Surgical management of chronic sixth cranial nerve palsy: case report and literature review.

Background: Esotropia resulting from sixth cranial nerve palsy can substantially impact an individual's visual acuity and overall quality of life. If the condition does not resolve in 6-10 months, surgical intervention may be necessary. Various muscle surgeries may be considered, with vertical rectus muscle transposition emerging as the primary option for treatment of complete palsy. However, this technique carries the risk of anterior segment ischemia and post-surgery deviations. Herein, we present a successful treatment of chronic complete sixth nerve palsy using a modified Nishida procedure, without splitting or tenotomy, and an adjunct botulinum toxin A (BTA) injection in the ipsilateral medial rectus muscle. Case Presentation: A 59-year-old woman with a history of traumatic sixth nerve palsy had previously undergone horizontal muscle strabismus surgeries. Following multiple left medial rectus recessions, lateral rectus resection, and BTA injections, esotropia persisted. The worsening of her condition led to emotional distress and impaired social interaction. Initial examination revealed marked esotropia and limited left eye abduction. Magnetic resonance imaging (SIGNA MR750w, GE Healthcare, Waukesha, WI, USA) of the left eye revealed a contracted medial rectus muscle and substantial atrophy of the left lateral rectus muscle. A modified Nishida procedure was performed with an injection of 3 units of BTA into the ipsilateral medial rectus muscle, resulting in improved ocular alignment and stable findings after nine postoperative months. Furthermore, we supported our successful outcome with a summary of similar reported cases of sixth nerve palsy managed using the modified Nishida procedure with or without adjunctive procedures. Conclusions: Following the modified Nishida procedure, the patient experienced a reduction in diplopia, improved ocular alignment and stability, and an increased binocular diplopia-free field. This case underscores the importance of an individualized approach to complex strabismus cases and highlights the modified Nishida procedure as a valuable tool in such circumstances. In the future, strabismus management will focus on refining personalized treatment and exploring innovative techniques for complex cases. Our success in using a combination of Nishida procedure and BTA injection should be further investigated in large-scale studies.

Advances in the diagnosis and treatment of acute acquired comitant esotropia.

Acute acquired comitant esotropia (AACE) is mainly characterized by sudden onset, accompanied by diplopia, without extraocular muscles paralysis or ocular motility disorders. In recent years, the incidence of AACE has been increasing, researchers have found that this phenomenon may be related to the widespread use of electronic devices and the increase in the number of people working from home during the COVID-19 pandemic. However, its neural mechanisms have not been fully elucidated. This article primarily reviews the latest developments in the diagnosis and treatment of AACE from the perspectives of etiology and treatment methods, aiming to provide direction for future in-depth exploration of the pathogenesis and treatment approaches of this disease.

Genome-Wide Association Study with Three Control Cohorts of Japanese Patients with Esotropia and Exotropia of Comitant Strabismus and Idiopathic Superior Oblique Muscle Palsy.

Esotropia and exotropia in the entity of comitant strabismus are multifactorial diseases with both genetic and environmental backgrounds. Idiopathic superior oblique muscle palsy, as the predominant entity of non-comitant (paralytic) strabismus, also has a genetic background, as evidenced by varying degrees of muscle hypoplasia. A genome-wide association study (GWAS) was conducted of 711 Japanese patients with esotropia (n= 253), exotropia (n = 356), and idiopathic superior oblique muscle palsy (n = 102). The genotypes of single nucleotide polymorphisms (SNPs) were determined by Infinium Asian Screening Array. Three control cohorts from the Japanese population were used: two cohorts from BioBank Japan (BBJ) and the Nagahama Cohort. BBJ (180K) was genotyped by a different array, Illumina Infinium OmniExpressExome or HumanOmniExpress, while BBJ (ASA) and the Nagahama Cohort were genotyped by the same Asian array. After quality control of SNPs and individuals, common SNPs between the case cohort and the control cohort were chosen in the condition of genotyping by different arrays, while all SNPs genotyped by the same array were used for SNP imputation. The SNPs imputed with R-square values ≥ 0.3 were used to compare the case cohort of each entity or the combined entity with the control cohort. In comparison with BBJ (180K), the esotropia group and the exotropia group showed CDCA7 and HLA-F, respectively, as candidate genes at a significant level of p < 5 × 10-8, while the idiopathic superior oblique muscle palsy group showed DAB1 as a candidate gene which is involved in neuronal migration. DAB1 was also detected as a candidate in comparison with BBJ (ASA) and the Nagahama Cohort at a weak level of significance of p < 1 × 10-6. In comparison with BBJ (180K), RARB (retinoic acid receptor-ß) was detected as a candidate at a significant level of p < 5 × 10-8 in the combined group of esotropia, exotropia, and idiopathic superior oblique muscle palsy. In conclusion, a series of GWASs with three different control cohorts would be an effective method with which to search for candidate genes for multifactorial diseases such as strabismus.

