Accommodative esotropia following surgical treatment of infantile esotropia: frequency and risk factors

Purpose: We aimed to examine the frequency of and risk factors for the development of accommodative esotropia following surgical treatment for infantile esotropia. Methods: A total of 29 children were recruited. Potential risk factors for the development of accommodative esotropia included: sex; angle of deviation at initial and final visits; cycloplegic refractive error at initial and final visits; increase in hyperopia; amblyopia; amblyopia treatment; age at surgical treatment; pre‐ and postoperative latent nystagmus; dissociated vertical deviation or inferior oblique muscle overaction; additional surgical procedures; unstable alignment, and binocular sensory status. Results: Overall, 14 (48.2%) of 29 children developed accommodative esotropia during the 36‐ to 132‐month postoperative follow‐up period. Twelve (85.7%) of the 14 patients developed refractive accommodative esotropia and two developed non‐refractive accommodative esotropia. The onset of accommodative esotropia occurred at a mean of 8.8 months (range 6–24 months) after the initial surgical alignment. This corresponded to a mean age of onset for accommodative esotropia of 43.2 months. We determined that, among children with infantile esotropia, those who had hyperopia of ≥ 3.0 D and increasing hyperopia after surgery and those who did not develop dissociated vertical deviation during the follow‐up period were more likely to develop accommodative esotropia. Conclusions: Children who have the established risk factors should be followed closely for the development of accommodative esotropia. The treatment of these children with appropriate glasses may prevent the development of adverse effects of accommodative esotropia on sensory and motor functions.     

Stereopsis and long-term stability of alignment in esotropia.

PURPOSE: Recent studies of infantile and accommodative esotropia (ET) have focused on stereoacuity as a final outcome measurement for judging the success or failure of treatment. The purpose of the present study was to extend this approach by evaluating whether the presence of stereopsis developing immediately after surgical alignment or optical correction plays a role in maintenance of long-term alignment. METHODS: Random-dot stereoacuity was assessed within 3 months of initial surgical alignment in 70 children with infantile ET and within 3 months of initial optical correction in 66 children with accommodative ET. At > or = 5 years of age, adverse outcomes were assessed including loss of alignment, amblyopia, and nil stereopsis. Risk-factor analysis was used to evaluate whether early nil stereopsis increased the risk for subsequent adverse outcomes. RESULTS: In the infantile ET cohort, early nil stereopsis was associated with a 3.6 times (95% confidence interval [CI] 2.4 to 4.1) greater risk of surgery for recurrent ET or consecutive exotropia and a 4.2 times (95% CI 3.3 to 4.4) greater risk for nil stereopsis at > or = 5 years of age. In the accommodative ET cohort, early nil stereopsis was associated with a 17.4 times (95% CI 3.3 to 32.2) greater risk of surgery for ET and a 32.2 times (95% CI 15.8 to 35.6) greater risk for nil stereopsis at > or = 5 years of age. CONCLUSION: Treatment protocols designed to optimize stereoacuity outcomes promote long-term stability of alignment.     

Risk factors for accommodative esotropia among hypermetropic children

PURPOSE: Identification of risk factors for accommodative esotropia may help to determine which children with hyperopia may benefit from early spectacle correction or preventive therapy. METHODS: Participants in the family history study were 95 consecutive patients, aged 18 to 60 months, with accommodative esotropia. Participants in the binocular sensory function study were a subgroup of 41 children enrolled in the family history study within 1 month of onset, while the esodeviation was still intermittent. Participants in the hypermetropia study were 345 consecutive patients, ages 12 months to 8 years, with refractive error of +2.00 D or greater and no esodeviation before age 12 months. RESULTS: In the family history study, 23% of children with accommodative esotropia had an affected first-degree relative, and 91% had at least one affected relative. In the binocular sensory function study, random-dot stereoacuity was abnormal in 41% of children, whereas an abnormal motion VEP, Worth 4-dot, or positive 4-PD base-out prism responses were present in 4% or less of the children. In the hypermetropia study, patients with a mean spherical equivalent of < +3.00 D and significant anisometropia had a 7.8-fold increased risk for accommodative esotropia over nonanisometropic patients. CONCLUSIONS: A positive family history, subnormal random-dot stereopsis, and hypermetropic anisometropia each pose a significant risk for the development of accommodative esotropia. Assessment of these risk factors in conjunction with refractive screening should help to identify those children who are most likely to benefit from early spectacle correction or preventive treatment.     

