Ocular Misalignment Research Articles

Diplopia and eye movement disorders

Diplopia—seeing double—is a symptom with many potential causes, both neurological and ophthalmological. Accurate diagnosis and appropriate plans of management can be achieved with careful history taking and clinical examination. In...

Convergence accommodation to convergence (CA/C) ratio in patients with intermittent exotropia and decompensated exophoria.

To evaluate the convergence accommodation to convergence (CA/C) ratio in strabismic patients and to clarify its clinical implications. Seventy-eight consecutive patients (mean age: 12.9 +/- 6.0 years) with intermittent exotropia and decompensated exophoria who showed binocular fusion at least at near viewing were recruited. The CA/C ratio was estimated by measuring accommodative responses induced by horizontal prisms with different magnitudes under accommodation feedback open-loop conditions. The CA/C ratios were compared with accommodative convergence to accommodation (AC/A) ratios and other clinical parameters. A linear regression analysis indicated that the mean (+/-SD) CA/C ratio was 0.080 +/- 0.043 D/prism diopter or 0.48 +/- 0.26 D/meter angle. There was no inverse or reciprocal relationship between CA/C and AC/A ratios. The patients with lower CA/C ratios tended to have smaller tonic accommodation under binocular viewing conditions and larger exodeviation at near viewing. The CA/C ratio, like the AC/A ratio, is an independent parameter that characterizes clinical features. A lower CA/C may be beneficial for the vergence control system to compensate for ocular misalignment with minimum degradation of accommodation accuracy.

Phakometric measurement of ocular surface radii of curvature, axial separations and alignment in relaxed and accommodated human eyes.

Measurements (autokeratometry, A-scan ultrasonography and video ophthalmophakometry) of ocular surface radii, axial separations and alignment were made in the horizontal meridian of nine emmetropes (aged 20-38 years) with relaxed (cycloplegia) and active accommodation (mean +/- 95% confidence interval: 3.7 +/- 1.1 D). The anterior chamber depth (-1.5 +/- 0.3 D) and both crystalline lens surfaces (front 3.1 +/- 0.8 D; rear 2.1 +/- 0.6 D) contributed to dioptric vergence changes that accompany accommodation. Accommodation did not alter ocular surface alignment. Ocular misalignment in relaxed eyes is mainly because of eye rotation (5.7 +/- 1.6 degrees temporally) with small amounts of lens tilt (0.2 +/- 0.8 degrees temporally) and decentration (0.1 +/- 0.1 mm nasally) but these results must be viewed with caution as we did not account for corneal asymmetry. Comparison of calculated and empirically derived coefficients (upon which ocular surface alignment calculations depend) revealed that negligible inherent errors arose from neglect of ocular surface asphericity, lens gradient refractive index properties, surface astigmatism, effects of pupil size and centration, assumed eye rotation axis position and use of linear equations for analysing Purkinje image shifts.

Can misalignments in typical infants be used as a model for infantile esotropia?

To investigate the nature of early ocular misalignments in human infants to determine whether they can provide insight into the etiology of esotropia and, in particular, to examine the correlates of misalignments. A remote haploscopic photorefraction system was used to measure accommodation and vergence in 146 infants between 0 and 12 months of age. Infants underwent photorefraction immediately after watching a target moving between two of five viewing distances (25, 33, 50, 100, and 200 cm). In some instances, infants were tested in two conditions: both eyes open and one eye occluded. The resultant data were screened for instances of large misalignments. Data were assessed to determine whether accommodative, retinal disparity, or other cues were associated with the occurrence of misalignments. The results showed that there was no correlation between accommodative behavior and misalignments. Infants were more likely to show misalignments when retinal disparity cues were removed through occlusion. They were also more likely to show misalignments immediately after the target moved from a near to a far position in comparison to far-to-near target movement. The data suggest that the prevalence of misalignments in infants of 2 to 3 months of age is decreased by the addition of retinal disparity cues to the stimulus. In addition, target movement away from the infant increases the prevalence of misalignments. These data are compatible with the notion that misalignment are caused by poor sensitivity to targets moving away from the infant and support the theory that some forms of strabismus could be related to failure in a system that is sensitive to the direction of motion.

