Intermittent exotropia evaluation using the propedeutics proposed by Kushner: a 25-year study / Avaliação de exotropia intermitente usando propedêutica proposta por Kushner: estudo de 25 anos

ABSTRACT Purpose: To evaluate the clinical and surgical impacts of phenomena that could occur in intermittent exotropia. Methods: The medical records of intermittent exotropia cases from 1991 to 2014 were retrospectively reviewed. All patients underwent a series of measures, including a protocol to assess monocular occlusion based on the propedeutics proposed by Kushner. Results: Outdoor sensitivity was observed in 31% of patients with an undercorrection rate of 44% vs. 18% of cases with no outdoor sensitivity. After 1 h of monocular occlusion, 41% of all patients achieved an increase in deviation with an undercorrection rate of 40%, whereas 25% did not. Conclusion: The results show the importance of complete propedeutics, since there is a higher rate of late undercorrection in cases with outdoor sensitivity and increased deviation after occlusion.

RESUMO Objetivo: Avaliar os impactos clínico e cirúrgico dos fenômenos que podem ocorrer na exotropia intermitente. Métodos: Os prontuários de casos de exotropia intermitente de 1991 a 2014 foram revisados retrospectivamente. Todos os pacientes foram submetidos a uma serie de medidas incluindo o protocolo com oclusão monocular com base na propedêutica proposta por Kushner. Resultados: Outdoor sensitivity foi observada em 31% dos pacientes com taxa de subcorreção de 44% vs. 18% dos casos sem outdoor sensitivity. Após 1 hora de oclusão monocular, 41% de todos os pacientes apresentaram um aumento no desvio com uma taxa de subcorreção 40%, enquanto 25% não. Conclusão: Os resultados demonstram a importância da propedêutica completa, uma vez que há maior taxa de subcorreção tardia nos casos de outdoor sensitivity e maior desvio após a oclusão.

Retroceso bilateral de rectos laterales comparado con retroceso/resección unilateral para el tratamiento de la exotropia intermitente básica / Bilateral lateral rectus recession versus unilateral recession/resection for basic intermittent exotropia

Resumen INTRODUCCIÓN: En determinadas circunstancias clínicas, la exotropia intermitente básica requiere resolución quirúrgica. Existen dos técnicas para ello: el retroceso bilateral de rectos laterales y el retroceso/resección unilateral. Aunque el retroceso bilateral es la técnica más utilizada, no está claro cuál de estas técnicas tiene mejores resultados. MÉTODOS: Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, reanalizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos cinco revisiones sistemáticas que en conjunto incluyeron siete estudios primarios, de los cuales tres son ensayos aleatorizados. Concluimos que el retroceso/resección unilateral podría tener un mayor éxito quirúrgico y probablemente disminuiría la tasa de subcorrección/recurrencia, cuando se le compara al retroceso bilateral de rectos laterales.

Abstract INTRODUCTION: Intermittent exotropia requires surgical resolution under some clinical circumstances. The main techniques are bilateral lateral rectus recession and unilateral recess/resection. Although bilateral recession is the most widely used, it is not clear whether it leads to better results. METHODS: To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified five systematic reviews including seven studies overall, of which three were randomized trials. We concluded unilateral recess/resection might achieve greater surgical success and probably decrease the rate of undercorrection/recurrence when compared to bilateral lateral rectus recession.

The Stabilization of Postoperative Exo-drift in Intermittent Exotropia after Surgical Treatment

PURPOSE: To investigate the long-term clinical course of intermittent exotropia after surgical treatment to determine whether and when postoperative exo-drift stabilizes, and the required postsurgery follow-up duration in cases of intermittent exotropia. METHODS: We retrospectively reviewed the medical records of patients diagnosed with intermittent exotropia who underwent surgical treatment between January 1992 and January 2006 at Yeungnam University Hospital and postoperatively performed regular follow-up examinations for up to 7 years. We also analyzed the difference in exo-drift stabilization, according to surgical procedure. RESULTS: A total of 101 patients were enrolled in the study. Thirty-one patients underwent lateral rectus recession and medial rectus resection (R&R) and 70 patients underwent bilateral lateral rectus recession (BLR). The postoperative angles of deviation increased significantly during the initial 36 months, but no subsequent significant changes were observed for up to 84 months. Follow-ups for 7 years revealed that more than 50% of the total amount of exo-drift was observed within the first postoperative year. In addition, the angles of deviation at 1 year correlated with those at 7 years postoperatively (Pearson correlation coefficient r = 0.517, p < 0.001). No significant exo-drift was observed after 36 months in patients who underwent BLR, whereas after 18 months in patients who underwent R&R. CONCLUSIONS: The minimum postoperative follow-up required after surgical treatment to ensure stable results is 36 months. In particular, careful follow-up is necessary during the first postoperative year to detect rapid exo-drift. Patients who underwent BLR required a longer follow-up than those who underwent R&R to ensure stable postoperative alignment.