儿童部分调节性内斜视的手术矫正与立体视觉

为探讨儿童部分调节性内斜视的手术时机，观察了７８例儿童部分调节性内斜视矫正术后的立体视恢复情况；分析各种因素对其立体视恢复的影响。结果：７８例中，５５例术后获得立体视，功能治愈率为７０．５％，且术后立体视的恢复率与术前相比，差异非常显著（ｐ＜０．０１）；早期手术组及具有融合功能组的立体视的恢复率显著高于较晚手术组及无融合功能组（ｐ＜０．０１）；发病越早，术后建立立体视的预后越差。结论：儿童部分调节性内斜视与部分调节因素有关，其由于解剖因素所引起的斜视需手术矫治。从立体视恢复上考虑，当患儿全矫配镜半年眼位仍不能正位时，应尽早手术矫正其残存的内斜度。术中应根据戴全矫眼镜后的眼位决定手术量。术后由于调节因素所致的内斜视仍需配镜矫正。     

Early surgery for infantile esotropia

AIM: To investigate the postoperative eye alignment and binocular visual function after early surgery for infantile esotropia. METHODS: Both the postoperative eye position and stereopsis were reviewed using the Titmus stereo test in nine patients who received uniocular medial rectus recession and lateral rectus resection under general anaesthesia before 8 months of age and were followed up for a minimum of 4 years. RESULTS: Orthophoria was attained in three cases, whereas esotropia was found in four patients. Dissociated vertical deviation was noted in two other cases at the final examination. Static stereoacuity was achieved in five cases. These results also showed that most infants in whom stereopsis was attained had satisfactory eye alignment during the follow up period and at the final examination. Infants who did not achieve stereopsis still had deviation throughout the follow up period. CONCLUSIONS: It was concluded that early surgery in infantile esotropia is beneficial to achieve binocular visual function, but it is necessary to confirm a stable angle of deviation with accurate preoperative evaluation, and to maintain good postoperative eye alignment throughout the follow up period.     

Why does early surgical alignment improve stereoacuity outcomes in infantile esotropia?

PURPOSE: Recent studies of infantile esotropia suggest that early surgical alignment may enhance stereopsis and that alignment during the first 6 months of life may be optimal. Early surgery both establishes alignment during an early critical period for the development of stereopsis and minimizes the duration of misalignment. Here we examine the role of these 2 factors in promoting improved stereopsis outcomes. METHODS: Participants were 129 consecutive patients enrolled in a prospective study of infantile esotropia who were followed up for a minimum of 5 years. At ages 5 to 9 years, Randot stereopsis was evaluated. RESULTS: Multiple linear regression indicated that duration of misalignment, but not age at alignment or age at onset, was a significant factor in determining random dot stereopsis outcomes. Moreover, patients with stereopsis were less likely to have a loss of horizontal eye alignment requiring surgery than patients without stereopsis (14% versus 32%; z = 1.96, P =.05). Patients with stereopsis were also less likely to have dissociated vertical deviation than patients without stereopsis (25% versus 63%; z = 3.36, P <.001). CONCLUSIONS: The results suggest that early surgical alignment is associated with better stereopsis in those patients with infantile esotropia who were treated during the first 24 months of life, because early surgery minimizes the duration of misalignment, not because alignment is achieved during an early critical period of visual maturation. Random dot stereopsis can also be achieved in patients with alignment provided that the duration of misalignment is not prolonged. Improved outcomes of random dot stereopsis are associated with more stable long-term alignment outcomes.     

