Functional acute acquired comitant esotropia: clinical characteristics and efficacy of single Botulinum toxin type A injection

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.

Efficacy of augmented-dosed surgery versus botulinum toxin A injection for acute acquired concomitant esotropia: a 2-year follow-up

BACKGROUND/AIMS

This study aims to evaluate the clinical efficacy of botulinum toxin type A (BTXA) injection and augmented-dosed surgery in the treatment of acute acquired concomitant esotropia (AACE), and explore potential risk factors associated with recurrence.

METHODS

A total of 104 patients diagnosed with AACE between October 2020 and January 2021 were included and voluntarily chose to undergo augmented surgery or BTXA injection. The follow-up assessments ended in November 2022. Multivariable linear regression analysis was used to identify potential factors that influence the dose-response of bilateral medial rectus recession (MRrec). Kaplan-Meier survival analyses and Cox proportional hazards models were performed to evaluate rate and risk factors for AACE relapse.

RESULTS

A total of 31 AACE patients chose augmented-dosed esotropia surgery, and 73 chose BTXA treatment. During the 2-year follow-up, the surgical group achieved more stable postoperative results with no recurrence of diplopia, while only 68.68% (95% CI 55.31% to 78.79%) patients achieved orthophoria in the BTXA group. For patients undergoing BTXA treatment, hours of near work per day were demonstrated to be a significant risk factor for AACE relapse (HR 1.29, 95% CI 1.00 to 1.67). The dose-response of augmented-dosed bilateral MRrec was positively correlated with preoperative deviation angle (R2=0.833; β=0.043, 95% CI 0.031 to 0.055; p<0.001).

CONCLUSION

Our findings provided quantitative evidence that augmented-dosed surgery would achieve more stable and favourable surgical outcomes for AACE patients compared with BTXA injection. However, BTXA treatment is still proposed for patients with small deviation angles due to its advantages of reduced trauma, operational simplicity, low cost and quick recovery.

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 refractive errors on the results of botulinum neurotoxin administration in patients with infantile esotropia

PURPOSE

To investigate the effect of refractive errors on the results of patients followed up with infantile esotropia (IE) and treated with botulinum neurotoxin (BNT) injection.

METHODS

The files of patients with IE who presented to the ophthalmology pediatric ophthalmology unit and underwent BNT injection into both medial rectus muscles between 2019 and 2021 were reviewed retrospectively. Sixty eyes of 30 patients were included in the study. Patients with additional systemic or ocular diseases and those with a history of ocular surgery were excluded. Distance and near deviations were measured (with the prism cover test or Krimsky method) before and at the first, third, and sixth months after BNT injection.

RESULTS

In Group 1 (n = 20) with a spherical equivalent of + 2.0 diopters (D) or less, the mean near and distance deviation value was both 36.8 ± 12.7 prism diopter (PD) before injection. In Group 2 (n = 10) with a spherical equivalent of above + 2.0 D, the near deviation was measured as 35.0 ± 7.1 PD and distance deviation as 31.8 ± 7.9. At six months after BNT injection, the near and distance deviation values were 20.6 ± 12.3 and 20.6 ± 11.6 PD, respectively in Group 1 and 10.1 ± 10.3 and 8.8 ± 10.8 PD, respectively in Group 2. The change in deviation did not statistically significantly differ between the groups (p > 0.05), but the distance and near deviation values were lower in Group 2 at sixth months after BNT injection.

CONCLUSIONS

BNT injection is a preferred method in IE. Higher hypermetropic values seem to increase the success of BNT injection.

Analysis of independent risk factors for acute acquired comitant esotropia

AIM

To explore the risk factors for acute acquired comitant esotropia (AACE).

METHODS

A retrospective cohort study was conducted by analyzing 83 patients (case group) with AACE who underwent strabismus correction surgery from January 1, 2021 to June 30, 2022. Totally 73 outpatient volunteers were recruited during the same period as the normal control group. The case group's binocular vision time, near and distance esotropia angle, and near stereo vision function were recorded, and the age, gender, refractive status, and best-corrected visual acuity (BCVA) of both groups were analyzed. Additionally, multiple logistic regression analysis was conducted using an eye usage condition questionnaire to determine the independent risk factors for AACE.

