Horizontal Strabismus Surgery 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.].

Outcomes and Factors Associated with Successful Strabismus Surgery for Abducens Nerve Palsies: A Retrospective Study and Literature Review.

Several studies reported surgical outcomes for abducens nerve palsy, but information on factors that affect treatment success remains lacking. These factors are crucial for developing a treatment plan and providing disease counseling. This study aimed to investigate the outcomes of strabismus surgery for abducens nerve palsy and determine the factors that influence its success, including a review of relevant literature. This retrospective analysis included abducens nerve palsy cases, focusing on surgical interventions and relevant patient data, at the outpatient clinics of Phramongkutklao Hospital from April 1, 2012, to April 30, 2022. A relevant literature review included the surgical success rate and factors that influence surgical outcomes. This study enrolled 32 patients, including 19 with partial and 13 with complete abducens nerve palsy. The overall success rate of strabismus surgery was 78.1%. Trauma was the leading cause of abducens nerve palsy in this population (28.13%). Fisher's exact and Mann-Whitney U-tests revealed that shorter abducens nerve palsy onset and smaller preoperative angle were significantly associated with successful surgical outcomes of strabismus surgery among the groups. In contrast, subgroup analysis revealed that only preoperative smaller angles were significantly associated with good surgical outcomes in horizontal strabismus surgery. However, the vertical rectus muscle transposition group demonstrated no significant factors. The literature review revealed that the success rate of surgery in abducens nerve palsy was 25%-82.6% for horizontal rectus muscle surgery and 46.2%-91% for rectus muscle transposition. The surgical success rate for abducens nerve palsy reached 78.1%, including 78.95% for partial and 76.92% for complete abducens nerve palsy. Notably, a shorter onset preceding surgery and a smaller preoperative angle significantly correlated with successful surgical outcomes one year postoperatively.

Variation between surgeons in rate of reoperation after horizontal strabismus surgery among Medicare beneficiaries: associations with patient and surgeon characteristics and adjustable sutures.

Objective: To quantify variation between surgeons in reoperation rates after horizontal strabismus surgery, and to explore associations of reoperation rate with surgical techniques, patient characteristics, and practice type and volume. Methods: Fee-for-service payments in a national database to providers for Medicare beneficiaries having strabismus surgery on horizontal muscles between 2012 and 2020 were analyzed retrospectively to identify same calendar year reoperations. Multivariable linear regression was used to determine predictors of each surgeon's reoperation rate. Results: The reoperation rate for 1-horizontal muscle surgery varied between 0.0% and 30.8% among 141 surgeons. Just 7.8% of surgeons contributed over half of the reoperation events for 1-horizontal muscle surgery, due to the presence of high-volume surgeons with high reoperation rates. Surgeon seniority, gender, surgery volume, and use of adjustable sutures were not independently associated with surgeon reoperation rate. We explored associations of reoperation with patient characteristics, such as age and poverty. Surgeons in the South tended to have a higher reoperation rate (p=0.03) in a multivariable model. However, the multivariable model could only explain 16.3% of the inter-surgeon variation in reoperation rate for 1-horizontal muscle surgery. Discussion: Strabismus surgery is similar to other areas of medicine, in which large variations in outcomes between surgeons are observed. Future work can be directed towards explaining this variation. Conclusions: Patient-level analyses that fail to consider variation between surgeons will be dominated by a small number of high-reoperation, high-volume surgeons. Order-of-magnitude variations exist in reoperation rates among strabismus surgeons, the cause of which is largely unexplained.

