Essential Infantile Esotropia Research Articles

Alteration of Neurotrophic Factors and Innervation in Extraocular Muscles of Individuals With Concomitant Esotropia.

To determine whether neurotrophic factors and innervation in extraocular muscles (EOMs) were altered in different types of concomitant esotropia, and to explore the possible association between neurotrophic factors and innervation of EOMs in humans. Patients with concomitant esotropia who required strabismus surgery were recruited from January to December 2022. Lateral rectus EOMs were obtained from patients, and controls were obtained from deceased organ donors. Immunofluorescence (IF) was performed to detect innervation of EOMs (neurofilament and synaptophysin), and immunohistochemistry (IHC) was used to detect the neurotrophic factors insulin-like growth factor-1 (IGF-1), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and neurotrophin-3 (NT-3). The positive IHC results were further verified using western blotting (WB). One-way ANOVA followed by a Dunnett's multiple comparison post hoc test was used for continuous variables and the χ2 test for categorical variables. Spearman correlation analysis was used for the correlation analysis. We collected lateral rectus EOM samples from acute and chronic types of concomitant esotropia and controls. Consistent with IHC, WB showed that IGF-1 was significantly increased in patients with acute acquired comitant esotropia or essential infantile esotropia compared with controls. In IF, synaptophysins were significantly increased only in acute acquired comitant esotropia compared with controls. Furthermore, Spearman correlation analysis showed that the correlation between IGF-1 and synaptophysin was borderline (P = 0.057) for patients with acute acquired comitant esotropia. Our study highlights the role of IGF-1 and altered innervation of EOMs in acute acquired comitant esotropia, suggesting that an effect of increased IGF-1 on nerve innervation may temporarily cause a compensatory increase in the strength of lateral rectus muscles.

Эссенциальная младенческая эзотропия

Relevance. Essential infantile esotropia (EIE) is the most common type of childhood strabismus. The incidence of EIE varies on average from 0.1 to 1.0% in the general population of children, which is significant for timely diagnosis and provision of appropriate assistance to this category of patients. The exact etiology of infantile essential esotropia remains unknown, but historically a number of conflicting theories have been proposed. Purpose. To summarize the accumulated experience in the field of studying EIE to determine the optimal path to achieving the main goal of treatment – achieving orthoposition with the subsequent formation of binocular vision in this category of patients. Material and methods. To complete the review, a search of literature sources was carried out in the PubMed and Scopus abstract databases for the period up to 2022 inclusive. A total of 32 articles relevant to the review topic were selected and analyzed. Results. Having analyzed the literature data, we can conclude that today there is no unified classification of infant essential esotropia, but a certain symptom complex of clinical manifestations has been identified that are pathognomonic for this type of strabismus. Usually, EIE manifests in the first 6 months of life, appears a large horizontal esodeviation, may be accompanied by latent nystagmus, compensatory head rotation, and cross-fixation syndrome. This type of strabismus occurs in infants with normal age-related refraction and normal neurological status. The clinical approach to tactics and methods of treatment of infantile esotropia varies widely in the strabismus world. There are conflicting opinions regarding the following issues: the optimal timing for the operation, the most effective type of operation, and what determines the favorable outcome of the treatment of essential congenital esotropia. Conclusion. Many aspects of EIE remain controversial and poorly defined. To optimally realize the main goal of EIE treatment – achieving orthoposition with the subsequent formation of binocular vision – is a feasible task, which will soon find a solution. Key words: essential infantile esotropia, latent nystagmus, cross fixation syndrome, binocular vision

Изменение угла косоглазия у пациентов с эссенциальной младенческой эзотропией в условиях общей анестезии и его влияние на выбор оптимального хирургического протокола