Association between schizophrenia with ocular misalignment and polyalanine length variation in PMX2B

The increased incidence of minor physical anomalies (MPAs) in schizophrenia is the fundamental basis for the neurodevelopmental hypothesis of schizophrenia etiology. Ocular misalignment, or strabismus, falls into the category of MPAs, but this phenotype has not been assessed in schizophrenia. This study reveals that a subtype of strabismus, constant exotropia, displays marked association with schizophrenia (P=0.00000000906). To assess the genetic mechanisms, we examined the transcription factor genes ARIX (recently identified as a causative gene for syndromic strabismus) and its paralogue, PMX2B. We identified frequent deletion/insertion polymorphisms in the 20-alanine homopolymer stretch of PMX2B, with a modest association between these functional polymorphisms and constant exotropia in schizophrenia (P=0.029). The polymorphisms were also associated with overall schizophrenia (P=0.012) and more specifically with schizophrenia manifesting strabismus (P=0.004). These results suggest a possible interaction between PMX2B and other schizophrenia-precipitating factors, increasing the risk of the combined phenotypes. This study also highlights the unique nature of the polyalanine length variations found in PMX2B. In contrast with other transcription factor genes, the variations in PMX2B show a high prevalence, with deletions being more common than insertions. Additionally, the polymorphisms are of ancient origin and stably transmitted, with mild phenotypic effects. In summary, our study lends further support to the disruption of neurodevelopment in the etiology of schizophrenia, by demonstrating the association of a specific MPA, in this case, constant exotropia with schizophrenia, along with molecular variations in a possible causative gene.

Pediatric Vision Screener 2: pilot study in adults

Amblyopia is a form of visual impairment caused by ocular misalignment (strabismus) or defocus in an otherwise healthy eye. If detected early, the condition can be fully treated, yet over half of all children with amblyopia under age 5 escape detection. We developed a Pediatric Vision Screener (PVS) to detect amblyopia risk factors. This instrument produces a binocularity score to indicate alignment and a focus score to indicate focus. The purpose of this study is to assess the performance of the PVS by testing adults who were fully cooperative for testing. The study group includes 40 subjects (20 controls, 20 patients) aged 22 to 79 years. 12 patients had constant strabismus (8 to 50Delta), and eight had variable strabismus (12 to 55Delta). All controls had binocularity scores >50%. Binocularity was <50% in 11/12 patients. The patient with binocularity >50% had a well-controlled intermittent exotropia and was not at risk for amblyopia. Focus scores were highly sensitive for good focus but not specific. The PVS shows high sensitivity and specificity for detection of strabismus in adults. Future studies will determine whether this performance can be achieved in preschool children, who are at greatest risk for vision loss.

Pediatric Vision Screener 1: instrument design and operation

We develop the Pediatric Vision Screener (PVS) to automatically detect ocular misalignment (strabismus) and defocus in human subjects. The PVS utilizes binocular retinal birefringence scanning to determine when both eyes are aligned, with a theoretical accuracy of <1 deg. The device employs an autoconjugate, bull's-eye detector-based system to detect focus. The focus and alignment pathways are separated by both wavelength and data acquisition timing. Binocular focus and alignment are detected in rapid alternating sequence, measuring both parameters in both eyes in <0.5 sec. In this work, the theory and design of the PVS are described in detail. With objective, automated measurement of both alignment and focus, the PVS represents a new approach to screening children for treatable eye disease such as amblyopia.