Long-term surgical outcomes of one-muscle vs. two-muscle horizontal strabismus surgery

ABSTRACT Purpose While horizontal strabismus surgery is generally considered to have favorable outcomes, success rates can vary by type of procedure. Our purpose is to compare the long-term outcomes of patients who underwent one-muscle vs. two-muscle horizontal strabismus surgery. Methods This is a retrospective study comparing one-muscle to two-muscle strabismus surgery for small to moderate angle horizontal strabismus. Demographic data and eye exam parameters were compared at baseline and postoperatively (6 months up to 6 years). Surgical success was defined as a post-operative angle of 10 PD or less. We also compared outcomes by strabismus type: esotropia vs exotropia and adjusted the analysis for previous strabismus surgery. Results Out of 89 patients with moderate angle horizontal strabismus (25 PD or less), 17 patients had a one-muscle operation, and 72 patients had two-muscle surgery. The mean age was 14.12 ± 9.30 years and 11.70 ± 11.30 years for the one-muscle and two-muscle groups, respectively (p = .74). The baseline characteristics of both groups were comparable. Follow-up time was 32.82 ± 26.93 months in one-muscle and 37.67 ± 23.81 in two-muscle groups (p = .29). Success rate was 70.6% for the one-muscle group and 68.10% for the two-muscle group (p = .69). Outcomes were similar when divided into esotropia and exotropia. The success rate was not affected by previous strabismus surgeries nor by the initial angle of deviation. Conclusion One-muscle and two-muscle horizontal strabismus surgery had similar long-term outcomes and did not differ by strabismus type nor by angle of deviation.

The outcome of horizontal strabismus surgery in Anbar governorate in Iraq: an interventional study

Background: Strabismus is the loss of ocular alignment, which can lead to amblyopia, defective binocularity, and defective depth perception. Objectives: To assess the results of strabismus surgery among patients older and younger than six years and study the influencing and predictive factors. Methods: Surgical treatment for 202 patients clinically diagnosed with horizontal strabismus aged 4-45 years was carried out in Fallujah Teaching Hospital between September 2021 and October 2022. Surgical outcome was assessed at the end of 6 months post-operatively. Chi-square and Mann-Whitney Univariate tests were performed to evaluate the statistical relationship between pre-operative factors and surgical outcomes. Results: Overall, the success rate of horizontal strabismus surgery was 68.3% (138 patients), and the rate of success among the esotropia group (55.1%) was better than the exotropia group (44.9%). Among age groups, a higher recorded success rate was for ages above 6 (71.7%). The success rate was higher in males than females (54.3% and 45.7%, respectively). Chi-square and univariate analysis showed a significant association between gender (p < 0.068), refractive error (p < 0.033), and surgical outcome. Conclusion: Surgical correction of strabismus improved overall ocular deviation and binocular function. Esotropia patients benefited the most compared to exotropia patients.

Results of horizontal strabismus surgery in the period from 2017 to 2023 at the Clinic for Eye Diseases Tuzla

Aim: To evaluate results of surgical intervention of horizontal strabismus or to evaluate results of horizontal strabismus surgery intervention and to identify factors that influence the success of the surgery. Medical documentation of 144 patients that have done their first horizontal strabismussurgery at the Clinic for Eye Diseases in Tuzla from February 2017 until February 2023. Main measure of successful surgery was defined as an eye deviation no more than 10 prism diopters 2 years after the surgery. Results of post-operative binocular vision and vision acuity improvements were analyzed. Pre-operative deviation, diagnosis, binocular function, visual acuity and age were analyzed as factors that influence the success of the surgery.Patients and methods: Patients were divided into 2 groups, first under the age of 7 (48.6%) and above the age of 7 (51.4%). In order to assess set goals of the research, Chi square test, Wilcoxon matched-pairs signed-rank test and logistic regression analysis with forced entry were used. Average age of the respondents was 9.67±4.15 years old (med. 8, mod. 7, min. 5 and max 20), while 69 (47.9%) had esotropia and 75 (52.1%) had exotropia. Average pre-operative deviation was 6.62±42.28 PD, (median 0, modus 60 PD), while minimum and maximum deviation was in range from -60 PD to +35 PD. Average post-operative deviation was 5.46±10.06 PD.Results:Success of the surgery for esotrpia was 49.3% and for 97.3%. Before surgery, 13 (9%) had binocular vision, and after the surgery 80 (55.6%) of the respondents had the binocular vision. Success rate of the surgery was 67.1% for respondents younger than 7 and was 81.1% for the respondents older than 7.Conlusion: No statistically significant improvement for vision acuity was observed.