Childhood esotropia

PURPOSE: To review the most recent studies on childhood esotropia, and to summarize recent changes in treatment approach. RECENT FINDINGS: Constant, large-angle esotropia present in the first few months of life may be suitable for early surgery. Earlier surgical intervention, within the first several months of onset, is associated with better sensory outcomes. Similar findings are true for accommodative esotropia; children treated within the first 4 months of constant esotropia have better outcomes. Refractive surgery has been used successfully in adult patients to treat accommodative esotropia. SUMMARY: New developments pertaining to infantile esotropia have helped clarify the pathophysiology of the condition and the best treatment approaches. Abnormal binocular visual input early in life contributes to poor outcomes in both infantile and accommodative esotropia.     

Bilateral phakic hypermetropic epikeratoplasty for accommodative esotropia

Optical correction of high hypermetropia with glasses is the primary treatment for accommodative esotropia. These glasses are often poorly accepted by adolescents and young adults for they are cosmetically undesirable, heavy, and esotropia occurs with their removal. We report an 11 1/2-year-old, physically mature female with high hypermetropia and accommodative esotropia corrected to orthophoria with glasses who was unable to be weaned from her glasses. She became intolerant to glasses wear, refused contact lenses, and was treated successfully with bilateral phakic hypermetropic epikeratoplasty. Two years postepikeratoplasty her visual acuity is 20/40 and 20/20 uncorrected and the vision in the amblyopic right eye has remained at its maximum preoperative level. She is orthophoric at distance and has a 2 prism diopter monofixational esophoria at near without glasses. Epikeratoplasty is an option in the treatment of accommodative esotropia for patients who are past the amblyopia forming age, have a stable angle of strabismus, and who require their full hypermetropic optical correction to maintain orthophoria.     

Changes in deviation following correction of hyperopia in children with fully refractive accommodative esotropia

Changes in deviation may occur following the correction of hyperopia in children with accommodative esotropia. We analyzed possible factors involving the development of changes in deviation. We examined 49 children (23 boys and 26 girls) who had fully refractive accommodative esotropia at the age of 3 or 4 years. All children wore glasses to correct the fully cycloplegic refractive errors. At the age of 10 or 11 years, 28 (57.1%) of these children had good alignment, 12 (24.5%) developed partial accommodative esotropia and 9 (18.4%) developed consecutive exotropia. The age at onset of esotropia, age at initial visit, and refraction, deviation and presence of stereopsis, as determined by the Titmus test using a fly at the initial visit, were similar among the three groups. In the consecutive exotropia group, amblyopia at the initial visit was significantly higher (89%) than that of the good alignment group (50%). The age at the start of the correction, and the refraction, amblyopia and presence of fusion (10 or 11 years) were almost equal among the three groups. We conclude that some children with fully refractive accommodative esotropia associated with amblyopia at the age of 3 or 4 years may be predisposed to developing consecutive exotropia.     

Risk factors for abnormal binocular vision after successful alignment of accommodative esotropia.

PURPOSE: The purpose of this study was to identify clinical factors associated with abnormal binocular vision outcomes among children with accommodative esotropia (ET) whose eyes were successfully realigned with spectacles only or with spectacles and surgery. METHODS: The participants were 69 children with accommodative ET who were followed up prospectively from the time of diagnosis. Clinical factors examined in this study included high accommodative convergence-to-accommodation (AC/A) relationship, high hyperopia, anisometropia, age of onset, and duration of eye misalignment. Binocular vision was assessed using measures of stereopsis, fusional vergence, sensory foveal fusion, and motion visual-evoked potential (mVEP). RESULTS: Children with a high AC/A relationship are 2.2 times more likely to have an absence of fusional vergence than are children with a normal AC/A relationship. Children having a duration of constant eye misalignment >/= 4 months before being successfully treated are 4.6 times more likely to have abnormal stereopsis, 33 times more likely to have no stereopsis, 37 times more likely to have an absence of fusional vergence, 31 times more likely to have an absence of sensory foveal fusion, and 17 times more likely to have an asymmetric mVEP response than children with a duration of constant ET diagnosed at 0 to 3 months. CONCLUSIONS: Following successful eye alignment, as many as 75% of patients with accommodative ET had anomalous binocular vision. A high AC/A relationship poses a significant risk for abnormal fusional vergence only. A constant eye misalignment lasting >/= 4 months poses a significant risk for anomalous binocular vision on all measures studied.     

