Large-angle Strabismus Research Articles

Botulinum Toxin A Augmentation of Strabismus Surgery for Large-Angle Strabismus: A Retrospective Case Series and Literature Review.

To report the results of botulinum toxin A (BTA)-augmented bilateral recession or monocular recession/resection surgery in a case series of patients with large-angle strabismus and review the relevant literature. This retrospective study reviewed the medical records of 24 patients treated with BTA-augmented strabismus surgery for large-angle horizontal strabismus (55 prism diopters or greater) with a minimum 6-month follow-up. Patients underwent unilateral recession-resection or bilateral rectus muscle recession surgery with intraoperative BTA injection into the recessed muscle(s). Main outcome measures were postoperative angle of deviation and success rate, defined as a final deviation of 10 prism diopters or less. Of 24 patients (20 esotropia, 4 exotropia), the mean age was 9.2 years (range: 1 to 64 years). Mean preoperative deviation was 61.2 prism diopters for esotropia and 66.2 prism diopters for exotropia. Mean final postoperative deviation was 6.6 prism diopters for esotropia and 14.5 prism diopters for exotropia. Successful outcomes were achieved in 75% of patients with esotropia and 50% of patients with exotropia. BTA augmentation of conventional strabismus surgery dosages is a promising approach for managing large-angle strabismus, particularly esotropia. Optimal patient selection and follow-up are needed to maximize surgical success rates. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XXX-XXX.].

SURGICAL OUTCOME OF MUSCLE TRANSPLANTATION AS A MONOCULAR SURGERY FOR LARGE ANGLE STRABISMUS

Introduction: The management of large-angle strabismus can be difficult for surgeons, and successful outcomes may require multiple surgeries. However, modern surgical techniques aim to achieve desired results with a single operation. Muscle transplantation is one such technique that increases the effective muscle length, allowing for a large correction in a one-stage surgery. Objective: To report the outcome of muscle transplantation surgery in large-angle strabismus. Case Illustration: Three patients presented with large-angle strabismus, of which two cases showed >50∆ ET and one case had >50∆XT. All patients had normal anterior and posterior segment findings and underwent muscle transplantation under general anaesthesia. The first and second cases showed good alignment post-surgery, with no limitations in ocular motility in all gaze directions and improved visual acuity. However, none of the cases achieved stereoscopic vision due to chronic strabismus. In the third case, improvement in the primary position was observed two weeks post-operative, but ocular motility still had limitations. Conclusion: Muscle transplantation is a good option to correct large-angle strabismus, specifically in the unilateral case in a single procedure.

SURGICAL OUTCOME OF THREE MUSCLES SURGERY IN ONE SINGLE PROCEDURE OF LARGE-ANGLE EXOTROPIA: A CASE REPORT

Introduction : The management of large-angle horizontal strabismus poses special difficulties. Literature has outlined large-angle strabismus in a variety of ways. A threshold of 40 to 60 PD has been employed to determine large-angle strabismus.
 Case Illustration : A 19-year-old male with complaint of right eye that had been crossed outward since he was 12 years old. There was 90 prism diopter exotropia in near, distance, upgaze, and downgaze. The patient underwent bilateral lateral rectus recession of 10 mm and unilateral medial rectus resection of 6.5 mm in the right eye. Post-operative outcome revealed orthophoria without any misalignment of prism diopter examination in 1 day, one week, and two weeks follow-up.
 Discussion : When the deviation exceeds 50 prism diopter, there is no established consensus regarding the number and quantity of extraocular rectus muscles for surgery. The lack of uniform criteria and suggested surgical dosage is the greatest obstacle in using three muscles surgery. In this case, we used surgical dose according to Kenneth Wright exotropia binocular surgery table. We performed bilateral rectus lateral recession of 10 mm and a right rectus medial resection of 6.5 mm. This surgical dose gives good outcome. Moreover, this option can leave one horizontal rectus muscle unharmed.
 Conclusion : Determination of the surgical dose is essential in the management of large-angle exotropia. Appropriate surgical dose results in excellent outcomes with low risk of residual deviation.

