Mechanisms for Positive Bielschowsky Head Tilt Testing in Horizontal Strabismus.

PURPOSE: To elucidate the induced effects of horizontal strabismus on the Bielschowsky Head Tilt Test (BHTT). DESIGN: Prospective clinical study. METHODS: Prospective analysis of BHTT testing in 85 patients with exotropia and 71 patients with esotropia who were examined in a strabismus clinic. RESULTS: Eighty-four of 85 patients with exotropia (98.82%) showed a positive BHTT with an induced hyperdeviation on the side of the tilt (to both sides in 67% and to one side in 32%). Fifty-seven of 71 patients with esotropia (80.2%) showed a positive BHTT with an induced hypodeviation on the side of the tilt (to both sides in 57.7% and to one side in 22.5%). These induced vertical deviations were greater in patients with larger horizontal deviations and in those with constant rather than intermittent deviations; however, they were not influenced by the presence or absence of associated primary oblique muscle overaction. CONCLUSIONS: Exotropia and esotropia produce hyperdeviations during BHTT testing, with a hyperdeviation on the side of the tilt observed in patients with exotropia, and hypotropia on the side of the tilt observed in patients with esotropia. These diametrical results are not attributable to any preexistent alteration of neurologic output inherent to these two forms of horizontal strabismus or to associated torsion. Rather, they arise directly from the altered anatomical positions of the two eyes, which cause the eyes to approximate their visual axes more closely to the vertical rectus muscles (in exotropia) and the oblique muscles (in esotropia), enabling the vertical actions of specific cyclovertical muscles to predominate in response to altered utricular output generated by the BHTT.

Sensory exotropia versus sensory esotropia: A comparative clinical features study.

PURPOSE: This study aimed to compare the preoperative clinical features of patients with sensory esotropia (ET) and sensory exotropia (XT). METHODS: In a retrospective study, the medical records of 13,252 patients who underwent strabismus surgery were reviewed at the Farabi Eye Hospital, Iran, from 2012 to March 2022. There were 1017 patients with sensory horizontal strabismus whose, in their worse eye, had corrected distance visual acuity (CDVA) equal to or <20/160 tested with the Snellen chart. RESULTS: The mean age of patients was 29.0 ± 12.4 years [574 (56.4%) males and 443 (43.6%) females]. Sensory XT and ET were observed in 717 (70.5%) and 300 (29.5%) patients, respectively (P<.001). The mean CDVA in the strabismic and non-strabismic eyes was 1.40 ± 0.75 and 0.05 ± 0.13, respectively (P<.001). Also, the CDVA in the strabismic eyes was significantly worse in the patients with sensory XT than in the patients with sensory ET (P<.001). Sphere and spherical equivalent (SE) components were more hyperopic in both eyes of patients with sensory ET than sensory XT (P<.001). In sensory ET group, the mean horizontal deviation at far and near was significantly higher than the sensory XT group (both P<.001). The prevalence of moderate and severe amblyopia among all patients with sensory strabismus was 274 (26.9%) and 727 (71.5%), respectively (P<.001). There were 398 (39.1%) patients who needed more than one surgery. CONCLUSION: The frequency of sensory XT was about 2.5 times more than the sensory ET. Most patients with sensory ET were operated at a younger age, had better CDVA, more hyperopic spherical and SE, and higher angle of deviation compared with patients with sensory XT. The chance of reoperation in patients with sensory strabismus was about 40%.

Lemierre's Like Syndrome: Retropharyngeal Abscess With Internal Jugular and Cerebral Venous Thromboses and Septic Embolization Leading to Pulmonary Embolism and Cerebral Abscesses Complicated by Papilledema and Residual Sixth Cranial Nerve Palsy.

