Risk factors for the development of accommodative esotropia following treatment for infantile esotropia.

PURPOSE: One aim of the study was to determine whether accommodative esotropia after surgical alignment in infantile esotropia occurs because a pre-existing accommodative component is unmasked at the time of surgery or whether it occurs as a sequela of infantile esotropia. A second aim of the present study was to examine risk factors for accommodative esotropia after surgery for infantile esotropia. METHODS: A total of 80 consecutive patients who were enrolled in a prospective study of infantile esotropia had been followed for more than 4 years and had achieved orthoposition were included. Twelve potential risk factors were examined: age at onset, initial esodeviation, initial refractive error, age at alignment, delay in alignment, presurgical glasses, amblyopia, additional surgical procedures, unstable alignment, increase in hypermetropia, peripheral fusion, and stereopsis. Mantel-Haenszel odds ratios were computed for each factor and were corrected to relative risks. RESULTS: Overall, 48 of 80 children (60%) developed accommodative esotropia at a mean age of 33 months. Increasing hypermetropia, delay in alignment, and poor stereopsis posed significant risks for accommodative esotropia. The remaining 9 factors were not associated with increased risk for accommodative esotropia. CONCLUSIONS: Accommodative esotropia is unlikely to be a pre-existing condition in most cases because the mean age of onset was 23 months postoperative and the prevalence of preoperative hypermetropia greater than +3.00 D was low. Both delay in alignment and stereopsis risk factors may reflect compromised binocular sensory status that allows accommodative esotropia to occur at low to moderate levels of hypermetropia. Identification of children treated for infantile esotropia who are at risk for accommodative esotropia may allow for prevention or early treatment.     

Factors influencing stereoacuity in accommodative esotropia.

PURPOSE: Despite successful optical realignment, many children with accommodative esotropia (ET) have abnormal stereoacuity. In a prospective study, we examined the influence of age of onset, age at alignment, duration of constant misalignment, and accommodative convergence/accommodation ratio on random dot stereoacuity outcomes in accommodative ET. METHODS: Participants were 111 consecutive children with accommodative ET. Random dot stereoacuity was measured using the Randot preschool stereoacuity test, the Randot stereoacuity test, the infant random dot stereoacuity cards, and the Lang 1. RESULTS: Age of onset has only a minor influence on stereoacuity (P <.02); children with onset >/=age 25 months have better stereoacuity compared with children with an onset between ages 7 and 17 months. Age at alignment has a minor influence on stereoacuity (P <.001); children with intermittent ET who have been treated have better stereoacuity than children with a constant ET aligned between ages 6 and 24 months and after age 24 months. Duration of constant misalignment has the strongest influence on stereoacuity (P <.001); children who had intermittent misalignment or who had a constant misalignment of less than 4 months' duration have better stereoacuity than patients who had a constant misalignment greater than 4 months' duration. The accommodative convergence/accommodation ratio does not influence stereoacuity outcomes (P >.10). CONCLUSIONS: Fine random dot stereoacuity is associated with a constant misalignment of less than 4 months' duration. These findings promote prompt and aggressive treatment of accommodative ET at the onset of intermittent or constant misalignment.     

Motion VEPs, stereopsis, and bifoveal fusion in children with strabismus

PURPOSE: The link between nasal-temporal motion asymmetries and anomalous binocular sensory function in infantile esotropia (ET) has led to the idea that visual evoked potential responses to horizontal motion (mVE) is an alternative measure of sensory binocularity to stereopsis. A second hypothesis is that the mVEP response is a marker for bifoveal fusion. The purpose of this study was to directly evaluate these two hypotheses by examining the correspondence between the mVEP response and both stereoacuity and bifoveal fusion in a cohort of strabismic patients with variable binocular sensory function. METHODS: Motion VEPs, random dot stereopsis, and bifoveal fusion were measured in 94 children: 20 with infantile ET, 16 with infantile accommodative ET, 22 with late-onset accommodative ET, 10 with intermittent infantile strabismus, and 26 normal control participants. RESULTS: Patients with infantile ET and infantile accommodative ET had high concordance between mVEP responses and stereoacuity and mVEP responses and bifoveal fusion. Asymmetric mVEP responses were highly concordant with both no measurable stereopsis and an absence of fusional vergence. Patients with late-onset accommodative ET and intermittent infantile strabismus revealed discordance between the mVEP response and stereoacuity and high concordance between the mVEP response and bifoveal fusion. Asymmetric mVEP responses were highly concordant with the absence of bifoveal fusion and the minimum-size prism to elicit fusional vergence. CONCLUSIONS: The qualitative and quantitative relationship between the mVEP response and fusional vergence suggests that the mVEP response is an objective measure of bifoveal fusion. The availability of such a test will facilitate studies of normal development of bifoveal fusion and development of monofixation syndrome in strabismus.     