A Review on Prognostic Factors for Successful Outcome of Horizontal Strabismus Surgery in Pediatric Group

Introduction: Strabismus is a misalignment caused by abnormalities in binocular vision or by anomalies of neuromuscular control of ocular motility. Both children and adults may present with strabismus in the health care center for management. Proper choice of management plan can provide satisfaction to the patients. The aim of surgical management is to optimize the best corrected visual acuity (BCVA) of both eyes, maintain normal binocular fusion and improve cosmesis. Purpose: To review the scientific literature that evaluates the prognostic factors for successful outcome of horizontal strabismus surgery in pediatric group. Methods: The relevant articles are collected and reviewed from Google scholar, PubMed web search and published national and international journals. Our main focus is to concentrate about factors of successful strabismus surgery for pediatric group. Results: This review shows that factors affecting surgical and cosmetic outcome of squint surgery are related to age of presentation, gender distribution, pattern of laterality, types of squint- alternate / unilateral, Pre-operative deviation, binocular vision, association of refractive error etc. This resultant workable framework further helps to evaluate and take proper decision regarding management of these patients for better successful outcome. Conclusion: Proper preoperative assessment followed by proper choice of surgical options leads to surgical success. Effective surgical options coupled with effective post-surgical rehabilitation will provide the best outcome for such strabismus surgery. J.Natl.Inst.Ophthalmol.2023;6(1): 48-53

Assessment of retinal and choroidal microcirculation after unilateral recession–resection surgery for horizontal strabismus by swept-source optical coherence tomography angiography

This study explored the possible hemodynamic changes of the retina and choroid after horizontal strabismus surgery using swept-source optical coherence tomography angiography (SS-OCTA). 32 eyes of 32 patients who underwent unilateral horizontal rectus muscle recession–resection surgery were included. SS-OCTA examinations were performed preoperatively and one week postoperatively. Several OCTA measurements were used, including vessel density (VD) of the superficial vascular complex (SVC), VD of the deep vascular complex (DVC), VD of the choriocapillaris (CC), choroidal vascular index (CVI) and choroidal thickness (CT). No significant change in VD of SVC, DVC, and CC was observed whereas CT increased significantly with CVI unchanged. Recession–resection surgery for horizontal strabismus seemed not to significantly influence the microcirculation of the retina and CC in the early postoperative period. However, choroidal thickening happened with a constant CVI probably due to the postoperative inflammation. Further studies are needed to investigate the long-term effects of unilateral recession–resection surgery for horizontal strabismus on the microcirculation of the retina and choroid.

Incidence, Risk Factors and Management of Postoperative Complications in Horizontal Strabismus Surgery

ABSTRACT Objective To report the incidence, risk factors and management of postoperative complications after horizontal strabismus surgery. Design Retrospective Cohort study. Participants The study assessed 1,273 patients with 1,035 cases of exotropia and 238 cases of esotropia, with a minimum 18-month follow-up. Methods Retrospective review of strabismus operation patients’ medical records included baseline demographics, age at surgery, pre/postoperative visual acuity, and deviation. Complications were categorized as surgical site (infection, scarring, cyst, granuloma, ischemia) and strabismus-related (recurrence, diplopia), with analysis of incidence, risk factors, and management. Results Among surgical site complications, the incidence of infection, pyogenic granuloma, and anterior segment ischemia were similar between the exotropia (0.3%, 0.3%, 0.2%) and esotropia (0.8%, 0%, 0.4%) groups (p = .221, 0.406, 0.515). In contrast, the esotropia group presented a higher risk of conjunctival inclusion cyst and conjunctival scar than the exotropia group, with incidences of 5.0% vs 2.2% and 6.3% vs 1.3%, respectively (p = .004, <0.001). Regarding strabismus complications, the incidence of early recurrence was not significant between the two groups, with 10.0% in the exotropia group and 10.5% in the esotropia group (p = .553). Older age and poor initial visual acuity were associated with early recurrence (p < .001). The esotropia group had a higher risk of persistent diplopia than the exotropia group, with incidences of 4.2% vs 2.0%, respectively (p = .003). Conclusion Esotropia carries a higher risk of conjunctival inclusion cysts, conjunctival scarring, and persistent diplopia compared to the exotropia group, while both groups exhibit similar rates of early recurrence and other surgical site complications.