283例手术治疗共同性内斜视临床特点分析

目的探讨共同性内斜视各类型分布、不同类型及手术年龄对双眼单视功能的影响。方法回顾分析手术治疗的共同性内斜视283例,统计各类型内斜视的分布。重点分析婴儿内斜视、非调节性内斜视和部分调节性内斜视三种类型及其手术年龄对双眼单视功能的影响。结果 283例共同性内斜视患者中,婴儿内斜视136例(48.57%)、非调节性内斜视77例(27.21%)、部分调节性内斜视44例(15.55%)、残余性内斜视18例(6.36%)、知觉性内斜视4例(1.41%)、连续性内斜视4例(1.41%)。部分调节性内斜视存在融合功能和远近立体视的比率均高于婴儿内斜视和非调节性内斜视,P<0.05;而婴儿内斜视和非调节性内斜视远近立体视差别不大,P>0.05;<2岁患儿融合及近立体视存在率高于2～9岁和>9岁患儿,P<0.05。结论在手术治疗的共同性内斜视中,婴儿内斜视占首位。部分调节性内斜视对双眼单视功能影响最小。手术年龄小有助于双眼单视功能的改善。     

Update on accommodative esotropia

PURPOSE: The aim of this study was to present an update on accommodative esotropia. METHODS: The diagnosis, clinical features, etiology, treatment, prognosis, and clinical course for the 3 types of accommodative esotropia are presented. RESULTS: Accommodative esotropia is the most common pediatric strabismus and must be differentiated from other pediatric esotropias. Although its average age of onset is 2.5 years, it can begin during the first year of life and is seen rarely in older children and teenagers. Refractive accommodative esotropia and nonrefractive accommodative esotropia have a better prognosis for achieving normal binocular vision and high-grade stereopsis with appropriate and timely treatment than partly accommodative esotropia. Children with successfully treated accommodative esotropia need to be followed up with to prevent possible deterioration and development of a superimposed nonaccommodative esotropia, which in some cases may require extraocular muscle surgery. Emmetropization and spontaneous resolution of the esotropia occur rarely and may take many years. CONCLUSION: Approximately 50% of all pediatric esotropias are either entirely or partly accommodative. Proper care is long term and includes monitoring the refractive error and binocular vision status over the years.     

Early-onset refractive accommodative esotropia.

INTRODUCTION: We studied the natural history of pure refractive accommodative esotropia after spectacle correction in patients with onset before 1 year old to determine whether their outcomes and characteristics were different from those of patients with more typical age at onset of refractive accommodative esotropia. METHODS: We retrospectively reviewed the charts of 17 children with onset of refractive accommodative esotropia before 1 year old. Records of 26 children with onset after 2 years old were reviewed as controls. RESULTS: The mean ages at diagnosis were 9 months and 48 months for the study and control groups, respectively. All 17 study patients and all 26 control patients were initially well aligned with spectacles at distance and near. Follow-up averaged 34 months for study patients and 41 months for control patients. Three study patients (17.6%) and 1 control patient (3.8%) had eventual deterioration and required strabismus surgery (P = .28). None of the study patients developed amblyopia, whereas 42% of control patients did (P = .001). Seven of 15 (47%) of the study patients with known birth history were born prematurely, whereas only 3 of 24 (12%) control patients were born prematurely (P = .03). CONCLUSIONS: Refractive accommodative esotropia was diagnosed at as early as and age 4 months. Prematurity appeared to be a risk factor. Amblyopia was not detected in any patient with early-onset refractive accommodative esotropia. Treatment with full hyperopic spectacle correction led to long-term stable alignment, with relatively few patients requiring surgery.     