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.     

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.     

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.     

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.     

Long-term motor and sensory outcomes after early surgery for infantile esotropia.

PURPOSE: The proper timing of surgery for infantile esotropia remains controversial. Early surgery may yield better sensory outcomes whereas later surgery may result in better alignment. Several recent studies reported promising sensory outcomes in small groups of children that underwent surgery by 6 months of age. Here, we present motor and sensory outcomes of a cohort of 50 consecutive children enrolled in a prospective study who had surgery by 6 months of age and were followed for 4-17 years. METHODS: Angle of deviation, subsequent surgeries, treatment with spectacles, amblyopia, fusion, and stereopsis were evaluated during follow-up. Outcomes from the early surgery group were compared with a concurrently recruited cohort who had surgery at 7-12 months (n=78). RESULTS: On the initial visit, both cohorts had the same median angle of deviation (45(Delta)) and similar refractive error; the median angle of deviation increased by the final preop visit (55(Delta)). Postoperatively, both cohorts had alignment within 6(Delta) in 83-94% of cases on all visits. Both cohorts had similar rates of additional surgery, and 44-48% wore hyperopic correction postoperatively. Compared with the 7- to 12-month cohort, more children in the early-surgery cohort had peripheral fusion (78% vs 61%; p < 0.02), central fusion (15% vs 2%; p < 0.01), Randot stereopsis (38% vs 16%; p < 0.003), and Randot stereoacuity of 200 seconds or better (20% vs 9%; p < 0.05). CONCLUSIONS: Early surgery was associated with a higher prevalence of fusion and stereopsis, without adverse motor outcomes.     

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.     

Treatment outcomes in refractive accommodative esotropia.

PURPOSE: To document and compare the clinical features and functional outcomes in patients with accommodative esotropia. To assess the efficacy of conventional management of accommodative esotropia, to determine functional outcomes of amblyopia and binocular vision, and to analyze possible risk factors involving the development of amblyopia. METHODS: We retrospectively reviewed the charts of 147 patients whose esotropia was corrected to within 10 prism diopters of orthotropia at both distance and near with use of full cycloplegic hyperopic correction. Multiple parameters were reviewed, including initial and final cycloplegic refraction, distance, and near deviation with and without glasses, stereoacuity, age of onset, and initiation of treatment, presence of anisometropia, and change in hyperopia. RESULTS: At presentation, 87 (59.2%) of the 147 patients were amblyopic, and anisometropia was found to be the only statistically significant risk factor for this (P = .001). Only 24.2% of these patients have stereo acuity between 40 and 100 sec/arc, 20.96% of patients have 200 to 800 sec/arc, and 22.58% of patients have 1980 to 3000 sec/arc; the remaining 32.26% had no stereo acuity. Fusion was achieved in 73.5% of the patients and later presentation (> 24 months) of esodeviation significantly determined their fusional ability (P = .031). Consecutive exotropia developed in 5.4 % of the patients an average of 5.5 years after institution of full optical correction. For clinical and functional outcomes we did not find any statistically significant difference between early onset (before 1 year old) and typical onset (2 to 3 years) age groups. The trend towards decreasing hyperopia was apparent, averaging -0.16 +/- 0.20 diopters annually in 80.5% of the patients with at least 5 years follow-up, although 23% of patients still had 20/40 or worse visual acuity in the amblyopic eye. CONCLUSIONS: Amblyopia is a commonly associated finding at presentation for patients with accommodative esotropia. Most of the patients developed good fusion but poor stereopsis at the end of treatment.     