Şaşılık Cerrahisinin Refraksiyon Kusuru ve Ön Segment Ölçümleri Üzerine Etkisi

Aim: This study aimed to investigate the effects of horizontal strabismus surgery on refractive error and anterior segment parameters.&#x0D; Material and Methods: Fifty-four eyes of 27 patients were included in this study. Patients underwent repeated refraction measurements and anterior segment evaluation preoperatively, first week, first month, third month, and sixth month postoperatively. Patients were divided into three groups, those who underwent resection (group 1), recession (group 2), and healthy eyes without any surgical intervention (group 3).&#x0D; Results: The mean age of the patients was 24.4±11.1 years and 14 (51.9%) were female. There was a statistically significant difference in central corneal thickness in group 2 before and after surgery (p=0.037). The mean central corneal thickness was highest in the first week with 548.14±40.42 µm and lowest in the first month with 541.50±41.75 µm after surgery. There was a statistically significant difference in cell density (p=0.004) and mean cell area (p=0.004) between groups 1 and 2 in the first week after surgery. The cell density level was statistically significantly higher in group 1 in all postoperative measurements. In addition, the mean cell area level was statistically significantly lower in group 1.&#x0D; Conclusion: Strabismus surgery has an effect on anterior segment parameters in addition to correcting eye movements and visual axis. Depending on the type of intervention, the number of affected anterior segment parameters also varies. In the management of the patient in the postoperative period, the anterior segment structures should be carefully evaluated at each examination and the findings should be noted.

Short-term Effect of Strabismus Surgery on Choroidal Vasculature.

To investigate the effect of strabismus surgery on choroidal structure using the binarization method. Forty-two eyes of 27 patients who had surgery for horizontal strabismus were included in the study. Optical coherence tomography (OCT) images of the patients before the operation and at 1 day and 1 week after the operation were binarized. Total choroidal area (TCA), stromal area (SA), luminal area (LA), and choroidal vascularity index (CVI) were calculated and compared. The mean age of the patients was 16.7 ± 13.5 years; 12 were female, and 15 were male. The mean spherical equivalent was 0.125 ± 0.50 diopters (D). The mean axial length value was 23.3 ± 1.3 mm. Preoperative TCA was 599686 ± 113451, LA was 394259 ± 67259, SA was 209180 ± 47723, and CVI was 0.66 ± 0.02. At 1 day postoperatively, TCA was 615575 ± 103686, LA was 395364 ± 60314, SA was 218418 ± 45620, and CVI was 0.65 ± 0.02. At 1 week postoperatively, TCA was 610997 ± 110578, LA was 394002 ± 65186, SA was 214995 ± 46481, and CVI was 0.66 ± 0.04. A statistically significant decrease in CVI and increase in TCA and SA were observed on the first postoperative day; these changes were observed as returning to preoperative values at 1 week postoperatively. Strabismus surgery temporarily decreases the CVI by increasing the SA of the choroidal layer, possibly due to hemodynamic changes and/or inflammatory causes in the early period. [J Pediatr Ophthalmol Strabismus. 2024;61(2):114-119.].

Long-term outcomes of single monocular resection-recession in adult sensory strabismus and factors affecting the postoperative drift.

The purpose of our study was to analyze the clinical characteristics and outcome of horizontal strabismus surgery in patients having sensory strabismus and to analyze the factors that affect the postoperative drift in these patients over a follow-up of three years. This was a retrospective case series. Patients aged ≥18 years, having low vision (visual acuity ≤20/60) in one eye, and undergoing horizontal strabismus surgery (standard recess-resect procedures) in the same eye were recruited. All patients were advised patching of the good eye six weeks prior and continued for six weeks post strabismus surgery. We excluded patients who had paralytic disorders, motility defects, or those with chronic systemic conditions. Patients with a minimum follow-up of three years were recruited. The study included 56 patients whose mean age was 22.9 ± 4.93 years. Exotropia (n = 38; 67.8%) was more common than esotropia (n = 18; 32.1%). Preoperative visual acuity was 1.1 ± 0.85 (range perception of light to 6/18p). The cause of low vision was amblyopia (n = 30; 53.5%) followed by trauma (n = 22; 39.2%). The mean preoperative distance deviation was 57.7 ± 15.5 PD in the primary position (range: 20-65 PD). The success rate of exotropia (78.9%) was more than esotropia (52.9%) at three years. Two patients with esotropia were overcorrected. All patients with exotropia showed an exotropic drift with time. The motor alignment after a single recession-resection procedure was satisfactory at the long-term in our cohort of sensory strabismus. The duration or extent of visual impairment had no relation to the postoperative outcome.