Disconjugacies of saccade duration and trajectories in strabismus.

Introduction: For decades, the saccadic system has been a favorite target of neurophysiologists seeking to elucidate the neural control of eye movements, partly because saccades are characterized by a set of highly stereotyped relationships between amplitude, duration, and peak velocity. There is a large literature describing the dynamics and trajectories of these movements in normal primates, but there are no similarly detailed analyses for subjects with infantile strabismus syndrome. Previous studies have shown the amplitudes and directions of saccades often differ for the two eyes in this disorder, but it is unknown whether a similar disconjugacy exists for duration. The present study was designed to determine whether or not saccade duration differs for the two eyes in strabismus, and whether there are abnormalities involving the trajectories of these movements. Methods: Dynamic analyses of saccade trajectories and durations were performed for two normal monkeys, two with esotropia and two with exotropia. The amount of curvature was compared for the two eyes. For each monkey with strabismus, the amount of curvature was compared to normal controls. Saccades were placed into 12 bins, based on direction; for each bin, the mean saccade duration was compared for the two eyes (duration disconjugacy). The duration disconjugacy for each bin was then compared for monkeys with strabismus, versus normal control animals. Results: Surprisingly, the amount of curvature was not consistently greater in subjects with pattern strabismus. However, saccade curvature differed for the two eyes by a significantly greater amount for all monkeys with strabismus, compared to normal controls. In addition, for a subset of saccades in subjects with strabismus, saccade duration differed for the two eyes by more than 10 ms, even when the animal was fully alert. Discussion: To the best of the author's knowledge, this is the first study to show that, in strabismus, saccade durations can differ for the two eyes by an abnormally large amount. These data also suggest that, in monkeys with pattern strabismus, abnormal horizontal-vertical crosstalk in brainstem can lead to directional disconjugacy without significantly impairing component stretching. These results place important constraints on future attempts to model the neural mechanisms that contribute to directional disconjugacy in pattern strabismus.

Clinical Characteristics and Management of Patients with Esotropia and Moderate Myopia.

Although the incidence of acquired esotropia associated with moderate myopia is on the rise, there is minimal research on the clinical profile and pathophysiology of this condition. To gain deeper insights into the clinical characteristics and management of these patients, a literature search was conducted, resulting in the identification of six relevant studies. Collectively, these studies encompassed a total of 304 patients. The mean age of onset of esotropia across all studies was 37.52 years. The mean deviations for distance were not considerably larger than those reported at near, even though symptoms were reported more frequently at distance. The overall mean of the distance deviation was 25.16 prism diopters, and the overall mean of the near deviation was 20.82 prism diopters. There were very few reports of vertical deviations across all studies. Limited data suggests that increased near work may be associated with larger esodeviations. Only three articles assessed surgical management; however, it appears that surgical correction may need to be increased by approximately one-third compared to traditional surgical tables and smaller deviations may require even greater augmentation.

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

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

Factors influencing the therapeutic effect of hyperopic correction on esotropia in patients with partially accommodative esotropia.

