-op overcorrection with lower reoperation rates compared to hyperopic or emmetropic patients.

Clinical characteristics and surgical outcomes in patients with superior oblique muscle palsy: a retrospective study on 1057 patients.

BACKGROUND: To evaluate the clinical findings of patients with SOP who underwent surgery. METHODS: This historical cohort study was performed on 1057 SOP patients managed with surgery in Farabi Hospital, Iran, from 2011 to 2022. RESULTS: There were 990 (93.7%) patients with unilateral SOP with the mean age of 21.8 ± 14.8 years. Of these, 715 patients (72.2%) were diagnosed with congenital SOP, and 275 patients (27.8%) had acquired SOP (P < 0.001). In contrast, 67 (6.3%) patients were diagnosed with bilateral SOP, with the mean age of 19.4 ± 15.6 years. Among these, 18 cases exhibited the masked type. The mean angle of vertical deviation in primary position at far in unilateral and bilateral cases was 15.6 ± 8.3 and 13.3 ± 9.1 △, respectively (P < 0.001). In unilateral cases, abnormal head posture (AHP) was detected in 847 (85.5%) patients and 12 (1.2%) had paradoxical AHP. Amblyopia was found in 89 (9.9%) unilateral and 7 (10.3%) bilateral cases. Solitary inferior oblique myectomy, was the most common surgery in both unilateral (n = 756, 77.1%) and bilateral (n = 35, 52.2%) patients. The second surgery was performed for 84 (8.6%) unilateral and 33 (49.3%) bilateral cases (P < 0.001). The prevalence of amblyopia and the mean angle of horizontal deviation were significantly higher in patients who needed more than one surgery (all P < 0.05). CONCLUSION: Congenital SOP was more than twice as frequent as acquired SOP and about 90% of unilateral and 50% of bilateral cases were managed with one surgery. Amblyopia and significant horizontal deviation were the most important factors for reoperation. TRIAL REGISTRATION: The Institutional Review Board approval was obtained from the Tehran University of Medical Sciences (IR.TUMS.FNM.REC.1400.012) and this study adhered to the tenets of the Declaration of Helsinki and HIPAA.

Small tuck for superior oblique palsy.

PURPOSE: To investigate the surgical outcomes of small superior oblique (SO) tuck-denoting minimal tendon laxity-in patients with unilateral SO palsy. METHODS: The medical records of consecutive patients treated with ≤6 mm SO tuck from 2000 to 2018 at Kellogg Eye Center, University of Michigan, were reviewed retrospectively. Tendon tucks were performed to a fairly uniform tension in an amount that just eliminated slack in the tendon. Pre- and postoperative motility measurements were compared. Patients were excluded if they had a history of prior strabismus surgery or concurrent vertical rectus or inferior oblique surgery. RESULTS: A total of 27 cases (14 males) met inclusion criteria. The median age at surgery was 47 years (range 3-74 years). The mean SO tuck (total, both arms of tuck) was 4.9 mm (range, 2-6 mm). After surgery, median hypertropia decreased from 9Δ to 1Δ in primary position and from 20Δ to 4Δ in the SO field of action (contralateral downgaze). Lateral incomitance (difference in hypertropia between contralateral and ipsilateral gaze) decreased from 10Δ to 2Δ (P < 0.001 in each case). Six patients had diplopia in upgaze postoperatively that was not symptomatic enough to require reoperation. Six patients had residual hypertropia requiring additional surgery. CONCLUSIONS: Small SO tuck provided disproportionate correction of hypertropia in the SO field of action and nearly eliminated lateral incomitance without producing unacceptable iatrogenic Brown syndrome. Even in the absence of tendon laxity, SO tuck was a good surgical option for SO palsy in our cohort where there was marked lateral incomitance and the greatest deviation was in the SO field of action.

Long-term comparison of horizontal rectus surgery with vertical tendon transposition and combined vertical tendon transposition and inferior oblique-weakening in V-pattern exotropia.

PURPOSE: To compare the efficacy of bilateral lateral rectus recession with vertical tendon transposition (LRVT) and LRVT combined with inferior oblique (IO) disinsertion for V-pattern exotropia. METHODS: The medical records of patients who had mild-to-moderate (+1 and +2) inferior oblique overaction (IOOA) and underwent half-tendon-width upward LRVT (transposition group), and LRVT with IO disinsertion (combined surgery group) for V-pattern exotropia and who had at least 3 years of postoperative follow-up were reviewed retrospectively. RESULTS: A total of 45 patients were included: 22 in the transposition group and 23 in the combined surgery group. Preoperatively, there were no differences in V pattern, IOOA, or horizontal misalignment in primary position, upgaze, or downgaze between groups. The amount of exotropia in the primary position was 30.2Δ ± 10.7Δ in the transposition group, and 31.6Δ ± 14.1Δ in the combined surgery group (P = 0.974). A significant decrease in V pattern was observed in the combined surgery group and the transposition group at 6 months and 3 years postoperatively (P < 0.001). The reduction of V pattern in the combined surgery group at 6 months (20.2Δ ± 7.8Δ vs 15.6Δ ± 6.9Δ [P = 0.02]) and 3 years (20.1Δ ± 8.1Δ vs 15.2Δ ± 7.1Δ [P = 0.014]) was found to be greater than the transposition group. There were no differences in the success rate in the primary position at 6 months (P > 0.05). CONCLUSIONS: Both tendon transposition with horizontal rectus surgery and combined tendon transposition and IO-weakening surgery decreased V-pattern exotropia. However, combined surgery had a greater effect on decreasing V pattern in patients with mild-to-moderate IOOA.