The effect of strabismus surgery performed by preserving the anterior ciliary vessels on the choroid in pediatric patients

BackgroundHorizontal strabismus surgery is one of the most common eye operations. Many studies have shown that strabismus surgery has an effect on choroidal thicknesses. This study aimed to evaluate choroidal changes after the anterior ciliary vessels (ACV) conservation surgery using Enhanced Depth Imaging-Optical coherence tomography (EDI-OCT). MethodsThis study included 41 eyes of 26 pediatric patients that were diagnosed with esotropia and underwent surgery with the standard procedure and 38 eyes of 25 pediatric patients treated with ACV preservation. Preoperative and postoperative refraction error measurements, biomicroscopic examinations, intraocular pressure measurements, dilated fundus control, and strabismus examinations were performed, and the best corrected visual acuity was determined. The patients were operated on under general anesthesia by the same surgeon using two different procedures: the standard procedure (Group 1) and by preserving the ACV (Group 2). Using EDI-OCT, choroidal measurements were performed preoperatively, on postoperative week 1, month 1, and month 3. ResultsThe preoperative and postoperative choroidal thickness measurements of the patients in Group 1 decreased in all regions postoperatively (p<0.05) especially at week 1 and month 1, but approached the preoperative values at the third -month evaluations (p>0.05). In Group 2, there was no statistically significant difference in the choroidal measurements between the preoperative ​​and postoperative week 1, month 1, and month 3 values (p>0.05). ConclusionsACV preservation is recommended to prevent choroidal changes occurring in the early period after horizontal strabismus surgery.

The Effect of Surgical Treatment of Horizontal Strabismus on Refractive Changes in Adult Patients

Concomitant strabismus and refractive anomalies are often common pathological conditions in adult patients. The patient’s desire to get rid of both problems poses a question to the surgeon about the order of surgical interventions. With non-accommodative concomitant strabismus, the question is not so unambiguous. Despite a significant number of studies devoted to this topic, there is still no unequivocal opinion on the significance of refractive error after strabismus surgery. Thus, it remains an urgent task to study of possible surgically induced refractive changes after interventions on extraocular muscles and their assessment during the observation period.Purpose. Evaluation of the effect of surgical treatment of horizontal strabismus in adults on refractive and astigmatic status.Patients and methods. A prospective study of 30 patients with concomitant convergent or divergent strabismus. Each patient underwent surgery for horizontal strabismus, which consisted in recession and resection of the extraocular muscles of one eye. The spheroequivalent (SE) and cylinder (Cyl) values were determined before surgery, 1, 3, and 6 months after surgery. Refractive changes were calculated in the postoperative period, both for the spheroequivalent and for the cylinder, after 1 month (SIRC1), 3 months (SIRC2) and 6 months (SIRC3). In addition, the difference (d) between SIRC1 and SIRC3 was calculated to determine if they were temporary or permanent. Analysis of the induced changes in the magnitude and direction of astigmatism was performed using vector analysis.Results. The dynamics of SE values within 6 months after surgery shifted to insignificant myopia, however, no significant static difference in this parameter was found (p = 0.17). The mean change in spherical equivalent (SE) refraction was 0.22 ± 0.47 diopters in SIRC1, 0.15 ± 0.44 diopters in SIRC2, and 0.12 ± 0.51 diopters in SIRC3. There was no statistically significant difference between changes in surgically induced refraction at different times after surgery (p = 0.34). The difference (SIRC d) between SIRC1 and SIRC3 for the spheroequivalent was 0.096 ± 0.480 and can be interpreted as a decrease in surgically induced refraction error within 6 months after surgery. Surgically induced astigmatism at different times after surgery was: SIRC1 = 0.44 ± 0.39, SIRC2 = 0.47 ± 0.41, SIRC3 = 0.43 ± 0.29. There was no statistically significant difference in this parameter during the study period (p = 0.1). The difference (SIRC d) between SIRC1 and SIRC3 for astigmatism was 0.0001 ± 0.3200, which indicates stable values of astigmatism. According to the vector analysis, the magnitude and axis of preoperative astigmatism was 1.131 ± 0.410 ax172 and is close to the actual postoperative values of 1.17 ± 0.50 ax172. The vector of surgically induced astigmatism was 0.43 ± 0.10 ax84. These changes were not statistically or clinically significant.Conclusion. In general, the refractive and astigmatic status does not change after surgical treatment of horizontal strabismus. However, in this study, there was a myopic refraction shift during the first 3–6 months after surgery. In this connection, it is possible to recommend refractive operations to adult patients 3–6 months after strabismus surgery.