Relationship between Control Grade, Stereoacuity and Surgical Success in Basic Intermittent Exotropia

PURPOSE: This study was conducted to identify the relationship between control grade, stereoacuity and surgical success in basic intermittent exotropia. METHODS: This retrospective study involved 44 basic intermittent exotropia patients who underwent strabismus surgery and completed at least 6 months of follow-up. The 44 patients were divided into three subgroups according to their control grade: group 1 (good control group, n = 12), group 2 (fair control group, n = 18), and group 3 (poor control group, n = 14). Evaluation was done to identify the relationships between near and distance stereoacuity and control grade, and between surgical success and control grade. Surgical success was defined as ocular alignment between 5 prism diopters esodeviation and 10 prism diopters exodeviation in the primary position at the final visit. RESULTS: Mean near stereoacuity measured by the graded circle test was 57.50 seconds of arc (seconds) in group 1, 77.77 seconds in group 2, and 131.43 seconds in group 3 (p < 0.01). Mean distance steroacuity measured by Mentor B-VAT II BVS contour circle was 108.33 seconds in group 1, 148.33 seconds in group 2, and 262.82 seconds in group 3 (p < 0.01). Ten patients (83.33%) in group 1, 12 (66.67%) in group 2, and 9 (64.29%) in group 3 obtained surgical success (p = 0.28). CONCLUSIONS: In basic intermittent exotropia, better control grade was significantly accompanied by better stereoacuity. Better control grade was accompanied by higher surgical success rate but with no statistical significance.

Relationship between Control Grade, Stereoacuity and Surgical Success in Basic Intermittent Exotropia

PURPOSE: This study was conducted to identify the relationship between control grade, stereoacuity and surgical success in basic intermittent exotropia. METHODS: This retrospective study involved 44 basic intermittent exotropia patients who underwent strabismus surgery and completed at least 6 months of follow-up. The 44 patients were divided into three subgroups according to their control grade: group 1 (good control group, n = 12), group 2 (fair control group, n = 18), and group 3 (poor control group, n = 14). Evaluation was done to identify the relationships between near and distance stereoacuity and control grade, and between surgical success and control grade. Surgical success was defined as ocular alignment between 5 prism diopters esodeviation and 10 prism diopters exodeviation in the primary position at the final visit. RESULTS: Mean near stereoacuity measured by the graded circle test was 57.50 seconds of arc (seconds) in group 1, 77.77 seconds in group 2, and 131.43 seconds in group 3 (p < 0.01). Mean distance steroacuity measured by Mentor B-VAT II BVS contour circle was 108.33 seconds in group 1, 148.33 seconds in group 2, and 262.82 seconds in group 3 (p < 0.01). Ten patients (83.33%) in group 1, 12 (66.67%) in group 2, and 9 (64.29%) in group 3 obtained surgical success (p = 0.28). CONCLUSIONS: In basic intermittent exotropia, better control grade was significantly accompanied by better stereoacuity. Better control grade was accompanied by higher surgical success rate but with no statistical significance.

Comparison of Surgical Outcomes with Unilateral Recession and Resection According to Angle of Deviation in Basic Intermittent Exotropia