Outcomes of the intraoperative relaxed muscle positioning technique in strabismus surgery for thyroid eye disease

The intraoperative relaxed muscle positioning (IRMP) technique for strabismus surgery in thyroid eye disease (TED) involves recessing muscles' insertions to positions where they rest without tension. We evaluate the long-term outcomes of patients who underwent surgery using this technique. The medical records of patients with TED and diplopia who underwent strabismus surgery with IRMP between 1999 and 2021 were reviewed retrospectively. Excellent outcomes were defined as no diplopia in primary and reading gazes without the use of prisms; good outcomes, as residual deviation of <10Δ with diplopia in primary and reading gazes. Good or excellent outcomes were considered successes. Poor outcomes were defined as residual deviation >10Δ with diplopia in primary and reading gazes or the inability of patients to tolerate prismatic correction. A total of 129 patients were followed for an average of 4.24 ± 5.13 years (longest follow-up 20 years): 96 (73.6%) underwent a single surgery, and 33 (26.4%) underwent additional interventions. Seven of these had been planned as staged procedures, and all were successful. Five patients experienced disease reactivation and underwent additional surgery, with successful outcomes in 4 (80%). Of the remaining 21 patients, 6 underwent a third procedure, and a single patient underwent a fourth. Overall, 93.6% of patients had a successful outcome: 77.5% excellent and 16.3% good. In our study cohort, the IRMP approach resulted in durable relief from large-angle strabismus and diplopia in a large majority of patients.

Surgical Outcomes of Transposition Surgery for the Correction of Large-Angle Strabismus.

Many potential surgical options exist to address large-angle deviations and head turns that result from various forms of paralytic strabismus. Muscle transposition surgeries serve as suitable alternatives to simple resection-recessions. Here, we report outcomes of augmented Hummelsheim and X-type transpositions for the correction of large-angle strabismus and provide insights for surgical planning. We performed a retrospective chart review of 40 consecutive patients with strabismus who were treated with an augmented Hummelsheim or X-type transposition surgery at a single academic medical center. Etiologies included cranial nerve palsies (n = 26), monocular elevation palsy (n = 3), Duane syndrome (n = 1), traumatic extraocular muscle damage (n = 8), and chronic progressive external ophthalmoplegia (n = 2). All patients were followed for a minimum of 2 months postsurgery. Logistic regression analyses were performed to assess for predictors of surgical outcome. Forty consecutive patients were enrolled in our series. The median preoperative deviation was 46.5Δ (interquartile range [IQR] 35-70). The median postoperative deviation 2 months after surgery was 0.5Δ (IQR 0-9.5), which represented a significant improvement (P < 0.001). Thirty-three patients (82.5%) experienced an improvement in range and/or centration of binocular single vision (BSV). More patients who underwent an augmented Hummelsheim procedure and had a small overcorrection at postoperative day 3 had a favorable result on postoperative month 2 (79%) compared with those that were initially under-corrected (38%). Multiple logistic regressions found larger preoperative deviation (P < 0.005) and esotropia (P < 0.021) to be predictors of a less favorable surgical outcome (C-statistic = 0.83). Subgroup analysis revealed that less, favorable outcome after X-type transposition occurred most frequently in patients undergoing correction of an esodeviation. Augmented Hummelsheim transposition techniques offer effective treatment options for paralytic strabismus with esotropic deviations, whereas X-type transpositions are effective for exotropic deviations and deviations from severe inferior rectus damage. In addition to potentially providing a wider field of BSV, improved centration is often achieved.

Outcome of large angle exotropia treated by single stage adjustable strabismus surgery with monitored conscious anesthesia.