OBJECTIVES: To collate data on partially accommodative esotropia (PAET) to better understand this condition's aetiology and to evaluate and predict the therapeutic effect of a hyperopic correction on PAET. METHODS: Eighty-nine consecutive patients diagnosed with PAET with a spherical equivalent (SE) refractive error >+2.50 D were included in this retrospective review. Clinical characteristics, including gender, age, SE, angle of esodeviation, accommodative convergence/accommodation (AC/A) ratio, near-distance disparity (NDD) and anatomical features of the rectus muscles were compared among different PAET subgroups. Multiple linear regression was used to identify independent factors that influenced the therapeutic effect of a hyperopic correction on esotropia. RESULTS: No significant differences were observed for the angle of esodeviation as a function of age in individuals with PAET. The incidence of SE in PAET participants >9 years old was significantly greater than in those <5 and 6-8 years of age. The therapeutic effect of hyperopic correction on esotropia was positively associated with SE both at distance and near. In addition, the limbus insertion distance (LID) of the lateral rectus (LR) muscle was positively associated with NDD at distance, but negatively associated at near. CONCLUSION: A greater incidence of hyperopia was observed in older (>9 years old) PAET patients. A hyperopic correction had a greater effect on esotropia in individuals with a higher SE, larger LID of the LR muscle and a smaller NDD.

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

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

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

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

Botulinum toxin type A in treating early-stage patients with small-angle acute acquired comitant esotropia.

AIM: To investigate botulinum toxin A (BTXA) efficacy on small-angle (≤25Δ) acute acquired concomitant esotropia (AACE) in early-stage patients. METHODS: The electronic medical record data of AACE patients during March 2019 and June 2023 were collected in this retrospective and hospital-based cohort study. A total of 72 small-angle AACE patients received BTXA extraocular muscle injection. Patients were grouped by onset-to-treatment time (Group A: ≤6mo, Group B: >6mo). Deviation of esotropia, eye alignment and stereopsis were analyzed at the period of pre/post-injection (1wk, 1, 3, and 6mo). Orthophoria rate at 6mo (horizontal deviation <10Δ and binocular single vision) were considered as outcome index. RESULTS: There were no significant baseline differences (P>0.05) between two groups except onset-to-treatment time (2mo vs 11mo, P<0.001). Higher orthophoria rates were in Group A at last follow-up (94.74% vs 73.53%, P=0.013). Post-BTXA deviations of two groups at 1mo showed no difference (P>0.05); while in 3 and 6mo Group A was significantly smaller than group B (all P<0.001). No statistically significant differences were observed among all post-BTXA deviations of near and distance in Group A. In Group B, deviation at 3mo (near: 2Δ vs 0, P<0.001; distance: 4Δ vs 0, P<0.001) and 6mo (near: 6Δ vs 0, P<0.001; distance: 6Δ vs 0, P<0.001) was significant increased compared to deviation at 1wk after treatment. Group A showed better stereopsis recovery in last follow-up compared to Group B (80″ vs 200″, P=0.002). Both groups obtained improved stereopsis after treatment (Group A: 80″ vs 300″, P<0.001; Group B: 200″ vs 300″, P=0.037). CONCLUSION: BTXA is effective for AACE with small deviation (≤25Δ) in early stage. Delayed treatment (>6mo) may reduce BTXA efficacy. Early BTXA intervention benefits long-term eye alignment and stereopsis recovery.

Effect of 4-week preoperative prism adaptation in preventing postoperative residual esotropia.

BACKGROUND: Preoperative prism adaptation (PPA) simulates postoperative status and possibly can predict postoperative undercorrection before surgery in esotropia. The present study aimed to assess the effect of 4-week PPA in preventing postoperative residual esotropia. METHODS: Seventy-five (75) esotropes who had undergone surgery at a single strabismus center were retrospectively enrolled. They included 25 basic, 31 acute comitant, 10 partially accommodative, and 9 recurrent esotropia patients. The preoperative deviation angle, which had been determined using the alternating prism and cover test, was fully corrected with press-on prisms 4 weeks before surgery. If there was an increase of 5 PD or more of esodeviation, the prisms were changed accordingly at 2 weeks. The deviation angle measured at 4 weeks was determined as the surgical target angle. Patients were then divided into increase (≥ 5 PD increase of angle during 4-week PPA) and non-increase groups. Success was defined as either esodeviation of 8 PD or under or exodeviation of 5 PD or under at distance at postoperative 6 months. RESULTS: The increase group included 44 patients (58.7%). The mean deviation angle before PPA was 27.4 PD, and after the 4-week PPA, there was an average increase of 9.4 PD. The success rate was 90.9% in the increase group and 96.8% in the non-increase group (p = 0.316). There were no intergroup differences in preoperative clinical characteristics, esotropia types, postoperative deviation angle or postoperative near stereopsis (p > 0.05). CONCLUSIONS: The results of this study indicated a beneficial effect of 4-week PPA in esotropia of various types, specifically by uncovering the hidden esodeviation in the increase group and simulating the postoperative alignment in both the increase and the non-increase groups.