Long-term postoperative stability in infantile esotropia

The purpose of this paper is to present the ocular motility status of a group of patients with infantile esotropia who underwent surgery before 2 years of age and were followed for a minimum period of 4 years until discharge from Ophthalmology and Orthoptic review. This retrospective review included 40 children with a diagnosis of infantile esotropia. There were 22 females and 18 males. The children were identified from surgical records between 1987 and 1992. Each child had surgery before the age of 2 years at an average age of 17 months (7 months to 22 months). Many patients (60%) achieved a small-angle (less than 20 prism dioptres), cosmetically acceptable strabismus. Nine patients (22.5%) achieved binocular vision postoperatively, five with microtropia, one with intermittent exotropia and three with bifoveal exophoria. The bifoveal patients did not exhibit high grade stereopsis, which may relate to the time of onset of infantile esotropia when development of cortical stereopsis is critical. Persistent amblyopia postoperatively was significantly associated with a poorer outcome and lack of binocular function.     

Long-term postoperative stability in infantile esotropia

The purpose of this paper is to present the ocular motility status of a group of patients with infantile esotropia who underwent surgery before 2 years of age and were followed for a minimum period of 4 years until discharge from Ophthalmology and Orthoptic review. This retrospective review included 40 children with a diagnosis of infantile esotropia. There were 22 females and 18 males. The children were identified from surgical records between 1987 and 1992. Each child had surgery before the age of 2 years at an average age of 17 months (7 months to 22 months). Many patients (60%) achieved a small-angle (less than 20 prism dioptres), cosmetically acceptable strabismus. Nine patients (22.5%) achieved binocular vision postoperatively, five with microtropia, one with intermittent exotropia and three with bifoveal exophoria. The bifoveal patients did not exhibit high grade stereopsis, which may relate to the time of onset of infantile esotropia when development of cortical stereopsis is critical. Persistent amblyopia postoperatively was significantly associated with a poorer outcome and lack of binocular function.     

Characteristics of early onset esotropia

Some 115 patients with a reported onset of esotropia within the first six months of life were studied retrospectively to assess ocular findings and the evolution of any changes with time. All patients had been treated by one ophthalmologist and one orthoptist since 1972.
Of the 115 patients, 27% had an accommodative element associated with the esotropia. Patients with an accommodative esotropia had higher levels of hypermetropia when compared to the non-accommodative group, but there were no other distinguishing characteristics.
The groups exhibited a large variation in angle size, ranging from four to 45 degrees at the initial visit. The presence of fusion, amblyopia and the degree of hypermetropia had no significant effect on the course of the squint. Amblyopia was noted in 67% of cases and appeared to stabilise at a later-than-expected age, with 66% of patients with ambylopia stabilising between eight and 11 years. Surgical intervention had no effect on the incidence of amblyopia at the initial or final visits.     

Decision analysis with Markov processes supports early surgery for large-angle infantile esotropia

PURPOSE: To assess tradeoffs in time spent with aligned visual axes or stereopsis and risked reoperations between three strategies for the treatment of large-angle infantile esotropia: first surgery at 6, 24, or 48 months of age. DESIGN: Decision analysis. METHODS: We simulated three hypothetic cohorts of children with this condition until their eighth year. Potential achievement of stereopsis, the diagnosis of dissociated vertical divergence or inferior oblique overaction, and various complications were modeled. Probability estimates were obtained from a comprehensive literature review. Analyses aimed to determine the strategy that was associated with longer time spent with aligned eyes and/or stereopsis and fewer reoperations. RESULTS: Eight-year-old children are expected to spend 72.6 vs 58.0 vs 37.8 months with aligned eyes and 26.8 vs 9.0 vs 1.5 months with stereopsis and to receive on average 1.76 vs 1.67 vs 1.46 surgeries, if they first underwent operation at 6 vs 24 vs 48 months, respectively. Children at 8 years are expected to have stereopsis at the rate of 36.1% vs 17.2% vs 5.1%, respectively. Operation at 6 months instead of 48 months is expected to yield an additional 9% of total follow-up time in health states with eye alignment and 11% in health states with stereopsis, per 5% increase in risk for extra operations (5% and 7%, respectively, per 5% increase in risk for operation at 6 vs 24 months). Wide-range sensitivity analyses and long-term projections point to the same direction. CONCLUSION: Given the benefit/risk tradeoffs, it is probably warranted to attempt to correct large-angle infantile esotropia as early as possible.     