The threshold for the detection of strabismus

Purpose To identify the threshold at which horizontal or vertical strabismus becomes reliably detectable by observers and to determine the effects of interpupillary distance, age, gender, and observer experience. Methods Six models of different gender, age, and interpupillary distance were digitally photographed in several predetermined gaze positions off-axis in the horizontal and vertical planes. Standardized distance, zoom factor, and lighting were used. The images were digitally altered to exactly superimpose one eye deviated and one eye aligned with the axis of the camera. This simulated horizontal and vertical strabismus ranged from 2.5 to 20 prism diopters (PD). The images were arranged in random order and presented to groups of lay and professional observers, and their responses were recorded. Results The statistically significant threshold for detecting esotropia, exotropia, and hypertropia was 12.5 PD. Hypotropia had a higher threshold of 20 PD. Observer experience and model age each had a significant effect on the ability to detect strabismus. Conclusion Our study demonstrates a unique method for assessing the significance of different types and degrees of strabismus. Our findings may be used to help patients with strabismus as they consider others' perception of their ocular misalignment. Physicians can also use this information in making decisions regarding surgery.

Binocular vision with primary microstrabismus.

Patients with primary microstrabismus have a high degree of binocularity, which suggests that their ocular misalignment may have a sensory rather than an oculomotor origin, as in large-angle strabismus. The purpose of these experiments was to determine whether microstrabismic subjects have sensory abnormalities that could give rise to a small angle of strabismus. The binocular disparity response functions for sensory and motor processes were compared in seven orthotropic subjects and six strabismic subjects (four with primary microstrabismus and two with infantile esotropia). Binocularity was assessed by disparity vergence (central and peripheral stimuli) and depth discrimination (relative and absolute disparities) measures. Motor and sensory disparity response functions were both determined by psychophysical methods: vergence responses by dichoptic nonius alignment and sensory responses by forced-choice depth discrimination. All the strabismic subjects demonstrated normal retinal correspondence with peripheral binocular stimuli and anomalous retinal correspondence with central fusion stimuli. The microstrabismic subjects' disparity vergence responses with peripheral fusion stimuli were centered on disparities relative to their angle of strabismus. However, with central fusion stimuli, the disparity vergence responses were relative to the subjective angle of strabismus. The microstrabismic subjects' stereoacuities were substantially reduced, but their discrimination responses did not show an asymmetry indicative of an unrepresented population of disparity-selective mechanisms. The data do not support a sensory abnormality as the primary cause of microstrabismus. The results are not compatible with an oculomotor adaptation to an inherent anomalous correspondence or with a strabismus caused by an absence of a class of disparity-selective mechanisms. Thus, just as in large-angle strabismus, the anomalous retinal correspondence and defective stereopsis of microstrabismus appear to be consequences of abnormal visual experience caused by an interocular deviation.

Development of generalized disease at 2 years in patients with ocular myasthenia gravis. Kupersmith MJ, Latkany R, Homel P. Arch Neurol 2003;60:243–248