PURPOSE: The purpose of this study is to compare the surgical outcomes and near stereoacuities after unilateral medial rectus (MR) muscle resection and lateral rectus (LR) recession according to deviation angle in basic intermittent exotropia, X(T). METHODS: Ninety patients with basic type X(T) were included in this study. They underwent unilateral recession of the LR and resection of the MR and were followed postoperatively for at least 12 months. Patients were divided into three groups according to their preoperative deviation angle: group 1 or =40 PD. Surgical outcomes and near stereoacuities one year after surgery were evaluated. Surgical success was defined as having a deviation angle range within +/-10 PD for both near and distance fixation. RESULTS: Among 90 patients, groups 1, 2, and 3 included 30 patients each. The mean age in groups 1, 2, and 3 was 9.4 years, 9.4 years, and 11.0 years, respectively. The surgical success rates one year after surgery for groups 1, 2, and 3 were 80.0%, 73.3%, and 73.3% (chi-square test, p = 0.769), respectively. The undercorrection rates for groups 1, 2, and 3 were 16.7%, 23.3%, and 26.7%, and the overcorrection rates were 3.3%, 3.3%, and 0%, respectively. The mean preoperative near stereoacuities for groups 1, 2, and 3 were 224.3 arcsec, 302.0 arcsec, and 1,107.3 arcsec, and the mean postoperative near stereoacuities were 218.3 arcsec, 214.7 arcsec, and 743.0 arcsec (paired t-test; p = 0.858, p = 0.379, p = 0.083), respectively. CONCLUSIONS: In basic X(T) patients, the amount of angle deviation has no influence on surgical outcomes in unilateral LR recession and MR resection. The near stereoacuities by one year after LR recession and MR resection for intermittent X(T) were not different among patient groups separated by preoperative deviation angle.

Comportamiento de la estabilidad ocular posterior a cirugía de exotropía intermitente / Behaviour of the ocular stability after intermittent exotropia surgery

Objetivo: describir la estabilidad ocular en los pacientes operados de exotropía intermitente y su relación con algunos factores de riesgo. Métodos: se realizó un estudio longitudinal, descriptivo, prospectivo de serie de casos, en pacientes operados de exotropía intermitente en el servicio de Oftalmología Pediátrica del Ramón Pando Ferrer, en el período de enero de 2009 a septiembre de 2011. El universo fue de 35 pacientes con exotropía intermitente con ángulo de desviación preoperatoria ›20 dioptrías prismáticas, valorados al año de la cirugía. Las variables fueron: ángulo de desviación preoperatoria y posoperatoria, edad quirúrgica, la agudeza visual estereoscópica preoperatoria y posoperatoria a los 6 meses y al año de la cirugía y la presencia o no de defecto refractivo. Resultados: el 48,6 por ciento de los pacientes operados de exotropía intermitente estaban alineados a los 6 meses de cirugía, mientras que la estabilidad quirúrgica al año fue de 32,4 por ciento. Todos los paciente que lograron estabilidad ocular después de la cirugía presentaban estereopsia, el 75 por ciento de los pacientes que presentaban buena estereopsia no lograron estabilidad quirúrgica al año. El 100 por ciento de los pacientes de 4 a 5 años tuvieron un buen alineamiento ocular. El 65,6 por ciento de los pacientes presentaron defecto refractivo. Conclusiones: la intervención quirúrgica temprana resulta importante para mejorar el resultado funcional motor. Los pacientes que logran el máximo de estabilidad del alineamiento ocular tienen buena agudeza visual estereoscópica. No existe relación significativa entre el defecto refractivo y el logro de la estabilidad del alineamiento ocular

Objective: to describe the ocular stability of patients undergoing intermittent exotropia surgery and its relationship with some risk factors. Methods: a longitudinal, prospective, and descriptive case series study was conducted in patients undergoing intermittent exotropia surgery at pediatric ophthalmology service of Pando Ferrer Cuban Institute of Ophthalmology in the period of January 2009 to September 2011. The universe of study was 35 patients with intermittent exotropia and preoperative deviation angle of ? 20 diopters, measured one year after surgery. The variables were deviation angle preoperatively and postoperatively, age at surgery, stereoscopic visual acuity preoperatively and postoperatively, at 6 months and one year later, and the presence or absence of refractive error. Results: iIn this group, 48.6 percent of patients who underwent intermittent exotropia surgery showed eye alignment at 6 months, whereas surgical stability after a year was 32.4 percent. All the patients who achieved stability after ocular surgery had stereopsis, 75 percent of the patients, who showed good stereopsis, failed in reaching surgical stability one year later. All the patients aged 4 to 5 years had a good eye alignment and 65.7 percent of patients had refractive error. Conclusions: early surgical intervention is important in improving motor functional outcome. The patients who achieve the maximum stability in ocular alignment have good stereoscopic visual acuity. There is no significant relationship between refractive error and the stability of eye alignment