Purpose:To evaluate the outcomes of large-angle exotropia by single-stage adjustable strabismus surgery (SSASS) under monitored conscious anesthesia.Methods:A prospective study was done in 33 patients above 14 years with ≥40 prism diopters (PD) of exotropia. All patients underwent SSASS under monitored conscious anesthesia (topical anesthesia plus intravenous sedation). For deviations of ≤55 PD, two horizontal rectus muscles, and for >55 PD, three rectus muscles were operated and a decision on adjustment/operating on an additional rectus muscle was taken after assessing the alignment. Monitored conscious anesthesia allowed us to check our results after surgery and plan further surgery/adjustment to achieve the desired alignment.Results:Mean preoperative deviation for distance was 52 ± 11.1 PD. The target alignment was achieved with the initial surgical plan in 10/21 patients with <55 PD exotropia and 4/12 patients with >55 PD exotropia, and one patient in each group needed adjustment. The remaining patients needed additional rectus muscle surgery. One patient with >55 PD exotropia needed both adjustment and additional rectus surgery. The success rate for distance correction was 85% at 6 months and 1 year. The overall success rate was 71% at 6 months. Percentage of patients with binocular single vision improved from 31% preoperatively to 78% by 6 months. Incidence of oculocardiac reflex was 6.1%.Conclusion:SSASS under monitored conscious anesthesia is a viable option for large-angle strabismus correction with good patient comfort and safety.

Anaesthetic considerations for strabismus surgery in children and adults.

Strabismus correction surgery is the most common eye operation in children. Adults have approximately a 4% lifetime risk of developing strabismus. Current treatment options include pharmacological injection of botulinum toxin or bupivacaine, conventional corrective surgery, adjustable suture surgery and minimally invasive surgery. Repeated surgery is common as each operation has a 60%-80% chance of successful correction. The benefits of early surgical correction in large-angle strabismus in children outweigh the risks of anaesthesia. General anaesthesia is suitable for patients of all age groups, for complicated or repeated surgery, and bilateral eye procedures. Regional ophthalmic block reduces the incidence of oculocardiac reflex and emergence agitation, and provides postoperative analgesia, but requires a cooperative patient as many experience discomfort. Topical anaesthesia has been used in pharmacological injection, minimally invasive surgery, uncomplicated conventional strabismus surgery and some adjustable suture strabismus surgery. Its use, however, is only limited to cooperative adult patients. Prophylactic antiemesis with both ondansetron and dexamethasone is recommended, especially for children. A multimodal analgesia approach, including paracetamol, intravenous non-steroidal anti-inflammatory drugs, topical local anaesthetic and minimal opioid usage, is recommended for postoperative analgesia, while a supplementary regional ophthalmic block is at the discretion of the team.

Supramaximal Recession and Resection Surgery in Large-Angle Strabismus

Purpose:To assess the postoperative surgical outcomes and the changes in deviation in patients treated by supramaximal recession and resection (R&R) of rectus muscles to correct the large-angle exotropia and esotropia.Methods:This study was a prospective interventional case series, and patients with esotropia of ≥65 prism diopter (PD) or exotropia of ≥60 PD who had undergone supermaximal R&R in non-fixating eye with lower vision in unilateral strabismus or bilateral medial rectus (BMR) recession up to 8.5 mm for esotropia and bilateral lateral rectus (BLR) recession up to 12.5 mm for exotropia in bilateral strabismus were enrolled. Successful results were achieved if postoperation deviation was <10 PD for esotropia and <15 PD for exotropia during their final examinations.Results:A total of 131 cases (48 patients with esotropia and 83 patients with exotropia) were included. The mean ages of the patients with esotropia and exotropia were 16.83 ± 15.06 and 23.19 ± 11.29 years, respectively. The mean preoperative esodeviations for bilateral and unilateral surgeries were 69.5 ± 6.5 and 80.7 ± 10.3, respectively, and these values for bilateral and unilateral exodeviations surgeries were 67.3 ± 7.6 and 74.2 ± 12.1, respectively. The overall successful outcomes were achieved in 50% of the esotropic patients and 79.5% of the exotropic patients. At final follow-up examination, no patient had diplopia on lateral gazes.Conclusion:Based on our surgical results, it is possible to consider monocular recession-resection surgery in non-fixating eye (with poor vision) or BLR and BMR recession in both eyes as a viable option for surgical treatment of large angles deviations.