A male child with a history of sinusitis presented to the emergency medicine department with a high fever, neck swelling, headache, vomiting, and double vision. He was diagnosed with retropharyngeal abscess (RPA) with bilateral internal jugular vein (IJV) and cerebral venous thromboses. The child was treated promptly and transferred to a specialty center, where the abscess was drained. However, he developed papilledema and septic embolism, leading to pulmonary embolism and cerebral abscesses. The child was an inpatient for six weeks and had outpatient treatment for three months. He developed exotropia due to bilateral sixth cranial nerve palsy. This existed even at the 24-month follow-up. This case report highlights the rare complications and morbidity from the retropharyngeal abscess. It also emphasizes the early diagnosis and management options in a busy emergency medicine department.

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

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.

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

BACKGROUND: Previous research on the factors associated with surgical dose-response in strabismus surgery for exotropia has yielded inconsistent results. This study determined the factors influencing surgical dose-response in exotropia patients who underwent recession and resection (R&R). METHODS: Exotropia patients who underwent unilateral R&R at the National Taiwan University Hospital between 2006 and 2021 were evaluated. Deviation-angle differences in prism diopters (PD) were measured preoperatively and at 1 month postoperatively. Surgical dose-response (PD/mm) was defined as the difference in deviation angle (in PD) divided by the surgical dose in millimeters. Linear and non-linear regression models were used to evaluate the influence of variables including age, sex, axial length, and preoperative deviation on surgical dose-response. RESULTS: Overall, 295 patients (162 children; 133 adults) were included. Average surgical dose-response in the pediatric and adult groups was 2.82 ± 0.60 PD/mm and 3.02 ± 0.62 PD/mm, respectively. Male sex was negatively correlated with surgical dose-response in children. The surgical dose-response was larger in adults with longer axial length (>25.64 mm) and patients with larger preoperative deviation (>42.6 PD and >38.7 PD in pediatric and adult groups, respectively). Surgical dose-responses peaked at 35.1 years. CONCLUSION: Age, axial length, and preoperative deviation have a nonlinear effect on surgical dose-responses in exotropia patients undergoing R&R. Surgical dose-responses were larger in patients in young adulthood, with longer axial length and larger preoperative deviation angle. A table with fitted values for surgical dose-response based on age, axial length, and preoperative deviation was established for clinical reference.

Intermittent Exotropia: The Effect of Alternating Occlusion Therapy on Control of Strabismus.

BACKGROUND: Intermittent exotropia is a common form of pediatric strabismus characterized by intermittent misalignment of the eyes. This study investigated the clinical effectiveness of alternating occlusion therapy as a non-surgical alternative for children aged 3-10 with intermittent exotropia. METHODS: A comprehensive review of recent research, including randomized controlled trials and case series, was conducted. These studies utilized standardized control scores to assess the impact of alternating occlusion therapy on both distance and near control of alignment. RESULTS: The findings indicated a significant improvement in exotropia control, particularly at distance fixation, among children undergoing alternating occlusion therapy. While some variability in outcomes exists, all articles demonstrate positive responses to this noninvasive approach. Notably, the patients with poor initial control tended to benefit the most. DISCUSSION: The potential advantages of alternating occlusion therapy are its cost-effectiveness and noninvasive nature. However, it is essential to manage patient and parental expectations and address potential drawbacks, including social stress, irritation associated with occlusion therapy and the possibility that strabismus surgery may still be needed in the future because of decompensation. CONCLUSION: Alternating occlusion therapy is a promising option to improve exotropia control in children with intermittent exotropia. It offers a viable non-surgical strategy to delay or potentially avoid strabismus surgery, although approximately 45% of the patients might eventually still require strabismus surgery. Healthcare providers should carefully weigh the benefits and limitations of this intervention to make informed decisions through shared decision-making with the patients and their families. This review offers diverse insights into the clinical management of intermittent exotropia and provides an evidence-based alternative to surgical interventions.

The impact of simultaneous correction of the V pattern on the results of surgical treatment in children with intermittent exotropia.