Evaluation of Strabocheck® as an objective measurement method of comitant horizontal strabismus in children undergoing surgery

ABSTRACT The gold standard of angle measurement is the prism alternating cover test (PCT). This method requires cooperation from the child, experience, and presents a significant inter-observer variability. Strabocheck®(SK) is a new simple tool for objective and semi-automated angle measurement. Our purpose is to evaluate Strabocheck® in children undergoing surgery for comitant horizontal strabismus. The study population was divided into 3 groups: infantile esotropia, partially accommodative esotropia and intermittent exotropia. The primary endpoint was the agreement between Strabocheck®and the PCT. A total of 44 children were included prospectively. The correlation between the angle measured by the PCT and the angle measured by SK was strong (R = 0.87). The mean absolute difference in the angle measured by the two methods was Δ = 11.9+/- 9.8 diopters. The Bland-Altman plot shows a 95% interval limit between −30.0 [−34.4; −25.6] and 31.0 [26.7; 35.4] diopters. SK is an interesting tool to evaluate the angle of strabismus in children. However, the residual discordance between PCT and SK leads us to question the real value of the angle, which can only be approximated. A better clinical experience of this new tool in relation to the clinical condition and the PCT will allow to have a more accurate idea on the true angle and will probably help the surgeon to adapt this procedure.

Evaluation of aberrometry changes following strabismus surgery in patients with horizontal strabismus.

The aim is to investigate the change in aberrations following strabismus surgery in patients with horizontal strabismus. This prospective study included patients who underwent surgery for horizontal strabismus. The patients were assessed preoperatively and 1 month and 3 months after the surgery, in terms of logMAR best-corrected visual acuity, eye deviation, spherical equivalent refractive error, tomographic and aberrometric corneal changes. Corneal tomography was performed using Orbscan II device. Wavefront analyses were performed using Bausch and Lomb Zywave II. A total of 25 patients (48 eyes) with exotropia or esotropia were entered in this study. Mean values of exotropia in the distance and near deviations were reported as 31.42 ± 7.13 and 28.82 ± 6.96 prism diopters (PD), respectively. Mean scores of esotropia in the distance and near deviations were 25.22 ± 5.41 and 30.45 ± 9.4 PD, respectively. Evaluation of irregularity in 5 mm zone, horizontal coma, spherical aberration changes, and root mean square of higher-order aberrations (HOAs) in 6 mm, and HOA w/o Z 400 changes showed that there was a significant difference before the intervention and 1 month after the surgery (P < 0.05). However, no difference was observed in the aforementioned variables before and 3 months after the intervention (P > 0.05). Results of the present study indicated a transient increase in HOAs and corneal irregularity following strabismus surgery on horizontal eye muscles that returned to the baseline after 3 months.

Pattern Strabismus in a Tertiary Hospital in Southern China: A Retrospective Review.