The initial symptoms or signs of myasthenia gravis (MG) are ptosis, extraocular muscle weakness, or ocular misalignment in up to 65% of patients. Clinically apparent generalized disease develops in more than 50% of patients who present with ocular MG, typically within 2 years. The optimal treatment of ocular MG, including the use of corticosteroids, remains controversial. In addition, the prevalence of thymoma and the optimal performance of the edrophonium chloride test for ocular myasthenia remain unknown. The goal of this study was to assess the effect of oral corticosteroid therapy on the frequency of development of generalized MG within 2 years, the incidence of thymoma, and the amount of edrophonium needed for a positive test result in patients with ocular MG. The authors reviewed an MG database of 147 patients. Patients underwent measurement of acetylcholine receptor (AChR) antibody levels and chest computed tomography. Unless contraindicated, patients with diplopia were recommended for therapy with prednisone, up to 40 to 60 mg/day, with the dosage tapered for 5 to 6 weeks. Most continued to receive daily or alternate-day doses of 2.5 to 10 mg to prevent diplopia. Patients not given prednisone (untreated group) received pyridostigmine bromide or no medication. After the diagnosis, the authors documented the signs and symptoms of ocular and generalized myasthenia gravis and performed 2-year follow-up in 94 patients. The mean dose of edrophonium chloride to give a positive response was 3.3 mg (standard deviation, 1.6 mg) for ptosis and 2.6 mg standard deviation, 1.1 mg) for ocular motor dysfunction. Thymoma was diagnosed in 1 patient (0.7%). Generalized MG developed within 2 years in 4 of 58 treated and 13 of 36 untreated patients. The odds ratio (OR) for development of generalized disease in the treated group was 0.13 (95% confidence interval [CI], 0.04–0.45) compared with the untreated group. The AChR antibody level was not predictive of development of generalized MG at 2 years, but the risk was greater in patients with abnormal AChR antibody levels (OR, 6.33; 95% CI, 1.71–23.42). Logistic regression that included age, abnormal AChR antibody level, and prednisone therapy yielded significance only for abnormal AChR antibody level (OR, 7.03; 95% CI, 1.35–36.64) and treatment (OR, 0.06; 95% CI, 0.01–0.30). The authors conclude that at 2 years, prednisone treatment appears to reduce the incidence of generalized MG to 7% in contrast to 36% of patients who did not receive prednisone. Thymoma, although uncommon, may occur in ocular myasthenia gravis. Only small amounts of edrophonium are needed to diagnose ocular myasthenia gravis.—Valérie Biousse

Decompensation of Exodeviation After Corneal Refractive Surgery for Moderate to High Myopia

To evaluate strabismus and binocular decompensation of exodeviation and their surgical treatment following corneal refractive surgery. A retrospective study of a noncomparative case series was conducted. Seven patients whose strabismus worsened after photorefractive keratectomy or laser in-situ keratomileusis for correction of myopia underwent orthoptic evaluation before and after refractive surgery, as well as after corrective strabismus surgery. The motor alignment and regaining of binocularity after strabismus surgery to correct the misalignment following refractive corneal surgery were evaluated and compared at three time points. After corneal refractive surgery, there was a deterioration in mean distance exodeviation from 7.1 +/- 5.2 to 25.7 +/- 10.1 prism diopters (PD) (P = .028) and in mean near exodeviation from 7.1 +/- 5.1 to 29.7 +/- 8.1 PD (P = .18), with loss of binocular function in 6 of the 7 patients. Following strabismus surgery, the mean distance exodeviation was reduced from 25.7 +/- 10.1 to 2.0 +/- 1.8 PD (P = .027) and the mean near exodeviation from 29.7 +/- 8.1 to 3.7 +/- 1.5 PD (P = .028). Five of the six patients regained binocular function. All at-risk patients with exophoria and exotropia should undergo a thorough orthoptic evaluation before corneal refractive surgery. Patients with ocular motility and misalignment problems should be warned preoperatively of the risk of decompensation of their strabismus.

The management of strabismus in adults—I. clinical characteristics and treatment

Introduction This is the first in a series of articles intended to evaluate the management of strabismus in adults, including clinical outcomes and the quality, cost, and value of treatment from the perspectives of patients and health care providers. Here we present clinical characteristics, complexity of surgery, treatment success, and resolved complaints in a group of adult patients who underwent strabismus surgery. Methods This is a multicenter retrospective study analyzing the type and amount of ocular misalignment before and after surgery in adult patients with strabismus onset before (BVM, or age < 9 years) or after (AVM, or age ≥ 9 years) visual maturation. Success was evaluated in terms of alignment, motility, and the presence of diplopia; subjective success was measured in terms of resolved complaints. The complexity of surgery was determined using the Intensity/Complexity Index and compared with success rates. Results Data are reported on 299 patients (90 BVM and 145 AVM) whose eyes were successfully aligned in 63% of the BVM cases and 81% of the AVM cases. Subjective complaints resolved at similar rates in the BVM and AVM subgroups. Successful alignment was not correlated with complexity of surgery, but motility and sensory success rates were correlated with complexity of surgery. Conclusion Within each of the BVM and AVM subgroups, this study of adult strabismus showed similar surgical success rates compared with published data. This qualifies these patient groups as clinically typical of adults undergoing strabismus surgery. Additional studies will expand on health value analyses.