Unilateral lateral rectus palsy following dengue: a case report.

Introduction and importance: Dengue fever is a mosquito-borne viral infection presenting with high-grade fever and other constitutional symptoms. Case presentation: This case report details a rare occurrence of lateral rectus palsy in an 18-year-old male subsequent to dengue infection. The patient initially presented with fever, a generalized tonic-clonic seizure (GTCS), and symptomatic hypoglycemia, leading to multiple organ dysfunction syndrome (MODS) necessitating intensive care. Remarkably, no haemorrhagic manifestations were observed. The MODS gradually resolved by the 12th day of admission, coinciding with the emergence of complaints about uniocular diplopia and right esotropia. Systemic examination, including a normal computed tomography (CT) head scan, did not reveal any abnormalities. Additionally, potential causes contributing to esotropia and diplopia were ruled out. The patient was subsequently managed expectantly for lateral rectus palsy following severe dengue. Follow-up assessments indicated a gradual improvement in esotropia and diplopia, and the patient was advised to continue the prescribed medications. Conclusion: This is the first documented case report of paralytic squint post-severe dengue in Nepal, emphasizing the importance of considering it as a differential diagnosis in tropical regions with endemic dengue infections. The case report advocates early identification and treatment of ophthalmic issues, notably with prednisolone, to achieve favourable outcomes, as evidenced by improvements in visual acuity, esotropia, and diplopia during follow-ups. Further research is essential to determine optimal treatment strategies for such neurological complications associated with dengue fever.

Successful prism treatment for cyclic esotropia: A case report.

Purpose: To report a case of cyclic esotropia successfully treated with prismatic correction. Observations: A 9-year-old girl presented with intermittent esotropia and diplopia occurring over the previous 4 months. The patient had 30 prism diopters (PD) of esotropia at both distance and near. Ocular motility testing, other ophthalmic examinations, and brain magnetic resonance imaging revealed no abnormalities. At the third visit, the patient had 6 PD of intermittent esotropia without diplopia, and the eye position diary demonstrated esotropia every other day, which led to a diagnosis of cyclic esotropia with a 48-h cycle. The cyclic pattern persisted for 9 months following the initial visit. However, during a subsequent regular visit, the patient reported a newfound ability to self-adjust from "esotropic" days to "straight" days by tightly closing the eyes immediately after waking up in the morning, particularly when wishing to avoid strabismus. To address the condition, we affixed a Fresnel membrane prism on the glasses to compensate for the latent deviation on a "straight" day. During the subsequent 18 months, the esotropia completely resolved, and the patient was followed up with gradual decreases in prism power. Conclusions and Importance: Correcting latent deviation using a prism lens is a simple approach without potential side effects. The present findings suggest that this approach is a viable treatment option for cyclic esotropia during its early and periodic stages.

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%.

Effect of the prism and Maddox rod test as the surgical target for type III acute acquired comitant esotropia.

Introduction: This study aims to explore more accurate and efficient examination methods to provide precise target surgical measurements for patients with type III acute acquired comitant esotropia (AACE). Methods: The study conducted a retrospective analysis of 108 patients diagnosed with AACE who received surgical treatment at the Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University, from January 2018 to September 2023. All patients underwent examinations of the deviation angle, including the Hirschberg test, prism and Maddox rod test (PMT), and prism and alternate cover test (PACT). For the PACT, the minimum value (PACTmin) and maximum value (PACTmax) were obtained based on differences in examination methods, as well as the deviation angle range (PACT range), which represents the difference between PACTmax and PACTmin. Postoperatively, these patients were followed up for at least 6 months to assess changes in eye position and whether diplopia symptoms recurred. Results: In both near and distant examinations, the results of PACTmax were significantly greater than those of PACTmin (p < 0.001), while the deviation angles obtained from PACTmax and PMT showed no significant statistical difference [p = 0.689 (33 cm), p = 0.436 (5 m)]. There was a strong linear correlation between PACTmin and PMT at both near (R = 0.8887) and distant (R = 0.8950) distances, but each PACTmin corresponded to multiple PMT values. There was no significant difference between the results of PACT range at near and distant distances (p = 0.531). The deviation angles obtained by PMT and PACTmin significantly decreased postoperatively compared to preoperative values, and diplopia disappeared in all patients, with alternative cover test showing no movement or presenting as an esophoria state. Conclusion: The PMT can provide precise target surgical measurements for type III AACE, making it a fast, effective, and cost-efficient examination method. It is worthy of being promoted and applied in clinical practice.