Purpose. To evaluate the dynamics of esodeviation in patients with essential infantile esotropia in the awake state and under general anesthesia in order to determine the optimal surgical protocol. Material and methods. A study was made of changes in the angle of strabismus and traction test in 15 patients aged 4 to 18 months under physiological conditions and under general anesthesia. Results. Four patients were diagnosed with orthotropia, a negative traction test, so the actual dose of the drug was reduced. In three patients with cross-fixation syndrome, the magnitude of esotropia in anesthesia decreased, a positive traction test was recorded, and they required the maximum dose of Botox. In the remaining patients, the magnitude of esodeviation ranged from 3 to 8°, the traction test was negative, the planned dose of the drug did not require correction. Conclusions. The dynamics of the strabismus angle under general anesthesia in patients with essential infantile esotropia is a fundamental factor determining the choice of the optimal dosage of Botox for chemodenervation of m. rectus medialis. Keywords: essential infantile esotropia, cross-fixation syndrome, chemodenervation, general anesthesia, esodeviation

Timing of surgery in essential infantile esotropia - What more do we know since the turn of the century?

This review summarizes the results and interpretations of studies pertaining to the long-standing debate regarding the timing of surgery in infantile esotropia, more recently referred to as essential infantile esotropia. A systematic search of studies from the year 2000 onward pertaining to the timing of surgery in infantile esotropia as listed in PubMed, Google Scholar, and the Cochrane database was performed. Appropriate cross-references from the articles were also included. Data collected included demographics, presentation, time of surgery, complications, and outcomes. Very early surgery, that is, within 6 months of the onset of infantile esotropia, offers significant advantages in terms of the quality of stereopsis and binocular vision as well as promoting the development of cortical visual processing, thereby benefiting cortical development in human infants. However, the postoperative alignment was not found to be significantly different in the very early, early, or late surgery groups. The reduction in the incidence of manifest dissociated vertical deviation postoperatively in the very early surgery group also showed measurable benefits. The results of this recent literature review demonstrated that very early surgery, within 6 months of misalignment, showed demonstrable benefits in essential infantile esotropia.

Essential Infantile Esotropia: A Course of Treatment From Our Experience.

Background: Essential infantile esotropia (EIE) is the most common type of childhood esotropia. Although its classical approach is surgical, less invasive techniques have been proposed as an adjunct or alternative to traditional surgery. Among them, chemodenervation with botulinum toxin (BT) has been investigated, showing variable and sometimes conflicting results.Objectives: To compare the outcomes of bilateral BT injection and traditional surgery in a pediatric population with EIE in order to optimize and standardize the therapeutic approach. Other purposes are to evaluate whether early intervention may prevent the onset of vertical ocular deviation (which is part of the clinical picture of EIE) and/or influence the development of fine stereopsis, and also to assess changes in refractive status over time among the enrolled population.Methods: A retrospective consecutive cohort study was conducted in 86 children aged 0–48 months who underwent correction of EIE. The primary intervention in naïve subjects was either bilateral BT injection (36 subjects, “BT group”) or strabismus surgery (50 subjects, “surgery group”).Results: Overall, BT chemodenervation (one or two injections) was effective in 13 (36.1%) subjects. With regard to residual deviation angle, the outcomes at least 5 years after the last intervention were overlapping in children receiving initial treatment with either injection or surgery; however, the success rate of primary intervention in the surgery group was higher, and the average number of interventions necessary to achieve orthotropia was smaller. Both early treatment with chemodenervation and surgery at a later age were not found to prevent the onset of vertical ocular deviation, whereas, surprisingly, the percentage of subjects developing fine stereopsis was higher in the surgery group. Finally, with regard to the change in refractive status over time, most of the subjects increased their initial hyperopia, whereas 10% became myopic.Conclusions: Our data suggest that a single bilateral BT injection by age 2 years should be considered as the first-line treatment of EIE without vertical component; whereas, traditional surgery should be considered as the first-line treatment for all other cases and in subjects unresponsive to primary single BT injection.

Botulinum neurotoxin injections in essential infantile esotropia-a comparative study with surgery in large-angle deviations.