PURPOSE: This study is to investigate the impact of the coexistence of basic intermittent exotropia and vertical incomitance in the form of the V and sub-V pattern on the results of surgical correction of intermittent exotropia. METHODS: The records of 81 pediatric patients who had surgery for intermittent exotropia and a follow-up of more than 1 year were reviewed retrospectively. They were divided into groups: a concomitant group which underwent only horizontal muscle surgery of bilateral lateral rectus recession and a V pattern group which had additional inferior oblique recession, further separated into two subgroups: ≥ 15 prism diopters (classic V pattern group) and ≥ 10 < 15 prism diopters (sub-V pattern group). The surgical outcome, deviation control, stereoacuity, and postoperative drift were assessed after 3 months and 1 year postoperatively. RESULTS: Patients with sub-V and classic V pattern intermittent exotropia showed significantly better surgical success rate (p = 0.025) and less postoperative drift (p = 0.042) than patients without vertical incomitance. One year after surgery, successful surgical outcome was achieved in 83.72% of the vertically incomitant group: 80.76% for the classic V pattern and 88.24% for the sub-V pattern group, while only in 60.53% of nonpattern patients. CONCLUSIONS: Patients operated for intermittent exotropia with a coexistent V pattern have consistently better surgical long-term results than those with only horizontal deviation. Additional inferior oblique recessions in the sub V pattern group provided excellent outcomes with no overcorrections; therefore, surgeons should consider addressing vertical incomitance even when the typical criteria for the V pattern are not met.

Self-reported Findings of the Korean Intermittent Exotropia Multicenter Study Questionnaire.

Purpose: To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population. Methods: The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus (KAPOS) including 5385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS. Results: The mean age of symptom onset was 5.5 years of age. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery. Conclusions: The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.

Prevalence and Types of Strabismus in Cerebral Palsy: A Global and Historical Perspective Based on a Systematic Review and Meta-Analysis.

PURPOSE: Strabismus is more frequent in cerebral palsy (CP) than in the normal population, but reports differ how much it is increased. We here examined the global prevalence and types of strabismus in CP, whether esotropia or exotropia is more frequent, and whether the prevalence differs between ethnicities and/or country income levels, and between generations. METHODS: We compiled in a systematic review and meta-analysis the results of 147 CP studies that report the prevalence of strabismus or the ratio of esotropia to exotropia, and we conducted subgroup analyses for region (income level) and ethnicity. We performed a pooled analysis for the CP strabismus prevalence, and estimated the global number of CP cases with strabismus. RESULTS: The pooled prevalence of strabismus in CP is 49.8% in high-income countries and 39.8% in lower-income countries. We estimate the global number of strabismus cases in CP as 12.2 million, with 7.6 million males and 4.6 million females, based on current estimates of 29.6 million global CP cases. Esotropia is more frequent than exotropia in Caucasians, while exotropia is more frequent than esotropia in Hispanic and in some Asian and African populations. The strabismus prevalence in CP increases with increasing country income levels. CONCLUSION: Generational changes in strabismus prevalence appear to reflect a transition of CP types and an increase in prevalence as countries attain higher income and more effective maternal health care. The distribution of esotropia and exotropia in CP patients largely reflects the horizontal strabismus type that is predominant in the subject's ethnicity.

Six-month binocular stereopsis recovery and its influencing factors in children with intermittent exotropia.