Management of strabismus in nanophthalmic patients: A long-term follow-up report

Purpose The purpose of this study is to identify the characteristics of strabismus that coexist with nanophthalmos and to report the results of strabismus surgery performed on these small eyes. Design Retrospective, consecutive, noncomparative interventional case series. Participants Fifteen bilateral nanophthalmic patients, of whom five underwent horizontal muscle surgery, were included in this study. Methods Chart review. The clinical examination included visual acuity assessments using the linear Snellen and the Lea charts, slit-lamp and fundus examinations, intraocular pressure, and axial length measurements. The orthoptic examination consisted of measurements of ocular deviations using the prism cover test with an accommodative target at both near and distance with and without refractive correction, assessment of ocular motility with ductions and versions, binocularity with Worth’s four-dot test, and the Titmus test. Amblyopia was treated with part-time occlusion. Surgery for the correction of esotropia included bilateral medial rectus recessions or recess–resect procedures. Main outcome measures Magnitude of strabismic deviation, best-corrected visual acuity, and the level of binocular vision achieved were monitored. Results The average age of enrollment in the study was 4.7 (range, 1–12) years. The patients were followed for an average of 7.0 (range, 4–14) years. The mean axial length was determined as 18.4 mm (range, 15.5–20.7). The mean refractive error in spherical equivalents was measured as +9.9 and ranged between +4.0 and +15.0 diopters. Five patients (33%) had nonaccommodative esotropia, four (27%) had partially refractive esotropia, four (27%) had microesotropia, and two (13%) had exotropia. Five patients, all having nonaccommodative esotropia, underwent surgery for the correction of ocular misalignment. Diminishing the surgical dose in these small eyes resulted in undercorrections. Despite patching, 3 patients (20%) had unilateral and 12 patients (80%) had bilateral amblyopia at the conclusion of the study. Conclusions Strabismus in nanophthalmos usually manifests as nonaccommodative and partially refractive esotropia. Medial rectus recession should be applied with care to prevent adduction deficit and convergence insufficiency. Otherwise, there seems to be no need for decreasing the surgical dose with regard to the smaller axial length. Amblyopia tends to be persistent in these patients.

Double Trouble

A 78-year-old woman presented with vertical double vision. The Bielschowsky–Parks' three-step test suggested a left inferior rectus muscle paresis. Diagnostic testing confirmed the diagnosis of myasthenia gravis. Despite treatment with pyridostigmine bromide (mestinon) the diplopia persisted.She refused corticosteroid treatment and sought a second opinion, resulting in three unsuccessful strabismus surgeries to correct her ocular misalignment. The evaluation and management of ocular myasthenia gravis is reviewed and the appropriate timing of strabismus surgery is discussed.

Retroequatorial recession of horizontal recti with loop suture in the treatment of congenital nystagmus