Background and objectives: To analyze demographic and clinical features of pattern strabismus patients and assess the relationship among these clinical variables and risk factors. Materials and Methods: Medical records of pattern strabismus patients who had undergone strabismus surgery at our center between 2014 and 2019 were retrospectively reviewed. Data collected included gender, age at onset, age at surgery, refraction, Cobb angle, pre- and post-operative deviations in the primary position, up- and downgaze, angle of ocular torsion, type/amount of pattern, grade of oblique muscle function and presence/grade of binocular function. To verify the clinical significance of the Cobb angle, 666 patients who had undergone surgery within one week after ocular trauma between 2015 and 2021 were enrolled as controls. Results: Of the 8738 patients with horizontal strabismus, 905 (507 males and 398 females) had pattern strabismus, accounting for 10.36%. Among these 905 patients, 313 showed an A-pattern and 592 showed a V-pattern. The predominant subtype was V-exotropia, followed by A-exotropia, V-esotropia and A-esotropia. Over half of these patients (54.6%) manifested an A- or V-pattern in childhood. The overall mean ± SD Cobb angle was 5.03 ± 4.06° and the prevalence of thoracic scoliosis was 12.4%, both of which were higher than that observed in normal controls (4.26 ± 3.36° and 7.8%). Within A-pattern patients, 80.2% had SOOA and 81.5% an intorsion, while in V-pattern patients, 81.5% had IOOA and 73.4% an extorsion. Patients with binocular function showed decreases in all of these percent values. Only 126 (13.9%) had binocular function, while 11.8% of A-pattern and 15.1% of V-pattern patients still maintained binocular function. Pre-operative horizontal deviation was negatively correlated with binocular function (r = −0.223, p < 0.0001), while the grade of oblique muscle overaction was positively correlated with the amount of pattern (r = 0.768, p < 0.0001) and ocular torsion (r = 0.794, p < 0.0001). There were no significant correlations between the Cobb angle and any of the other clinical variables. There were 724 patients (80.0%) who had received an oblique muscle procedure and 181 (20.0%) who received horizontal rectus muscle surgery. The most commonly used procedure consisted of horizontal rectus surgery plus inferior oblique myectomy (n = 293, 32.4%), followed by isolated horizontal rectus surgery (n = 122, 13.4%). Reductions of pattern were 14.67 ± 6.93 PD in response to horizontal rectus surgery and 18.26 ± 7.49 PD following oblique muscle surgery. Post-operative deviations were less in V- versus A-pattern strabismus. Post-operative binocular function was obtained in 276 of these patients (30.5%), which represented a 16.6% increase over that of pre-operative levels. The number of patients with binocular function in V-pattern strabismus was greater than that of A-pattern strabismus (p = 0.048). Conclusions: Of patients receiving horizontal strabismus surgery, 10.36% showed pattern strabismus. In these patients, 54.6% manifested an A- or V-pattern in childhood, and V-exotropia was the most frequent subtype. Pattern strabismus patients showed a high risk for developing scoliosis. Cyclovertical muscle surgery was performed in 724 of these patients (80.0%), and horizontal rectus surgery was effective in correcting relatively small levels of patterns. Binocular function represented an important factor as being involved with affecting the occurrence and development of pattern strabismus.

Plication combined with vertical displacement of horizontal rectus muscles to treat combined horizontal and vertical deviations

To report the results of horizontal rectus muscle recession-plication with vertical displacement in the treatment of combined vertical and horizontal strabismus. From October 2016 to December 2019, 15 patients with horizontal deviation of 15Δ-60Δ, 3 associated with vertical deviation of 8Δ and 12 with vertical deviation of 10Δ-20Δ, underwent horizontal strabismus surgery (recession-plication) in addition to vertical displacement of both horizontal rectus, half or total muscle width, depending on whether the amount of vertical strabismus was small (8Δ) or large (10Δ-20Δ), respectively. A total of 15 patients (8 females) were included; average age at surgery was 27 years. All cases showed improvement in alignment of the eyes, with a single case showing a small residual vertical deviation (4Δ).There were no intra- or postoperative complications. This case series demonstrates the feasibility of this vessel-sparing recession-plication technique in the treatment of combined horizontal and vertical deviations, without the need to operate on vertical muscles.