Parent-Reported Symptoms of Attention Deficit Hyperactivity Disorder in Children with Intermittent Exotropia before and after Strabismus Surgery

PURPOSE: To investigate the symptoms of attention deficit hyperactivity disorder (ADHD) as reported by parents in children with intermittent exotropia [X(T)] and to determine whether strabismus surgery for X(T) affects ADHD symptoms. MATERIALS AND METHODS: Fifty-one consecutive children undergoing muscle surgery for X(T) were prospectively recruited. One parent of each child completed the ADHD rating scale IV (ADHD RS-IV) assessment consecutively before and one year after surgery. Patients whose preoperative scores were above the cut-off point, the 90th percentile based on a Korean sample, were regarded as demonstrating the ADHD trait. The impact of muscle surgery on ADHD symptoms was assessed by comparing the preoperative scores with the post-operative scores. RESULTS: Eight (15.7%) of the 51 patients demonstrated the ADHD trait. ADHD RS-IV scores following strabismus surgery significantly decreased in patients with the ADHD trait (p=0.014), while they did not differ in patients without the ADHD trait. Seven (87.5%) of the 8 patients with the ADHD trait showed improvement in their ADHD RS-IV scores after surgery. There was no difference in surgical success rates between X(T) patients with and without the ADHD trait. CONCLUSION: The ADHD trait was relatively common in children with X(T), and the parent-reported symptoms of the children with the ADHD trait improved after strabismus surgery. These results suggest that childhood X(T) may be one contributing factor to ADHD-related symptoms.

Postoperative Stabilization of the Strabismic Angle in Intermittent Exotropia

PURPOSE: To analyze the postoperative strabismic angle for five years or more and to investigate when the angle stabilized in intermittent exotropia. METHODS: We retrospectively reviewed the clinical records of 89 patients who had undergone surgery for intermittent exotropia. The postoperative strabismic angles measured were analyzed at one-year intervals up to five years postoperatively. We divided them into two groups according to their age at the time of surgery. Group 1 was less than 5 years of age, while Group 2 participants were 5 years of age or older. RESULTS: For our 89 total patients, average exo-angles were 7.8 +/- 7.26, 7.9 +/- 7.51, 9.5 +/- 7.05, 10.1 +/- 6.87, and 9.4 +/- 6.90 prism diopters at one, two, three, four, and five years postoperatively, respectively. Average exo-angles between postoperative year one and year three, as well as between postoperative year two and year three, were statistically significant (p = 0.015, 0.022). However, the angles were not statistically significant between postoperative year three and year four or between years three and five, respectively (p = 0.707, p = 0.948). The stabilization characteristics of the angle were somewhat different according to age group. In Group 1, the average exo-angle in postoperative years one and three were statistically significant (p = 0.016), but the angle in the same period was not statistically significant in Group 2 (p = 0.203). CONCLUSIONS: There was no significant interval change after three years postoperatively in intermittent exotropia, but if the patient's age at surgery was 5 years or higher, no significant change of exo-angle was found following postoperative year one in this study.

Supermaximal Recession and Resection in Large-Angle Sensory Exotropia

In cases of extropia with an exodeviation angle over 50 prism diopter (PD), a 3- or 4-muscle surgery is a rational option. But, in patients with sensory exotropia, there is usually a strong preference for a monocular procedure to avoid surgery on the single seeing eye. Thus, we confined surgery to visually poor eyes, and performed a medial rectus muscle resection with a mean of 10.3 mm (range, 9-11 mm) and a lateral rectus muscle recession with a mean of 12.8 mm (range, 10-14 mm) in 4 adult sensory exotropia patients who had a mean deviation of 82.3 PD (range, 75-90 PD). The mean postoperative angle of exodeviation was 2.0 PD (range, ortho-8 PD). The limitation on abduction was not disfiguring. Other expected disfigurements, such as narrowing of the palpebral fissure or enophthalmos, were not conspicuous. The mean follow-up period was 4.5 months (range, 3-7 months). In large-angle sensory exotropia, instead of additive surgery on the seeing eye, supermaximal medial rectus resection and lateral rectus recession only on the visually poor eye is a clinically feasible surgical option.