RESULTS

In the case group, 61 patients (73.49%) had myopia, with a mean equivalent spherical power (SE) of -3.35±3.31 D (range: +2.75 to -10.62 D) of the right eye and -2.87±3.35 D (range: +2.75 to -11.12 D) of the left eye. The average duration of diplopia in the case group was 29.83±35.72mo, of which 80 patients (96.39%) were primarily with distance diplopia. The near and distance esotropia angle after wearing glasses were 52.36±20.95 prism degree (PD) and 56.71±19.54 PD, respectively, and there was no statistically significant difference between the two (t=1.38, P=0.169). The incidence of improper glasses wearing and unhealthy eye habits in the case group was significantly higher than those in the control group (P<0.05). Close-up work without glasses [β=2.30, odds ratio (OR)=10, 95% confidence interval (CI) 2.35-42.51, P=0.002] and near work in supine position (β=1.80, OR=6.02, 95%CI 3.29-11.02, P<0.001) were independent risk factors for AACE.

CONCLUSION

Patients with AACE mainly present with distance diplopia, and there is a high degree of variation in myopia. Near work without wearing glasses and in supine position are independent risk factors for AACE.

Clinical presentations of acquired comitant esotropia in 5-35 years old Japanese and digital device usage: a multicenter registry data analysis study

PURPOSE

To describe clinical presentations of acquired comitant esotropia and digital device use in children, adolescents, and young adults without neurological problems.

STUDY DESIGN

Multicenter prospective observational study.

METHODS

Patients with acquired comitant esotropia, without intracranial diseases aged 5-35 years at the time of visit, who were seen at pre-registered facilities within 1 year of onset were enrolled. The duration from the onset of symptoms and the time of digital device usage approximately 1 month before onset and their lifestyles were surveyed. Visual acuity, cycloplegic refraction, and strabismus angles were measured. Data were analyzed in three age groups (Child: 5-12 years, Adolescent: 13-18 years, and Young adult: 19-35 years).

RESULTS

Between November 2019 and December 2021, 218 patients were enrolled from 55 facilities, and 194 patients (including 62 children, 69 adolescents, and 63 young adults) were analyzed. The child group spent the least amount of time using digital devices (children: 159; adolescents: 210; young adults: 267 min/work day, p < 0.05; (mean time in the same order below) 229, 338, 314 min/holiday, p < 0.05) and had the largest strabismus angle (mean strabismus angle at near: 30, 22, 18 PD, p < 0.01; at far: 28, 26, 21 PD, p<0.05).

CONCLUSION

The clinical features of acquired comitant esotropia and hand-held digital device usage differed between children aged ≤ 12 years and older patients. This report gives the current clinical characteristics of young patients with acquired esotropia and digital device usage.

The efficacy of botulinum toxin type A treatment and surgery for acute acquired comitant esotropia

Aim

To compare the long-term efficiency of botulinum toxin type A (BTXA) injection and surgery on acute acquired comitant esotropia (AACE).

Methods

This retrospective study enrolled patients with AACE from January 2020 to August 2022. The horizontal angle of deviation pre- and post-treatment was measured. Deviations in BTXA and surgical treatment were compared. The BTXA group was divided into adequate treatment (AT) and inadequate treatment (inAT) subgroup based on the deviation of no more than 4 prism diopters (at near and distance) or temporary exotropia at the 2 week follow-up. The two subgroups were compared to determine the long-term efficacy of BTXA treatment.

Results

Ninety-two patients with AACE were included. Follow-up was 6 months. The deviations of the surgery and BTXA group were significantly smaller at the 6 month follow-up than at pre-treatment (p < 0.001). The deviation before treatment in the surgery group was larger than in the BTXA groups (p < 0.001) but smaller at the 6 month follow-up (p < 0.001). The deviation was similar in the AT-BTXA and inAT-BTXA subgroups before treatment (p = 0.322 for distance and p = 0.051 for near) but smaller in the AT-BTXA subgroup at 6 month follow-up (p < 0.001 for near and distance).

Conclusion

Surgery and BTXA successfully treat AACE. Surgery has a more precise and lasting therapeutic effect than BTXA. AACE patients adequately treated with BTXA and with deviations of no more than 4 prism diopters at 2 weeks follow-up had better outcomes.