A Comparison of the Long-Term Surgical Outcomes of Horizontal Strabismus Surgery between Resident Clinic and Private Clinic Patients

ABSTRACTPurposeTo compare the long-term surgical outcomes of patients with horizontal strabismus whose surgery was performed in an outpatient department (OPD) setting (by residents-in-training) to those whose surgery was performed in a private clinic (PC) setting (by staff-ophthalmologists) in the same operating room/institution.MethodsTwo hundred and forty-four patients’ charts who had horizontal strabismus surgeries from January 2007 to 2020 were reviewed retrospectively. A total of 92 patients were operated on by residents and followed in OPD, and 152 patients by staff-surgeons and followed in PC. Demographic data and eye exam parameters were collected. Distance and near deviation (in prism diopters, PD) were extracted and compared between groups at baseline and postoperatively (6 months and yearly for up to 6 years). Success was defined as a postoperative motor alignment of 10PD or less.ResultsThe mean age of the 244 patients was 10.5 ± 11.7 years, with no significant differences between groups. A longer follow-up duration was reported in the PC group (34.9 ± 24.3 months vs 25.3 ± 20.2 months). Patients had similar success rates in both groups in the early postoperative period (6 months and 1 year); however, a higher success rate was observed in the PC group compared to OPD at 3, 5 and 6 years with the following respective values: 72.2% vs 50% (p < .001), 75% vs. 66.7% (p = .02), and 68.6% vs. 66.7% (p = .03). The difference was more pronounced in the esotropia subgroup mostly at 3 years follow-up.ConclusionThis study showed a similar success rate of horizontal strabismus surgery performed in a PC setting by staff surgeons as compared to that performed in an OPD setting by residents at 6 months and 1 year. A significantly higher success rate was observed at long term follow-up (after 2 years) in the PC group compared to the OPD group, possibly related to the difference in compliance with post-operative follow-up management and not to surgery itself.

Adjustable Suture Technique Is Associated with Fewer Strabismus Reoperations in the Intelligent Research in Sight Registry

To compare the reoperation rates after strabismus surgery with and without the adjustable suture technique. Retrospective cohort study. Patients 18 years of age or older in the Intelligent Research in Sight (IRIS®) Registry who underwent strabismus surgery between January 1, 2013, and December 31,2018. Data were collected from the electronic health records of practices participating in the IRIS Registry. The primary exposure of interest was use of the adjustable suture technique, identified by Current Procedural Terminology coding. The primary outcome was repeat strabismus surgery within 1 year of initial strabismus surgery. Odds ratios (ORs) were derived from a multivariable logistic regression model evaluating the association between the use of adjustable sutures and reoperation rate, adjusting for patient demographics and surgical factors. A total of 34 872 patients who underwent strabismus surgery during the study interval were identified: 72% underwent horizontal muscle surgery, 17% underwent vertical muscle surgery, and 11% underwent combined horizontal and vertical muscle surgery. Adjustable sutures were used in 18% of patients. The overall reoperation rate within 1 year of strabismus surgery was 7.7%. The 1-year reoperation rate was 6.0% for patients treated with adjustable sutures and 8.1% for patients treated without adjustable sutures (P < 0.001). The multivariable regression model revealed a statistically significant 30% decrease in the odds of reoperation within 1 year of surgery when adjustable sutures were used (OR, 0.70; 95% confidence interval [CI], 0.62-0.78), a 40% increase in those with a history of prior strabismus surgery (OR, 1.40; 95% CI, 1.28-1.53), and a 9% increase per decade of age at surgery (OR, 1.09; 95% CI, 1.06-1.11). In adults cared for in practices participating in the IRIS Registry, the adjustable suture technique was associated with a significantly lower reoperation rate within 1 year of undergoing horizontal or combined horizontal and vertical strabismus surgery. Adjustable suture use in vertical strabismus surgery alone did not reduce the 1-year reoperation rate significantly. A history of prior strabismus surgery was associated with increased odds of reoperation.