Effectiveness of Home-Based Pencil Push-ups (HBPP) for Patients with Symptomatic Convergence Insufficiency

PURPOSE: To report the effectiveness of home-based pencil push-ups (HBPP) therapy for patients with symptomatic convergence insufficiency. METHODS: Data was collected prospectively on 16 patients who were diagnosed with convergence insufficiency beginning in January 2009. The study group was composed of ten male and six female patients. The duration of symptoms, refractive error, distant and near deviation angles, and near point of convergence (NPC) prior to and after 12 weeks of HBPP therapy were measured in all patients. RESULTS: The mean age of the patients was 19.3 years. The mean deviation angle of exophoria was 3 prism diopters (PD) at distant and 11.2 PD at near. The mean value of NPC prior to HBPP therapy was 36.3 cm; however, the near point of accommodation was within the normal range. After 12 weeks of HBPP therapy, the mean deviation angle of exophoria decreased to orthophoric at distant and 4 PD at near. The mean value of NPC decreased to 14.4 cm. CONCLUSIONS: Twelve weeks of HBPP therapy appears to be an easy, cost-free and effective therapy for patients with symptomatic convergence insufficiency.

Comparison of Outcomes of Unilateral Lateral Rectus Recession for Exotropia between First and Second Operations

PURPOSE: To compare the outcomes of unilateral lateral rectus recession between the first operation and second operation for exotropia. METHODS: Thirty-two patients who underwent unilateral lateral rectus recession for exotropia of 15 to 20 prism diopters (PD) were investigated. The follow-up period was at least 6 months. We classified 17 patients without a surgical history for exotropia (first operation group) and 15 patients with a previous procedure (second operation group). Surgical success was defined as an exodeviation or esodeviation of less than 10 PD at the primary position. Postoperative deviation angles and success rates were compared between the two groups. RESULTS: There were no significant differences in the age, gender, visual acuity (logarithm of the minimal angle of resolution), preoperative deviation, and amount of recession between the two groups. Postoperative deviations were -1.7 +/- 5.5:1.3 +/- 5.1 PD at one day, 4.3 +/- 3.8:5.6 +/- 5.1 PD at 1 month, 4.3 +/- 4.3:3.0 +/- 8.1 PD at 3 months, and 5.0 +/- 4.3:4.5 +/- 7.2 PD at 6 months post-operation, and there was no statistically significant difference between the two study groups. Surgical success rate were 95.2:100% at one day, 95.2:92.9% at 1 month, 90.5:85.7% at 3 months, and 90.0:92.9% a 6 months post-operation. CONCLUSIONS: In patients with exotropia of 15 to 20 PD, no significant difference was found in terms of the postoperative deviation angle and the surgical success rate between the first operation and the second operation groups. Unilateral lateral rectus recession can lead to similar results in 15 to 20 PD exotropia for the first operation or recurrent exotropia.

Comparison of Outcomes of Unilateral Lateral Rectus Recession for Exotropia between First and Second Operations

PURPOSE: To compare the outcomes of unilateral lateral rectus recession between the first operation and second operation for exotropia. METHODS: Thirty-two patients who underwent unilateral lateral rectus recession for exotropia of 15 to 20 prism diopters (PD) were investigated. The follow-up period was at least 6 months. We classified 17 patients without a surgical history for exotropia (first operation group) and 15 patients with a previous procedure (second operation group). Surgical success was defined as an exodeviation or esodeviation of less than 10 PD at the primary position. Postoperative deviation angles and success rates were compared between the two groups. RESULTS: There were no significant differences in the age, gender, visual acuity (logarithm of the minimal angle of resolution), preoperative deviation, and amount of recession between the two groups. Postoperative deviations were -1.7 +/- 5.5:1.3 +/- 5.1 PD at one day, 4.3 +/- 3.8:5.6 +/- 5.1 PD at 1 month, 4.3 +/- 4.3:3.0 +/- 8.1 PD at 3 months, and 5.0 +/- 4.3:4.5 +/- 7.2 PD at 6 months post-operation, and there was no statistically significant difference between the two study groups. Surgical success rate were 95.2:100% at one day, 95.2:92.9% at 1 month, 90.5:85.7% at 3 months, and 90.0:92.9% a 6 months post-operation. CONCLUSIONS: In patients with exotropia of 15 to 20 PD, no significant difference was found in terms of the postoperative deviation angle and the surgical success rate between the first operation and the second operation groups. Unilateral lateral rectus recession can lead to similar results in 15 to 20 PD exotropia for the first operation or recurrent exotropia.