Clinical features, etiological reasons, and treatment results in patients who developed acute acquired nonaccomodative esotropia

PURPOSE

To evaluate the clinical features, possible etiological reasons, and treatment results in children who developed acute acquired comitant esotropia (AACE) without strabismus in previous years.

METHODS

Medical records of the patients who were diagnosed with AACE between July 2017 and June 2021 were retrospectively reviewed. The children with ocular and orbital pathology, hypermetropia > 2.00 diopters, and anisometropia > 1.00 diopters were not included in the study. Possible etiological factors that could cause esotropia, treatment results, motor, and sensory functions were investigated.

RESULTS

The mean age at first admission, and the onset of AACE, was 8.8 ± 2.9 (4-13) years of three female (23.1%) and 10 male (76.9%) cases. The causes of AACE were determined to be occlusion of the eye due to corneal foreign body removal in one (7.7%), emotional stress in one case (7.7%), and excessive close work, on computer and smartphone screens in the other 11 cases (84.6%). Orthotropia was achieved in cases who underwent strabismus surgery (n = 10) and in cases using the prism (n = 2); except for one case, all (92.3%) achieved binocular single vision (100 s/arc stereopsis and fusion) after treatment, while there was no binocular single vision in any of the cases before treatment.

CONCLUSIONS

Acute acquired comitant esotropia is a rare clinical entity. Successful motor and sensory outcomes can be achieved by strabismus surgery or by prism therapy. It is critical to investigate the patientş with AACE in terms of intracranial pathologies, although rarely seen.

Independent risk factors of type III acute acquired concomitant esotropia: A matched case-control study

Purpose

To investigate the risk factors and surgical design for type III acute acquired concomitant esotropia (AACE).

Methods

In this retrospective, matched, case-control study, 51 patients developed type III AACE between March 2018 and September 2020, and the control group consisted of 60 patients matched by age and refractive power during the same period. A history of the duration of near work per day and the use of glasses were reviewed, and the refractive power of both eyes, deviation angles at both near and far vision, visual function, and treatment options were analyzed. Additionally, the distance from medial rectus insertion to the limbus was measured in surgical patients. The data were analyzed by logistic regression analysis.

Results

We found that 99.96% of the patients and 91.67% of the controls had myopia. Of these, 60.8% and 20.0%, respectively, did not wear glasses for near work. Twelve patients were treated with a prism and 39 were treated surgically. The average time devoted to near work per day was 7.24 and 3.7 h by the patients and controls, respectively. Univariate logistic regression analysis showed that increased hours of near work per day and near work without the use of spectacles were associated with the incidence of type III AACE. Multiple logistic regression analysis revealed that increased hours of near work per day and near work without the use of glasses were independent risk factors for AACE.

Conclusion

Increased hours of near work per day and uncorrected myopia in near work are independent risk factors for type III AACE.

The Effect of Different Treatment Methods on Acute Acquired Concomitant Esotropia

Objective

The application of botulinum toxin type A (BTXA) in the treatment of paralytic strabismus has been recognized, but there are few studies on the treatment of acute acquired comitant esotropia (AACE). This study was aimed to investigate the clinical characteristics of AACE and compare the therapeutic effects of BTXA and traditional surgery.

Methods

78 patients with AACE in Renmin Hospital of Wuhan University between March 2019 and March 2021 were reviewed. The relevant medical records of the patients were collected, and they were divided into surgical group (n = 46) and botulinum toxin type A (BTXA) group (n = 32) according to different treatment approaches. The surgical group was treated with squint correction, whereas the BTXA group was treated with microinjection of BTXA in MR. Eye alignment, esotropia, stereopsis, and complications were examined before and after treatment in both groups.

Results

The refractive status of 78 patients with AACE was mostly myopic refractive error. In general, the angle of esotropia at distance was larger than which at near, with a statistically significant difference. At follow-up assessments of 1 week, 1 month, 3 months, and 6 months after treatment, the total effective rates of the surgical group and the BTXA group were 100% and 90.48%, respectively. The residual angle of esotropia of both groups was lower after treatment. Additionally, the incidence rate of complications in the BTXA group was significantly lower than that in the surgical group.

Conclusion

AACE occurs mostly in people with myopic refractive errors and is associated with prolonged near work. Besides surgical treatment, micro-injection of BTXA is also an effective and safe treatment for AACE.