To compare botulinum neurotoxin (BNT) injections to surgery as first-line therapy in large-angle essential infantile esotropia (IE). Children between the ages 6 months and 6 years with IE of ≥40 prism dioptres (PD) were randomised to either a maximum of three BNT injections or surgical intervention of bimedial rectus muscle recession for angles ≤60 PD and augmented with BNT injection in angles >60 PD. Time taken for each procedure was documented. Orthophoria or misalignment of ≤10 PD was regarded as a complete response (CR). Follow-up visits were done at 3, 6, 12 and 24 weeks. Mean (SD) age and baseline angle of esotropia were 26.9 (14.5) months and 61.9 PD (12.8), respectively, for the overall cohort. The proportion of children who achieved CR was significantly higher in the surgery arm compared to the BNT injection arm (OR = 4.01, 95% CI 1.74-9.22) but the time taken was six times longer (p < 0.0001). In the BNT arm, 55.2% of children aged ≤24 months and 16% of children >24 months achieved CR. In children with esotropia ≤60 PD, CR was achieved in 50% while those with esotropia >60 PD CR was achieved in 25%. Surgery remains the gold standard for treatment of esotropia but BNT injection is a safe and effective alternative in children ≤24 m and with smaller angles of esotropia ≤60 PD in resource-limited centres.

Supramaximal recession of medial recti for correction of infantile esotropia of more than 50 prism diopters

Background Essential infantile esotropia is a manifest constant esodeviation that occurs during the first 6 months of life. It is characterized by a large angle of deviation of more than 40 prism diopters (PD) with alternation of fixation in the primary position and cross-fixation in side gazes. Hence, early intervention is highly recommended to avoid irreversible loss of the ability to attain single binocular vision and normal depth of perception. Aim This study aimed to report the results that we obtained after the supramaximal recession of medial recti in cases with large-angle infantile esotropia of more than 50 PD. Patients and methods In this prospective study, 7-mm bimedial recession was performed on 30 patients (1–5 years) for treatment of large-angle infantile esotropia with a follow-up period of about 6 months postoperatively. Surgical success could be defined as undercorrection within 10 PD. Results The mean of the preoperative angle of deviations was 40±7.8 PD (80 PD). The mean age at the time of surgery was of 1.9±0.9 years. The successful horizontal alignment was achieved in 24 (80%) patients. Six (20%) patients were undercorrected more than 10 PD. Conclusion A large-angle recession of bimedial recti is an effective and safe surgical treatment of large-angle infantile esotropia that does not significantly affect adduction and sparing other muscles for any necessary further surgical intervention. That procedure can be an alternative to three or four horizontal muscle surgeries in the treatment of large-angle infantile esotropia. There was not any adduction or convergence limitation of clinical significance postoperatively. Also, there were not any significant cases of consecutive exotropia, but a prolonged follow-up period is needed to detect any delayed appearance.

Is infantile esotropia subcortical in origin?

Essential infantile esotropia (EIE) is often attributed to a primary disturbance within the visual cortex based upon the findings of monocular horizontal optokinetic asymmetry and correlative horizontal motion detection asymmetry. However, these physiologic aberrations conform to what would be observed if the visual cortex secondarily reconfigured itself to the preexisting subcortical optokinetic motion template. This analysis examines the perspective that the measured cortical aberrations can be explained by prolonged subcortical neuroplasticity, leading to a secondary rewiring of cortical motion pathways. Evolutionary evidence indicates that EIE is generated by subcortical ocular motor centers that subserve nasalward optokinesis. These phylogenetically older subcortical visuo-vestibular pathways include the nucleus of the optic tract, accessory optic system, inferior olive, cerebellar flocculus, and vestibular nucleus. In normal humans, the subcortical visual system becomes inactivated after the first few months of infancy. Mutations or other perturbations that prolong subcortical neuroplasticity may create a persistent simultaneous nasalward optokinetic bias in both eyes to generate infantile esotropia.

Comparative Study of Y-Split Recession versus Faden Technique for Management of Infantile Esotropia in Egyptians.