Binocular sensory outcomes in accommodative ET

PURPOSE: To review what is known about the normal maturational sequence for fusion and stereopsis and the binocular sensory deficits associated with accommodative esotropia (ET) and to explore the clues that accommodative ET provides about critical periods for binocular sensory function. METHODS: Studies of binocular sensory function during infancy and early childhood are presented. RESULTS: Most of the maturation of binocular sensory function occurs during the first year of life, yet a later abnormal visual experience-such as the onset of accommodative ET--can profoundly and permanently disrupt fusion and stereopsis. CONCLUSIONS: Some binocular sensory deficits may exist before the onset of accommodative ET, but others may result directly from abnormal binocular experience. The functional organization of the maturing visual system appears to be maximally sensitive to disruption by abnormal visual experience during the first months of life, but susceptibility continues until at least 4 years of age.     

Clinical features of comitant strabismus related to family history of strabismus or abnormalities in pregnancy and delivery

PURPOSE: To elucidate the genetic or environmental background for clinical features in the three major types of comitant strabismus. METHODS: Interview based on a questionnaire asking background factors such as family history of strabismus and abnormalities in pregnancy and delivery was conducted with 101 consecutive patients with infantile esotropia (5-180 months of age), 83 with accommodative or partially accommodative esotropia (6-201 months of age), and 143 with intermittent exotropia (3-216 months of age) seen during 7 months from May to November 1998. The clinical features of strabismus obtained from medical records were analyzed statistically by logistic regression to determine their relation with these background factors. RESULTS: In infantile esotropia, patients with family history of strabismus had a significantly higher chance of showing latent nystagmus (odds ratio, 3.553; 95% confidence interval [CI], 1.077-11.717; P =.0373, logistic regression analysis). In a subgroup of 40 patients with infantile esotropia whose birth followed no abnormalities in pregnancy or delivery, patients with family history of strabismus had a significantly higher chance of showing inferior oblique muscle overaction (odds ratio, 7.714; 95% CI, 1.246-47.761; P =.0280), dissociated vertical deviation (odds ratio, 6.667; 95% CI, 1.176-37.787; P =.0321), and latent nystagmus (odds ratio, 7.333; 95% CI, 1.168-46.060; P =.0336). In accommodative or partially accommodative esotropia and intermittent exotropia, no relation was found between the clinical features and the background factors. CONCLUSIONS: Inferior oblique muscle overaction, dissociated vertical deviation, and latent nystagmus in infantile esotropia might have a genetic background.     

Factors Affecting Improvement of Stereopsis Following Successful Surgical Correction of Childhood Strabismus in Adults

ABSTRACT

Purpose: To evaluate the factors affecting improvement of stereopsis following successful surgical correction of childhood strabismus in adults.

Methods: In a prospective study, consecutive patients with childhood-onset, comitant, horizontal, constant strabismus; stereoacuity of more than 480 seconds of arc in TNO stereo test (absent stereopsis in TNO); and who had successful postoperative alignment (within 10 prism diopters [PD] of orthotropia) were enrolled. Postoperative stereopsis testing was performed using the TNO stereo test at 3 months after surgery.

Results: A total of 34 patients (20 exotropes and 14 esotropes) were included. The mean age at the time of surgery was 26.08?±?10.53 years (range, 14–53 years). Stereopsis was improved in 8 of 34 patients (23.5%). Postoperative alignment had influence on improvement of stereopsis; 38.1% of patients who had orthotropia gained stereopsis, whereas none of patients who had horizontal heterotropia (esotropia or exotropia) of 10 PD or less gained stereopsis (p?=?0.01). Misalignment of 10 years’ duration or longer did not preclude the development of postoperative stereoacuity (p?=?0.31). There was a statistically insignificant increase in improvement of stereopsis in nonamblyopic group (30.4%) compared with amblyopic group (9.1%) (p?=?0.22). Also, there was a statistically insignificant increase in improvement of stereopsis in exotropes (35%) compared with esotropes (7.1%) (p?=?0.1). The angle of preoperative deviation had no influence on improvement of stereopsis (p?=?0.44).