Analysis of the Effects of Medial Rectus Muscle Resection for Recurrent Exotropia

PURPOSE: The purpose of this paper is to investigate how much correction is obtained per millimeter of medial rectus (MR) resection for recurrent exotropia after bilateral lateral rectus (BLR) recession, and to determine the difference in the effects between unilateral and bilateral resection, and the influence of previous lateral rectus (LR) recession on the effects of MR resection. METHODS: A total of 59 patients who had undergone MR resection after BLR recession were included in this study. The unilateral group consisted of 38 patients and bilateral group, 21 patients. Thirty patients in the unilateral group were divided into two groups: patients who had undergone previous LR recession of 7 mm or greater (21 patients) and less than 7 mm (9 patients). Main outcome measures were average deviation corrected per millimeter of MR resection at 1 month postoperative. RESULTS: The average effect of MR resection was 4.2 prism diopters (PD, 2.0 to 6.7 PD)/mm. The average effect in the unilateral group was 4.2 PD/mm and 4.1 PD/mm in the bilateral group. There was no significant difference between groups (P = 0.60). The average effect in the recession 7 mm or greater group was 4.0 PD/mm, and the average effect in the recession less than 7 mm group was 4.2 PD/mm (P = 0.698). CONCLUSIONS: The effect of MR resection per millimeter was variable. The laterality and previous amount of LR recession did not influence the effect of MR resection. These variable outcomes dictate that caution be exercised when MR resection is performed for recurrent exotropia.

Analysis of the Effects of Medial Rectus Muscle Resection for Recurrent Exotropia

PURPOSE: The purpose of this paper is to investigate how much correction is obtained per millimeter of medial rectus (MR) resection for recurrent exotropia after bilateral lateral rectus (BLR) recession, and to determine the difference in the effects between unilateral and bilateral resection, and the influence of previous lateral rectus (LR) recession on the effects of MR resection. METHODS: A total of 59 patients who had undergone MR resection after BLR recession were included in this study. The unilateral group consisted of 38 patients and bilateral group, 21 patients. Thirty patients in the unilateral group were divided into two groups: patients who had undergone previous LR recession of 7 mm or greater (21 patients) and less than 7 mm (9 patients). Main outcome measures were average deviation corrected per millimeter of MR resection at 1 month postoperative. RESULTS: The average effect of MR resection was 4.2 prism diopters (PD, 2.0 to 6.7 PD)/mm. The average effect in the unilateral group was 4.2 PD/mm and 4.1 PD/mm in the bilateral group. There was no significant difference between groups (P = 0.60). The average effect in the recession 7 mm or greater group was 4.0 PD/mm, and the average effect in the recession less than 7 mm group was 4.2 PD/mm (P = 0.698). CONCLUSIONS: The effect of MR resection per millimeter was variable. The laterality and previous amount of LR recession did not influence the effect of MR resection. These variable outcomes dictate that caution be exercised when MR resection is performed for recurrent exotropia.

The Prismatic Effect on Stereoacuity in Intermittent Exotropia

PURPOSE: To evaluate the effect of acrylic refractive prism and Fresnel membrane prism on stereoacuity in intermittent exotropia. MATERIALS AND METHODS: Stereoacuities of fifty-two patients (mean age, 12.4 years; range 6 to 45 years) with intermittent exotropia were measured using the Titmus and TNO stereotests, while they wore prisms of varying power on nonfixating eye or evenly on each eye. RESULTS: Stereoacuities were significantly reduced with increasing prism power for both prisms, ranging from 8 to 25 prism dipotres. The effects on stereoacuity in single acrylic prism and single Fresnel prism were similar, whereas spilt Fresnel prisms reduced stereoacuity more than spilt acrylic prisms. Spilt prisms were found to have much less effect on stereoacuity than single prisms for both acrylic and Fresnel prisms. CONCLUSION: The use of acrylic refractive prism shared evenly on each eye would be optimal method to minimize the reduction of stereoacuity during the prismatic therapy for intermittent exotropia.