Strabismus Is Correlated with Gross Motor Function in Children with Spastic Cerebral Palsy

ABSTRACTPurpose: To investigate the correlation between clinical features of strabismus and motor dysfunction classified according to the Gross Motor Function Classification System (GMFCS) in patients with spastic cerebral palsy (CP).Methods: In this retrospective, cross-sectional study in single tertiary medical center, 62 patients who are diagnosed with spastic CP who had an ophthalmic examination between 2006 and 2014 were included. Only patients with vision sufficient to fixate were included and patients with restrictive or paralytic strabismus were excluded. The types of CP were classified as diplegia, hemiplegia, or quadriplegia for distribution of motor impairment. The GMFCS was used to grade gross motor dysfunction, which was then classified as mild (grade 1, 2 and 3) or severe (grade 4 and 5) motor impairment. Strabismus was investigated in terms of direction, constancy, and deviation angle. The relationship between strabismus characteristics and the level of GMFCS and type of CP were assessed.Results: Thirty-eight and 24 patients had mild or severe motor deficit, respectively. Forty patients had strabismus, which was more frequent in patients with severe motor impairment.(P = .014) Exotropia and esotropia occurred with similar frequency. Constant and large-angle strabismus was frequently observed in patients with severe motor impairment.(P < .005, 0.027) The topographical subtype of CP was not related to clinical features of strabismus.Conclusions: The prevalence of strabismus is higher in severe motor impairment. The constancy and angle of strabismus was related to the severity of motor impairment while the topographical subtype of CP has no significant relationship.

Innovative techniques for the treatment of adult strabismus

Adult strabismus is often characterized by surgical complexity. In recent years, several innovative techniques for the management of complex strabismus have been developed. Strabismus surgeons should understand the indications for various strabismus surgical techniques in the management of these difficult cases. This workshop describes several new surgical techniques to manage complex strabismus, including small-angle incomitant and very large-angle strabismus, torsional diplopia, and restrictive, paralytic, and secondary strabismus. Because strabismus surgery is an ever-evolving field, it is important to continue to refine our surgical armamentarium. Strabismus surgeons may wish to add these techniques to their surgical repertoire for select cases.

One-Year Outcome Predictors of Strabismus Surgery from Anterior Segment Optical Coherence Tomography with Multiple B-Scan Averaging

Strabismologists are eager to identify preoperative or intraoperative strabismus surgery outcome predictors because of the variable effects in each patient. Conjunctival closure position recession after rectus muscle recession is effective for correcting large angle strabismus. The elasticity of the conjunctiva and Tenon’s capsule is important for strabismus surgery management. In this longitudinal study, we evaluated the prognosis of conjunctiva and Tenon’s capsule thickness (CTT) near the limbus 1 year after strabismus surgery with a limbal conjunctival incision using swept-source anterior segment optical coherence tomography with multiple B-scan averaging. Also, we identified preoperative and/or intraoperative parameters associated with corrective effects 1 year after surgery in 15 consecutive treatment-naïve patients with exotropia or esotropia who underwent recession and resection. The 1-year CTT was greater than the preoperative CTT on the resection side (269 ± 111 vs 183 ± 53 μm, P < 0.001) but was smaller on the recession side (137 ± 54 vs 183 ± 71 μm, P = 0.02). The corrective effect of surgery (1.6 ± 0.3°/mm) was most strongly correlated with preoperative CTT on the recession side (P = 0.005, β = −0.73). Hence, CTT on the recession side may provide adjunctive information for strabismus treatment.