Purpose The authors wished to evaluate the effectiveness and safety of retroequatorial recession of all four horizontal recti using loop sutures for the treatment of congenital nystagmus. Subjects and methods Twelve patients with congenital nystagmus were enrolled in this prospective study. All patients underwent retroequatorial recession of horizontal recti with loop sutures. All recti were recessed 8mm measuring from the insertion, then the amount of loop suture was determined according to the preoperative ocular alignment of the patients. Electronystagmographic recordings were made in every patient preoperatively and postoperatively as well as an ophthalmological examination. The follow-up period ranged from 6 to 26 months. Results All four horizontal recti were recessed 9 to 12mm including the loop suture (range 1-4mm). Compared to preoperative values, postoperative amplitude and intensity of nystagmus decreased statistically significantly in all patients (p = 0.002). The postoperative decrease in the frequency of nystagmus was not statistically significant (p = 0.173). Improvement of both distance and near visual acuity was achieved in 10 patients. Five of seven patients who had ocular misalignment preoperatively were aligned within 10 PD postoperatively. Improvement in head posture was seen in two of three patients. The authors determined that the improvement in the nystagmus characteristics was most prominent in the immediate postoperative period. Conclusion Retroequatorial recession of all four horizontal recti using loop sutures is a safe and effective procedure for the management of congenital nystagmus.

Disorders of vertical optokinetic nystagmus in patients with ocular misalignment

Purpose. To compare responses to vertical and horizontal optokinetic (OK) stimulation in patients with disorders of ocular alignment. Methods. Using the magnetic search coil technique, we measured horizontal and vertical rotations of both eyes in six patients with strabismus since childhood and eight normal subjects. The OK stimulus subtended 72° horizontally and 60° vertically, consisted of black-and-white stripes with a spatial frequency of 0.04 cycles/degree, and moved either vertically or horizontally at 22.5 or 12°/s. All patients and controls were tested with both eyes viewing and monocularly. Results. Vertical OK responses were asymmetric in most normals and patients. The direction of this asymmetry varied between individuals, but upward stimuli more commonly elicited a greater response than downward stimuli. Monocular horizontal OK responses were symmetric in normals; patients showed either an asymmetry with greater responses for nasal motion, or a directional bias. During monocular and binocular viewing, vertical OK stimulation induced vertical nystagmus in normal subjects, but all patients showed diagonal responses, with horizontal components that were significantly greater than controls. The inappropriate horizontal component of the response increased at the higher stimulus speed, and was not simply due to latent nystagmus. Conclusions. Patients with disorders of ocular alignment since childhood show an inappropriate horizontal response to vertical OK stimuli, indicating directional abnormality of either motion vision pathways or the ocular motor response.

Homozygous mutations in ARIX (PHOX2A) result in congenital fibrosis of the extra ocular muscles type 2. Nakano M, Yamada K, Fain J, Sener EC, Selleck CJ, Awad AH, Zwaan J, Mullaney PB, Bosley TM, Engle EC. Nature Genetics 2001;29:315–320.

Isolated strabismus affects 1%–5% of the general population. Most forms of strabismus are multifactorial in origin; although there is probably an inherited component, the genetics of these disorders and even the exact locus of the abnormality resulting in ocular misalignment remain unclear. The congenital fibrosis syndromes (CFS) represent a subset of monogenic isolated strabismic disorders that are characterized by restrictive ophthalmoplegia, and include congenital fibrosis of the extraocular muscles (CFEOM) and Duane syndrome (DURS). Neuropathologic studies indicate that these disorders may result from the maldevelopment of the oculomotor (III), trochlear (IV), and abducens (VI) cranial nerve nuclei. To date, five CFS loci have been mapped (FEOM1, FEOM2, FEOM3, DURS1, and DURS2), but no genes had been identified. In this report, three mutations in ARIX (also know as PHOX2A) were identified in four CFEOM2 pedigrees. ARIX encodes a homeodomain transcription factor protein previously shown to be required for cranial nerves III and IV development in mouse and zebrafish. Two of the mutations are predicted to disrupt splicing, whereas the third alters an amino acid within the conserved brachyury-like domain. These findings confirm the hypothesis that CFEOM2 results from the abnormal development of cranial nerves III and IV and emphasize a critical role for ARIX in the development of these midbrain motor nuclei.—Nancy J. Newman

Does neonatal ocular misalignment predict later abnormality?