Refractive error changes in children with intermittent exotropia under overminus lens therapy / Alterações nos vícios refracionais em crianças com exotropia intermitente submetidas ao tratamento por meio da hipercorreção com lentes negativas

PURPOSE: Intermittent exotropia may be decreased by stimulation of accommodative convergence. Once excessive accommodation has been related to myopia, our objective was to evaluate refractive errors changes in children under overcorrecting minus lens therapy. METHODS: A retrospective chart review of 21 children with intermittent exotropia was performed. All patients were treated with occlusion, and a 13-patient subset of them received overminus lens therapy (group A). Eight children received spectacles as necessary (group B). Initial age, age interval, initial spherical equivalent (SE), and magnitude of overcorrection were considered as co-variables of the mean variation in refractive error (SE of each eye) between groups, through a multivariate analysis. RESULTS: Overcorrection used in group A ranged from 0.5 D to 3.5 D (2.46 ± 0.87 D). Although initial SE of each eye was significant different between group A and B (OD - p=0.02; OS - p=0.01), initial age (p=0.69), age interval (p=0.90), and mean variation in refractive errors (p=0.36) did not differ between groups. Multivariate analysis with linear regression showed no significantly difference regarding all co-variables enrolled. CONCLUSIONS: Treatment of intermittent exotropia with overcorrecting minus lens did not induce refractive errors changes, even considering age, treatment period, initial spherical equivalent and overcorrection magnitude used.

OBJETIVO: A exotropia intermitente pode ser diminuída pela estimulação da convergência acomodativa. Uma vez que uma acomodação excessiva tem sido relacionada à miopização, o objetivo deste trabalho foi o de avaliar alterações nos vícios de refração de crianças submetidas à hipercorreção com lentes negativas. MÉTODOS: Foi realizada revisão dos prontuários de 21 crianças com exotropia intermitente. Todos os pacientes foram tratados com oclusão, sendo que 13 deles foram submetidos à hipercorreção com lentes negativas (grupo A). As 8 crianças restantes receberam prescrições ópticas conforme necessário pelas suas ametropias (grupo B). A idade inicial, tempo de tratamento, equivalente esférico (EE) inicial e magnitude da hipercorreção foram considerados como covariáveis na análise das diferenças das médias de erro refrativo (EE de cada olho) entre os grupos, pela análise multivariada. RESULTADOS: A hipercorreção utilizada no grupo A variou entre 0,5 D e 3,5 D (2,46 ± 0,87 D). Embora o EE inicial de cada olho ter sido significativamente diferente entre os grupo A e B (olho direito - p=0,02; olho esquerdo - p=0,01), a idade inicial (p=0,69), o tempo de tratamento (p=0,90) e a variação média nos erros refrativos (p=0,36) não diferiram entre os grupos. A análise multivariada com regressão linear não mostrou diferença significativa, considerando as covariáveis em questão. CONCLUSÕES: O tratamento de crianças com exotropia intermitente por meio de hipercorreção óptica com lentes negativas não induziu alterações nos vícios de refração, mesmo considerando fatores como idade inicial, o tempo de tratamento, equivalente esférico inicial e a magnitude da hipercorreção utilizada.

Comparison of the Stability of Postoperative Alignment in Sensory Exotropia: Adjustable Versus Non-Adjustable Surgery

PURPOSE: To compare the success rates and stabilities of postoperative alignment between adjustable and the non-adjustable surgeries in the treatment of sensory exotropia. METHODS: A retrospective analysis was performed on all patients with sensory exotropia who had undergone unilateral lateral rectus recession and medial rectus resection (R&R) between January 1998 and August 2005. Thirty-four patients underwent conventional R&R, and 20 patients underwent R&R with adjustable suture of the lateral rectus. The surgical results between the two groups were analyzed with regard to the preoperative and post-operative deviation angles and the postoperative drift. The postoperative deviation angle was measured on postoperative day 1 as well as at two weeks, three months, six months and the final visit after surgery. RESULTS: There were no statistically significant differences in the mean preoperative and postoperative deviation angles between the two groups. In 30 (88%) patients in the non-adjustable group and 15 (75%) patients in the adjustable group, postoperative deviation was less than 15 prism diopters (PD) at the three month follow-up. There was no significant difference in the mean postoperative drift between the two groups. CONCLUSIONS: Strabismus surgery with adjustable sutures did not show a significantly better result than surgery without adjustable sutures in the treatment of sensory exotropia. Considering the amount of postoperative exodrift in both groups, we postulate that the immediate ocular alignment after surgery for sensory exotropia should be orthophoric or 5-6 PD of esodeviation.