Rectus Muscle Resection for Vertical Strabismus in Thyroid Eye Disease

ABSTRACTPurpose: Rectus muscle resection in thyroid eye disease (TED) is generally avoided due to the risk of worsening restriction or reactivating inflammation. However, for some patients with large-angle strabismus or diplopia in primary gaze despite maximum recession surgery, rectus muscle resection may be beneficial. We report our surgical experience with rectus muscle resection in the management of vertical strabismus associated with TED.Methods: Retrospective review of eight patients with TED and vertical diplopia who underwent vertical rectus muscle resection by a single surgeon (IBM) at a tertiary referral centre in Liverpool, UK, from 2001 to 2013. The goal of surgery was elimination of diplopia in primary and reading position. Vertical deviations were measured in prism dioptres (∆) before and after surgery at one month, four months and final visit by prism alternate cover testing at ⅓ m and 6 m.Results: The mean ± standard deviation vertical deviation for near and distance reduced significantly from 14.2∆ ± 8.4∆ and 15.8∆ ± 8.8∆ pre-operatively to 5.7∆ ± 4.9∆ and 6.7∆ ± 7∆ at the four-month visit, respectively (p< 0.05). At the four-month follow-up, five (62.5%) patients achieved binocular single vision in primary and reading position with either no prisms or prisms less than 5∆. Further recession surgery, Harada-Ito procedure, or lateral rectus resection were necessary in four (50%) patients with persistent diplopia. No patient developed recurrence of inflammation or increased muscle restriction.Conclusions: Vertical rectus resection could be considered as an additional surgical strategy in the management of TED patients with vertical strabismus without adverse sequelae.

Abnormal fixational eye movements in strabismus

IntroductionFixational saccades are miniature eye movements that constantly change the gaze during attempted visual fixation. Visually guided saccades and fixational saccades represent an oculomotor continuum and are produced by common...

Botulinum toxin as an adjunct to monocular recession-resection surgery for large-angle sensory strabismus

To evaluate the result of using intraoperative botulinum toxin A (BTA) as an adjunct tomonocular recession-resection surgery in the management of large-angle sensory strabismus. The medical records of patients diagnosed with sensory strabismus with constant large-angle strabismus were reviewed retrospectively to identify those who underwent monocular recession-resection surgery combined with 5 units of BTA injection into the recessed muscle of the nonfixating eye. Surgical outcome was considered successful if the final deviation was within the range of 0Δ-10Δ. A total of 13 patients (mean age, 31.04±18.5years) were included, 8 with exotropia and 5 with esotropia. The mean follow-up period was 52.77±10.9months. The mean preoperative deviation was 66Δ ± 16Δ in the esodeviation group and 56Δ ± 5Δ in the exodeviation group. The final postoperative mean deviation was 6Δ ± 7Δ in the esodeviation group and 6Δ ± 8Δ in the exodeviation group. There were 7 patients (87.5%) with final deviation of ≤10Δ in the exodeviaton group and 4 (80%) in the esodeviation group. Adjunctive usage of BTA with conventional surgery appears to enhance surgical outcomes by increasing the amount of expected correction. The combined use of BTA with monocular recession-resection rectus muscle surgery may be a good alternative in the treatment of large-angle sensory strabismus with the advantage of less risk of potential complications compared to supramaximal surgery or surgery in the "good" eye.

The role of rectus muscle myectomy in the management of large-angle strabismus for Graves' ophthalmopathy.

PurposeRetrospective noncomparative case series to investigate the role of rectus muscle myectomy for the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.Patients and methodsData from 47 consecutive patients with Graves' ophthalmopathy who underwent complete myectomy for large-angle strabismus (strabismus greater than 25 prism diopters (PDs)) were collected retrospectively. Pre- and postoperative deviations in primary and reading position were measured in PDs. Postoperative deviation of <5 diopters in primary gaze and functional binocular vision in central 30° field were considered as successful surgical outcomes.ResultsPatients undergoing complete myectomy of the restricted muscles in large-angle strabismus achieved a 78.7% success rate after the first surgery. Reoperation performed on seven patients resulted in 85.7% success rate in reoperation group. The overall success rate was 91.5%. The mean efficacy of the isolated rectus muscle myectomy was 34.3±7.7 PDs.ConclusionsThe complete rectus muscle myectomy technique is effective and predictable in the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.