Purpose This study compares the results of Y-split recession versus de Decker's (modified Cüppers) Faden techniques of medial rectus (MR) muscles for the management of essential infantile esotropia (IET). Patients and Methods Fifty patients had IET divided into Group A who underwent Y-split recession of MR muscles and Group B who underwent de Decker's Faden technique of MR muscles. All patients had complete ophthalmic examination done including deviation angle measurement and met the inclusion criteria of the study. Operations were performed using general anesthesia. Patients were followed up at day 1, week 1, and months 1, 3, and 6 after operation. Results The mean age distribution for group A was 21.56 months (SD 12.55) and for group B was 21.4 months (SD 12.35), and the mean postoperative follow-up interval was 6 months for both groups. The preoperative maximum angle of deviation in both groups ranged from 15 to 40 degrees, while the minimum angle of deviation ranged from 10 to 20 degrees. Immediately postoperatively both groups showed 88% of patients with satisfactory results (within 10 degrees of orthotropia). Group A showed two patients (8%) with ET and one patient (4%) with exotropia (XT). For group B, it showed one patient (4%) with ET and two patients (8%) with XT. Three patients in each group underwent a second intervention. All patients remained within the satisfactory range. Conclusion The results of this study suggest that both techniques show comparable results for the correction of IET.

Essential Infantile Esotropia: Potential Pathogenetic Role of Extended Subcortical Neuroplasticity.

Essential infantile esotropia is generated by prenuclear visual pathways that increase esotonus and gradually drive the eyes into a convergent position. Contrary to the prevailing notion that infantile esotropia reflects a primary disturbance within the visual cortex, accumulating evidence suggests that infantile esotropia is generated by lower subcortical centers that subserve nasalward optokinesis. These phylogenetically older visuo-vestibular pathways include the nucleus of the optic tract, accessory optic system, inferior olive, cerebellar flocculus, and vestibular nucleus. In humans, the subcortical visual system is normally turned off after the first few months of infancy but retains its function in children who develop infantile esotropia. Mutations or other perturbations that prolong subcortical neuroplasticity may therefore lead to a persistent simultaneous nasalward optokinetic imbalance in both eyes to generate infantile esotropia. Deficits in cortical motion processing and monocular nasotemporal asymmetry to foveated optokinetic targets are likely the effect, rather than the cause, of infantile esotropia.

Time and Factors Affecting the Direction of Re-drift in Essential Infantile Esotropia.

To investigate the development pattern and related factors of postoperative re-drift in infantile esotropia. A total of 112 patients with infantile esotropia who underwent surgery before 3 years of age were included. Surgical outcomes were divided into (1) consecutive exotropia: more than 8 prism diopters (PD) of exodeviation; (2) recurrent esotropia: more than 8 PD of esodeviation; and (3) monofixation syndrome: maintenance of deviations within 8 PD. The occurrence rate, time of onset, and associated factors of the re-drift were evaluated. At a mean follow-up of 9.5 years, consecutive exotropia developed in 37 patients (33.0%) and recurrent esotropia in 43 patients (38.4%). Whereas 76.7% of total recurrent esotropia cases were identified within postoperative 1 year, consecutive exotropia occurred constantly over 10 years postoperatively. The mean time to consecutive exotropia development from surgery was 78.6 months, greater than that of recurrent esotropia development (8.9 months) (P < 0.001). In multinomial logistic regression using monofixation syndrome as the reference category, fixation preference before surgery (odds ratio [OR]: 6.64, 95% confidence interval [CI]: 2.07 to 21.32) and the rate of myopic progression (OR: 15.07 per -1.00 D/year, 95% CI: 1.23 to 184.86) were associated with consecutive exotropia, whereas increase in the angle of esodeviation on postoperative day 1 (OR: 1.15, 95% CI: 1.04 to 1.26) was correlated with recurrent esotropia. This study demonstrates a difference between the development pattern of exotropic and esotropic drift after infantile esotropia surgery. Detailed preoperative assessment and close postoperative observation of deviations and refractive status will help to determine surgical outcomes of infantile esotropia. [J Pediatr Ophthalmol Strabismus. 2018;55(2):128-134.].