OBJECTIVE: To investigate the recovery of binocular stereopsis recovery and its influencing factors in children with intermittent exotropia after successful correction of eye position. METHODS: Prospective clinical study. A total of 178 patients, aged 9 ∼ 14 (10.8 ± 1.7) years, who were successfully corrected after intermittent exotropia surgery at the Beijing Tongren Hospital Affiliated to Capital Medical University from October 2023 to September 2023 were collected, the follow-up duration was six-month or longer. Paired t test, Pearson correlation analysis and multivariable linear regression analysis were used to probe preoperative clinical features that may predict the stereopsis six months after surgery. RESULTS: Six months after surgery, the angle of deviation of the patients met the orthotopic standard, and there was significant difference compared with that before surgery (distant: -2.7△±3.2△ vs. -30.5△±8.4△, t=-25.3, P < 0.001. Near:-3.7△±4.1△ vs. -33.7△±8.0△, t=-26.1, P < 0.001). Distant stereopsis (3.0 ± 0.6 vs. 3.9 ± 0.4, t = 4.9, P < 0.05) and near stereopsis (2.3 ± 0.5 vs. 2.6 ± 0.4, t = 3.8, P < 0.05) were both significantly improved compared with that of before surgery. 17% and 22% patients rebuilt normal distant stereopsis and normal near stereopsis, respectively. Preoperative distant stereopsis (r=-0.26, P = 0.004) and near stereopsis (r=-0.23, P = 0.011) was significantly negatively correlated with convergence reserve. Multivariable analysis showed that patients' age (ß = 0.003, p = 0.037), anisometropia (ß = 0.015, p = 0.043), and preoperative distant stereopsis (ß = 0.456, p < 0.001) were significantly associated with postoperative distant stereopsis. Patients' age (ß = 0.005, p = 0.044), anisometropia (ß = 0.127, p = 0.034), angle of deviation (ß=-0.230, p = 0.020), and preoperative near stereopsis (ß = 0.136, p < 0.001) were significantly associated with postoperative near stereopsis. CONCLUSION: IXT patients could get eye position fixed after surgery, about 20% patients benefited from stereopsis improvement. Patient's age, binocular anisometropia, angle of deviation and preoperative stereopsis were independent factors influencing postoperative stereopsis.

Abnormal occipital and frontal activity during voluntary convergence in intermittent exotropia: A task-fMRI study.

Intermittent exotropia (IXT) is characterized by intermittently outward deviation of the eye and involved with vergence dysfunction. This study aimed to investigate the brain areas related to voluntary convergence and cortical activation changes between IXT patients and normal subjects. A total of 21 subjects, including 11 IXT patients and 10 age- and sex-matched normal subjects, were recruited for this study. A voluntary convergence task was employed, with changes in brain function measured by functional magnetic resonance imaging (fMRI). Correlations between cortical activation and clinical measurements were conducted by Pearson's correlation analysis. fMRI results showed that during voluntary convergence, the medial frontal gyrus (MFG) and bilateral occipital cortex were activated in the normal group, whereas only activation of the occipital cortex in IXT patients. Compared with the normal, IXT patients showed hypo-activation of both the MFG and cuneus during the task. The activation of MFG was negatively correlated to the duration of IXT. This study demonstrates that both MFG and occipital cortex may participate in voluntary convergence in normal subjects, while IXT patients have an aberrant cortical function of the MFG and cuneus, and the duration of IXT likely influences the severity of MFG. These findings may provide valuable insights for understanding the relationship between convergence and IXT.

Physical therapy exercises for improving intermittent exotropia control post-strabismus surgery: A randomized controlled study.

Background: Exotropia control is deteriorated by post-strabismus surgery in many cases. Improving this control is considered as an important factor for success of the strabismus surgery like ocular motor alignment. Objective: To determine the therapeutic effect of postoperative eye exercises on exodeviation eye control after the strabismus surgery. Methods: Forty patients suffering from intermittent exotropia after strabismus surgery were randomly divided into experimental group and control groups. Both groups received the usual medical care, while the experimental group received different types of eye exercises using physiotherapy modalities in 24 sessions over three months (two sessions a week). The measurement of exotropia control for near target and far target using the office-based scale was done before and after the treatment. Results: There was a significant improvement in near eye control post-treatment (0.45±0.61) in the experimental group compared with control group (3.65±0.88) as the mean difference was -3.20 and 95% CI of the difference between them was -3.645--2.755 with P<0.01. Also, far eye control improved post-treatment in the experimental group (0.75±0.64) compared with control group (4.00±0.86) with mean difference of -3.250 and 95% CI of the difference between them was -3.727--2.773 with P<0.01. Conclusions: For patients with intermittent exotropia who had undergone strabismus surgery, the addition of physiotherapy exercises for the eye provided significant improvements in exotropia control for near target and far target.