The critical period for susceptibility of human stereopsis

PURPOSE: To define the critical period for susceptibility of human stereopsis to an anomalous binocular visual experience. METHODS: Random dot stereoacuity was measured in 152 children with a history of onset of either infantile or accommodative strabismus before 5 years of age. In each of these populations and in the combined population, the critical periods for susceptibility of stereopsis are described using four-parameter developmental weighting functions. RESULTS: In children with infantile strabismus, the critical period for susceptibility of stereopsis begins at 2.4 months and peaks at 4.3 months. In children with accommodative esotropia, the critical period for susceptibility of stereopsis begins at 10.8 months and peaks at 20 months. When the data are combined across the two populations, the critical period begins soon after birth and peaks sharply at 3.5 months but shows continued susceptibility to at least 4.6 years. CONCLUSIONS: An anomalous binocular visual experience during early infancy severely disrupts stereopsis, yet the critical period for susceptibility of stereopsis extends through late infancy and early childhood and continues to at least 4.6 years of age.     

Management of infantile esotropia

The population of patients with infantile esotropia is etiologically and neuroanatomically heterogeneous, and major advances in management will probably require more accurate subgroup delineation. Amblyopia is relatively common in patients with infantile esotropia. It should always be suspected and, when found, should be vigorously treated. Present methods of amblyopia detection and evaluation in young children are still imperfect. Most clinical evidence suggests rather strongly that sensory and motor functions are more nearly normal if alignment (within 10 prism diopters of orthotropia) is attained within the first 2 years of life. Whether alignment obtained within the first year of life provides higher grades of binocular vision is less certain. Virtually all patients with infantile esotropia fail to develop normal binocular vision. Central scotomas are almost always identifiable, even in patients with optimal motor alignment and with the highest levels of binocular vision. Past surgical protocols have tended to produce an excess of under-corrections. More recent surgical protocols are more generous in terms of millimeters of surgery per prism diopter of deviation. Higher cure rates are now being reported. Patients who are successfully aligned early in life still need careful postoperative monitoring for amblyopia, nystagmus, inferior oblique overactions, dissociated vertical divergence, and accommodative esotropia. These patients require frequent follow-up visits until they reach the age of approximately 9 years.     

Comparison of clinical characteristics of familial and sporadic acquired accommodative esotropia.

PURPOSE: To compare the clinical characteristics of patients with familial and nonfamilial acquired accommodative esotropia. METHODS: We recruited 48 patients from 33 families with acquired accommodative esotropia (an inward deviation of the eyes of 10 PD or more, a hypermetropia greater than or equal to +1.50 D, and an onset of esotropia at, or later than, 1 year of age). Our control group consisted of 20 patients with no known family history. Spherical error of refraction, stereoacuity, and need for strabismus surgery were determined and the 2 groups were compared. RESULTS: No statistically significant difference was found between the spherical equivalent error of refraction in familial cases (mean = +4.50 OD, +4.63 OS; range = +1.50 to +10.30 OD, +2.00 to +9.38 OS) versus those with nonfamilial disease (mean = +4.93 OD, +5.02 OS; range = +2.50 to +11.00 OD, +2.50 to +10.90 OS) (P =.47 OD; P =.47 OS). There also was no difference between the percentage of patients with familial disease who had some degree of stereoacuity (58%) and those without a family history (59%) (P > .99). Patients with familial acquired accommodative esotropia did not require more surgical interventions (26%) than those with nonfamilial acquired accommodative esotropia (30%) (P = .79). CONCLUSIONS: The general clinical characteristics of familial and nonfamilial acquired accommodative esotropia are very similar.