Essential infantile esotropia with inferior oblique hyperfunction: long term follow-up of 6 muscles approach.

To evaluate long term follow-up (10y) of 6 muscle surgical approach in essential infantile esotropia (EIE). A 6 muscle approach to EIE was retrospectively evaluated in patients with inferior oblique (IO) hyperfunction and lateral rectus (LR) pseudoparalysis, who underwent surgery at different ages. Different clinical characters were analyzed pre- and postoperatively, in patients who underwent a 6 muscles approach ≤4 years of age. All patients underwent a multiple muscles approach: bilateral medial recti (MR) recession (4-5 mm), bilateral LR resection (lower than 7 mm) and bilateral IO recession and anteroposition. Of 108 children with preoperative angle ≥+30 prism diopters (PD) and IO hyperfunction were selected from larger cohort of patients (n=213, 103 females and 110 males) after excluding patients with: angle variability, who underwent reoperation and with incomplete follow up. Preoperative assessment and complete orthoptic examination were performed. Follow-up was performed 3mo, 2, 5 and 10y after surgery. Statistical analysis was performes using SAS statistical software package (version 9.1, SAS Institute Inc., Cary, NC, USA). Ten years follow up data analysis showed the following percentage of orthotropic patients: (0 PD): 3mo, 22.2%; 2y, 16.7%; 5y, 25.0% and 10y, 27.8%. A slight, significant (P<0.01), increase of 2y follow up residual deviation was found when compared to 3mo one. Stationary surgical results is reported during time, with a trend of mean residual deviation reduction (P=0.04). Our results confirm the reliability of multiple muscles surgical approach in the treatment of patients affected by EIE with OI hyperfunction.

An Optokinetic Clue to the Pathogenesis of Crossed Fixation in Infantile Esotropia

This report demonstrates that patients with essential infantile esotropia (EIE) and crossed fixation tend to switch fixation to the eye receiving nasalward optokinetic input, suggesting that monocular nasotemporal optokinetic asymmetry (MNTA) could underlie the phenomenon of crossed fixation. As MNTA derives from the nasal retina, EIE can be conceptualized as a condition wherein the nasal retinas are repositioned to lie within the frontal plane, thereby permitting bidirectional horizontal motion detection (nasalward for each fixing eye). This explanation should not imply that EIE is generated for the purpose of restoring horizontal motion bidirectionality, but that the preexisting nasalward deviation of both eyes can be exapted under binocular conditions to promote this critical function. This mechanism dovetails with the subcortical hypothesis in the following chapter to suggest that a dynamic (optokinetic) imbalance could underlie a static deviation (essential infantile esotropia).

Essential Infantile Esotropia: Postoperative Sensory Outcomes of Strabismus Surgery

ABSTRACTBackground: The optimum age for Essential Infantile Esotropia surgery is a controversial subject. Sensory status was evaluated in patients who underwent surgery at different ages in a retrospective study. The setting of the study is the ophthalmology department of a teaching hospital. Methods: Different clinical characters were analyzed pre- and postoperatively; nine different surgeries were performed. A total of 188 patients presented valid postoperative sensorial data, divided in two groups: surgery at ≤2 years (n=69) or >2 years (n=119). Sensory status was dichotomized in binocular single vision (BSV) and exclusion. Univariate differences were assessed with the chi-square test (or Fisher exact test). To identify the independent role of factors associated with the sensory status, all variables showing in univariate analyses a significant association (p<0.05) with the outcome variable were entered into a multivariate logistic regression model. All statistical tests were two-sided. Results: Multivariate analysis confirmed that children operated >2 years were 0.4 times less likely to obtain BSV compared with children operated at ≤2 years (AOR. 0.38, 95% C.I. 0.17–0.89, p=0.025). Patients operated on by OO MR rec.+ OO LR res. + OO IO rec.-ap. (intervention type 6) were about 11 times more likely to have BSV than those by OO rec.MR + unilateral res. LR (operation type 2); AOR.: 10.67, 95% C.I.: 1.34 – 85.29, p=0.026). Twenty-nine patients (12.1%) operated at ≤2 years of age underwent a reoperation, compared to 33 (8.6%) who underwent surgery after two years (p>0.05). Conclusions: Our findings suggest to perform EIE surgery between age 1 and 2 and, when indicated, to prefer a six-muscle approach in order to achieve a better sensory function.