Comparison of retinal nerve fiber layer thickness between monocular and alternating exotropia in patients with intermittent exotropia.

PURPOSE: To investigate differences in intraocular structure based on the presence or absence of fixation preference in children with intermittent exotropia (IXT) by comparing the thickness of the retinal nerve fiber layer (RNFL). METHODS: From October 2018 to March 2022, RNFL thickness was retrospectively analyzed using spectral domain optical coherence tomography. Participants had uncorrected visual acuity of 20/20, refractive errors close to emmetropia, and no anisometropia. The patients were divided into monocular and alternating exotropia groups through a cover-uncover test. The average and sectoral thickness of the RNFL in both groups were compared. RESULTS: The average global thickness and average thickness of each of the six sectors of the RNFL did not significantly differ between dominant and non-dominant eyes in the monocular exotropia group and between right and left eyes in the alternating exotropia group. The thickness did not significantly differ between the monocular exotropia group and the right or left eye of the alternating exotropia group. Interocular differences in RNFL thickness were negative in the monocular exotropia group (dominant eye-non-dominant eye) and positive in the alternating exotropia group (right eye-left eye) for the average, inferonasal, and inferior sectors, exhibiting statistically significant between-group differences (p = 0.019, p = 0.003, p = 0.023, respectively). CONCLUSIONS: In children with IXT without obvious refractive error, there was a significant interocular difference in RNFL thickness of the average, inferonasal, and inferior sectors between monocular and alternating exotropia groups. The presence of fixation preference may affect RNFL thickness.

Factors Associated with Surgical Outcomes after Bilateral Lateral Rectus Recession in Children with Intermittent Exotropia.

Backgroud: To analyze the factors associated with surgical outcomes after bilateral rectus recession (BLR) in children with intermittent exotropia (IXT). Methods: A retrospective study was performed on 125 patients who had all received preoperative patch treatment with a ≥1 year follow-up. The surgical outcomes were grouped as success (esodeviation ≤5 PD to exodeviation ≤10 PD) or failure (esodeviation >5 PD or exodeviation >10 PD) according to the angle of deviation at 1 year postoperatively. The patients' magnitude of exodeviation, near and distant stereoacuity, and 3-mo patch responses were assessed. The factors associated with the surgical outcomes were determined using univariate and multivariate analyses. Results: Of the 125 patients, 102 (81.6%) and 23 (18.4%) were assigned to the success and failure groups, respectively. According to the univariate analysis, the absence of anisometropia, a smaller preoperative near exodeviation, a better near stereopsis, a smaller magnitude of deviation on day 1 postoperatively, and response to patching were significantly associated with surgical success for IXT after 1 year. In the multivariate analysis, distant esotropic deviation on day 1 postoperatively and response to patching were the factors affecting successful surgical outcomes. Conclusions: Esotropic distant deviation on day 1 postoperatively is a prognostic factor for favorable surgical outcomes. Preoperative patching could be a factor influencing surgical success in children with IXT.

Sensory Strabismus; A Literature Review.

Persistent unilateral or bilateral visual deprivation at any age, particularly in children, can compromise sensory fusion and result in a type of strabismus known as sensory or secondary strabismus. There are several pathologies that can induce visual impairment, such as severe anisometropia, congenital unilateral cataract, corneal opacity, retinal diseases, and optic nerve anomalies. Sensory strabismus may be horizontal or vertical or a combination of them; however, most reports indicate the development of horizontal deviation as sensory strabismus. Regardless of the direction of the sensory strabismus, early diagnosis and management of the underlying pathology are important before strabismus treatment. The primary treatment approach for patients with sensory strabismus is surgery to correct ocular misalignment and straighten the eyes. This can help to improve the patients' symptoms and diminish the negative psychosocial impacts. In this article, we review the underlying etiologies and background pathologies associated with sensory strabismus. In addition, we investigate the determinant factors of the direction of sensory strabismus and its management strategies.

Effectiveness of Strabismus Surgery in Intermittent Exotropia and Factors Influencing Outcome.