Size matters! The management of extra-large (XXL) strabismus

Very large-angle (80-100Δ) strabismus cannot be managed using the usual surgical dosage tables, and legitimate differences of opinion exist. Strategies include two, three, or even four muscle operations, extra large resections or recessions, or staged operations. This workshop delivered by a panel of experienced surgeons from tertiary referral institutes will discuss principles of treatment, pros and cons of the various approaches, and share treatment algorithms.

Rectus muscle transplantation combined with Jensen procedure for the correction of special strabismus

Objective To evaluate the efficacy of the combined surgery of rectus muscle transplantation and Jensen procedure in the correction of special types of paralytic strabismus. Methods Partial transplantation of the superior and inferior rectus were performed on the horizontal strabismus, while partial transplantation of the medial and lateral rectus were performed on the vertical strabismus. There were two stages in the combined surgery. On the first stage, recession operation of the antagonist muscles associated to the paralyzed or dysplastic muscle was performed. On the second stage, Jensen procedure was performed by combining the transplanted muscle and the paralyzed or dysplastic rectus on the basis of partial rectus transplantation. Results The postoperative eye position was finely corrected and the ocular movement was significantly improved. Besides, part of visual functions were improved, and the complication of anterior segment ischemia wasn't been observed. Conclusion This combined operation not only corrects the eye position of large angle strabismus, but also improves the ocular movement, as well as the binocular visual functions. Key words: Strabismus, paralytic, special type; Rectus muscle transplantation, partial; Jensen procedure; Combined surgery

Intraoperative botulinum toxin in large angle strabismus

The management of large angle strabismus (>50Δ) involves surgery on three or more extraocular muscles. An alternative approach is to use intraoperative botulinum toxin (BTX) as an adjunct to the surgical recess-resect procedure. Our study aim was to determine the effectiveness of BTX in combination with surgical treatment compared to surgical treatment alone for the correction of large-angle horizontal deviations.

Magnetic prism alignment system for measuring large-angle strabismus

Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces.

The perceived personality traits of adults with digitally induced large angle strabismus and the impact of its correction.

Purpose:To ascertain the effect of digitally induced large angle strabismus and its correction on social bias against strabismic adults.Subjects and Methods:This prospective, observational study included 10 orthotropic subjects whose face photographs were digitally altered to produce esotropia, exotropia, and hypertropia. Three batches of non-medical professionals, each consisting of 14 subjects, adjudged personality traits of the altered face photographs on a 10-item questionnaire. The same evaluators effected the appraisal of the orthotropic photographs. The personality score of the strabismic photograph of a subject was compared with its own orthotropic photograph.Subjects and Methods:This prospective, observational study included 10 orthotropic subjects whose face photographs were digitally altered to produce esotropia, exotropia, and hypertropia. Three batches of non-medical professionals, each consisting of 14 subjects, adjudged personality traits of the altered face photographs on a 10-item questionnaire. The same evaluators effected the appraisal of the orthotropic photographs. The personality score of the strabismic photograph of a subject was compared with its own orthotropic photograph.Results:The 10 subjects whose photographs were digitally modified were of the same age (21 years) and had equal gender distribution. The evaluation of the photographs was performed by 42 evaluators aged 38.3 ± 14.9 years, of whom 21 were males. Different personality traits were rated negatively in the strabismic photographs. The statistically significant negative impact was apparent on more number of personality traits for esotropia (7 out of 10) as compared to exotropia (4 out of 10) or hypertropia (3 out of 10). Rating of the strabismic photographs was significantly lower by female evaluators (P = 0.006). However, there was no difference whether the subject evaluating the photograph of the strabismic individual was of the same gender or the opposite gender. Internal consistency of the questionnaire was excellent (Cronbach's Alpha = 0.81).Conclusion:There was a significant negative impact of strabismus on the perceived personality traits of the digitally altered face photographs of the adults when compared to their orthotropic photograph.