The effect of strabismus surgery on the dynamic balance in children with strabismus.

Purpose: To evaluate the effect of strabismus surgery on dynamic balance by using computerized dynamic posturography in children with strabismus. Methods: This study was designed as a prospective observational study. Hearing tests and complete ophthalmological examinations were performed for all subjects. Patients with moderate and severe amblyopia, hearing loss at any level, and/or any suspicion of balance impairment were excluded from the study. Postural stability evaluation was performed by computerized dynamic posturography including sensory organization test, adaptation test, and rhythmic weight shift test. All tests were applied preoperatively and in the postoperative 1st and 3rd months, respectively. Results: Fifteen female and twelve male pre-adolescents aged between 7 and 12 (9.67 ± 1.62 years) were included in the current study. In the sensory organization test, the preoperative visual ratio percentages (73.19 ± 14.95%) improved statistically significantly at the postoperative 1st and 3rd months (78.59 ± 16.21% and 81.44 ± 14.18; p = .026, p = .021, respectively). The preoperative toes up (110.66 ± 33,48) and toes down (81.46 ± 28.36) adaptation tests improved statistically significantly in the postoperative 3rd month (88.74 ± 20.94 and 63.36 ± 16.03; p < .001, p = .001, respectively). In the Rhythmic Weight Shift test, the postoperative 3rd-month directional control (forward-backward) value (74.25 ± 11.51%) was statistically significantly higher compared to the preoperative directional control (forward-backward) value (67.76 ± 11.38%) (p = .011). The postoperative 3rd-month directional control (forward-backward) value (74.25 ± 11.51%) was statistically significantly higher compared to the postoperative 1st-month directional control (forward-backward) value (68.43 ± 14.00%) (p = .028). Conclusion: Surgical treatment resulted in an improvement in the maintenance of dynamic balance in children with strabismus.

Divergence excess and basic exotropia types of intermittent exotropia: a major review. Part 2: non-surgical and surgical treatment options.

INTRODUCTION: Currently, there is no consensus regarding the management of intermittent exotropia (IXT), which includes both surgical and non-surgical treatment options. Nonsurgical management of IXT has been suggested and includes watchful observation, patching, overminus lenses, prism, and vision therapy/orthoptics. While a significant portion of IXT patients are treated by surgery, it is reported that there is a substantial tendency for reoperation or recurrence of IXT. This paper provides a comprehensive review of non-surgical and surgical treatment options for the IXT. METHODS: Search strategies involving combination of keywords including intermittent exotropia, divergence excess, basic exotropia, refractive error, glasses, spectacles, natural history, untreated, observe, occlusion, patch, overminus, overcorrecting minus, prism, vision therapy, orthoptic, anti-suppression, fusion exercise, and surgery were used in Medline. All English articles from 01/01/1900 to 01/09/2020 were reviewed. The reference list of the identified articles was also checked for additional relevant articles. Studies focused on animal models or strabismus associated with neurologic disorders or injury were excluded. The following filters were used for surgical management due to the abundance of reports: full text, randomized controlled trial, review, in the last 5 years. RESULTS: Appropriate optical correction of refractive error is generally the starting point for all management approaches, but there is a lack of randomized clinical trial data regarding this treatment modality. Randomized clinical trial data indicate that both observation and occlusion are reasonable management options for children 3-10 years old, and there were insufficient data to recommend occlusion for children 12-35 months old. While overminus lenses were found to improve the control of IXT when assessed wearing overminus spectacles, this improvement did not persist after the treatment ended. The result of the only randomized clinical trial on the effectiveness of base-in prism indicated that this treatment is no more effective than nonprism spectacles for improving control. A recent randomized clinical trial showed that vision therapy/orthoptics is effective in improving the control of IXT when compared to observation alone. Surgery was found to alter a number of clinical characteristics of IXT, including reducing the distance and near angle of deviation, reducing photophobia, improving health-related quality of life, stereopsis, and the Newcastle Control Score. However, there are no randomized clinical trial data comparing surgery with a control group such as placebo or a no treatment observation group. DISCUSSION: Rigorously designed clinical trials to investigate the effectiveness of non-surgical and surgical treatments for intermittent exotropia are needed.