Conclusion: A postoperative correction of orthotropia was the only predictive factor for improvement of stereopsis in adults with childhood strabismus.     

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.     

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.     

Predictive factors for long-term outcome of stereoacuity in Japanese patients with pure accommodative esotropia

PURPOSE: To find clinical factors related to the long-term outcome of stereoacuity in Japanese patients with pure accommodative esotropia, including both the refractive type and the nonrefractive type. METHODS: The medical charts of 19 Japanese patients (8 boys and 11 girls) with pure accommodative esotropia who were followed for 10 years or more at Okayama University Hospital were reviewed retrospectively. Refractive accommodative esotropia was diagnosed in 8 patients while nonrefractive accommodative esotropia was diagnosed in 11 patients. The patients were divided into two groups, based on a stereoacuity of 120 seconds of arc or better versus 240 seconds of arc or worse as measured by the TNO test at the final visit, and the clinical factors were compared between the two groups. RESULTS: Clinical factors related to a stereoacuity of 240 seconds of arc or worse at the final visit were higher accommodative convergence to accommodation (AC/A) ratios at 6 years of age (p = 0.05), larger residual esodeviations at distance under full correction with glasses at 8 years of age (p = 0.03), and larger residual esodeviations at near at 6 years of age (p = 0.01, Mann-Whitney U-test). Overall, patients with nonrefractive accommodative esotropia tended to show poor levels of stereoacuity at the final visit compared to those with refractive accommodative esotropia (p = 0.059, Fisher exact probability test). CONCLUSION: This is the first study of the long-term visual outcome in Japanese patients with pure accommodative esotropia including both refractive and nonrefractive types. To obtain better levels of stereoacuity, the residual esodeviations at near and at distance should be kept as small as possible under full correction with glasses, including bifocals, especially at the ages of 6 and 8 years.     

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。     

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.     

Surgical outcomes for esotropia in children with high accommodative convergence/accommodation ratio

Purpose:To assess if high accommodative convergence/accommodation (AC/A) ratio impacts surgical outcomes in children with esotropia (ET), and evaluate the appropriate target angle in surgical dosing in the presence of high AC/A ratio.Methods:A retrospective chart review identified patients who underwent primary bilateral medial rectus (BMR) recessions for ET. Patients were excluded if follow-up was ≤2 months. Basic demographic information, visual acuity, stereopsis, alignment, and target angle for surgery were collected. High AC/A was defined as ≥10 prism diopter (Δ) deviation at near compared to distance. Outcome parameters were near and distance deviations ≤10Δ within orthophoria, and/or stereopsis postoperatively. Yates’ continuity correction, unpaired t-test, regression analysis, and one-way ANOVA were used.Results:We identified 103 patients, 23 with high AC/A and 80 with normal AC/A, preoperatively. Mean age was 4.0 ± 2.5 years. Surgical success measured by postoperative alignment was 48% and 45% in the high AC/A and normal AC/A groups, respectively (P = 1.0). There was a statistically significant difference in preoperative near deviation between high AC/A and normal AC/A groups (P = 0.0015); however, there was no significant difference in preoperative distance deviation (P = 0.061). In addition, there was not a significant difference in preoperative or postoperative stereopsis between high AC/A and normal AC/A groups (P = 0.88 and P = 0.44, respectively). There was a significant difference in the normal AC/A and high AC/A groups when target angle was directed toward preoperative near deviation as determined by one-way ANOVA (F = 170.88, P < 0.0001 and F = 14.61, P = 0.0010, respectively).Conclusion:In the setting of ET treated with BMR recession, the presence of high AC/A does not affect surgical success as measured by alignment and stereopsis. In addition, when high AC/A is present, surgical dosing with a target angle toward near deviation was found to yield the best surgical outcomes in our patient population.