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.

Comparison of Postoperative Outcomes According to Deviation Angle in Moderate-Angle Intermittent Exotropia of Basic Type

PURPOSE: This study was conducted to compare the surgical outcomes and stereoacuities after medial rectus (MR) muscle and lateral rectus (LR) muscle recessions, as deviation angle in 20-30 PD basic intermittent exotropia. METHODS: A total of 72 patients were classified into three groups, according to the deviation angle and measured stereoacuities. Twenty-five patients in Group 1, with a deviation angle of 20 prism diopter (PD), underwent MR resection of 4.0 mm and LR recession of 5.0 mm. Group 2, which consisted of 26 patients with 25 PD, underwent 5.0 mm and 6.0 mm. And 21 patients in Group 3 with 30 PD underwent 5.5 mm and 7.0 mm. The success of surgery was determined by the range of a deviation angle within +/-8 PD for both near and distance. RESULTS: The average age was 7.8 years, 7.2 years, and 8.6 years in Group 1, Group 2, and Group 3, respectively. On the final observation, the success rate of the surgery was 84%, 88%, and 90.4% in Group 1, Group 2, and Group 3, respectively. There was no case of overcorrection. Near stereoacuities was found without significant difference at preoperative with postoperative in Group 1, Group 2, and Group 3, respectively (p = 0.26). Postoperative distance stereoacuities showed significant improvements in Group 1, Group 2, and Group 3 (p = 0.04). CONCLUSIONS: Basic intermittent exotropia, which has deviation angle of 20, 25, 30 PD showed no difference in surgical outcomes, according to the deviation angle. There were improvements in the distance stereoacuities after MR resection and LR recession procedure.

Relationship between Control Grade and Stereoacuity in Basic Intermittent Exotropia

PURPOSE: The present study was conducted to identify the correlation between control grade and stereoacuity in basic intermittent exotropia (X[T]). METHODS: Eighty-six patients with basic X (T) were divided into 3 subgroups according to their control grade and the near and distant stereoacuities were evaluated. RESULTS: Group 1; good control group, consisted of 28 patients, group 2; fair control, 30 patients, and group 3; poor control, 28 patients. Mean near stereoacuities measured by the Titmus test were 58.21 arcseconds in group 1, 75.33 arcseconds in group 2, and 151.43 arcseconds in group 3. The mean distant stereoacuities measured by a Mentor B-VAT(R) II-SG videoacuity tester were 118.93 arcseconds in group 1, 165.33 arcseconds in group 2, and 276.43 arcseconds in group 3. When comparing the 3 groups, the poorer the control grade, the worse were the near and distant stereoacuities (p = 0.002, p < 0.001). When compared in pairs, however, group 1 showed a better near stereoacuity than groups 2 and 3 (p = 0.02, p = 0.002, respectively), while group 2 and group 3 did not show any distinct differences (p = 0.13). Group 1 also showed a better distant stereoacuity than groups 2 and 3 (p = 0.02, p < 0.001, respectively), as did group 2 compared to group 3 (p < 0.001). CONCLUSIONS: Control grade and distant stereoacuity have significant correlation in patients with basic X (T) and can function as helpful indicators for monitoring the deterioration and progression of exodeviation.

Changes of Deviation After the Patch and +3.00 Diopter Spherical Lens Test in Basic Intermittent Exotropia

PURPOSE: To assess the change of deviation angle after the patch test and +3.00 diopter (D) spherical lens test in basic intermittent exotropia. METHODS: The present study included 57 patients diagnosed with basic intermittent exotropia. The deviation angles at near and far before and after monocular occlusion of 40 minutes or more were measured. Afterward, change of deviation was also measured by placing +3.00 D spherical lenses at near. RESULTS: Results from the study revealed pre-occlusion mean deviation angles of 23.1 +/- 7.41 prism diopters (PD) at near, and 23.9 +/- 6.56 PD at far. After the patch test, the mean deviation angles were increased to 28.3 +/- 6.50 PD (p < 0.0001) at near, and 25.5 +/- 6.40 PD (p < 0.0001) at far. After the +3.00 D spherical lens test, the angle was increased to 31.5 +/- 7.53 PD (p < 0.0001) at near. Using the gradient method, the average accommodation convergence - accommodation ratio was 1.4 +/- 1.19 PD/D. CONCLUSIONS: Both the patch test and +3.00 D spherical lens test significantly increased the deviation angles at near and far, they helped to find the maximum deviation angle in patients with basic intermittent exotropia.

The Influence of Monocular Occlusion on the Preoperative Ocular Alignment and the Surgical Outcome in Basic Intermittent Exotropia

PURPOSE: This study was to evaluate the influence of monocular occlusion on the preoperative ocular alignment and the surgical outcome of basic intermittent exotropia. METHODS: We examined 42 patients with basic intermittent exotropia who were operated and followed for at least 6 months postoperatively from January 2001 to August 2002. In all patients, angle of misalignment measured while the patients fixate on an accommodative target at 6m and 33cm, and after 2 hours of monocular occlusion. The subjects were divided into two groups: Gruop 1-far angle of misalignment did not increase after 2 hours of monocular occlusion, Group 2-far angle of misalignment increased in 3PD or more after 2 hours of monocular occlusion. Group 2 underwent surgery for the increased deviation of far angle. RESULTS: Among 42 patients with basic intermittent exotropia, Group 1 included 27 (64.3%) patients and Group 2 15 (35.7%) patients. In Group 2, the mean ( +/- SD) increase in the angle of exotropia after 2 hours of monocular occlusion was 5.33 ( +/- 2.74)PD. The success rate of surgery was 77.8% (21/27 patients) in Group 1, 93.3% (14/15 patients) in Group 2 at 6 months after surgery and 70.4% (19/27 patients), 93.3% (14/15 patients) at the final visit. There was no statistically significant difference (p> 0.05). CONCLUSIONS: This study showed the significant influence of monocular occlusion on the ocular misalignment before surgery and surgical outcome in basic intermittent exotropia. Angle of misalignment measured after 2 hours or more of monocular occlusion seemed to be meaningful.

Anatomic Aspects of Intermittent Exotropia in Childhood

PURPOSE: This study aimed to find out the difference in between the anatomic properties children with intermittent exotropia and children with orthophoria. METHODS: The intermittent exotropia group consisted of 35 patients who had an angle of deviation of more than 15 prisms. The control group consisted of 35 orthophoric children with comparable age and sex ratio. From the view of skull AP, we compared the diameter, interlateral wall distance, and intermedial wall distance of the orbital rim. Also we compared the intercanthal distance, interlateral canthal distance of eyelids, and interpupillary distance. RESULTS: The average values of interpupillary distance, intercanthal distance, and interlateral canthal distance of exotropic group were 54.23+/-1.85 mm, 34.75+/-1.66 mm, and 78.25+/-4.21 mm, respectively. Compared to those of control group, which were 53.59+/-1.21 mm, 33.56+/-1.54 mm, and 76.68+/-3.23 mm, respectively, there was no significant difference (P>0.05). The average values of the diameter, interlateral wall distance and the intermedial wall distance of the orbital rim were not significantly different between two groups (p>0.05). CONCLUSIONS: Our results showed that the anatomic properties including orbital rim size and orbital exodeviation did not seen to influence the development of intermittent exotropia.