Intermittent exotropia (IXT) is known to relapse after surgery. No factors to predict or prevent recurrence are known with certainty. This study investigated surgical outcome, potential influencing factors, and reoperation rate in patients with IXT. Medical records of 537 patients who underwent surgery for IXT from 2000 to 2022 with preoperative angles of exodeviation of 6 to 50 prism diopters (PD) were retrospectively studied. Multivariate regression analyses of factors influencing surgical outcome on postoperative day 1 (POD1) and reoperation rate were performed. A Kaplan-Meier analysis was performed to illustrate the reoperation rate. After the first surgery, 83.8% of patients had a successful surgical outcome on POD1 (esodeviation ≤ 5 PD or exodeviation ≤ 10 PD). Logistic regression analysis revealed that small preoperative angles of exodeviation increased the probability for surgical success. Follow-up data at different times (4 days-20 years) after surgery were available for 176 patients: 40 patients were still in the range of surgical success, 133 patients had exotropia > 10 PD. Of the follow-up patients, 65 (12.1%) underwent reoperation. A total of 8.5% had their reoperation within one year after the first surgery, 52.9% within five years. Cox regression analysis revealed that large preoperative angles of exodeviation, far/near incomitance and alphabet pattern strabismus increased the risk of reoperation. Most patients achieved surgical success on POD1, yet the squint angles often increased after surgery, resulting in reoperation in some patients. Prospective studies are needed for a better assessment of pre-, peri- and postoperative factors for surgical success in IXT.

Prevalence and types of strabismus in cerebral palsy: A global and historical perspective based on a systematic review and meta-analysis.

Purpose: Strabismus is more frequent in cerebral palsy (CP) than in the normal population, but reports differ how much it is increased. We here examined the global prevalence and types of strabismus in CP, whether esotropia or exotropia is more frequent, and whether the prevalence differs between ethnicities and/or country income levels, and between generations. Methods: We compiled in a systematic review and meta-analysis the results of 147 CP studies that report the prevalence of strabismus or the ratio of esotropia to exotropia, and we conducted subgroup analyses for region (income level) and ethnicity. We performed a pooled analysis for the CP strabismus prevalence, and estimated the global number of CP cases with strabismus. Results: The pooled prevalence of strabismus in CP is 49.8% in high-income countries and 39.8% in lower-income countries. We estimate the global number of strabismus cases in CP as 12.2 million, with 7.6 million males and 4.6 million females, based on current estimates of 29.6 million global CP cases. Esotropia is more frequent than exotropia in Caucasians, while exotropia is more frequent than esotropia in Hispanic and in some Asian and African populations. The strabismus prevalence in CP increases with increasing country income levels. Conclusion: Generational changes in strabismus prevalence appear to reflect a transition of CP types and an increase in prevalence as countries attain higher income and more effective maternal health care. The distribution of esotropia and exotropia in CP patients largely reflects the horizontal strabismus type that is predominant in the subject's ethnicity.

Trends and patterns in pediatric ophthalmology and strabismus surgeries: a decade review from a leading Portuguese university hospital.

PURPOSE: Strabismus and Pediatrics Ophthalmology surgeries are pivotal in addressing early-onset visual disorders. An 11-year retrospective study at a tertiary hospital center aimed to elucidate evolving surgical trends, focusing on esotropia cases. METHODS: The surgical records from January 2009 to January 2020 were analyzed according to the baseline diagnosis. Esotropia cases were evaluated based on the patients' deviation types, surgical techniques, and pre-operative characteristics. A total of 2050 surgeries were performed over the study period. RESULTS: Strabismus surgery accounts for 70% of the department's surgical activity. A trend toward a decrease in esotropia surgeries and a proportional increase in exotropia surgeries was noticeable. Esotropia cases, with a median surgical age of 6 years (p25-p75, 4-10) and uniform gender distribution (females, 54.8%), predominantly involved high angular deviations. Posterior fixation sutures emerged as the preferred surgical technique for esotropia. CONCLUSION: The study's insights, while aligning with prior European research, introduce new dimensions to the understanding of strabismus surgeries, emphasizing the significance of early interventions, evolving surgical preferences, and the challenges posed by severe deviations.