Essential infantile esotropia: postoperative motor outcomes and inferential analysis of strabismus surgery

BackgroundThe aim of this retrospective study is a long-term evaluation of postoperative motor outcomes and the inferential analysis of strabismus surgery in infant eyes with essential infantile esotropia.Methods576 patients were compatible with the criteria: confirmed EIE diagnosis, angle ≥ 30 pD, absence of associated ocular anomalies, onset by 6 months of age, absence of hyperopia > 3 Diopters, operation before age 4. Preoperative deviation classes (30–40 pD, 41–59 pD, ≥ 60 pD) were established, different types of surgery were performed. Follow-up was conducted for 5 years after surgery. Longitudinal data were analyzed using general linear mixed models stratified according to the class of pre-operative deviation. A random intercept and a random slope with time (in months) was assumed with an unstructured within subject correlation structure for repeated measurements.ResultsIn patients with preoperative angle ≤ 40 pD, a significant interaction effect for intervention by time (F5,155.9 = 3.56, p = 0.004) and a significant intervention effect (F5,226.1 = 6.41, p < 0.001) on residual deviation were observed; only the intervention 5 showed a residual deviation inside the limits of a partial success. In Class 41-59, a significant interaction effect for intervention by time (F4,166.7 = 5.16, p = 0.001), intervention (F4,178.1 = 2.48, p = 0.046) and time (F1,174.6 = 9.99, p = 0.002) on residual deviation were observed; intervention 7 had the highest degree of stability showing an outcome within the range of a partial success. In Class ≥ 60 pD no significant effect for intervention (F4,213.9 = 0.74, p = 0.567), time (F1,169.5 = 0.33, p = 0.569) or intervention by time (F4,160.9 = 1.08, p = 0.368) on residual deviation was observed; intervention 3,6 and 7 resulted in a residual deviation within the range of a partial success.ConclusionsWe suggest, where possible, a two-horizontal muscles approach in small angle EIE, while a multiple muscles surgery in large angle EIE.

Anomalous head posturing in essential infantile esotropia: a hypothesis

1This editorial presents our understanding of why a child with infantile esotropia syndrome may manifest a visually directed anomalous head posture (AHP). Many aspects of essential infantile esotropia (EIE) or infantile esotropia syn-drome remain controversial and ill-defined (1). The recent National Eye Institute, National Institutes of Health, USA–sponsored Classification of Eye Movement Abnormalities and Strabismus (CEMAS) workshop and document has at-tempted to consolidate its definition (2). Table I presents the CEMAS description of EIE.Torticollis in childhood is most commonly the result of ab-normalities of the central nervous system, the ocular motor system, or the neck musculature. Head posturing associ-ated with abnormalities of the ocular motor system is usu-ally compensatory. The visual purpose of head posturing serves to enhance bifoveal fixation, singular binocular vi-sion, or visual acuity. The ocular etiologies of anomalous head posture include strabismus, nystagmus, refractive errors, dissociated ocular deviations, and visual pathway obstruction (e.g., lid, corneal, lens, and vitreous anoma-lies). Although clinical differentiation of these disorders is accurately accomplished after a thorough history and ophthalmic examination, the etiology of anomalous head posture is often elusive in patients with a combination of strabismus and nystagmus. Children with nystagmus will have anomalous head posture due to multiple causes. A “gaze null” is a position of one or both eyes with respect to the orbit where the nystagmus intensity is the least and vision is the best and is usually associated with infantile nystagmus syndrome or more rarely, forms of acquired nystagmus with an eccentric gaze null position, e.g., gaze evoked, upbeat, and downbeat nystagmus. An “adduction null” is a position of a preferred eye in adduction charac-