A longitudinal prospective study was carried out to ascertain the significance of neonatal ocular misalignments. Pre-school vision screening and hospital records were examined to determine the visual outcome of 1150 infants classified into 'often' (> 15% of waking hours), 'occasionally' (< 15%) or 'never' having an ocular misalignment (neonatal squint) in the first 8 weeks of life. Chi2 and Fisher's exact tests and ANOVA were used to analyse the data. When compared with infants who had squinted occasionally or never, frequent squinting in the neonatal period (which occurred in 7.7% of the subjects) was significantly associated with having been prescribed spectacles (p = 0.04), both for hypermetropia (p = 0.04) and for myopia (p = 0.05). Frequent squinters also had a higher incidence of significant esodeviation (p = 0.04) and were more likely to be > 21 days premature (p = 0.05). Small numbers of abnormalities made statistical analysis limited, but there were weak trends towards more myopic and oblique astigmatism in the 'never' group. The esotropias in the 'often' group were more frequently intermittent than those found in the other groups. Occasional squinting in the first 8 weeks of life appears to be normal neonatal behaviour. Frequent squinting trebles the chances of developing a significant esodeviation or refractive error severe enough to require spectacles before 5 years of age but incidence of abnormality still does not exceed 9%.

Double Vision.

When evaluating a patient with a complaint of double vision, it is important to distinguish monocular versus binocular diplopia, which are differentiated by asking the patient to cover each eye separately. In the setting of binocular double vision, one of the two images disappears when either eye is covered, because diplopia is the result of ocular misalignment. On the other hand, monocular double vision resolves when the affected eye is covered, but remains when the opposite eye is occluded. Causes of monocular diplopia include cataract, refractive error, and retinal disease, which can be managed accordingly by an ophthalmologist. However, an unusual form of monocular double vision can occur in the setting of cortical dysfunction. Cerebral polyopia describes the perception of multiple images and arises from an occipital disturbance. It can occur with migraine headaches and can be accompanied by a homonymous hemianopia. Palinopsia refers to the persistence of an image that is no longer in view (visual perseveration or stroboscopic effect) and results from an occipital lesion as well. The exact mechanism of polyopia and palinopsia are uncertain and both conditions are extremely rare. The majority of this discussion will focus on binocular double vision and its management. The main treatment objective of binocular diplopia is to restore the largest area of single binocular vision. Ideally, patients would be able to achieve single vision in all fields of gaze, but this is not always possible. The majority of patients are treated with either prism lenses or eye muscle surgery.

Restoration of fusion in children with intracranial tumors and incomitant strabismus

Purpose Intracranial tumors may cause eye misalignment and interruption of sensory fusion. The ocular misalignment may be permanent or may be corrected after tumor treatment with or without specific strabismus treatment. This report analyzes the binocular vision outcome of children with misaligned eyes from brain tumors who regain orthotropia. Design A retrospective noncomparative case series. Participants Twenty-three surviving children less than 18 years of age with a new heterotropia and absence of fusion associated with the development of a brain tumor. Interventions Tumor resection/radiation/chemotherapy and necessary strabismus management. Main outcome measure Stereopsis (≥ 4 of 10 circles) measured with the Randot II stereo test at near fixation. Results Fourteen children regained orthotropia either after tumor therapy, strabismus treatment, or both. Ten of these 14 children with realigned vision regained high-grade stereovision. Nine patients did not regain orthotropia and were excluded. The mean age at tumor diagnosis of the fusing group was 9.9 years (range, 3–17 years) compared with 8.5 years (range, 6–12 years) in the four realigned nonfusing patients. The mean duration of misalignment was 12 months (range, 2–51 months) for the fusing group, and 45 months (range, 14–120 months) for the nonfusing group. Conclusions Children and adolescents with brain tumor–associated eye misalignment may regain the ability to fuse if their misalignment can be corrected. An improved prognosis was noted for those patients when the misalignment had been present for a shorter duration. These data suggest that the outcome may be better for incomitant strabismus than that reported for acute comitant esotropia.