Concurrent adjacent strabismus surgery with glaucoma drainage device placement in childhood glaucomas.

BACKGROUND: Determine outcomes of concurrent strabismus surgery with placement of a glaucoma drainage device (GDD) in children. METHODS: Retrospective review of pediatric patients who underwent simultaneous lateral rectus (LR) muscle surgery with superotemporal GDD placement. Strabismus and GDD success were defined as residual horizontal misalignment < 10 prism diopter (PD) and intraocular pressure (IOP) < 21 mmHg, no visually devastating complications, and no additional IOP-lowering surgeries. RESULTS: Fifteen eyes of 13 patients (69% male) underwent LR surgery (14 recessions, 1 resection) for exotropia or esotropia simultaneous with GDD placement (13 Baerveldt, 2 Ahmed) at 8.34 ± 5.26 years. Preoperative visual acuity (VA) in operative eye (0.89 ± 0.54) was worse than non-operative eye (0.23 ± 0.44, p = 0.0032). Preoperative horizontal deviation was 38.3 ± 9.4 PD and LR recession was 7.4 ± 1.1 mm. At final follow-up, VA in operative eye (0.87 ± 0.52) was unchanged from preoperative (p = 0.4062). Final IOP was significantly decreased (12.4 ± 4.7 mmHg vs. 31.1 ± 11.4 mmHg, p = 0.0001) as was number of glaucoma medications (2.7 ± 1.7 vs. 1.1 ± 1.3, p = 0.0037). Five (38%) and 9 patients (69%) met criteria for strabismus and GDD success, respectively. Two eyes required tube revision and endoscopic cyclophotocoagulation and 2 eyes had additional strabismus surgery. CONCLUSIONS: Concurrent strabismus and GDD surgery decreased horizontal deviation and obtained IOP control. It is important to consider correction of strabismus at time of GDD placement to maximize visual development and improve cosmesis in children with glaucoma.

Optimal Duration of Monocular Occlusion to Eliminate Fusion Effect in Intermittent Exotropia.

Purpose: To determine the optimal duration of monocular occlusion in patients with intermittent exotropia. Patients and Methods: This prospective cohort study enrolled 40 patients with intermittent exotropia at Ramathibodi Hospital between May 2023 and September 2023. Angles of deviation at distance (6 m) and near fixation (0.33 m) were measured before and after monocular occlusion for 30, 60, and 90 minutes. All measurements were performed by a single ophthalmologist. The mean angle of deviation was calculated at each time point. Results: The mean age at presentation was 12.5 years (range, 5-33 years). The mean angles of deviation before monocular occlusion were 27.8 ± 15.1 prism diopters (PD) at distance and 26 ± 13.7 PD at near fixation. At distance, mean angles of deviation after monocular occlusion were 32.2 ± 14.6, 32.9 ± 15.0, and 32.6 ± 14.7 PD at 30, 60, and 90 minutes, respectively. At near fixation, mean angles of deviation after monocular occlusion were 37.4 ± 15.0, 39.8 ±14.3, and 39.5 ± 14.6 PD at 30, 60, and 90 minutes, respectively. All angles significantly differed from the pre-occlusion deviation (all P < 0.01). For deviation at distance, there was no statistically significant difference between 60 and 30 minutes of monocular occlusion (P = 0.48). For deviation at near fixation, there was a significant difference between 60 and 30 minutes of monocular occlusion (P = 0.048), but the difference of 2.5 PD was not clinically significant. There were no statistically significant differences between 90 and 60 minutes of monocular occlusion at distance or near fixation (both P = 0.82). Conclusion: Monocular occlusion is necessary to eliminate the fusion effect in patients with intermittent exotropia; 30 minutes of monocular occlusion is sufficient to achieve the maximum angle of deviation.