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.

Effects of cycloplegia on crystalline lens morphology and location in acute acquired concomitant esotropia.

PURPOSE: The study aims to compare morphology and location of crystalline lens between acute acquired concomitant esotropia (AACE) patients and control subjects, both before and after cycloplegia. METHODS: This is a prospective and observational clinical study. Morphological and locational parameters of the crystalline lens in 53 AACE patients and 32 control subjects were assessed before and after cycloplegia using CASIA2 system, which represents the latest swept-source anterior segment optical coherence tomography. Cycloplegic refraction was recorded by administering 1% atropine in patients younger than 12 years and 1% cyclopentolate in those > 12 years old. Morphological parameters included anterior radius of curvature (ARC), posterior radius of curvature (PRC), lens thickness (LTH), and equivalent diameter of lens (LED). Locational parameters comprised lens decentration (LD) and lens tilt (LT). Comparison of these parameters before and after cycloplegia were conducted between AACE and controls. Additionally, the study analyzed and compared the changes in these parameter post-cycloplegia. RESULTS: Our findings suggest no significant difference in morphological parameters including ARC, PRC, LTH and LED between AACE patients and controls before or after cycloplegia. However, 2D-modeling data in the 0° meridian revealed that variation post-cycloplegia of LD (lens shift) in right eyes was different in AACE patients, measuring - 0.03(0.08) [median(interquartile range)] which was significantly distinct from the control group, exhibiting a measurement of 0.01(0.06) (z = - 2.373, p = 0.018). In left eyes, a similar trend was observed with lens shift in the 0° meridian being 0.02(0.06) in AACE, significantly differing from control group's measurement of - 0.02(0.08) (z = - 2.809, p = 0.005). Further, correlation analysis revealed that larger temporal shift of lens was associated with greater changes in ARC (r = 0.294, p = 0.006) and LTH (r = - 0.230, p = 0.031). CONCLUSIONS: The morphological features of the crystalline lens were similar in AACE patients and controls; however, the change of lens location by cycloplegia was observed only in AACE patients, suggesting an association with excessive accommodation.

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.

Emergence of lingual dystonia and strabismus in early-onset SCN8A self-limiting familial infantile epilepsy.

Pathogenic variants in SCN8A are associated with a broad phenotypic spectrum, including Self-Limiting Familial Infantile Epilepsy (SeLFIE), characterized by infancy-onset age-related seizures with normal development and cognition. Movement disorders, particularly paroxysmal kinesigenic dyskinesia typically arising after puberty, may represent another core symptom. We present the case of a 1-year-old girl with a familial disposition to self-limiting focal seizures from the maternal side and early-onset orofacial movement disorders associated with SCN8A-SeLFIE. Brain MRI was normal. Genetic testing revealed a maternally inherited SCN8A variant [c.4447G > A; p.(Glu1483Lys)]. After the introduction of valproic acid, she promptly achieved seizure control as well as complete remission of strabismus and a significant decrease in episodes of tongue deviation. Family history, genetic findings, and epilepsy phenotype are consistent with SCN8A-SeLFIE. Movement disorders are an important part of the SCN8A phenotypic spectrum, and this case highlights the novel early-onset orofacial movement disorders associated with this condition. The episodes of tongue deviation and protrusion suggest focal oromandibular (lingual) dystonia. Additionally, while infantile strabismus or esophoria is a common finding in healthy individuals, our case raises the possibility of an ictal origin of the strabismus. This study underscores the importance of recognizing and addressing movement disorders in SCN8A-SeLFIE patients, particularly the rare early-onset orofacial manifestations. It adds to the growing body of knowledge regarding the diverse clinical presentations of SCN8A-associated disorders and suggests potential avenues for clinical management and further research.