Why do the eyes cross? A review and discussion of the nature and origin of essential infantile esotropia, microstrabismus, accommodative esotropia, and acute comitant esotropia

To try to explain the long-term stability of bilateral medial rectus botulinum toxin (botox) chemo-denervation in essential infantile esotropia; to evaluate divergent fusion amplitude in accommodative esotropia and acute comitant esotropia of emmetropes; to look for accommodation anomalies in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes; and to discuss characteristics of microstrabismus. Retrospective analysis of 61 essential infantile esotropia patients with early treatment with one botox injection in both medial rectus; measurement of divergent fusion amplitude in accommodative esotropia and acute comitant esotropia; measurement of Near point of accommodation in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes. Stable results were found in 85.24% of essential infantile esotropia treated patients; reduced divergent fusion amplitude was detected in accommodative esotropia and acute comitant esotropia; hypo-accommodation was found in some patients with high AC/A ratio accommodative esotropia and a convergence spasm in acute comitant esotropia of myopes. Very early botox treatment probably eradicates the effect of an excessive convergence tonus in essential infantile esotropia. A prevention of accommodative esotropia with full retinoscopic correction is only mandatory with a significantly reduced amplitude of fusional divergence. A deficit in accommodation should be looked for in high AC/A ratio accommodative esotropia, before bifocal lenses prescription. Early diagnosed acute comitant esotropia of myopic patients can be treated as a convergence spasm. Only surgery treats acute comitant esotropia, in patients with emmetropia or moderate hypermetropia.

Botulinum toxin injection without electromyographic assistance.

To ascertain whether electromyographic control of the muscles when injecting botulinum toxin in the medial rectus muscles of children under sedation is necessary to obtain good results in terms of ocular alignment and postoperative complications. Forty neurologically normal children 6 to 48 months of age were entered consecutively into the study once the initial diagnosis of essential infantile esotropia had been made. The children were sedated with sevoflurane and both medial rectus muscles were injected with 7 IU of botulinum toxin using an insulin syringe with a 27-gauge needle. Postoperative controls were performed at 3 days, 3 weeks, 3 months, and 6 months after the injection. The effectiveness of the injection was noted in terms of tropia, paralysis, and associated complications. The mean tropia at 6 months postoperatively was 8.47 prism diopters of esotropia, ranging from 25 prism diopters of esotropia to 10 prism diopters of exotropia. Fifty-three percent of the patients had an esotropia between 0 and 10 prism diopters. The most common complications were ptosis and vertical deviation, affecting 23% and 21% of the patients, respectively, followed by conjunctival hemorrhage, which was recorded in 7% of the patients. There were no retrobulbar hemorrhages, ocular perforations, or anesthetic complications. If anesthetic risks are higher and the results are similar when using electromyographic control, we advocate not using it in congenital esotropia when injecting botulinum toxin in children.

Critical Age of Botulinum Toxin Treatment in Essential Infantile Esotropia

To assess the results of botulinum toxin treatment in 60 consecutive children with essential infantile esotropia. Bilateral simultaneous injection of botulinum toxin into the medial rectus muscle was performed in 60 patients under direct visualization with an "open sky" technique. Fluothane/sevoflurane insufflation anesthesia was used. Each patient underwent a single bilateral botulinum toxin injection. Patient age at the time of injection ranged from 5-8 months. Mean patient age at the time of treatment for the 88% of patients who gained a good alignment (within +10 prism diopters [delta] of residual esotropia) was 6.5 months, while mean patient age at time of injection for the 12% of patients who were undercorrected or the deviation relapsed was 7.8 months. Follow-up averaged 5.2 years (range: 2-9 years, SD 2). No variation of the angle of strabismus was observed after 6 months from injection. In some patients with hyperopic refraction, plus lens corrections were prescribed during follow-up to stabilize the alignment. Botulinum toxin can be effective in essential infantile esotropia when children are treated by age 7 months.

Management of essential infantile esotropia with botulinum toxin A: review and recommendations.

Management of essential infantile esotropia with botulinum toxin A: review and recommendations.